26 December 2010
Hydroponics and health
I've had friends of mine try to get me into hydroponics before, but I haven't ever been truly interested until today, when @TheEconomist tweeted links to these videos on "vertical farming," the brainchild of Dickson Despommier, professor of public health in environmental health sciences at Columbia University.
The magazine reports mainly on this urban-type agriculture as a way to bring local, sustainable food to places like New York City, the logistical problems, and what this might mean for battling climate change. There was also mention of how hydroponics allows for introduction of nutrients in the water, reduces need for fertilizing, and how it being a closed system recycles water.
And, the interview (below) with Despommier speaks to how this idea could potentially turn the "parasitism" of cities into productive ecosystems.
These are neat topics, although I still wonder about how realistic it is on a grand scale based on concerns about use of artificial lighting, expense, and so on.
However, from a nutritional standpoint, urban agriculture does lend to great possibilities for producing food that is healthier, cleaner and safer. As I see it, the possibilities for human health is endless.
Urban agriculture allows for much more control over heavy metals with use of refined minerals in the hydroponics fertilizer. Plus, you could standardized to reasonable exactness, the amounts the plants would receive of minerals. Then, with a controlled environment, the potential of having a standardized product comes into the picture too.
This might sound really lame to some people, but it's a nutritionist's dream -- Can you imagine walking into a grocery store and seeing fruits and vegetables with standardized nutrition facts panels complete with quantities of minerals, and possibly vitamins and phytonutrients?
You could also do a much better job controlling and enhancing the flavor of plants, which is highly dependent on what comes through the water. By adding in concentrated extracts, for example, of vanilla or orange, you could give plants certain notes or essences.
Anyway, I might have to head down to Tucson, Arizona, to check out what's currently largest system of hydroponics in the country -- and maybe have a bite of something tasty.
I might also have to order me some kind of home hydroponics system.
23 December 2010
How diet shaped human evolution
Anyone who is keenly interested in having a better understanding of why we eat what we eat as human beings should take an hour or so to watch this introductory talk given by anthropologist Teresa Steele, of UC Davis, given at the California Academy of Sciences on the topic of evolution of the human diet.
I found her talk fascinating, especially because I've been highly interested in how the use of fire and aquatic animals may have played a part in fueling human brain growth, so I ended up taking copious notes. I should note that there isn't anything new presented here, but Steele is excellent at presenting the chronology. If you don't have an hour to watch, then just see my notes below chapter by chapter from "Australopithecus to agriculture."
Human diet is unique among apes
Steele finds that diet is central to her research. "If we want to live, we have to eat," she says. Food is what ultimately supports demographic populations. One thing that is unique about humans in comparison to other apes is a long childhood, a long learning period, that is required for acquiring the knowledge necessary to become successful foragers in a wide environment. After all, humans have exploited almost every nutrient resource in their short time on the Earth.
Another unique thing is how much meat we consume. A large portion of our calories comes from meat. Unlike chimpanzees, who eat the most meat among apes, human eat about 10 times more, Steele said. And we eat animals that are usually larger than us like wildebeasts, reindeer, and mammoths. Steele shows a graph comparing chimp diets to that of tropical hunter gatherers groups, who typically eat little meat. Other hunter-gatherers of the North like the Inuit eat a diet almost entirely of meat. In general, humans specialize in acquiring nutrient-dense foods meats, tubers, and nuts, while chimps select non-nutrient dense like leaves that are more easily collected.
Research themes
When did these differences evolve? Steele presents us with her research themes, which include the following:
What methods does Steele use to construct ancient human diets? She says that zooarchaeology and tool analyses gives us a window into ancient demographies. There are stone, bone and antler tools. And, on occasion, organic wood and plant tools are preserved. Also, biological anthropology helps tell us more such as skeletal morphology and bone chemistry.
Lucy's diet
Steele introduces the diet of Lucy's species first, Austrolopithecus afarensis of 3.7-2.8 mya, who ate a flexible diet suitable for a variety of habitats.
The skeletal biomechanics and dental structure suggest they ate mostly soft fruits and occasional hard seeds. However, Steele says we assume that they may have eaten some meat because chimps eat meat, but it's unclear just how much.
She points out that, recently, there was a groundbreaking discovery published in Nature (and reported in Scientific American by the science writer Kate Wong (Twitter: @katewong) ) of cut-marked bones in Dikika, Ethiopia suggesting Lucy's species even used stone tools for eating meat.
"This has opened up a window," Steele says for more research, especially in the possibility of stone tool use for extracting nutrients from carcasses of smaller animals. It's worth noting that no stone artifacts were found associated with the cut-marked bones (paleoanthropologist John Hawks (Twitter: @johnhawks) has written more about this topic on his blog).
Cut-marked bones 2.5 million years ago
Typically, a discussion of human diet begins at about 2.5 mya when there is an abundance of cut-marked bones (such as the jaw of a wildebeest) and percussion marks from marrow extraction. Marrow has been an important human resource for nutrients up until modern times because it's high in fat, high in calories.
There is also evidence of Oldowan artifacts (hominin stone tools) available so we know what they were using to get to the marrow.
Then, at about 1.8 mya there are a lot more assemblages, more stone tools, as found in Olduvai Gorge, Tanzania, by Mary Leaky. There are also lots of large bodies bovids and carnivores on the landscape. Steele asks, How did these ancient hominids acquire these large carcasses? Is it conceivable that they could've brought down a wildebeast with just tools?
This is where we get into a discussion of scavenging versus hunting, she said. A related discussion is what percentage of the diet was meat-based versus plant-based. Also, were these ancient hominins practicing passive scavenging getting to a carcass to get the last scraps of meat or breaking open bones for marrow. Or was it active scavenging, chasing off carnivores?
These are all active areas of research. For answers, researchers look in locations of lakeside margins. Bovids came to drink, carnivores know this, we look into these locations to try and reconstruct the foraging.
Aquatic animals
Published recently in the springtime, was a paper suggesting that 1.9 mya in East Turkana, there's evidence of Oldowan foraging of carcasses of aquatic animals like crocodiles and turtles. Steele shows a cut marks on a toe bone of a croc, turtle shells and catfish bones.
"For the first time, we see exploitation of aquatic resources highlighting the diversity of diet. Hominins are very opportunistic, exploiting whatever was available," Steele said.
"This also raises a challenge as with cut-marked bones with Dekika, to try to see if there are cut-marks on similar bones," Steele explains. "The small animal component has been overlooked so we may need to look closer."
Steele also discusses another interesting aspect of using aquatic resources (which will interest any nutritionist like myself). The aquatic resources would have been an easier way to access long-chain omega-3 fatty acids, which are also present in organ meats and brain tissues of large animals.
"The long-chain unsaturated fatty acids are needed for brain growth," she explained. "At this time period we do see an expansion of brain sizes, so perhaps there's a relationship here. We need more data, more examples where we see brain expansion with this kind of diet."
Archeulean hunting and scavenging
Moving more recently in time, we see Homo erectus, hominins of larger body size, and who were first to populate Eurasia 1.6 mya to 285 kya. Were they hunting or actively scavenging? This is unclear, but earlier in Archeulan, we see evolution of technology.
Tear-drop shaped hand axes appear and body size changes. The humans are obviously living in social groups. An illustration she uses takes the liberty of showing piles of plant remains used to make wooden spears. The plant use is unknown.
There are a large number of animal bones with few cut marks. So, the question remains, were hominins still minor players as carnivores, simply cutting off limbs and eating elsewhere. The challenge is finding places away from water sites such as in caves.
Also, we start asking questions about use of fire at this time period.
Wood spears
At around 400 kya, Steele shares that there are one or two examples of exceptional preservation of organic materials such as wooden spears (survived in an oxygen-poor environments from marshes of Germany). They are more likely to be thrusting spears. They have been fire-hardened, sharpened, so it indicates use of fire.
Fire is really useful for warmth, protection from predators, for cooking and cooking really changes the nature of food. It helps make inedible foods edible, releases nutrients for our digestive systems. But fire doesn't preserve well.
The earliest known site where fire is documented is in Israel, dated to 780 kya. "We have an indicator of fire use and plant remains. They're preserve better once charred in archaeological sites," Steele says. "We don't find it common until about 300,000 years ago." This is between Oldowan and modern behavior in the Archeulian.
Neandertals
About 200 kya came the Neandertals and they were competent hunters and manufacturers of stone tools. Interestingly, despite these complex behaviors, they did not have as long a childhood. The Neandertals were able to pick up their abilities pretty early in life.
As part of her post-doc in Germany at Max Plank Institute, Steele worked with identifying species in archaeological sites where Neandertals hunted reindeer and bison. She showed antlers, elbows of reindeer fractured for extracting marrow, and examples of bones in discard piles due to little meat.
"We also see very little carnivore involvement and abundant human impacts, unlike the earlier where there was very heavy carnivore involvement meaning humans were hunting," she said. The Neandertals were dominant carnivores by this time.
Now we can ask about hunting strategy. Steele explains she uses a very low tech method: "We have a number of mandibles, so just looking at the eruption of teeth, we can reconstruct ages of animals." Also, reindeer are conveniently sexually dimorphic and because reindeer give birth at a moment in spring (babies are born at once) we can look at eruption of teeth to see if they're hunted. In a specific location, all ages are present, males and females, so it looks like the reindeer herd would have been slowed allowing the humans to hunt more of them.
Bone chemistry
Carbon isotopes tell us about the vegetation in the environment and nitrogen isotopes tell us about the trophic levels. Carnivores have more concentration of nitrogen. Animals that are aquatic even more nitrogen, so we can look at bone chemistry to reconstruct diet. There aren't much indicators of plant remains, but in a Neandertal tooth you see it's heavily etched by roots because of the acid of roots. The bone chemistry data put Neandertals right along the lines of other carnivores. The majority of protein came from meat (although not mentioned in the talk, new findings show they also practiced cannibalism, reported via science writer Carl Zimmer (Twitter: @carlzimmer)).
Hunting technology
How were the Neandertals doing the hunting? It appears they were using thrusting spears. We know this because it's possible to look at stone artifacts to see if they are aerodynamic or more asymetrical and lumpy for a thrusting spear. We can look at the breakage of the tip as well as the butt. In characteristic way we can look at the breakage.
Middle stone age in Africa 285,000
So while Neandertals are doing their thing in Europe, what's going on in Africa? In Africa, we have the middle stone age and humans who were morphologically similar to us. The big discussion in paleoanthropology is, How modern were they? Did they have symbolism? Were they just like us or behave more like Neandertals without as much symbolism?
In the middle stone age we have good evidence of hunting and burning. There was abundant burning. But, within the middle stone age, we see no evidence of consumption of fish. The people seem to be limited in capturing fish and birds, although there were people accessing coastal resources along the southern coast of Africa, eating a number of mollusks. Could mollusks have fueled brain growth and brought with it symbolic behavior? There were also a number of fireplaces. Did fire fuel brain growth (if you ask primatologist Richard Wrangham as I did last February, then the answer is a resounding "yes!")? This is something that requires further research.
Modern humans in Europe
In Europe about 40 to 10 kya, we have Upper Paleolithic with fully modern humans in Europe. They hunted large game similar to Neandertals and with projectile technology unlike Neandertals. People who were just like us in biology and behavior. This is when we see projectiles for the first time. We see the reconstruction of a spear thrower, with an adle addle.
These modern humans then also enjoyed a diverse diet with abundant small game like fish and flying birds. That's quite different than what their Neandertals cousins were doing, and what humans in Africa of the middle-stone age were doing.
We can also see this in the bone chemistry of the Upper Paleolithic humans. There was definitely protein coming in from aquatic sources, per the nitrogen values in the bones. It's also clear from the bone chemistry that modern humans were eating a much more diverse diet.
Plant use
Getting back to plant use, just recently in PNAS, an article was published about use of plants in Paleolithic times. Grindstones and pestles were used to grind starch grains, reeds, cattailes and ferns that have underground storage organs (roots). These grindstones pulverized the roots and perhaps made flour out of them. So, this is it, the diversity of diet that spread from Africa about 50 kya, and support for the hypothesis that humans replaced Neandertals because of flexibility of diet. Is this what allowed humans to be more successful?
Intensification of resource extraction, including agriculture
Bringing us into more recent time period to complete the story, 50kya humans colonized Europe and Asia and Australia. At around 15kya, they colonized the new world. So, by 10kya we have humans everywheere by 10kya other than Pacific islands and Antarctica. Diet tends to evolve and change. Humans don't stay focused on large game, and birds and fish. They intensify. What we see with intensification in the Holocene is the use of technology to extract nutrients from resources.
Steele shows pictures of mussel shells having accumulated over a short period of time. There was a heavier investment in technology. This creates a stable food supply that allows populations to grow. "We can see this in our local California native indians," she said. Just to highlight investment in technology, she shows slides on the natives' use of technology. "These are all the steps to take acorns and make it into something consumable. They're toxic, so you have to dry them, pulverize and leach them. It requires very heavy technological input."
The intensification brings with it the origins of agriculture at 10 kya. At 10kya we see changes in environment tha promote plant resources, a shift in global climate where there's more CO2, a more wet and stable environment, more admittable to plant production. People are becoming more dependent on smaller resources from agriculture. The fish, they help populations to grow and hunter-gatherer populations are more stable. It's clear from her slide that because of agriculture, there's an uptick in human population growth. Then, when industrialized agriculture arrives, there's an inflection point when we see a high rate of population growth. That's where we are today in the evolution of human diets. That's 4 million years (in 40 minutes).
Question 1: Why did humans replaced Neandertals?
The first question posed to Steele after her talk was about her thoughts were about why humans replaced Neandertals. She answered, "Yes, I think ultimately it's due to dietary differences." There's not much differences in species hunted, not so different butchery, but you do see a difference in stone artifacts and projectile points. The modern human tools were more reliable and accurate. They would've been able to obtain a larger number of reindeer, and been more consistent in hunting, along with having a more diverse diet.
The more ultimate explanation, however, was if it was cultural. Did modern humans have a more complex language? Could symbolism have allowed us to communicate in a more effective way, made our hunting more effective, that's where we're going now with the research. Language is fundamental, so if we can track where language evolved, then we'll find more answers?
Question 2: What conclusive evidence is there of cut marks?
The question asked to Steele reverted back 3.2 mya to how solid the evidence was of Australopithecus afarensis making cut marks. Steele answers that the cut marks are just as conclusive as later time periods. "If we are going to accept the later cut marks, then we have to accept the earlier," she said. "For me they're fine in terms of more recent assemblages. The challenge is to find more cut marks to see if it was widespread or a one-time thing. Who made them? Where are the stone tools?" That's the next project.
Question 3: What ratio of fatty acids in diet correspond to brain size?
Lastly, an audience member asked if recent work on long-chain omega-3s on mood disorders supports the theory that omega-3s from aquatic resources fueled brain growth. The quiestoner also mentions work by others on omega-3 to omega-6 ratios, which has changed since huntergatherer times (from 1:1-3 to 1:10 to 1:20). Could this be the reason that brain sizes are getting smaller?
Steele answers that, in general, there's body size reduction and brain size reduction. Hunter-gatherers of the anthropological record were quite robust. Now we see decrease in stature, brain size reducing, body size reducing. The change in body shape may be due to changes in diet. Whether it's omega-3/omega-6? Steele says she couldn't say for sure if that's the case.
(Note: Hat tip to @KeithNorris and @evolvify (see blog post here) for first alerting me to this new video via their tweets).
I found her talk fascinating, especially because I've been highly interested in how the use of fire and aquatic animals may have played a part in fueling human brain growth, so I ended up taking copious notes. I should note that there isn't anything new presented here, but Steele is excellent at presenting the chronology. If you don't have an hour to watch, then just see my notes below chapter by chapter from "Australopithecus to agriculture."
Human diet is unique among apes
Steele finds that diet is central to her research. "If we want to live, we have to eat," she says. Food is what ultimately supports demographic populations. One thing that is unique about humans in comparison to other apes is a long childhood, a long learning period, that is required for acquiring the knowledge necessary to become successful foragers in a wide environment. After all, humans have exploited almost every nutrient resource in their short time on the Earth.
Another unique thing is how much meat we consume. A large portion of our calories comes from meat. Unlike chimpanzees, who eat the most meat among apes, human eat about 10 times more, Steele said. And we eat animals that are usually larger than us like wildebeasts, reindeer, and mammoths. Steele shows a graph comparing chimp diets to that of tropical hunter gatherers groups, who typically eat little meat. Other hunter-gatherers of the North like the Inuit eat a diet almost entirely of meat. In general, humans specialize in acquiring nutrient-dense foods meats, tubers, and nuts, while chimps select non-nutrient dense like leaves that are more easily collected.
Research themes
When did these differences evolve? Steele presents us with her research themes, which include the following:
- Meat eating. We are consuming animals that are larger than ourselves like wildebeast, reindeer, horses, and so on. Chimpanzees hunt for colobus monkeys, birds, and small amphibians. So when did meat eating appear and when did the transition occur to eating animals larger than us?
- Hunting technology. What technology did humans use to acquire large animals? Spears, bows and arrows, projectile technology? These are complex, so they can represent greater cognition. When did they occur?
- Intensification of resource use, including agriculture. This happened much more recently.
What methods does Steele use to construct ancient human diets? She says that zooarchaeology and tool analyses gives us a window into ancient demographies. There are stone, bone and antler tools. And, on occasion, organic wood and plant tools are preserved. Also, biological anthropology helps tell us more such as skeletal morphology and bone chemistry.
Lucy's diet
Steele introduces the diet of Lucy's species first, Austrolopithecus afarensis of 3.7-2.8 mya, who ate a flexible diet suitable for a variety of habitats.
The skeletal biomechanics and dental structure suggest they ate mostly soft fruits and occasional hard seeds. However, Steele says we assume that they may have eaten some meat because chimps eat meat, but it's unclear just how much.
She points out that, recently, there was a groundbreaking discovery published in Nature (and reported in Scientific American by the science writer Kate Wong (Twitter: @katewong) ) of cut-marked bones in Dikika, Ethiopia suggesting Lucy's species even used stone tools for eating meat.
"This has opened up a window," Steele says for more research, especially in the possibility of stone tool use for extracting nutrients from carcasses of smaller animals. It's worth noting that no stone artifacts were found associated with the cut-marked bones (paleoanthropologist John Hawks (Twitter: @johnhawks) has written more about this topic on his blog).
Cut-marked bones 2.5 million years ago
Typically, a discussion of human diet begins at about 2.5 mya when there is an abundance of cut-marked bones (such as the jaw of a wildebeest) and percussion marks from marrow extraction. Marrow has been an important human resource for nutrients up until modern times because it's high in fat, high in calories.
There is also evidence of Oldowan artifacts (hominin stone tools) available so we know what they were using to get to the marrow.
Then, at about 1.8 mya there are a lot more assemblages, more stone tools, as found in Olduvai Gorge, Tanzania, by Mary Leaky. There are also lots of large bodies bovids and carnivores on the landscape. Steele asks, How did these ancient hominids acquire these large carcasses? Is it conceivable that they could've brought down a wildebeast with just tools?
This is where we get into a discussion of scavenging versus hunting, she said. A related discussion is what percentage of the diet was meat-based versus plant-based. Also, were these ancient hominins practicing passive scavenging getting to a carcass to get the last scraps of meat or breaking open bones for marrow. Or was it active scavenging, chasing off carnivores?
These are all active areas of research. For answers, researchers look in locations of lakeside margins. Bovids came to drink, carnivores know this, we look into these locations to try and reconstruct the foraging.
Aquatic animals
Published recently in the springtime, was a paper suggesting that 1.9 mya in East Turkana, there's evidence of Oldowan foraging of carcasses of aquatic animals like crocodiles and turtles. Steele shows a cut marks on a toe bone of a croc, turtle shells and catfish bones.
"For the first time, we see exploitation of aquatic resources highlighting the diversity of diet. Hominins are very opportunistic, exploiting whatever was available," Steele said.
"This also raises a challenge as with cut-marked bones with Dekika, to try to see if there are cut-marks on similar bones," Steele explains. "The small animal component has been overlooked so we may need to look closer."
Steele also discusses another interesting aspect of using aquatic resources (which will interest any nutritionist like myself). The aquatic resources would have been an easier way to access long-chain omega-3 fatty acids, which are also present in organ meats and brain tissues of large animals.
"The long-chain unsaturated fatty acids are needed for brain growth," she explained. "At this time period we do see an expansion of brain sizes, so perhaps there's a relationship here. We need more data, more examples where we see brain expansion with this kind of diet."
Archeulean hunting and scavenging
Moving more recently in time, we see Homo erectus, hominins of larger body size, and who were first to populate Eurasia 1.6 mya to 285 kya. Were they hunting or actively scavenging? This is unclear, but earlier in Archeulan, we see evolution of technology.
Tear-drop shaped hand axes appear and body size changes. The humans are obviously living in social groups. An illustration she uses takes the liberty of showing piles of plant remains used to make wooden spears. The plant use is unknown.
There are a large number of animal bones with few cut marks. So, the question remains, were hominins still minor players as carnivores, simply cutting off limbs and eating elsewhere. The challenge is finding places away from water sites such as in caves.
Also, we start asking questions about use of fire at this time period.
Wood spears
At around 400 kya, Steele shares that there are one or two examples of exceptional preservation of organic materials such as wooden spears (survived in an oxygen-poor environments from marshes of Germany). They are more likely to be thrusting spears. They have been fire-hardened, sharpened, so it indicates use of fire.
Fire is really useful for warmth, protection from predators, for cooking and cooking really changes the nature of food. It helps make inedible foods edible, releases nutrients for our digestive systems. But fire doesn't preserve well.
The earliest known site where fire is documented is in Israel, dated to 780 kya. "We have an indicator of fire use and plant remains. They're preserve better once charred in archaeological sites," Steele says. "We don't find it common until about 300,000 years ago." This is between Oldowan and modern behavior in the Archeulian.
Neandertals
About 200 kya came the Neandertals and they were competent hunters and manufacturers of stone tools. Interestingly, despite these complex behaviors, they did not have as long a childhood. The Neandertals were able to pick up their abilities pretty early in life.
As part of her post-doc in Germany at Max Plank Institute, Steele worked with identifying species in archaeological sites where Neandertals hunted reindeer and bison. She showed antlers, elbows of reindeer fractured for extracting marrow, and examples of bones in discard piles due to little meat.
"We also see very little carnivore involvement and abundant human impacts, unlike the earlier where there was very heavy carnivore involvement meaning humans were hunting," she said. The Neandertals were dominant carnivores by this time.
Now we can ask about hunting strategy. Steele explains she uses a very low tech method: "We have a number of mandibles, so just looking at the eruption of teeth, we can reconstruct ages of animals." Also, reindeer are conveniently sexually dimorphic and because reindeer give birth at a moment in spring (babies are born at once) we can look at eruption of teeth to see if they're hunted. In a specific location, all ages are present, males and females, so it looks like the reindeer herd would have been slowed allowing the humans to hunt more of them.
Bone chemistry
Carbon isotopes tell us about the vegetation in the environment and nitrogen isotopes tell us about the trophic levels. Carnivores have more concentration of nitrogen. Animals that are aquatic even more nitrogen, so we can look at bone chemistry to reconstruct diet. There aren't much indicators of plant remains, but in a Neandertal tooth you see it's heavily etched by roots because of the acid of roots. The bone chemistry data put Neandertals right along the lines of other carnivores. The majority of protein came from meat (although not mentioned in the talk, new findings show they also practiced cannibalism, reported via science writer Carl Zimmer (Twitter: @carlzimmer)).
Hunting technology
How were the Neandertals doing the hunting? It appears they were using thrusting spears. We know this because it's possible to look at stone artifacts to see if they are aerodynamic or more asymetrical and lumpy for a thrusting spear. We can look at the breakage of the tip as well as the butt. In characteristic way we can look at the breakage.
Middle stone age in Africa 285,000
So while Neandertals are doing their thing in Europe, what's going on in Africa? In Africa, we have the middle stone age and humans who were morphologically similar to us. The big discussion in paleoanthropology is, How modern were they? Did they have symbolism? Were they just like us or behave more like Neandertals without as much symbolism?
In the middle stone age we have good evidence of hunting and burning. There was abundant burning. But, within the middle stone age, we see no evidence of consumption of fish. The people seem to be limited in capturing fish and birds, although there were people accessing coastal resources along the southern coast of Africa, eating a number of mollusks. Could mollusks have fueled brain growth and brought with it symbolic behavior? There were also a number of fireplaces. Did fire fuel brain growth (if you ask primatologist Richard Wrangham as I did last February, then the answer is a resounding "yes!")? This is something that requires further research.
Modern humans in Europe
In Europe about 40 to 10 kya, we have Upper Paleolithic with fully modern humans in Europe. They hunted large game similar to Neandertals and with projectile technology unlike Neandertals. People who were just like us in biology and behavior. This is when we see projectiles for the first time. We see the reconstruction of a spear thrower, with an adle addle.
These modern humans then also enjoyed a diverse diet with abundant small game like fish and flying birds. That's quite different than what their Neandertals cousins were doing, and what humans in Africa of the middle-stone age were doing.
We can also see this in the bone chemistry of the Upper Paleolithic humans. There was definitely protein coming in from aquatic sources, per the nitrogen values in the bones. It's also clear from the bone chemistry that modern humans were eating a much more diverse diet.
Plant use
Getting back to plant use, just recently in PNAS, an article was published about use of plants in Paleolithic times. Grindstones and pestles were used to grind starch grains, reeds, cattailes and ferns that have underground storage organs (roots). These grindstones pulverized the roots and perhaps made flour out of them. So, this is it, the diversity of diet that spread from Africa about 50 kya, and support for the hypothesis that humans replaced Neandertals because of flexibility of diet. Is this what allowed humans to be more successful?
Intensification of resource extraction, including agriculture
Bringing us into more recent time period to complete the story, 50kya humans colonized Europe and Asia and Australia. At around 15kya, they colonized the new world. So, by 10kya we have humans everywheere by 10kya other than Pacific islands and Antarctica. Diet tends to evolve and change. Humans don't stay focused on large game, and birds and fish. They intensify. What we see with intensification in the Holocene is the use of technology to extract nutrients from resources.
Steele shows pictures of mussel shells having accumulated over a short period of time. There was a heavier investment in technology. This creates a stable food supply that allows populations to grow. "We can see this in our local California native indians," she said. Just to highlight investment in technology, she shows slides on the natives' use of technology. "These are all the steps to take acorns and make it into something consumable. They're toxic, so you have to dry them, pulverize and leach them. It requires very heavy technological input."
The intensification brings with it the origins of agriculture at 10 kya. At 10kya we see changes in environment tha promote plant resources, a shift in global climate where there's more CO2, a more wet and stable environment, more admittable to plant production. People are becoming more dependent on smaller resources from agriculture. The fish, they help populations to grow and hunter-gatherer populations are more stable. It's clear from her slide that because of agriculture, there's an uptick in human population growth. Then, when industrialized agriculture arrives, there's an inflection point when we see a high rate of population growth. That's where we are today in the evolution of human diets. That's 4 million years (in 40 minutes).
Question 1: Why did humans replaced Neandertals?
The first question posed to Steele after her talk was about her thoughts were about why humans replaced Neandertals. She answered, "Yes, I think ultimately it's due to dietary differences." There's not much differences in species hunted, not so different butchery, but you do see a difference in stone artifacts and projectile points. The modern human tools were more reliable and accurate. They would've been able to obtain a larger number of reindeer, and been more consistent in hunting, along with having a more diverse diet.
The more ultimate explanation, however, was if it was cultural. Did modern humans have a more complex language? Could symbolism have allowed us to communicate in a more effective way, made our hunting more effective, that's where we're going now with the research. Language is fundamental, so if we can track where language evolved, then we'll find more answers?
Question 2: What conclusive evidence is there of cut marks?
The question asked to Steele reverted back 3.2 mya to how solid the evidence was of Australopithecus afarensis making cut marks. Steele answers that the cut marks are just as conclusive as later time periods. "If we are going to accept the later cut marks, then we have to accept the earlier," she said. "For me they're fine in terms of more recent assemblages. The challenge is to find more cut marks to see if it was widespread or a one-time thing. Who made them? Where are the stone tools?" That's the next project.
Question 3: What ratio of fatty acids in diet correspond to brain size?
Lastly, an audience member asked if recent work on long-chain omega-3s on mood disorders supports the theory that omega-3s from aquatic resources fueled brain growth. The quiestoner also mentions work by others on omega-3 to omega-6 ratios, which has changed since huntergatherer times (from 1:1-3 to 1:10 to 1:20). Could this be the reason that brain sizes are getting smaller?
Steele answers that, in general, there's body size reduction and brain size reduction. Hunter-gatherers of the anthropological record were quite robust. Now we see decrease in stature, brain size reducing, body size reducing. The change in body shape may be due to changes in diet. Whether it's omega-3/omega-6? Steele says she couldn't say for sure if that's the case.
(Note: Hat tip to @KeithNorris and @evolvify (see blog post here) for first alerting me to this new video via their tweets).
10 December 2010
Living longer with an ideal BMI
Maintaining a healthy body mass index, or BMI, is one of the most important ways to help you live longer, according to a new study published in the December issue of New England Journal of Medicine.
BMI is not a perfect measure, but it is one of the simplest for estimating body weight. It is calculated by weight in pounds divided by height in inches squared and multiplying the number by 703, or by weight in kilograms divided by height in inches squared. What’s your BMI? Find out using this free calculator provided by the National Heart Lung and Blood Institute, of the National Institutes of Health.
The study’s findings support an optimal BMI in the “normal weight” range of 20 to 24.9, which is generally associated with the lowest risk of death from all causes including chronic diseases such as cardiovascular disease and cancer. The association was strongest among participants who were younger than 50 years old.
A BMI of 25 or more was associated with the highest mortality risks. The higher the BMI, the higher the likelihood of dying from cardiovascular disease.
“The results of our analysis are most relevant to whites living in affluent countries,” write the authors who pooled and analyzed data from 19 prospective studies encompassing 1.4 million white adults ages 19 to 80.
In the United States, among non-Hispanic whites, there was an estimated 11 percent of men and 17 percent of women with a BMI of 35 or higher in 2008.
The authors restricted the study to non-Hispanic whites based on self-reported ethnic group and controlled for pre-existing conditions, alcohol consumption, barbital status, education, and physical activity. They also excluded those with a BMI of less than 15 or higher than 50.
Smokers made up 25 percent of the study participants in the lowest BMI category of 15 to 18.4 and 8 percent of those in the highest BMI category.
Source: Berrington de Gonzalez A, Hartge P, Cerhan JR et al. Body-Mass Index and Mortality among 1.46 Million White Adults. NEJM 2010;363:2211-9.
Thoughts:
BMI is easy for anyone to measure, so this study gives us some back-up for using it as a way to speak to clients about real implications of obesity causing a shortened lifespan because of increased risk of cardiovascular disease and cancer.
It's important, however, to realize that while BMI may be easy it's possible for someone to be at a "normal weight" and still be "obese" -- dubbed normal weight obesity. This is still hazardous to your health, so you can't completely rely on BMI. Opt instead for body fat percentage measurement.
BMI is not a perfect measure, but it is one of the simplest for estimating body weight. It is calculated by weight in pounds divided by height in inches squared and multiplying the number by 703, or by weight in kilograms divided by height in inches squared. What’s your BMI? Find out using this free calculator provided by the National Heart Lung and Blood Institute, of the National Institutes of Health.
The study’s findings support an optimal BMI in the “normal weight” range of 20 to 24.9, which is generally associated with the lowest risk of death from all causes including chronic diseases such as cardiovascular disease and cancer. The association was strongest among participants who were younger than 50 years old.
A BMI of 25 or more was associated with the highest mortality risks. The higher the BMI, the higher the likelihood of dying from cardiovascular disease.
“The results of our analysis are most relevant to whites living in affluent countries,” write the authors who pooled and analyzed data from 19 prospective studies encompassing 1.4 million white adults ages 19 to 80.
In the United States, among non-Hispanic whites, there was an estimated 11 percent of men and 17 percent of women with a BMI of 35 or higher in 2008.
The authors restricted the study to non-Hispanic whites based on self-reported ethnic group and controlled for pre-existing conditions, alcohol consumption, barbital status, education, and physical activity. They also excluded those with a BMI of less than 15 or higher than 50.
Smokers made up 25 percent of the study participants in the lowest BMI category of 15 to 18.4 and 8 percent of those in the highest BMI category.
Source: Berrington de Gonzalez A, Hartge P, Cerhan JR et al. Body-Mass Index and Mortality among 1.46 Million White Adults. NEJM 2010;363:2211-9.
Thoughts:
BMI is easy for anyone to measure, so this study gives us some back-up for using it as a way to speak to clients about real implications of obesity causing a shortened lifespan because of increased risk of cardiovascular disease and cancer.
It's important, however, to realize that while BMI may be easy it's possible for someone to be at a "normal weight" and still be "obese" -- dubbed normal weight obesity. This is still hazardous to your health, so you can't completely rely on BMI. Opt instead for body fat percentage measurement.
09 December 2010
Gale Prince: "Food safety is a journey"
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| Gale Prince |
He began his talk by introducing us to the growing number of recalls in the United States. "Food safety has become a frequent topic for the media," he said. If you look at a 20-year trend, reccalls at retail have increased exponentially. Gail shared a graph of the trend and also details a few examples he's been involved with over the years.
The USDA has had a number of meat recalls, which Prince shows us picks up during the summer months of May through August. He says it is partly due to people cooking outside (such as at 4th of July) on the grill, who often leave their meat out or undercook their meat.
When you look at all the recalls of FDA, you also see the recalls going up, Prince said. He showed us a graph that showed that there were ove 8,000 just in the last year.
From 2004 to 2009 looking at class of recalls, most were class 1 due to salmonella problems. "Salmonella is a real challenge," Prince said.
There are three instances that accounted for 55 percent of food recalls in 2009.
- peanut paste
- powdered milk
- pistachios
Of all the recalls:
- 10 percent did not have a code - "this is like suicide for a company," Prince said.
- 51 percent involved multiple codes
Major Contributors
The major issues that generated recalls in 2009 were due to microbiological problems, allergens, mislabeling, foreign material (mainly plastic), chemical contamination, and inadequate processing.
Prince gave some advice in each of these areas. He tells the story of how Chinese honey is sometimes tainted with an antibiotic that is not allowed in the United States. The Chinese know that so they send to a different country to be relabeled as coming from that country.
Do recalls always happen late Friday afternoon? He has a theory that this is because manufacturers procrastinate to do it until the end of the week, which is a nightmare for the retailer. In addition, if you are a public company you need to inform the Securities and Exchange Commission (SEC) befoe you do the product recall, so companies often wait until thd market closes on Friday to do it.
New food vehicles identified in multistate outbreaks since 2006 are surprising like salmonella peanut butter despite lack of moisture, spinach and broccoli, carrot juice, hot peppers, pepper (salmonella can be in pepper for years), raw cookie dough, raw pistachios, and dog food.
What are the major contributing factors of recent recalls? Mostly, it's non-compliance with current Good Manufacturing Practices, failure to maintain food manufacturing facilities and equipment, non-compliant with a company's own Standard Operating Procedures (SOPs), and weaknesses in HACCP analysis.
Another factor is management responsibility for food safety for their products, for operations, for supply chain, etc. We're dealing with a global food ingredient procurement complexity these days, Prince said. It is much more difficult to manage.
He told the story of the infant formula recall that ended up leading to stores in cities of China not containing any infant formula, all due to melamine by some greedy businessmen who tainted their products.
When we see recalls of imported items, it is typically due to particular ingredients including milk powder. Food import problems include filth, production under unsanitary conditions, pesticide residues or use of approved pesticides, chemical contamination, or economic adulteration.
"There's a rough guess that 8 percent of food on the market is economically adulterated," he said.
Still, the biggest problem is simply salmonella. He showed us a slide of the variety of import alerts that are related to salmonella.
Recalls are also becoming more massive and expensive over time. The big peanut butter recall was a loss of over a year's worth of peanut butter. Ere is also a large legal impact coming from complaints. For example, the recall of 30,000,000 toys led to a hugely expensive settlement ($50 million).
"For those of you in the room in quality assurance, how would you like a new boss?" Prince asked. In these cases, when the government comes in, the government becomes your boss.
When you consider the economics of food safety, consider the loss of business, cost of loss of brand value, litigation, etc.
So, why the increase in all these cases?
- we concentrated our food production
- increased batch size
- product changes
- changes in food distribution
- consumer has changed
- science has changed (we're looking on ppb, versus ppt and ppm)
- epidemiology (the CDC plots info from food net surveillence trends in different parts of the country about salmonella, listeria, etc)
Salmonella is a serious problem. "When you look at what we've gone through as far as recalls, we're being bombarded from salmonella from everywhere around the world," Prince said.
The salmonella, campylobacter, and listeria outbreaks causes several fatalities when they occur.
The CDC uses the Pulse Net Database to track patterns, as in states, and has put together an outbreak team. In 2004, there was an outbreak in Tennessee that had outbreaks that the CDC tracked. They did a food history and through new technology was able to pin down peanut butter as the culprit of salmonella.
Then, peanut paste came along, which was more extensive because it was all over the country. "If it wasn't for Pulse Net they could've missed it," Prince said.
Traceability
What about traceability? Methods of traceability need to be improved. What Prince found is that most of the time traceability records were handwritten, which don't lend well to transferring electronically. Even a small accounting program or Excel spreadsheet would improve traceability.
Basically, traceability should include:
- Firm identification
- Product identification
- product coding, time code, etc.
Electronic traceability can have readable bar codes, tracking lot codes, shipping codes, etc.
"A good traceability program protects your business and provides a tool for managing supply chain," Prince said.
How do consumers see food safety? You can see that it's a big issue when you look at headlines of the melamine scandal, peanut butter recall, and so on. The data are clear: It's worth investing into food safety.
Consumers are largely concerned about germs, bacteria, pesticide residues (although not so much in this country), and terrorism. According to a Gallup poll, 29% felt recalls were serious concefn, 55 pecent would switch brands temporarily, 21% said would not purchase from company again. "Tell that to your sales department," Prince said. The changes in food purchasing is clear by sales shown in peanut butter and spinach well after a recall.
Don't forget social media, Prince warned. Monitor it well, because consumers are incredibly vocal, more than ever through these avenues.
Take Aways?
-Comply with GMPs
-Know your products
-Know your supply chain
-Know your process
-Audit your QC records (it's very educational)
-Maintain facility and equipment in sanitary manner
-Develop a food safety culture in your operation
FDA Food Safety Modernization Act
Prince then discussed the proposed FDA Food Safety Modernization Act, which is having troubles in the House currently. What will happen to it, is not known. Funding is an issue, along with other problems. These are the highlights:
-registration of facilities
-performance standards
-hazard analysis
-record access
-product traceability
-lab accreditation
-mandatory recall authority
-accreditation of 3rd party auditors (related to imports)
"If the bill is not passed before Christmas, the bill is dead and will need to be reintroduced in the new congress," he said.
Prince said that complacency is often a problem with food companies when it comes to food safety. "Are you taking things for granted," he said.
He gave these examples of companies, the first that went out of business, who offered up excuses.
- "We have been in business for 67 years and we have never had a problem."
- "We've always done it like that and it has never been a problem."
- "The inspector didn't say anything about that being a problem."
In summary, Prince said that companies must look to food safety as a majof focus of their business, to develop a culture of food safety, and to never become complacent.
"Food safety is a journey," he said.
Q&A
Amusingly, someone asked Prince what foods he avoids for sure. He said sprouts and raw oysters. He added, "The safest food is a hamburger."
04 December 2010
Aubrey de Grey Response to Rose and Coles
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| Aubrey de Grey |
This is my take as how I understood the arguments. It was, admittedly, a bit hard to follow.
What we heard from Rose and Coles, explained de Grey, was that we have an exponential rise in deaths and then, we have what de Grey called, a "weird leveling off."
So, he said that as we get older, the data point to the fact that we eventually do reach a plateau in old age when mortality rates decline (passing the "aging phase" into a "biological immortality phase"), an argument of which Coles vehemently disagrees with.
He also said that it would probably not be a plateau like the type that Rose discussed in his talk, and as he showed in fruitflies.
Basically the data are sparse in these older populations, so there's no way we can really know what to expect.
"We definitely need more data," de Grey summarized.
And everyone else appeared to agree with that.
He also re-hashed his SENS approach for ridding the "accumulation of damage" that he says eventually causes the end of an individual's life.
De Grey pointed to the Gompertz Curve to support his arguments and the fact that because there are so few old people, there's too few data to make any kind of sense of whether there's an immortality phase or not.
Previously, about de Grey:
- Anti-Aging with Aubrey de Grey
- How to Prevent an Aging Crisis
Previously, about de Grey:
- Anti-Aging with Aubrey de Grey
- How to Prevent an Aging Crisis
Building Methuselahs
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| Michael Rose, evolutionary biologist |
He told us at H+ @ Caltech that aging is just a normal process of natural selection. It's obviously a "big picture" view versus a cellular or molecular view.
But to prove his point, he decided to trick natural selection and produce fruitflies that live five times longer than the average.
The trick? Take the fruitflies that can reproduce in old age, which still have most of their physiological function, and repeat.
Pretty simple. Eventually, you get longer-living fruitflies selected for late-life reproduction. And he shared data on how this all worked.
From the fruitfly data, Rose then explained, we can learn a bit about why humans age in the way they do, with pressures of reproduction playing in as a major factor. Also, we can make use of data on the flies and other animals that suggests that species enter a "biological immortality" phase once reaching an older age.
Then, he gave a two-part strategy into how humans can deter aging using "natural immortality technology." The strategy is easy and can be started tonight, he said.
What is natural for humans?
-It's not industrial lifestyle with cars, Twinkies, TV
-But is it the agricultural lifestyle or the hunter-gatherer lifestyle that is natural for us?
As an experimental evolutionist, Rose has research that shows that populations have adapted well to new environments in just 30 to 60 generations, so Eurasian populations are better adapted to the agricultural lifestyle.
How this happens? History in the environment, smaller effective population sizes, and lots of early accidental mortality leading to earlier plateaus.
So, people of ages under 30, should take an Andrew Weil approach to diet (as opposed to a Paleo diet and lifestyle) with plenty of fruits and vegetables, whole grains, and dairy.
However, he adds that as we age, the physiology of people with Eurasian ancestry progressively reverts back to the hunter-gatherer lifestyle."You will lose that adaptation to the novel environment as you age," Rose said.
So, the recipe for natural immortality?
- adopt a hunter-gatherer lifestyle after 40 if Eurasian, earlier if ancestry is less Eurasian
- use best modern medicine
- use autologous tissue repair when it becomes available (5+ years)
- use next-generation pharmaceuticals with less side effects
Interestingly, Aubrey de Grey expressed outrage that his recipe of immortality did not include rejuvenation research. He'll be speaking soon.UPDATE: I ended up writing a more in-depth take into Michael Rose's talk for KurzweilAI, which can be found here.
Is there a maximum human lifespan?
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| Stephen Coles |
With Harrington's quote, Stephen Coles opened his talk on whether or not there is a maximum limit to human lifespan at H+ @ Caltech in Los Angeles.
As a biogerontologist, Coles studies old people, as well as old yeast, microscopic worms, flies and primates. Each of these species have lifespan limits, and, indeed, he answers, there is a maximum number of years that humans live.
However, he adds, the more we understand aging, and the diseases that kill us, it is possible to extend life's max limit.
"All bets are off if we can do something about it," Coles said.
Although, he explains that the entire process of aging is so complex that it is sort of like the blind men touching the elephant because, if your blind, it has a different shape depending on where you're touching.
Putting together the pieces that make up aging is the AMMG, which has met several times in the last couple of decades and has an accumulated "a whole lot of data."
Coles remains optimistic that Calment Limit of 120 will be surpassed, as he shows us data on the increase in the number of centenarians and supercentenarians in the world.
In addition, the average life expectancy has increased over these years.
Average life expectancies historically:
100 KYA 18
5 KYA (Ancient Egypt) 25
1400 AD (middle ages) 30
... Anyone else know the rest?
Most of us now die in our 70s from cardiovascular disease and cancer.
There's seriously a revolution going on in the understanding of aging, partly because of Stephen Coles's research in supercentenarians, including analysis of there genomes, etc. He's also worked with autopsies of centenarians.
Coles also showed data on autopsies of supercentenarians that revealed that most of them succumb to TTR (transthyretin amyloidosis).
He argues that if real life extension is to come in the future because of new technologies, then "we need a bridge plan."
These bridges are outlined here .
What is the ideal design of future humans?
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| Natasha Vita-More |
But what's to become of humanity's long tradition of creating art and design that is used to express ourselves, as a way to communicate who we are, that exists as a projection of our own personas?
This afternoon, cultural strategist and designer Natasha Vita-More discussed the question she is contemplating, "Will we wear technological interfaces as a means of expression, or will the technologies wear us?"
In this new age of using digital avatars, or creating virtual personhoods, it is unclear how human-technology interfaces are going to change what we think of when we consider on our own personas.
Vita-More discussed briefly her work in developing a prototype of a future body, a "Primo Post Human," and how we may be able to eventually design our own bodies enhanced with multi-functional technology and built for ultra-longevity.
"We're redesigning and resculpting our own identities," Vita-More said. Or, in other more techy terms, "the user-agent observer guides the enhanced atrributes of its own system." As wearable methods of technologies emerge and converge, she explained, we're only going to see more merging of techno-personas in the future.
As she explains it, on a slide: "Currently our biology can either enable physical expressions of our personalities, or can turn us into captives through physiological addictions. The fusion of personhood and technology forms a narrative in exploring perceptions of human enhancement in media design and science."
Plus, with new technologies that will enhance our brains, like mind uploading--looking into the brain and copying it--there's really no telling what our perception of "personhood" will be. Human enhancement will ultimately change the way we think of expression.
What Vita-More argues is that, as technology progresses, that art and design should continue to play a role, and that we "not to leave the humanity in the human behind."
She showed us some of fantastic visuals of her design work, which you can read about and see here and here. Plus, see Lisa Donchak's (@lisadonchak) summary post of her talk here.
Although I'm not an artist by any stretch, I did find myself thinking about this talk for a while afterward for what it means to humanity. I tried to imagine a future without art and design in it. It would be a sad place indeed.
Humanity's Future: Information Overload
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| Robert Tercek |
"The process of improving human life has always been governed by information," Tercek said. Now we're in this new information transformation age, or what he calls living in the era of B.S., or "before singularity."
Just as electricity, vaccines and plumbing once radically changed health of humans in history, we will eventually gain the knowledge to completely change the way we think about health, as well as radically increase the human lifespan in the future.
It will happen by using anti-aging therapies like those posed by Aubrey de Grey, as well as other scientists, increasing knowledge about the human genome, or in other ways never before thought.
Plus, these huge increases of info are changing life as we know it in other ways; for example, the way we use energy today. "We're going to look back at this period and see it as tremendously inefficient," Tercek said.
Tercek goes on about how information drives the advance of civilization. The first major one was speech, followed by writing, for example.
And he points out pretty amazing facts about how the Internet is wiring the world:
- we have people tweeting and blogging, communicating to the world right now
- 35 hours is being uploaded to YouTube per minute
- Facebook sees 2.5 billion uploads of photos per month
- we'll eventually upload all of humanity's knowledge from universities to the Internet.
"Every 2 days we create as much information as we did up to 2003," Tercek said, which is the most info created in all of human history, a history that has been bound by the limitations of the book for the last 500 years.
"If you look at the advances of the last 15 years and look at the next 15," Tercek said, this gives us quite a lot of reason to be amazed about what the future will bring.
Then, Tercek gave several more examples of how past advances in increasing information changed the world like the printing press, and how new technologies using "metadata" like mobile devices are changing the world again.
Plus, he gives us a picture of the future with automated cars (that you can program to pick you up using your iPad), and mentions also Sixth Sense mobile interfaces (which is what I happen to want for Xmas this year).
In short, information overload is going to make life pretty cool in the future.
30 November 2010
New vitamin D guidelines, a disappointment
Over the past decade, there has been tremendous excitement in the world of nutrition centered around the "sunshine vitamin" for its association with reducing risk of influenza, osteoporosis, autoimmune diseases, heart disease, and even some cancers such as prostate and breast cancer.
However, this morning, the Institute of Medicine, of the National Academy of Sciences released new guidelines for vitamin D (and calcium) that will come as a disappointment to several researchers who consider the report too conservative to deal with a widespread epidemic.
"Vitamin D is the most common medical condition in the world, believe it or not" said Michael Holick, of Boston University Medical Center, to me in a recent interview. Holick, who routinely prescribes 2000-3000 IU per day to his patients, has studied Vitamin D for more than 40 years. In the 1970s he was the first to isolate the major circulating form of Vitamin D in plasma, 25-hydroxyvitamin D, as well as the active form produced in the kidneys.
In his recently published book, The Vitamin D Solution, Holick cites evidence that:
Clinton added that, "especially in Canada, we don't want to close the door on those supplements. There's possibility of using supplements." Although, he said he wondered about whether or not the Canadian Cancer Society would change its recommendation from 1,000 IU to 600-800 IU in light of the IOM's new recommendations.
When asked what to make of the new recommendations when it's clear that skin synthesis upon sun exposure yielded amounts of 20000 IU or higher, Brannon responded: "We set our recommendations based on data for total consumption of vitamin D."
She added that the difference between dietary intakes and the skin synthesis is that the body has a natural ability to rid itself of excess made by the sun, "The sun giveth, the sun taketh away."
Apart from Holick, other scientists have voiced their opinions like those representing the Vitamin D Council: Bruce Hollis of Medical University of South Carolina and Robert Heaney of Creighton University.
They have long recommended taking a supplement by as much as 5,000 IU per day to maintain blood levels between 50-80ng/mL year-round.
As Science News reports, Hollis called the IOM report "a big waste of money," although agreed with the panel's decision to double recommendations for children. In addition, Heaney said, “I don’t think this does anything to create confidence in IOM recommendations."
The entire IOM report is summed up by registered dietitian Debra Riedesel, who posted on Twitter, as @NutritionistaRD, in response to the debate, "Do you trust the scientists who've researched Vit D for years or 14 IOM scientists who only read the research?"
However, this morning, the Institute of Medicine, of the National Academy of Sciences released new guidelines for vitamin D (and calcium) that will come as a disappointment to several researchers who consider the report too conservative to deal with a widespread epidemic.
"Vitamin D is the most common medical condition in the world, believe it or not" said Michael Holick, of Boston University Medical Center, to me in a recent interview. Holick, who routinely prescribes 2000-3000 IU per day to his patients, has studied Vitamin D for more than 40 years. In the 1970s he was the first to isolate the major circulating form of Vitamin D in plasma, 25-hydroxyvitamin D, as well as the active form produced in the kidneys.
In his recently published book, The Vitamin D Solution, Holick cites evidence that:
- Half of all children in the US and Europe are Vitamin D deficient at some time, but almost every single one has vitamin D insufficiency.
- Over the last 10 years there's been 22 percent reduced levels of vitamin D in the US
- Last year, a study published in Archives of Internal Medicine, showed 70 percent of whites, 90 percent of Hispanics and 97 percent of blacks in the US have insufficient levels.
- Even near the equator (where you'd think people were getting plenty of sun –think Saudi Arabia, India, Australia, Brazil, Mexico – between 30 to 80 percent of children and adults are deficient or insufficient.
- Three out of four people in the US are deficient, most are insufficient. Twenty years ago it was only 1 out of 2.
- New research has linked several common problems of poor health and accelerated aging to one single thing – vitamin D deficiency or insufficiency
Despite these data, the IOM reported that most people in the U.S. and Canada should be able to obtain sufficient amounts from their diet to meet Dietary Recommended Intakes (DRIs), assuming no other vitamin D was synthesized from the sun in the skin.
The IOM raised the DRIs of vitamin D to 600 International Units (IU) for ages 1-70 and to 800 IU for ages 70 and older. Previously the DRIs were 200 IU for ages 1-50, 400 IU for ages 51-70, and 600 IU for ages 70 and older.
The Tolerable Upper Limit was also raised from 2,000 IU to 4,000 IU for adults, which will allow major manufacturers such as the dairy industry and Coca Cola who make Minute Maid orange juice to consider doubling vitamin D in their products.
The IOM committee chair Catharine Ross, of Penn State, said that after reviewing more than 1,000 published studies and listening to testimonies of scientists there still wasn't enough solid evidence for raising vitamin D DRIs or ULs any higher.
In a press conference this morning, she said, "What we were not able to do is take the currently available clinical data including randomized clinical trials and use that information for Dietary Recommended Intakes. The data are not sufficient at present to conclude that intakes should be higher."
When asked about why the Upper Limit was not raised higher, Ross said, "We needed to take a cautious approach because we're looking to reduce risk to the public. There's evidence of harm at the level of 10,000 IU. So we used 4000 IU per day." She said that there was a gap in evidence in between the two numbers.
Other scientists on the committee chimed in:
"There's considerably more evidence, a tremendous amount for vitamin D," said Patsy Brannon, of Cornell, yet not enough to guide decision making on greater intake. She added, "There is research that points to risk. There's also research that shows no risk. We also lack RCTs. We're still needing more research."
Oncologist Steven Clinton, of Ohio State University, said, "As you look across the literature there are inconsistencies." For example, regarding calcium, it's associated with less colon polyps, but increased risk in prostate cancer. He says that in the future as more data become available, there will be more individualized approaches.
"We are still interested in this molecule that affects thousands of genes in the body. But we cannot make this leap at this point," added biochemist Glenville Jones, of Queens University.
The committee had been asked to set new guidelines for DRIs of calcium and vitamin D as well as Upper Limit intakes.
What about supplements?
Despite headlines from the New York Times and several other news outlets, the IOM committee voiced that they did not intend for this kind of position and clarified that they did not specify where the vitamin D amounts should come from--whether it be from the sun, supplements or diet.
The IOM raised the DRIs of vitamin D to 600 International Units (IU) for ages 1-70 and to 800 IU for ages 70 and older. Previously the DRIs were 200 IU for ages 1-50, 400 IU for ages 51-70, and 600 IU for ages 70 and older.
The Tolerable Upper Limit was also raised from 2,000 IU to 4,000 IU for adults, which will allow major manufacturers such as the dairy industry and Coca Cola who make Minute Maid orange juice to consider doubling vitamin D in their products.
The IOM committee chair Catharine Ross, of Penn State, said that after reviewing more than 1,000 published studies and listening to testimonies of scientists there still wasn't enough solid evidence for raising vitamin D DRIs or ULs any higher.
In a press conference this morning, she said, "What we were not able to do is take the currently available clinical data including randomized clinical trials and use that information for Dietary Recommended Intakes. The data are not sufficient at present to conclude that intakes should be higher."
When asked about why the Upper Limit was not raised higher, Ross said, "We needed to take a cautious approach because we're looking to reduce risk to the public. There's evidence of harm at the level of 10,000 IU. So we used 4000 IU per day." She said that there was a gap in evidence in between the two numbers.
Other scientists on the committee chimed in:
"There's considerably more evidence, a tremendous amount for vitamin D," said Patsy Brannon, of Cornell, yet not enough to guide decision making on greater intake. She added, "There is research that points to risk. There's also research that shows no risk. We also lack RCTs. We're still needing more research."
Oncologist Steven Clinton, of Ohio State University, said, "As you look across the literature there are inconsistencies." For example, regarding calcium, it's associated with less colon polyps, but increased risk in prostate cancer. He says that in the future as more data become available, there will be more individualized approaches.
"We are still interested in this molecule that affects thousands of genes in the body. But we cannot make this leap at this point," added biochemist Glenville Jones, of Queens University.
The committee had been asked to set new guidelines for DRIs of calcium and vitamin D as well as Upper Limit intakes.
What about supplements?
Despite headlines from the New York Times and several other news outlets, the IOM committee voiced that they did not intend for this kind of position and clarified that they did not specify where the vitamin D amounts should come from--whether it be from the sun, supplements or diet.
Clinton added that, "especially in Canada, we don't want to close the door on those supplements. There's possibility of using supplements." Although, he said he wondered about whether or not the Canadian Cancer Society would change its recommendation from 1,000 IU to 600-800 IU in light of the IOM's new recommendations.
When asked what to make of the new recommendations when it's clear that skin synthesis upon sun exposure yielded amounts of 20000 IU or higher, Brannon responded: "We set our recommendations based on data for total consumption of vitamin D."
She added that the difference between dietary intakes and the skin synthesis is that the body has a natural ability to rid itself of excess made by the sun, "The sun giveth, the sun taketh away."
Apart from Holick, other scientists have voiced their opinions like those representing the Vitamin D Council: Bruce Hollis of Medical University of South Carolina and Robert Heaney of Creighton University.
They have long recommended taking a supplement by as much as 5,000 IU per day to maintain blood levels between 50-80ng/mL year-round.
As Science News reports, Hollis called the IOM report "a big waste of money," although agreed with the panel's decision to double recommendations for children. In addition, Heaney said, “I don’t think this does anything to create confidence in IOM recommendations."
The entire IOM report is summed up by registered dietitian Debra Riedesel, who posted on Twitter, as @NutritionistaRD, in response to the debate, "Do you trust the scientists who've researched Vit D for years or 14 IOM scientists who only read the research?"
24 November 2010
Food sharing: Hunter-gatherer "health insurance"
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| Kim Hill |
I previously wrote an article for Scientific American on an Arizona State University workshop that Hill headed up along with Curtis Marean and Lawrence Krauss last February.
Most of Hill's talk was basically the same stuff I wrote about before like that humans are outliers, not unique in any specific way, but contain a combination of non-unique traits that arose through non-unique processes produced a unique outcome -- a "spectacular anomaly."
"If aliens from outerspace came to the Earth," Hill said, then they would be questioning humans instantly because we're so dominant in several ways: technologically, agriculturally, population-wise, etc.
Some would point to the industrial revolution, but Hill argues that hunter-gatherers would have still attracted aliens' attention because they were still the most prosperous species even before agriculture.Humans engage in more ecological niches than all other species combined.
Besides humans, the most successful terrestrial vertebrate is "Canis lupus" (wolves, and that's not counting dog domestication). Both humans and wolves share something in common: cooperative breeding.
So, how do you get this spectacular anomaly?
Hunter-gatherers colonized all the land mass, produced massive megaliths, created complex institutions, and developed languages and cultures.
Hill discusses how he and other scientists came together to discuss what makes humans unique looking at fields of primatology, evolution, hunter-gatherer work, etc.
What makes us uniquely human is a combination of traits that were critical for producing outlier outcomes:
-Cumulative culture
-Cooperation
-Language
-Cognition
OK, so we know all of this. But now here's the interesting part!
Hill showed data from his work that has to do with the economics of cooperation in humans as compared to chimps. Humans are hypercooperators.
What led to hypercooperation in humans?
Hill discusses that it may be due to:
a) a shift on the feeding niche going from collected foods to extracted foods and predation. This is shown in the paleoanthropolical record from 1) emergence of waist, 2) evidence of cooking, 3) stone tool cut marks.
b) extracted and hunted foods caused by juvenile dependence and long learning period.
Basically, adults need to take care of children for several more years in comparison to chimps. Human kids produce virtually nothing, even as they grow older they produce little versus the adults.
c) high variance in large-package foods promotes food sharing
In other words, Kim says, some adults are hunting and bringing home lots of food, way more than they can eat, or that their nuclear family can eat. This promotes food sharing.
He gives an example of the Ache tribe (hunter-gatherers from Paraguay who he's studied for over 30 years) and how at the end of the day everyone brings their extra food to distribute among the group. Children too are taught to share food from the time they're two years old.
Hill gives data on the percent of food types that are kept versus produced by a nuclear family. Some families give away the majority of food (70 to 90 percent!) they produce (and he joked about comparing that to a tax bracket and socialism).
Food sharing among hunter-gatherers is interesting and complicated, Hill says. The sharing is a type of "health insurance" so that if a man, for example, gets sick or injured taking him out of the production three months, he is covered by the sharing of others. He gives data on "health insurance premiums" given by hunter-gatherers like Ache, Efe, Yora, Tsimane.
Food sharing networks helped us survive and have long lives, Hill said. Because in comparison to chimps, humans have less risk of premature death because if a "chimp falls out of a tree and breaks its arm, it's dead" even though the chimp will heal simply because it will starve to death.
Hill then gave more data on hunter-gatherer habits of women overproducing and then led into cooperative breeding, which is reproducing with the help of others in birth and child rearing.
And, again, wolves are also cooperative breeders, so it's definitely an effective strategy.
"What we now know," says Hill, "is that individuals go through periods of time when they are producing a surplus and other times when families cannot feed all the mouths they have."
To illustrate the point, Hill shows us a picture of a typical hunter-gatherer family that has breeders, helpers, and dependents. He gives data on how these families subsidize food.
"It takes a 'band' to raise a child," is typed up on the slide.
He compares hunter-gatherer systems to an institutionalized social security system. "This is a universal pattern among hunter-gatherer societies," he says. A family without this would not be able to be successful. Kinship like cousins, aunts, and uncles are usually the foundation of human cooperative breeding.
But Hill has been studying how kinship moves to larger social organizations of hunter-gatherer societies.
He showed how chimp communities often are not in contact with each other and often kill each other. But, based on work by Bernard Chapais, pair bonding -- transferring females among groups, for example -- which leads to cooperation between groups.
When a sister is married to a man in another group, a brother will create an alliance with the husband. It leads to sharing food communally.
Hill said people like Paul Davies who are looking for alien species should not be looking for "intelligent life on other planets," but actually be looking for cooperative species -- species that work together to accomplish big tasks.
"Chimps are intelligent and dolphins are intelligent," he said, "but ants are closer to building a spaceship than chimps."
Learn more link: Here's some other crazy neat info from Hill on Amazonian hunter-gatherers widespread belief that they have multiple fathers.
20 November 2010
Chemicals in Store Register Receipts and Fast Food Wrappers
Before the next time you ask a cashier for a receipt, think twice! It might be tainted with bisphenol A, aka BPA.
A recent study in Environmental Health Perspectives showed that cashiers had highest BPA exposure because of its use in thermal paper for register receipts in a monomer form that is readily absorbed through skin.
BPA is also used as a polymer complex in hard, clear polycarbonate plastic water bottles and as epoxy resins lining aluminum cans.
The study raises concerns about widespread exposure to BPA from a variety of sources, especially for women who are pregnant.
Although the actual BPA amounts in receipts is so little it may not pose enough risk to worry about, it does raise concerns for people—those behind a register, for example—who are in contact with the thermal paper regularly.
The news comes no later than a month after Health Canada officially declared BPA a toxic substance that mimics estrogen, potentially increasing risks of breast cancer and prostate cancer.
Additionally, do you need another reason to avoid junk food? Here’s one: New research shows chemicals used to line fast food wrappers and microwave popcorn bags are contaminating the food and can be observed in the blood stream.
According to research from University of Toronto in the same journal, the greaseproof paper that is frequently used in the packaging of these products contain polyfluoroalkyl phosphate esters (PAPs) that break down into perfluorinated carboxylic acids (PFCAs).
PCFAs are known carcinogens and the scientists suggest that food packaging as well as non-stick and other water- and stain-repellant products like kitchen pans and clothing may be increasing exposure.
Controlling human exposure to these, and other, chemicals has become an active area of research recently as the public gains more understanding about the potential health implications caused by these toxic compounds.
Sources:
Braun JM, Kalkbrenner AE, Calafat AM, Bernert JT, Ye X, et al. 2010 Variability and Predictors of Urinary Bisphenol A Concentrations during Pregnancy. Environ Health Perspect doi:10.1289/ehp.1002366
D’eon JC, Mabury SA, 2010 Exploring Indirect Sources of Human Exposure to Perfluoroalkyl Carboxylates (PFCAs): Evaluating Uptake, Elimination and Biotransformation of Polyfluoroalkyl Phosphate Esters (PAPs) in the Rat. Environ Health Perspect doi:10.1289/ehp
A recent study in Environmental Health Perspectives showed that cashiers had highest BPA exposure because of its use in thermal paper for register receipts in a monomer form that is readily absorbed through skin.
BPA is also used as a polymer complex in hard, clear polycarbonate plastic water bottles and as epoxy resins lining aluminum cans.
The study raises concerns about widespread exposure to BPA from a variety of sources, especially for women who are pregnant.
Although the actual BPA amounts in receipts is so little it may not pose enough risk to worry about, it does raise concerns for people—those behind a register, for example—who are in contact with the thermal paper regularly.
The news comes no later than a month after Health Canada officially declared BPA a toxic substance that mimics estrogen, potentially increasing risks of breast cancer and prostate cancer.
Additionally, do you need another reason to avoid junk food? Here’s one: New research shows chemicals used to line fast food wrappers and microwave popcorn bags are contaminating the food and can be observed in the blood stream.
According to research from University of Toronto in the same journal, the greaseproof paper that is frequently used in the packaging of these products contain polyfluoroalkyl phosphate esters (PAPs) that break down into perfluorinated carboxylic acids (PFCAs).
PCFAs are known carcinogens and the scientists suggest that food packaging as well as non-stick and other water- and stain-repellant products like kitchen pans and clothing may be increasing exposure.
Controlling human exposure to these, and other, chemicals has become an active area of research recently as the public gains more understanding about the potential health implications caused by these toxic compounds.
Sources:
Braun JM, Kalkbrenner AE, Calafat AM, Bernert JT, Ye X, et al. 2010 Variability and Predictors of Urinary Bisphenol A Concentrations during Pregnancy. Environ Health Perspect doi:10.1289/ehp.1002366
D’eon JC, Mabury SA, 2010 Exploring Indirect Sources of Human Exposure to Perfluoroalkyl Carboxylates (PFCAs): Evaluating Uptake, Elimination and Biotransformation of Polyfluoroalkyl Phosphate Esters (PAPs) in the Rat. Environ Health Perspect doi:10.1289/ehp
How our senses help us decide what we eat
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| Senses help us select our food. |
What makes people choose the foods that they do? This question may seem obvious to yourself--after all, you know what you like--but this is a question posed by food industry scientists ask themselves day in and day out.
The science of food selection can get crazy complex when you think of the huge variety of foods that you find at your corner grocery store. Food scientists must continually find new "niches" for products to be placed in the marketplace.
How do they do it? The same question can be asked of musicians who endlessly produce new songs that the radio blares as latest hits, but using the same 12 musical notes. Only, in the case of food, scientists only have five notes, or tastes, the "Five-Taste Stimuli":
-sweet
-sour
-bitter
-salty
-savory (umami - think MSG, mushrooms, tomatoes, broth)
Taste rates high in the evaluation for selection from consumers. As it happens, the sensation is produced when the food comes into contact with cilia (tiny hairs) on gustatory cells, which make up around 10,000 taste buds (depending on age; people lose them as they age).
By itself, taste isn't all that complex, but then food is mixed with other sensory criteria:
-sight
-smell
-touch (texture, mouthfeel)
-hearing (yes, the sound of food)
Sight has to do with the presentation or appearance of the food. When we first look at food, we are in a sense already "eating it" with our eyes: judging for shape and color, ripeness or rottenness, smoothness or crunchiness, well-cooked or burnt.
Visual signals, mixed up with several other stimuli, instantly tell your brain whether or not you're ready to eat that grilled chicken breast or let it brown a little longer, or whether to eat that banana or wait until it turns from green to yellow (but not to black).
Smell is a wholly vital part of what it is to create food -- and I would argue that any good food scientist is also an expert at using volatile molecules from food to reach our olfactory epithelium. Flavor, in fact, is around 75 percent smell.
In the olfactory epithelium, which is inside the nasal cavity, is where volatile molecules will act on between 10 to 20 million olfactory cells. These cells can pick up between 2,000 to 4,000 different odors. A few experts are so well trained, they can distinguish closer to 10,000 -- an extremely keen sense of smell.
Touch is a sense that we use for picking our foods because it allows us to pick up on texture, astringency, consistency and temperature. Generally, with food, we start our touch evaluations with our fingers and then as the food moves toward our lips, next is the mouthfeel.
Mouthfeel of a food can tell us a lot more: a smooth texture may mean more fat content, which is more desirable to our energy-seeking brains. It also tells us whether that steak is tender or chewy, dry or moist, if the soda pop is bubbly or flat, if the vegetables are crispy or rubbery, if citrus fruits or vinegar is astringent.
Of course, touch inside the mouth also determines a food's temperature and spiciness. Heat and cold are picked up by the taste buds. The sensation of spiciness, like the one caused by capsaicin in hot peppers, is caused by irritating nerves.
A sense of hearing might not seem as important in food selection, but most of us evaluate food all the time with sound without even realizing it. We like to hear the snap of a celery stick, the crackle of potato chips, the pop of popcorn.
The sounds give clues about whether a food is fresh or sufficiently cooked. Think also of the sound a watermelon makes when you tap it to make sure it's fresh, or the sound stir-fry makes when it's sizzling.
So, back to how food scientists use all these sensory criteria: With the five-taste stimuli and other sensory signals (as in music with 12 notes, beats and rhythms), food scientists can continue creating thousands of foods that flood our grocery stores annually.
Each and every satisfying food can be appreciated for its particular complexity of visual presentation, flavor aroma, texture and sound -- they are what makes us love to eat.
Source:
Brown, A. 2000. Understanding Food: Principles and Preparation. Wadsworth: Belmont, CA.
16 November 2010
What happens on a high omega-6 diet
A while back I wrote a review of Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do about Them. Susan Allport's book goes into the history of how omega-3s were discovered and what they'll mean for us in the future.
A controversial topic of the book is how omega-6 (king) and omega-3 (queen) compete for space in eicosanoid pathways. The omega-6s, the king, are the greater competitor and more inflammatory, while the omega-3, the queen, are a lesser competitor and less inflammatory.
She goes on about this relationship between omega-6 and omega-3 and gives examples from nature of how both the oils are found and used -- omega-3s in leaves (leaf fats), omega-6s in seeds (seed fats); omega-3s eaten more often in summer months, omega-6s in winter months by animals. The omega-6s are thought to bring on extra fat for warmth, for storage, for hibernation.
It's all pretty interesting stuff. And again, as I said, a bit controversial.
Now, in a new article, Susan gives a single-person account -- herself -- of results one gets from eating a high omega-6 diet for one month. I mean, we're not talking about a randomized, clinical trial. But nevertheless, her results are particularly interesting:
- reduced RMR
- omega-3 drop in blood (10% to 6%)
- omega-6 rise from 21% to 29%
- brachial artery dilation drop by 22%
- gain of 5 pounds
You can read more about her small experiment here. In the meantime, I'm popping my fish oil pills.
A controversial topic of the book is how omega-6 (king) and omega-3 (queen) compete for space in eicosanoid pathways. The omega-6s, the king, are the greater competitor and more inflammatory, while the omega-3, the queen, are a lesser competitor and less inflammatory.
She goes on about this relationship between omega-6 and omega-3 and gives examples from nature of how both the oils are found and used -- omega-3s in leaves (leaf fats), omega-6s in seeds (seed fats); omega-3s eaten more often in summer months, omega-6s in winter months by animals. The omega-6s are thought to bring on extra fat for warmth, for storage, for hibernation.
It's all pretty interesting stuff. And again, as I said, a bit controversial.
Now, in a new article, Susan gives a single-person account -- herself -- of results one gets from eating a high omega-6 diet for one month. I mean, we're not talking about a randomized, clinical trial. But nevertheless, her results are particularly interesting:
- reduced RMR
- omega-3 drop in blood (10% to 6%)
- omega-6 rise from 21% to 29%
- brachial artery dilation drop by 22%
- gain of 5 pounds
You can read more about her small experiment here. In the meantime, I'm popping my fish oil pills.
12 November 2010
Resveratrol influences belly fat behavior
Fat can not only be unsightly, but if it’s sitting on your belly, may also contribute to overproduction of signaling hormones called adipokines, which are linked to metabolic changes that can worsen health.
New research from Aarhus University has found that abdominal adipose tissue extracted from overweight adults, and then exposed to resveratrol, exhibited reduced adipokine production. According to these authors, "small interfering molecules such as resveratrol are, in this matter, hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity."
The scientists obtained the abdominal adipose tissue via liposuction from seven women and one man, ages 43-55, who had body mass indexes categorized as overweight. All subjects were Caucasian, healthy and not on any medication that could confound the results.
Because previous studies in rodents have shown that calorie restriction reduces production of adipokines by activating an enzyme called Sirtuin 1, the scientists had hypothesized that resveratrol may act similarly. Resveratrol is well-known as a potent Sirtuin 1 activator.
This most recent in vitro study, published in International Journal of Obesity, suggests that regular dietary intake of resveratrol may guard against the metabolic changes that occur when there is excess fat on the body – as it has with rodents and monkeys.
Resveratrol is a phytoalexin (a plant-produced antimicrobial substance) found in small amounts, most notably, in red wine, as well as in other common foods such as grapes, peanuts, and chocolate. The most concentrated natural source is the Japanese Knotweed (Polyganum cuspidatum).
Resveratrol gained scientific interest after it demonstrated effects similar to calorie restriction in slowing the rate of aging and increasing the lifespan in a number of species including nematode worms, mice, and rhesus monkeys. In addition, resveratrol protects overfed mice from weight gain and lemurs from seasonal weight gain.
Source: Olholm J, Paulsen SK, Cullberg KB, Richelsen B, Pedersen SB. Int J Obes (Lond) 2010;34:1546-53.
New research from Aarhus University has found that abdominal adipose tissue extracted from overweight adults, and then exposed to resveratrol, exhibited reduced adipokine production. According to these authors, "small interfering molecules such as resveratrol are, in this matter, hypothesized to possess beneficial effects and might improve the metabolic profile in human obesity."
The scientists obtained the abdominal adipose tissue via liposuction from seven women and one man, ages 43-55, who had body mass indexes categorized as overweight. All subjects were Caucasian, healthy and not on any medication that could confound the results.
Because previous studies in rodents have shown that calorie restriction reduces production of adipokines by activating an enzyme called Sirtuin 1, the scientists had hypothesized that resveratrol may act similarly. Resveratrol is well-known as a potent Sirtuin 1 activator.
This most recent in vitro study, published in International Journal of Obesity, suggests that regular dietary intake of resveratrol may guard against the metabolic changes that occur when there is excess fat on the body – as it has with rodents and monkeys.
Resveratrol is a phytoalexin (a plant-produced antimicrobial substance) found in small amounts, most notably, in red wine, as well as in other common foods such as grapes, peanuts, and chocolate. The most concentrated natural source is the Japanese Knotweed (Polyganum cuspidatum).
Resveratrol gained scientific interest after it demonstrated effects similar to calorie restriction in slowing the rate of aging and increasing the lifespan in a number of species including nematode worms, mice, and rhesus monkeys. In addition, resveratrol protects overfed mice from weight gain and lemurs from seasonal weight gain.
Source: Olholm J, Paulsen SK, Cullberg KB, Richelsen B, Pedersen SB. Int J Obes (Lond) 2010;34:1546-53.
09 November 2010
Middle-aged Mice fed BCAAs live longer
Scientists are actively seeking aging-intervention strategies to help people maintain their youth in anticipation of a sharp rise in the elderly population – due to the "baby boomer" generation – and an unprecedented number of elderly in North America and throughout the developed world.
Now, a new study in the October issue of Cell Metabolism reports that middle-aged, male mice given a cocktail of branched-chain amino acids (BCAAs) – leucine, isoleucine, valine – in their drinking water lived an average of 12 percent longer (869 days compared to 774 days) than middle-aged, male mice drinking regular water.
The scientists, from Milan University, found that the BCAA-fed mice exhibited similar changes as those seen with calorie restriction or resveratrol supplementation, showing an increase in longevity-gene SIRT1 activity and an increase in cardiac and skeletal muscle mitochondria levels.
The treated mice also showed improved exercise endurance and motor coordination, and had fewer signs of damage from oxidative stress.
In future studies, the researchers plan on performing similar experiments with female mice.
"This is the first demonstration that an amino acid mixture can increase survival in mice," said lead researcher Enzo Nisoli, referring to prior studies that showed that the cocktail of BCAAs extends lifespan in yeast.
Getting BCAAs in the Diet
Nisoli suggests that older people may find similar anti-aging benefits from including BCAAs in their diets by eating protein or taking supplements high in BCAAs as part of a complete “nutritional approach” for aging gracefully.
Supplements of BCAAs are widely used by athletes, including bodybuilders, because they help to trigger protein synthesis and drive muscle growth, especially when taken within 20 minutes after workouts.
However, one of the most convenient ways to obtain greater amounts of BCAAs in the diet is by drinking one or more servings of a whey protein-based shake daily.
BCAA-rich whey protein has been shown consistently in several studies to aid in maintaining muscle as well as speeding up muscle recovery and growth after exercise. Preserving skeletal muscle and strength is a significant factor for maintaining long-term health.
Source: D’Antona G, Ragni M, Cardile A, Tedesco L, Dossena M, Bruttini F, Caliaro F, Corsetti G, Bottinelli R, Carruba MO, Valerio A, Nisoli E. Branched-Chain Amino Acid Supplementation Promotes Survival and Supports Cardiac and Skeletal Muscle Mitochondrial Biogenesis in Middle-Aged Mice. Cell Metabolism, 12(4):362-372, October 2010, doi:10.1016/j.cmet.2010.08.016.
Now, a new study in the October issue of Cell Metabolism reports that middle-aged, male mice given a cocktail of branched-chain amino acids (BCAAs) – leucine, isoleucine, valine – in their drinking water lived an average of 12 percent longer (869 days compared to 774 days) than middle-aged, male mice drinking regular water.
The scientists, from Milan University, found that the BCAA-fed mice exhibited similar changes as those seen with calorie restriction or resveratrol supplementation, showing an increase in longevity-gene SIRT1 activity and an increase in cardiac and skeletal muscle mitochondria levels.
The treated mice also showed improved exercise endurance and motor coordination, and had fewer signs of damage from oxidative stress.
In future studies, the researchers plan on performing similar experiments with female mice.
"This is the first demonstration that an amino acid mixture can increase survival in mice," said lead researcher Enzo Nisoli, referring to prior studies that showed that the cocktail of BCAAs extends lifespan in yeast.
Getting BCAAs in the Diet
Nisoli suggests that older people may find similar anti-aging benefits from including BCAAs in their diets by eating protein or taking supplements high in BCAAs as part of a complete “nutritional approach” for aging gracefully.
Supplements of BCAAs are widely used by athletes, including bodybuilders, because they help to trigger protein synthesis and drive muscle growth, especially when taken within 20 minutes after workouts.
However, one of the most convenient ways to obtain greater amounts of BCAAs in the diet is by drinking one or more servings of a whey protein-based shake daily.
BCAA-rich whey protein has been shown consistently in several studies to aid in maintaining muscle as well as speeding up muscle recovery and growth after exercise. Preserving skeletal muscle and strength is a significant factor for maintaining long-term health.
Source: D’Antona G, Ragni M, Cardile A, Tedesco L, Dossena M, Bruttini F, Caliaro F, Corsetti G, Bottinelli R, Carruba MO, Valerio A, Nisoli E. Branched-Chain Amino Acid Supplementation Promotes Survival and Supports Cardiac and Skeletal Muscle Mitochondrial Biogenesis in Middle-Aged Mice. Cell Metabolism, 12(4):362-372, October 2010, doi:10.1016/j.cmet.2010.08.016.
08 November 2010
My tour of Yale biotech facilities
I had the good fortune of touring Yale University's biotech facilities today, including the 2007-built Yale Stem Cell Center, with its director as our guide: cell biology professor Haifan Lin, PhD.
Walking through a high-tech stem cell facility with Lin was nothing like I expected. Lin was incredibly personable, and he and his staff took us through their labs and offices with a sense of enjoyment and courtesy if introducing us as friends to their home -- "come on into my lab, here's our million-dollar microscope, there's our genomic analyzer, would you like some tea?"
OK, so Lin didn't actually offer us tea, but he might as well have with his ultra-nice Chinese hospitality. On the tour, there were only three of us, all journalists, so it lended to opportunity of intimate discussion and questions.
Lin generously answered everything we wanted him to and with a genuine excitement about it. He shared that he had an appreciation for what we science writers do, saying, in fact, that he'd thought of joining the ranks so he could spread his own message -- that the science of stem cells is promising us a spectacular future free of certain diseases like neurological diseases and cancer.
The Yale Stem Cell Center is actually a conglomeration of several departments rich in expert faculty in areas of stem cell genetics, translational regulation, transcriptional regulation, stem cell assymetry, clinical transplantation, stem cell programming, cancer stem cells, and stem cell for tissue repair.
They all interact and the way the center is built -- with open labs and offices -- allows for plenty of collaboration. All their objectives are centered around a specific goal. "The key is personalized medicine through stem cells," Lin says.
For example, faculty member Dr. Eugene Redmond showed that Parkinson's Disease could be improved in mice and monkeys by injecting neural stem cells. With more trials underway, stem cell injections will likely become the future of treatment for humans.
Also, faculty members Drs. Christopher Breur and Toshihanau Shinoka have built blood vessels to treat congenital heart disease with stem cells. This is important to help the many "blue babies" born each year. In pigs, they had 100 percent success with treatment. The babies that have received the stem cells grow beautifully.
They actually "create living, growing blood vessels from scratch," which means we could eventually replace temporary treatments of today (that have autoimmune rejection problems) with tissue engineering treatments of tomorrow. In Breur and Shinoka's work, the vessels made were indistinguishable from any other vessels in the body.
Lin will soon be presenting a "big talk" at the next world stem cell meeting and he's hoping that the public will begin to become more thrilled about the possibilities that stem cells will bring to medicine.
Several other examples exist of how stem cells will help solve serious medical puzzles, but each all starts with basic research. This basic research is what Yale Stem Cell Center is all about.
Lin illustrates an example of basic research: he gave us a brief overview of DNA, mRNA, rRNA, and tRNA transcription of proteins, then reminded us that only 1 percent of DNA is involved in transcription. The rest, commonly called "junk DNA," is terra incognita. Lin's lab has been able to show that it's not junk, but produce piRNA, important in regulation of the other "big" genes. They sequenced 60,000 plus piRNA!
New technologies at Yale are allowing these developments to happen. "It is like discovering a new world of genes," Lin says, comparing the development in scope to Columbus discovering America. It will lead to new genetic mechanisms, drugs and therapies.
We toured core labs, Lin's own lab, saw high-powered microscopes, a genomic analyzer that could sequence an entire human genome in a week, and lots and lots of miscellaneous science stuff.
New Paradigms and the Future of Medicine
What is the future of medicine and how will we get there? On Monday morning, as part of New Horizons of Science at Yale, Director of Institutes of Systems Biology Lee Hood discussed the advent of 21st-century medicine: p4 medicine.
What are paradigm changes in biology leading to p4, or proactive medicine? There are several changes needed and all overlap and interconnect, but the main drivers in the process are:
- bringing engineering to biology through high throughput biology
- the human genome project
- cross-disciplinary biology
- systems biology
"What's fascinating is that these four paradigm changes are creating a new foundation in medicine," says Dr. Hood. "And they were each met with skepticism."
What does p4 medicine represent? predictive, preventive, personalized, participatory (p4). In other words, it's the taking of genomics and systems biology to finally unravel the complexity of pathology and seeking out preventive and personalized strategies of healthcare.
When Hood was at Caltech, he realized that he would be working on new bioinformatics technologies. At the time, they had known about DNA, RNA, proteins -- but with technology, he realized, they could transform how to understand biology.
His team created five instruments that changed biology. The instruments were automated (in collecting data), integrated information, and served to produce new ways of understanding biology.
The first instrument he produced was a protein sequencer, two hundred times more sensitive than other instruments. With it, they found the first "cancer gene," a platelet-derived growth factor. It sequenced prions related to Mad Cow Disease. It sequenced the first billion-dollar biotechnology product, epo. Also, it discovered the first blood development factor.
Why not commercialize the instruments? Hood pitched this to the University, but was told, "It's not the role of Academia". So, he went out to sell it himself. There have now been 14 companies founded by Hood Labs.
He discussed the human genome projecg and how, in Spring 1985, his bioinformatics technologies helped shape the feasibility of the challenge in the face of opponents who were "vehemently against" the project -- because it would take a way from "legitimate science" (including the National Institutes of Health).
Why has the genome project transformed biology? It provides complete parts of gene lists, transforms biology by providing access to genomics of species, and increases understanding of evolution, understanding of nutrition, and understanding of medicine.
Another instrument, the DNA sequencer, helped bring forth a cross-disciplinary approach of meeting current medical challenges -- merging chemistry, biology, mathematics, molecular biotechnology. The first cross-disciplinary department, at University of Washington, pioneered the new field of proteomics.
The problem with biology and systems biology is that it's "way too complex," but moving into the 21st century, scientists now have the computational and mathematical tools to turn biology into an informational science. Then, taking a systems approach, p4 medicine can attack vexing challenges of healthcare.
"If you think of yourself as a living creature, there are two types of information" that make you -- digital information about your genome, and environmental imprints -- the genotype and phenotype.
"It's a combination of these two types of information that leads to most diseases," Hood says. We need to think about the relationships between the two sets of information to effectively solve disease.
How you think about systems biology is critical: you need to be able to integrate data types, delineate biological networks, acquire global data, and formulate models for "discovery science."
The agenda: Use biology to drive technology and computation needed to create a cross-disciplinary approach to biology.
The Institutes for Systems Biology has just had its 10th anniversary. Back in 2000 when Hood first started the institute there was a lot of skepticism, but now there are 70 more institutes worldwide.
In short, the impact made by systems biology and a computational and systems approach to disease is grand -- it's the approach of seeing etiology of disease as altered biological networks.
He shows how his technologies compute the dynamics of a brain network in prion disease in mice. They found four networks involved in the disease. There about 300 genes in a mouse, two thirds mapped into the networks.
Going on, Hood explains that blood is a window into health and disease with systems diagnosis to identify key network nodal points for early detection, prevention, treatment. In the future, we should have complete genome sequencing of families, the human proteome project, the second human genome project.
Family genome sequencing has itself demonstrated that scientists can use principles of Mendellian genetics to identify 70 percent of sequencing errors, discover variants, and more rapidly find genetic encoding that leads to disease.
What about the future? "One of the most revolutionary biology fields is single-cell analysis," Hood says. This is along with stem cells and computational, systems, integrative biology.
Concluding, he says, there needs to be a transition in healthcare to p4 medicine, so ISB has set up partnerships for "inventing the future." They will be creating 21st century biomedicine involving systems analysis of biology and medicine, technology development, and preventive strategies.
"P4 medicine is about 1) wellness and 2) demystifying disease," Hood says, noting that the ultimate solution is prevention by using systems biology and bioinformatics technologies.
In the Q&A part after this talk, it was asked "when will we reach the p4 zone?" and Hood replied that there are several examples of companies that are reaching this point (and he names 23andme as a pioneer).
Some day, with Hood's leadership and technologies, our own complex biologies will be hacked, reduced to information, for the development of healthcare strategies built around personalized medicine.
If interested in following p4 medicine as it grows in acceptance, check out ISB's newsroom
What are paradigm changes in biology leading to p4, or proactive medicine? There are several changes needed and all overlap and interconnect, but the main drivers in the process are:
- bringing engineering to biology through high throughput biology
- the human genome project
- cross-disciplinary biology
- systems biology
"What's fascinating is that these four paradigm changes are creating a new foundation in medicine," says Dr. Hood. "And they were each met with skepticism."
What does p4 medicine represent? predictive, preventive, personalized, participatory (p4). In other words, it's the taking of genomics and systems biology to finally unravel the complexity of pathology and seeking out preventive and personalized strategies of healthcare.
When Hood was at Caltech, he realized that he would be working on new bioinformatics technologies. At the time, they had known about DNA, RNA, proteins -- but with technology, he realized, they could transform how to understand biology.
His team created five instruments that changed biology. The instruments were automated (in collecting data), integrated information, and served to produce new ways of understanding biology.
The first instrument he produced was a protein sequencer, two hundred times more sensitive than other instruments. With it, they found the first "cancer gene," a platelet-derived growth factor. It sequenced prions related to Mad Cow Disease. It sequenced the first billion-dollar biotechnology product, epo. Also, it discovered the first blood development factor.
Why not commercialize the instruments? Hood pitched this to the University, but was told, "It's not the role of Academia". So, he went out to sell it himself. There have now been 14 companies founded by Hood Labs.
He discussed the human genome projecg and how, in Spring 1985, his bioinformatics technologies helped shape the feasibility of the challenge in the face of opponents who were "vehemently against" the project -- because it would take a way from "legitimate science" (including the National Institutes of Health).
Why has the genome project transformed biology? It provides complete parts of gene lists, transforms biology by providing access to genomics of species, and increases understanding of evolution, understanding of nutrition, and understanding of medicine.
Another instrument, the DNA sequencer, helped bring forth a cross-disciplinary approach of meeting current medical challenges -- merging chemistry, biology, mathematics, molecular biotechnology. The first cross-disciplinary department, at University of Washington, pioneered the new field of proteomics.
The problem with biology and systems biology is that it's "way too complex," but moving into the 21st century, scientists now have the computational and mathematical tools to turn biology into an informational science. Then, taking a systems approach, p4 medicine can attack vexing challenges of healthcare.
"If you think of yourself as a living creature, there are two types of information" that make you -- digital information about your genome, and environmental imprints -- the genotype and phenotype.
"It's a combination of these two types of information that leads to most diseases," Hood says. We need to think about the relationships between the two sets of information to effectively solve disease.
How you think about systems biology is critical: you need to be able to integrate data types, delineate biological networks, acquire global data, and formulate models for "discovery science."
The agenda: Use biology to drive technology and computation needed to create a cross-disciplinary approach to biology.
The Institutes for Systems Biology has just had its 10th anniversary. Back in 2000 when Hood first started the institute there was a lot of skepticism, but now there are 70 more institutes worldwide.
In short, the impact made by systems biology and a computational and systems approach to disease is grand -- it's the approach of seeing etiology of disease as altered biological networks.
He shows how his technologies compute the dynamics of a brain network in prion disease in mice. They found four networks involved in the disease. There about 300 genes in a mouse, two thirds mapped into the networks.
Going on, Hood explains that blood is a window into health and disease with systems diagnosis to identify key network nodal points for early detection, prevention, treatment. In the future, we should have complete genome sequencing of families, the human proteome project, the second human genome project.
Family genome sequencing has itself demonstrated that scientists can use principles of Mendellian genetics to identify 70 percent of sequencing errors, discover variants, and more rapidly find genetic encoding that leads to disease.
What about the future? "One of the most revolutionary biology fields is single-cell analysis," Hood says. This is along with stem cells and computational, systems, integrative biology.
Concluding, he says, there needs to be a transition in healthcare to p4 medicine, so ISB has set up partnerships for "inventing the future." They will be creating 21st century biomedicine involving systems analysis of biology and medicine, technology development, and preventive strategies.
"P4 medicine is about 1) wellness and 2) demystifying disease," Hood says, noting that the ultimate solution is prevention by using systems biology and bioinformatics technologies.
In the Q&A part after this talk, it was asked "when will we reach the p4 zone?" and Hood replied that there are several examples of companies that are reaching this point (and he names 23andme as a pioneer).
Some day, with Hood's leadership and technologies, our own complex biologies will be hacked, reduced to information, for the development of healthcare strategies built around personalized medicine.
If interested in following p4 medicine as it grows in acceptance, check out ISB's newsroom
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