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Showing posts from 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 …

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…

Fate of fructose: Interview with Dr. John Sievenpiper

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, bl…

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:

Thank god for this!!! GMO anything is not healthful to the environment or …

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 a…

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 DarwinOn 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 pherom…

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.

Sadly, I learned at Experimental Biology, misclassification also occurs frequently across all ages depending on ethnicity. Asian Americans …