Though going grain-free is a popular diet trend, grains -- especially in their whole form -- provide a significant portion of important nutrients in the diet.
Who should avoid certain grains? Clearly, those with an allergy to wheat or other grains must avoid them. And the 1 percent of the population with celiac disease and the 6 percent with non-celiac gluten sensitivity must avoid all gluten, a protein found in grains, including wheat, rye and barley. With a doctor's approval, most people with a gluten sensitivity can eat small amounts of uncontaminated oats; all other uncontaminated, gluten-free grains are typically allowed.
Gluten and autoimmune disease. According to an August 2013 review in Current Allergy and Asthma Reports, multiple case reports suggest gluten can play a role in some autoimmune diseases beyond celiac disease, but large studies are lacking. Autoimmune diseases that occur most commonly in combination with celiac disease are autoimmune thyroid disease, autoimmune liver disease, type 1 diabetes, Sjogren's syndrome and psoriasis. If you have an autoimmune condition or health concern that has a scientifically documented relationship with gluten, talk with your doctor about celiac disease testing.
The nutrient gap. Gluten-free diets carry the concern of nutritional deficiencies, and completely grain-free diets only heighten that risk. Julie Miller Jones, PhD, CNS, LN, professor emerita of nutrition at St. Catherine University in St. Paul, Minnesota, summarizes data showing grains provide the following amounts of nutrients in the U.S. diet:
70 percent of folate
60 percent of thiamin
50 percent of iron
40 percent or more of niacin, riboflavin and selenium
25 percent of magnesium and zinc
Jones is especially concerned about the impact a grain-free diet could have on folic acid intake. "Since the mid-1990s when it became mandatory to add folic acid to enriched grain products, the incidence of neural tube birth defects, such as spina bifida, has dropped by more than 50 percent," she says.
Anti-nutrient solutions. Proponents of grain-free diets voice concern about anti-nutrients in grains. Grains, especially whole grains, contain a substance called phytate that impairs the body's absorption of some minerals. However, in populations with well-balanced diets, this may be of little consequence. There are ways to minimize phytate, too. "Breads made with longer fermentation times, such as Julia Child's French bread (which requires at least 6 hours of rise time), and classic sourdough bread, have significantly lower phytate levels," Jones says. Lectins, another type of anti-nutrient in grains, also may be inactivated by lengthy fermentation, and some are destroyed by heat.
Unique fiber in grains. Fiber in grains is not the same as the fiber in other foods. "Some people reason that if they eat more broccoli, for instance, then it won't matter if they don't eat grains. But, thinking you don't need grain fiber because you get a lot of vegetable fiber is like saying that if you get enough vitamin A you don't need any vitamin C. That's just plain wrong," Jones says. For example, beta glucan, the fiber best at lowering cholesterol, is present only in oats and barley. It's grain fiber, rather than fiber from any source, that is linked with a reduced risk of colon cancer.
Feeding the good bugs. A 2009 study published in the British Journal of Nutrition found that healthy adults on a gluten-free diet for a month had a significant decrease in protective gut bacteria, while potentially unhealthy bacteria increased in number. These findings are similar to an earlier study of children with celiac disease following a long-term gluten-free diet (Journal of Medical Microbiology, 2007). In the typical American diet, wheat supplies at least 70 percent of inulin and oligofructose, which are prebiotic starches that fuel the growth of good bacteria.
When all is said and done, the more restricted your food options are, the more careful you'll need to be to ensure your body gets what it needs. So, look beyond diet books' bestseller headlines and sensationalistic stories to make sure any dietary change is appropriate for you.
(Environmental Nutrition is the award-winning independent newsletter written by nutrition experts dedicated to providing readers up-to-date, accurate information about health and nutrition in clear, concise English. For more information, visit http://www.environmentalnutrition.com.)
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ENVIRONMENTAL NUTRITION: Think twice before giving up grains
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