23 August 2012

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.

07 July 2012

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.)

13 June 2012

Changes in genetic expression during weight loss and weight maintenance

by Amanda Jensen* 

ResearchBlogging.org 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.

08 June 2012

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."

30 May 2012

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.

27 May 2012

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.

26 May 2012

Fate of fructose: Interview with Dr. John Sievenpiper

Fructose metabolism. Ref: Tappy & Ka 2010.
Sugar is a hot topic these days. Evidently, it's also a touchy topic. I've been a little amazed at some of the responses (both positive and negative) received since my first rant post about media reporting unfairly that hummingbird fuel was "toxic". There clearly exists a continued need for education about the state of the evidence as it stands now surrounding sugar and its implications on health.

As a follow-up to my report of the "Sugar Showdown" at Experimental Biology -- a debate where scientists voiced clear dissatisfaction with the sensationalism surrounding sugar both in news reports and in the scientific literature -- I decided to seek out greater insight by an expert who was at the event.

John Sievenpiper, M.D., of St. Michael's Hospital, University of Toronto, brings a valuable perspective to our understanding of sugar. He is the lead author of three recent systematic reviews and meta-analyses evaluating fructose's effects on body weight, blood pressure, and glycemic control in humans from randomized controlled feeding trials.

With only very light edits made (for clarity) to my transcribed interview with him by telephone, I give you the take of Dr. Sievenpiper on fructose in his own words:

20 May 2012

Have a cuppa pesticide and #dontdestroyresearch

Earlier today, biologist Mary Mangan (@mem_somerville) shared the bad news that anti-biotechnology activists had succeeded in breaking into and damaging a publicly funded research project at Rothamsted Research Station in Harpenden, England. The vandalism happened only a week ahead of a planned demonstration organized by the Take the Flour Back environmentalist group (which I wrote previously about here).

Mangan wrote on her Google+ page:
Sadly, the destruction has begun. Forces opposed to science have vandalized a research project in the UK that has been underway for many years. It is a publicly funded project, and it attempts to use a biological method of control of insects on wheat plants. It could someday help reduce the use of pesticides and improve food security.
This led to a series of comments from people who mostly expressed sadness and anger about the damage. But, then, there were both of these comments:

18 May 2012

Confusing messages about sugar are stupid

I'm a bit late in weighing into the "Sugar Makes You Stupid" mess of poor health reporting on a rat study. At the Embargo Watch blog, Ivan Oransky already covered the mishandling of the study's embargo and ripped into the press release for misleading readers into believing that the study had any meaningful conclusions for college students. Then, Deborah Blum at Knight Science Journalism Tracker went further, bringing more reason and logic, by clarifying what the rat study was really about -- the neuroprotective role of omega-3 fatty acids!

Mainly, I hope to bring a little more overall perspective to a study that, while perhaps could be valuable, has brought along with it unnecessary fears that a little hummingbird fuel, aka sugar, will make people walk around aimlessly as brainless as zombies. It's nonsense, of course, that sugar makes you stupid. After all, neurons run on a constant supply of glucose delivered by the bloodstream (as they don't store glucose as glycogen like other cells), a fact that several media reports completely failed to mention.

13 May 2012

What environmental groups don't understand about biotech

It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change.
- Charles Darwin
On May 27, the "Take the Flour Back" environmentalist group plans to take "mass action" in efforts to remove more than $1 million worth of research in biotechnology. Their purpose, according to their website, is one of "mass decontamination" of what they see is a threat to farmers, the food supply, health of consumers, and biodiversity. What this protest group doesn't understand is that it's exactly this kind of research that they, as environmentalists, should be placing on a pedestal.

In an interview with Karl Haro von Mogel, Rothamsted's biologist Dr. Gia Aradottir explains the details of the experiments the protest group wants to uproot at Rothamsted Research Station in Harpenden, England: The research is on a variety of wheat that is genetically engineered to emit aphid alarm pheromone (E)-β-farnesene (EBF); in other words, the scientists are testing plants that can produce their own non-toxic aphid repellent, using pheromones. An aphid-resistant wheat variety could lead to less use of pesticides overall, less pesticide runoff, less effects on beneficial plants and insects in the surrounding environment, less possibility of pesticide resistance.

11 May 2012

BMI puts young Asian-American women at risk of being "skinny fat"

As if we needed any more reason to pick on Body Mass Index (BMI): new research finds that this most accepted approach for assessing overweight and obesity based on height and weight could lead to misclassification of young Asian-American women as healthy when they're really "skinny fat," which could put them at greater risk for type 2 diabetes and cardiovascular disease.

In my last post, I discussed the scary, growing problem of sarcopenic obesity (aka "skinny fat") in older adults, described as age-related muscle loss in combination with the accumulation of body fat. One common result of sarcopenic obesity is a misclassification using BMI as "normal-weight" in these aged individuals. Misclassification in older adults with sarcopenic obesity is just one reason why BMI is loathed by those interested in public health.

05 May 2012

Nevermind body fat; put focus on muscle with age

With all the attention given to body fat, a result of the high prevalence of obesity and type 2 diabetes, skeletal muscle is often given the back seat. Yet holding on to lean muscle mass alone, in itself, may be the most important factor in avoiding health problems above. What's often forgotten is that skeletal muscle is a metabolically active tissue that plays a critical role in consuming energy and determining metabolic rate, it's the large site for fat burning, and it's a primary site for blood glucose disposal. It's time to give muscle its due.

When you reach age 60 or older, it gets harder to keep, let alone build, muscle. The reasons are a combination of lack of energy, exercise, dietary protein, and hormones. One more is a blunted protein synthesis response that is described as anabolic resistance in aging. Left to run their course, these factors eventually bring on a decrease of muscle mass over time, or sarcopenia. The loss is also often accompanied with an increase in fat mass, or sarcopenic obesity. Sarcopenic obesity brings along with it the lack of both mobility and physical function, with compounding effects, that eventually lead to increased risk of chronic disease.

25 April 2012

Holding on to brain function through nutrition


By the year 2050, the number of people in the world over 80 years old will reach 370 million. About 50 percent of adults currently 85 and older have Alzheimer’s disease. The statistics are sobering and warn of a growing and serious epidemic. A high prevalence of Alzheimer’s disease, which is a debilitating and costly disease, can severely impact the population.

With this perspective, the American Society for Nutrition hosted a symposium on the nutritional prevention of cognitive decline on Wednesday at Experimental Biology in San Diego. At the event, speakers presented a comprehensive overview of epidemiological, animal, and clinical trials regarding the role of B vitamins, omega-3s, vitamin D, and caffeinated beverages such as coffee and tea in the prevention and treatment of cognitive impairment.

How to fight "job-esity"


Workplace programs are an effective and worthwhile way for employers to help improve the health of their employees and reduce medical costs, scientists said Tuesday at Experimental Biology 2012 in San Diego at a session organized by the American Society for Nutrition. 

The medical expenses for employees who are obese are estimated at about 42 percent higher than for those with a healthy weight, according to the Centers for Disease Control and Prevention. Yet for the approximately 60 percent of Americans who are employed, it may be the workplace itself that is at the root of weight gain in the first place.

24 April 2012

The future of nutrition research


There is little question that nutrition provides the foundation of health and wellbeing and that research into better nutrition is central to enabling a population live healthier, more productive, and longer lives.

With this perspective in mind, the American Society for Nutrition assembled a working group of leading nutrition thought leaders to identify a list of nutritional research areas that required greater or further analysis and prioritization.

In a symposium entitled "The Future of Nutrition Research" on Tuesday at Experimental Biology 2012 (#EB2012), these thought leaders outlined what was generally agreed as the six areas of nutrition research that deserved attention.

A way forward: Meeting vitamin and mineral needs globally


Lindsay Allen

Efforts to curb or eliminate vitamin and mineral deficiencies globally have existed for almost a century, although there are now still as many questions if not more than ever before about what the next steps should be. There are seldom solutions that are simple to guide public policy internationally and there remain large challenges when it comes to making informed recommendations. 

Lindsay Allen, Ph.D., R.D, who is the 2012-2013 recipient of the E. V. McCollum International Lectureship in Nutrition, discussed a new way forward to improve the health of infants, children, and pregnant women internationally on April 22 at the McCollum Lecture organized by the American Society for Nutrition at Experimental Biology 2012 in San Diego. She currently serves as the Center Director of the USDA, ARS Western Human Nutrition Research Center. 

She discussed the challenges faced in global research and policy on micronutrient deficiencies as well as new methodologies on the horizon to improve research. She also called for the bringing together of more nutritional biology expertise—such that was present at the meeting—to assist in overcoming the difficulties in nutritional research such as ethical considerations when performing intervention studies in pregnant women and children.

23 April 2012

Sugar Showdown: Science Responds to "Fructophobia"


The scientific community lashed out against "sugar is toxic" sensationalism on Sunday, April 22, identifying it as a distraction from more meaningful areas of research and debate on the causes of obesity and disease.

In a highly attended debate at Experimental Biology 2012 in San Diego sponsored by the Corn Refiners Association, scientists expressed clear frustration about the repeated assaults on sugar both in recent news reports and in the scientific literature.

"You don't often see this at a meeting," said John White, Ph.D., of White Technical Research, to me after the event, referring to what he said was "the groundswell of researchers pushing back" against inflammatory remarks and overstatements.

22 April 2012

Beyond calories in, calories out -- look to the Amish


What is wrong with "eat less, move more"? Most of us are familiar with this mantra as weight-loss advice. However, a new consensus statement from the American Society for Nutrition (ASN) and the International Life Sciences Institute (ILSI) contends that this energy-in-energy-out framework isn't really so simple.

The problem lies in that consuming fewer calories and burning more through physical activity doesn’t always translate well to weight management. That is not to say that the framework of energy balance—negative energy balance for weight loss; positive energy balance for weight—is wrong. At some level, it’s right; however, several factors come into the equation.

During a Saturday morning session of Experimental Biology (#EB2012) in San Diego, Calif., researchers discussed the topic of this complexity and promoting a new paradigm on energy balance.

Can carotenoids in the brain protect against Alzheimer’s?

Carotenoids are thought to protect against Alzheimer's disease because of their antioxidant properties and their accumulation in the brain. However, a new study from Tufts University is putting the theory into question.

More than a century has passed since the German physician Dr. Alois Alzheimer first presented evidence on the case of Auguste Deter, who at only 51 suffered from severe memory loss and other psychological changes. At autopsy, Dr. Alzheimer found his patient had severe shrinkage and abnormal deposits of the nerve cells.

"That was in 1906," said nutritionist Annie Roe, a USDA researcher at Tufts University, who presented her laboratory's findings on April 21 at Experimental Biology 2012 in San Diego. "There's still disparity among scientists as to the etiology of this rapidly growing disease as we now know as Alzheimer's disease."

20 April 2012

Could how much and often people eat depend on their genes?

Thanks to the Human Genome Project, we humans now know that we are all really very much the same at the level of our DNA. Our genomes are 99.9 percent identical, leaving really only 0.1 percent responsible for giving each of us what we would consider our differences or unique qualities. It's within this 0.1 percent that may also explain why some of us may be more likely to be overweight, obese, or susceptible to a disease such as type 2 diabetes.

One of the most promising developments in nutrition research are the insights provided by studies on how dietary components interact with genes. The knowledge gleaned could one day be used for reducing risk of disease and staying healthier, longer. This area of research is nutritional genomics, or nutrigenomics for short. Eventually understanding more about nutrigenomics could lead to our ability to better personalize our diet plans and make better food choices based on our genetic code.

Interestingly, however, new research suggests that it may be genes themselves that are guiding how much we eat as well as our food choices. The Genetic Subgroup of Look AHEAD and the Look AHEAD Research Group have recently reported findings in the American Journal of Clinical Nutrition that obesity-related gene sequences (loci) may affect how overweight or obese with type 2 diabetes consume food.