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The jury is out on the effects of a gluten-free diet on your health. Well-being editor Mary Carpenter advises not rushing to judgment in her column first published early this year.
MOST OF THE MOTIVATION to eliminate gluten from our diets comes from books like “Wheat Belly” and “Grain Brain.” The latter, by David Perlmutter, links high-gluten consumption to dementia, and he advises limiting carbohydrates including fruits, while increasing consumption of fats to 50-60 percent of daily calories. One-third of Americans now aim to be gluten-free.
Everyone agrees that eliminating gluten is essential for the 1 percent of Americans who have celiac disease, in which gluten spurs the body’s immune system to attack the small intestine, leading to serious nutritional deficits. An additional 6 percent of the population believes they have “non-celiac gluten sensitivity” (NCGS) and that gluten-free eating makes them feel better.
In a small study, 37 people who blamed NCGS for their digestive ills, including bloating and stomach pain — symptoms collectively known as irritable bowel syndrome (IBS) — were put on three similar diets with levels of gluten ranging from none to a lot: gluten had no measurable effect on their symptoms. Instead, the differentiating variable was a substance called FODMAPS (fermentable, oligo-…you don’t want to know) found in foods such as wheat, apples, garlic and milk — considered possible instigators of IBS and other “gut problems.”
Critics of Perlmutter’s thesis point out that conclusive research pinpointing a clear cause of dementia would make an enormous splash among health professionals and media outlets around the world, which has not yet occurred. In the Mayo Clinic study often cited by Perlmutter as linking high-carbohydrate diets to dementia, healthy whole grains like wheat were not distinguished from refined carbohydrates like white flour — which has been stripped of fiber, protein, vitamins and minerals — although the two have remarkably different effects on the body over time.
In addition, while some subjects had episodes of mild cognitive impairment, no one in the study developed dementia. The Mayo Clinic, along with most medical experts, recommends limiting dietary fat to 20-35 percent of daily calories. Meanwhile, Perlmutter himself has authored no peer-reviewed paper on the topic, and much of his “Grain Brain” book focuses on exercise and sleep, rather than on grains.
Then there is the issue of which ingredients replace gluten in the gluten-free diet. Just as “low-fat” foods often contain lots of sugar, salt and refined carbohydrates, the labels of gluten-free products include rice starch, corn starch, tapioca starch and potato starch – highly refined carbohydrates that release high levels of sugar into the bloodstream. In a recent New Yorker article, Dr. Peter Green, Director of the Celiac Disease Center at Columbia University Medical School, asks, “…what are the things that sell food? Salt, sugar, fat and gluten. If the makers take one away, then they add more of another.”
Perlmutter’s advice on diet could in fact be dangerous. “Ignoring LDL [consuming too much of the “bad” cholesterol] could absolutely result in heart attacks and strokes,” says Dr. David Katz, epidemiologist and nutrition expert at Yale University, in James Hamblin’s article, “This is your Brain on Gluten,” in The Atlantic. Katz points out another drawback to high-fat diets: “people who are eating more meat and dairy…are eating fewer plants.”
Meanwhile, among thousands of studies on risks for dementia, gluten is not a factor. Among the most important risks: lack of exercise, high blood pressure and high cholesterol, poorly controlled diabetes and lack of social engagement – also being over 65, genetics and being a woman, because women live longer. In the U.S. News and World Report list of healthiest diets, those at the top – DASH, TLC, Mayo Clinic and Mediterranean – recommend whole grains, while high-fat diets like Paleo are at the bottom.
In a rare health claim, the FDA announced, “Diets rich in whole grain foods…low in saturated fat and cholesterol, may help reduce risk of heart disease.” And in 2011, the American Society for Nutrition published the statement that whole grains lower the risk of heart disease, diabetes and cancer and contribute to weight management and gastrointestinal health. For a healthy brain, the only super-foods contain high levels of omega-3 fatty acids, especially those in fatty fish like salmon.
The truth is that eliminating any major component of your diet — gluten, meat, dairy, fat — makes you pay closer attention to what you eat, and that in turn often results in eating more healthily. Eliminating gluten, for example, might mean you replace breakfast foods like cereal, toast or pastries with yogurt or eggs, high-protein foods that may increase your energy levels. And paying more attention to your diet can result in weight loss.
When you hear friends touting their gluten-free lives, listen to their specific food choices and calorie counts. If you give it a try, don’t load up on fats, think carefully about your personal nutrition needs and observe how you feel over the course of several weeks before giving your final verdict.
— Mary Carpenter
