The Evolving Health blog is moving to evolvinghealth.wordpress.com

Although I've enjoyed posting from Blogger for five years now, I've found that Wordpress offers me a lot more of the functionality that I need.

So, I hope you'll join me for more posts about evidence-based food, nutrition and medicine updates over at http://www.evolvinghealth.wordpress.com.

Also, don't miss my coverage of Experimental Biology 2013 from April 19-24!

Sincerely,
David

Why we should adopt a "zoobiquitous" approach to health

We are all animals. It's a fact that may be unsettling for some, but for others it is a fountain of understanding and of inspiration. Since 1859, thanks to Charles Darwin, our place in the animal world has been firmly established. Yet, to this day, it is all too common within medicine (and nutrition) to have the tendency to develop a narrow-mindedness about ourselves that disconnects us from the natural world. Rarely do medical doctors ever look beyond, to other animals, for a broader perspective about their fields. As the veterinarian insider joke goes, "What do you call a physician? A veterinarian who can only treat one species." 

 This is where zoobiquity (a different, zoobiquitous approach to medicine) comes in.

What is zoobiquity? When a story of how two obese Alaskan grizzlies lost hundreds of pounds helps inform nutritionists about how they might advise their human patients on weight management, you could say that is an example of zoobiquity. When a psychiatrist finds she is able to kindly comfort a patient diagnosed with anorexia by pointing out that an eating disorder is nothing ashamed of and that, in fact, it is quite common across several species, that's zoobiquity. And, when a veterinarian oncologist and human oncologist come together to discuss the similarities of their animal and human patients and share data in an effort to improve medical outcomes of their patients, that's zoobiquity.

Calories aren't right on labels and maybe that’s OK

Has it ever crossed your mind that the number of listed Calories (Kcals) of, say, a large, raw, whole apple at 116 Kcals and that of a glazed doughnut at 125 Kcals might not be an accurate comparison*? Surely, you might think, isn’t the doughnut more likely to add inches to your waistline?

You'd be right. The difference that you might have understood intuitively is that, although the number of listed Kcals are similar, your body is likely to extract more of them from the doughnut than the apple. Why the disparity then on the Kcals listing? You can lay blame on the shortcomings of the Atwater Specific-factor System.

Here's a little nutrition science history lesson: In the early 20th century, American chemist William Olin Atwater pioneered calculation of energy values from measures of heat combustion of proteins, fats and carbs. This is how we arrived to the familiar protein at 4 Kcals per gram, lipids at 9 Kcals per gram, and carbs 4 Kcals per gram. It would come to be known as the Atwater General Factor System. At the time, Atwater couldn’t account for fiber, so, in 1955, Bernice Watt and Annabel Merrill refined the system with specific Calorie conversion factors of foods, which has led to what the system is now.

Experts on the evolution of human nutrition

Want to eat a diet that mimics that of our Paleolithic ancestors? It might be a little more complicated than what the popular books say.

The fact is, there was never one Paleo Diet; it's more likely there were hundreds of them and that they were continually changing and broadening over evolutionary time.

That was the overarching message of an impressive lineup of experts on ancient human diets at a symposium entitled "The Evolution of Human Nutrition" organized by the Center of Academic Research and Training in Anthropogeny (CARTA) at UC San Diego on December 7, 2012.

Now, I'm happy to report, the videos of a few of the talks have been made available (embedded in this post below). You can also read what other folks on Twitter had to say about the event using the #CARTAsymp hashtag in my Storify story.

The nutritional biology of human skin color

The amount of melanin found within our skin has long been a source of division for humans culturally, but anthropologist Nina Jablonski of Penn State tells the story of how human skin color unites us all biologically.

It's become one of my favorite stories to share as it relates to nutritional biology: More pigment was naturally selected because it acted as a sunscreen needed to protect against DNA damage and destruction of folate, needed for reproduction. Depigmentation was selected for when humans dispersed from Africa and into the Northern Hemisphere where they needed skin light enough to absorb sufficient UVB rays to produce vitamin D.

I first heard Jablonski discuss the nature of human skin pigmentation almost two years ago at the AAAS conference in Washington DC. Later, I discovered her TED talk, which I've posted above. It's older, but worth watching over and over again. Jablonski has a simple message: instead of using skin color to discriminate, use skin color to teach people about evolution and health.

What a Komodo dragon can teach us about energy balance

Credit: San Diego Zoo

Try telling a Komodo dragon that physical activity doesn't matter and that all one needs to do to lose weight is eat a diet lower in carbohydrates.

Meet Sunny, the obese Komodo dragon. Her San Diego Zoo keepers have put her on a strict diet based on her animal energy and metabolic requirements. She eats only mice, rats, and ground turkey mixed with vitamins and calcium. Yet, it's not enough to keep Sunny from steadily gaining weight. When in captivity, dragons are prone to obesity because of their mainly sedentary lifestyle. They do little else than sleep, bask in the sun or shade, and eat breakfast or supper.

In their native habitat of Indonesian islands, Komodo dragons are extremely active. They travel up to 10 kilometers a day, run up to 13 miles per hour, swim several kilometers from island to island, then dig or climb as they hunt. Once they capture their prey, they can eat as much as 80 percent of their body weight in a single meal. That energy they will serve to store for often days or weeks.

When I asked senior zookeeper Ken Morgan what he was doing to help get Sunny moving and losing weight, he replied that they were trying a series of enrichment programs. But getting a 200-pound dragon to do any activity at all is no easy task, he said. It takes some creativity. One enrichment program Morgan has used involves burying a ball with a dead mouse inside. Sunny picks up the scent, spends some time searching for it, then digs around before finally discovering the treasure. It's activity accomplished. These games can help Sunny burn more calories to keep weight off.

What journalists should know before writing about fructophobia

"Pick your poison" Sugars by vavroom, on Flickr

In his new book, Fat Chance, Dr. Robert Lustig argues that "sugar is more toxin than it ever was nutrient." He writes that sugar is as addictive as cocaine, that it should be regulated like tobacco, and that children should be carded before having a soda. He compares the fructose component of sugar to ethanol. "Pick your poison," he writes, arguing that fructose will "fry your liver and cause all the same diseases as does alcohol." He also challenges energy balance (calories-in-calories-out) as the dominant paradigm of understanding obesity and and argues that sugar is harmful in ways beyond the calories it provides.

With statements as controversial as these, it's no wonder that the media, who tend to crave sensationalism to obtain readers or viewers, eat them up like candy. And Dr. Lustig knows what he's doing and just what to say to elicit attention. He's no stranger to the spotlight, as Elizabeth Weil writes in her article featuring the pediatric endocrinologist. The showman-doctor also knows just how to tell a classic falling-prey-to-cruelty story. He'd have his readers believe just what they want to hear: that their weight gain is not their fault, that the great evil monster of the food industry is putting addictive "poison" in their food in the form of sugar, and that the government is standing "idly by" letting it all happen. After reading Dr. Lustig's book, it's easy to understand why readers are entertained and maybe even enraged enough to give up on sugary sodas, cheese cake, and apple pie. But are the arguments Dr. Lustig makes in the book right or wrong?

Why you can all stop saying meat eating fueled evolution of larger brains right now

Hadza returning from hunt in Tanzania. Credit Andy Lederer.

In William Shakespeare's comedy Twelfth Night, Sir Andrew, who was worried that a joke may have been made at his expense, reasons out loud that maybe his diet had something to do with his lack of intelligence, saying, "But I am a great eater of beef, and I believe that does harm to my wit" (Act I, Scene III). Dialogue like that was how Shakespeare famously poked fun at what he considered "foolery" in his time; it was a common belief of the Elizabethan Age that eating too much meat made you a meat-head. Now, it appears the tables have turned. Vegetarians are getting a taste of similar medicine from comedians of our time.

On November 15th's episode of The Colbert Report, Stephen Colbert interviewed one of the world's foremost paleoanthropologists, Chris Stringer of the Natural History Museum, about his newly published book. During their conversation, Stringer sums up nicely why meat eating may have been the primary force that drove evolution of a brain-gut tradeoff, where a shrinking gut allowed for more energy input into the brain. Here is Stringer's explanation at about minute 18:30 in the episode:

Chris Stringer: "There's a thing called 'expensive tissue hypothesis'. And this says we evolved our large brains by changing our diets. Our ancestors had great big guts because they were vegetarian. They never had enough spare energy because their guts were using 20 percent of their energy; they never had enough spare energy to evolve a large brain. When we started eating meat, a much more concentrated sort of food, it freed up energy and we could start to run a bigger brain."

Stephen Colbert: "That's why vegetarianism seems so stupid to me."

Human vs. chimps: What the "regulome" tells us about meat eating & bigger brains

Source: Greg Wray

The story about how humans evolved bigger brains begins some seven million years ago in central Africa. There, in a dense rainforest, there lived the last ancestor that we share with our closest living relatives. Our evolutionary paths diverged when the global climate changed and a new habitat took shape. While ancestors of chimpanzees retreated deeper into the rainforest to subsist on a diet mainly of fruits, our ancestors found themselves in on strange, new, dry grassland.

The savanna would mean a new way of life for our ancestors. They'd learn to use tools, communicate with each other using language, and work together to hunt animals for food. Based on fossil evidence and stable isotope data, our hominin ancestors shifted to a diet where meat was a principal energy source about two million years ago. It would be a major shift in diet that coincided with an increase in cranial capacity.

Now, scientists like Greg Wray, a professor of biology at Duke University, are beginning to better understand the genetic basis for the adaptation to eating meat and how it guided the development of our larger brains. During his plenary talk at the Council for the Advancement of Science Writing's (CASW) "New Horizons in Science 2012" annual conference in Durham, North Carolina, Wray said that the Encyclopedia of DNA Elements (ENCODE) project gave scientists like himself a "detailed street map" for seeking out the genetic changes that took place since the divergence of humans and chimpanzees over evolutionary time.

Food is "star stuff"

Champagne supernova. Credit: Space Daily

"If you want to make an apple pie from scratch, you must first invent the universe."

When you eat a slice of apple pie, or any pie, or any food at all today, on Carl Sagan Day, it may be worthwhile to reflect on this quote, one of the beloved television series host's most famous from Cosmos: A Personal Voyage.

A look back at our origins is a good way to gain some perspective, amidst the accumulating scientific evidence, on how to understand our own biology and predicting ways in which we can keep our own healthy. Or, at least, that has been my conclusion. Starting at the beginning with the chemistry of life, our own evolution, and to that of our close cousins, then on to our current situation, and the future, this blog has explored all sorts of topics relating to diet and health in the past and forthcoming.

Why lemurs get sick: A lesson for humans, too

Female blue-eyed lemur

What lessons can humans learn from our far distant prosimian primate cousins about living well and eating a healthy diet?

This was the question on my mind as I toured the Duke Lemur Center in Durham, North Carolina with colleagues attending Science Writers 2012. (Read Christie Wilcox’s full report about our tour over at Science Sushi on Scientific American.)

When I learned on the tour that lemurs were getting sick, I inquired further from our tour guides, education associate Chris Smith and education manager Niki Barnett. The thought of these adorable creatures—somehow related to me because of a common ancestor some 50 to 80 million years ago—suffering from the same types of chronic diseases as modern-day humans encouraged me to want to find out more about their care and treatment.

Of bunnies and bacteria

I remember when I first learned that a rabbit ate its food twice.

This curious dietary practice, called coprophagy, is something I'd witnessed as a child raising my own rabbits and guinea pigs in the backyard. Disgusted by the sight of my pets eating their own feces, I recall trying to keep their cages as clean as possible. Had I known better, I would not have been so quick to remove droppings from their cage because I might've put these animals at risk for nutritional deficiency (1-2). Luckily, I wasn't ever very consistent at keeping their cages clean all the time.

Rabbits and guinea pigs, as it turns out, need to eat their own droppings because they provide a valuable source of nutrients like vitamin B12. In the wild, they will normally leave soft droppings at the mouths of their burrows while they go off foraging at dawn or dusk. When they've had their fill of foliage, they return and -- far from being repulsed by having a stack of droppings at the foot of their doorstep -- they eat up these droppings, which are by this time a nutrient-rich fermented dessert.

Why aren't we talking about organic GMOs? And, why can't we all get along?

You've heard the rants about Mitt Monsanto versus Organic Obama. You've read the arguments on both sides for "Yes" or "No" on labeling GMOs in California. You've read the research surrounding the wholesomeness of "organic" versus "conventional." There's the divisive talk, the reasoned talk, and the rat-shi# crazy talk.

What I want to ask is this: Why aren't there more people, beyond scientists and academics, talking about organically grown GMOs? These last few weeks have had me thinking a lot about how the terms used to describe our food -- "organic," "conventional," and genetically modified" -- which only serve to confuse and distract from greater issues at hand.

The greater issues (in a nutshell): Agricultural and food scientists are given a heavy task of feeding nine billion people by 2050. Most will agree that it will come with substantial costs. Soil quality will suffer, excess pesticide and herbicide use will destroy biodiversity, nutrient runoff will keep fueling the algal booms, or "dead zones," that suffocate life in our lakes and oceans. The world's phosphorus reserves will be depleted. If you add in climate change to the mix, you can count on destroyed crops and suffering farmers, especially in the developing world. Food production will be more expensive. Food will be more expensive. Small farmers and the poorest among us will suffer.

Making lazy, stupid plants work harder

Plants with larger root systems take up minerals more easily.

Plants these days. They're coddled, entitled, fed with a silver spoon.

Use of man-made fertilizer and traditional breeding, over the years, has selected for traits that led to today's modern-variety plants that grow fat with yields.

But the downside of easy access to nutrients is that it has allowed for the breeding out of desirable traits that has left plants, well, acting like enabled, spoiled children.

"They're lazy," said plant biochemist Roberto Gaxiola, an assistant professor of cellular and molecular biosciences at Arizona State University. Because nutrients are plentiful, they don't bother with growing large root systems. Yet, he explained to me, larger root systems are needed for them to take up more phosphate and nitrogen from the soil.

More now than ever, plants depend on these fertilizers for growth. Wild crop plant varieties, on the other hand, have had to evolve in an environment of everyday nutrient scarcity. It's these wild crop plant root systems that have been the focus of Gaxiola's research for more than a decade.

When I won't accept a guest post

I get regular requests from people who want to guest post on my blog. Then, I got this unbelievable one yesterday. More unbelievable was that I saw it almost directly after giving a lecture on evidence-based nutrition. Thought I'd share.

Sievenpiper: Fructose should not "worry" in diabetes

As the fructose debate rages on, one serious concern has been what the message should be for people who have diabetes. There's no question that the alarming media headlines, articles, and YouTube videos have confused many with prediabetes and both type 1 and type 2 diabetes.

Even health professionals and organizations like the American Diabetes Association have taken a cautious approach by recommending avoidance of fructose as a sweetening agent. That is, for fear it may raise plasma lipids. They stop short of recommending people avoid fructose from fruit.

There is also the extreme arguments of Internet marketers like Joe Mercola blasting out articles about the supposed danger of fructose including that of which comes from fruit. (I've had more questions than I can count about Mercola's unreasonably scary headlines and viral copy. He makes baseless recommendations that those with diabetes should cut fructose from all sources to amounts of less than 15g per day.)

Changes in genetic expression during weight loss and weight maintenance

by Amanda Jensen* 

Losing weight is an ambition with no end. To get fit, live longer, reduce injury, look better, feel better and sleep better will pave the road toward your skinny. Yes, losing weight is known to help the heart and boost insulin sensitivity, but the question still asked is: how?

There are differences between losing weight and keeping it off. From the Department of Clinical Sciences Malmo in Sweden, researchers found seven key genes expressed in adipose tissue (fat tissue) that change with weight loss and weight maintenance—a finding that brings science one step closer to understanding how the body responds to and regulates fat loss.

Videos from the EB2012 Sugar Showdown and a Few Comments from Dr. Lustig

If you've been following this blog, then you're probably aware that back in April I blogged about a highly attended debate at Experimental Biology 2012 in San Diego (dubbed the #sugarshowdown in a hashtag on Twitter; here's the Storify story in case you missed it). The event was sponsored by the Corn Refiners Association.  

In that symposium, Dr. Robert Lustig, of University of California, San Francisco, who is famed for sensationalizing the position that sugar is "toxic" in media coverage and the scientific literature, was seriously challenged by not only speakers, but also by fellow scientists (from industry and non-industry alike) in the crowd during the question-and-answer period.

One of those scientists was Dr. John Sievenpiper, of St. Michael's Hospital, University of Toronto, who told me in an interview after the event, "Having both sides better represented was far more balanced than what came out of his two-million hit sensation on YouTube and a lot of the media coverage."

Why a fat brain made us more vulnerable to heart disease

Natural selection granted us large brains. The evolutionary cost is having to feed them. The human brain's high-energy demands led to development of a strong preference for fat. We consume more fat than any other primate on average. We are also adapted to more easily digest and metabolize fats.

There are two major kinds of fat that our brains depend on most for its development and regular maintenance. These are the long-chain polyunsaturated fatty acids (LC-PUFAs), omega-3 docosahexaenoic acid (DHA) and omega-6 arachidonic (AA). These two LC-PUFAs can't be made de novo, making them essential in the diet. DHA and AA are supplied by seafood, eggs, or animals. They can also be supplied as their 18-carbon precursors alpha-linolenic acid (ALA) and linoleic acid (LA), found mainly in plants and their seeds.

ALA and LA precursors require conversion to become long-chained through a series of steps of desaturation and elongation. In particular, delta-5 and delta-6 fatty acid desaturases build onto the carboxyl end of the carbon chains of the ALA and LA by introducing double bonds. These converting enzymes are rate-limiting.

The rate-limiting enzymes are encoded into the genome by FADS1 and FADS2. The FADS region has been of special interest to researchers because of variations in single-nucleotide polymorphisms (SNPs) that could lend clues about human evolution including our larger brains. Yet, to date, there have not existed any studies evaluating FADS mutations among humans and related species.

Good insulin, bad insulin: Its role in obesity?

Gary Taubes makes insulin out to be a bad guy. In his latest article in Newsweek Magazine commenting on HBO's Weight of the Nation documentary, he once again challenges energy balance (energy intake versus energy expended) as a paradigm for understanding obesity. The author of Good Calories, Bad Calories offers an alternative theory: refined sugars and grains trigger insulin, which leads to fat accumulation. He also doesn't think much of physical activity as playing a "meaningful role in keeping off the pounds."

Is Taubes right? Not according to Jim Hill, Ph.D., a professor of pediatrics and medicine at the University of Colorado School of Medicine, Denver. Hill is the cofounder of the National Weight Control Registry, a registry of individuals who've succeeded in maintaining weight loss over time. He is also the co-founder of America on the Move, a national weight-gain prevention initiative.

At a session at Experimental Biology, Hill said that the the "energy-in energy-out" framework continues to dominate as correct in current scientific literature on obesity. When asked whether or not the rise of obesity epidemic is related to diet or physical activity, Hill simply responds, "Yes." That is because studies have shown that either restriction of calories or greater physical activity can lead to weight loss.

Then, what's wrong with Taubes's insulin hypothesis? First, it's important to point out that insulin is also a good guy. As kinesiologist John Ivy, Ph.D., of the University of Texas at Austin, pointed out to me a few years ago, insulin is too often misunderstood. The unfortunate consequence can be a detriment of muscle and strength. Ivy's own research is on muscle insulin resistance and how it is reduced with exercise.