It’s Been a Bad Month For Carbs
August marked the debut of Grain Brain, an outstanding book by my good colleague Dr. David Perlmutter. In Grain Brain, Dr. Perlmutter offers evidence of the deleterious effects of excess sugar and refined carbohydrates on the brain, focusing in particular on gluten as an instigator of cognitive decline. You can listen to my podcast with him at http://www.drhoffman.com/podcasts/channel-1/drhoffman-com-2013-08-09-52.mp3
Dr. Perlmutter goes so far as to advocate a very low carb diet for those with, or concerned over, brain disorders. The underlying concept is that the brain prefers fat over carbohydrates as a fuel, and that carb restriction reverses power outages that impair the functioning of neurons.
As if to underscore the point, a blockbuster article appeared in the New England Journal of Medicine the very day I interviewed Dr. Perlmutter: “Higher blood glucose levels, shy of the diabetic range, increase the risk for dementia in adults, new data from the longitudinal Adult Changes in Thought (ACT) study suggest.” http://www.medscape.com/viewarticle/809165
There was bad news for sugar consumers in another big study that came out in August. Researchers discovered that when mice consumed a diet that consisted of 25% added sugar, there were serious behavioral and reproductive changes. Females died at twice normal rates, and males were 25% less likely to reproduce. The males appeared listless, and were less likely to defend their territories.
The researchers estimate that the equivalent amount of sugar in a human diet would be contained in just 3 soda drinks per day—something well within in the reach of the typical American. http://www.cbsnews.com/8301-204_162-57598401/even-recommended-levels-of-sugar-shown-to-be-toxic-to-mice
As if to underscore the point, another study this month showed that, in children, ANY soft drink consumption was associated with increased aggression. “Children who drank 4 or more soft drinks per day were more than twice as likely to destroy things belonging to others, get into fights, and physically attack people. They also had increased attention problems and withdrawal behavior compared with those who did not consume soft drinks.”
Scientific American took a critical look at carbs in an article entitled “Whole Grain Foods Not Always Healthful”: http://www.scientificamerican.com/article.cfm?id=whole-grain-foods-not-always-healthful.
They contend that the standards for labeling foods as “whole grain” are very lax. Many self-described whole grain products are low in fiber and/or nutrient-depleted.
“Researchers found that the only whole-grain-rich diets that reduced the risk of heart disease and type 2 diabetes were those that included bran as a whole grain or those that contained high amounts of fiber. Studies of “whole grains using the currently accepted definition don’t have enough data to support them for preventing these different chronic diseases,” says co-author David Klurfeld, the national program leader for human nutrition in the Agricultural Research Service at the U.S. Department of Agriculture.
But there are always those who advocate for a low-fat, quasi-vegetarian diet bereft of fat and meat as the ultimate longevity pathway. Bill Clinton has Dean Ornish and Caldwell Esselstyn on speed-dial, and vegan acolytes often cite Colin Campbell’s “China Study” as proof positive that animal protein kills you.
There’s bad news for Colin Campbell devotees in this month’s American Journal of Nutrition. It turns out that new-found prosperity has ushered more meat into the Asian diet. If Campbell’s hypothesis were true, this would have caused cancer and heart disease rates to soar.
Au contraire says a recent study entitled “Meat intake and cause-specific mortality: a pooled analysis of Asian prospective cohort studies”: http://ajcn.nutrition.org/content/early/2013/07/31/ajcn.113.062638.short
Researchers found NO association between intake of red meat, poultry and fish and all-cause mortality, or death from heart disease or cancer among men and women in Asia. Oops. I guess it’s back to the drawing board for Campbell and his acolytes, but they have already made up their minds about the virtues of brown rice, beans, and tofu.
In fact, a recent study from Greece showed that a Mediterranean Diet or a diet low in carbohydrates offered the best protection against Type 2 Diabetes. Even when saturated fats were combined with fish, olive and nuts, the benefits of low-glycemic index diets trumped low-fat diets based largely on complex carbohydrates. http://www.sciencedaily.com/releases/2013/08/130815203715.htm
For suggestions on how you can implement a healthy, low-carb diet check out my Salad and Salmon Diet at http://www.drhoffman.com/page.cfm/21