Though going grain-free is a popular diet trend, grains – especially in their whole form – provide a significant portion of important nutrients.
You’ve likely noticed the proliferation of books, websites and specialty foods aimed at helping people avoid gluten-containing grains – and all other grains, too. While a small group of scientists, medical professionals and bloggers are leading the charge for grain-free diets – declaring grains a mismatch based on human evolution – the majority of experts believe grain-free diets for the masses are a wrong move.
If you’ve considered ditching grains, it’s important to understand the science and the potential pitfalls if you do so.
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.
According to a review last August 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.
Gluten-free diets carry the concern of nutritional deficiencies, and completely grain-free diets only heighten that risk. Julie Miller Jones, professor emerita of nutrition at St. Catherine University in St. Paul, Minn., summarizes data showing grains provide the following amounts of nutrients in the U.S. diet:
70 percent of folate; 60 percent of thiamin; half 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 said.
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 six hours of rise time), and classic sourdough bread, have significantly lower phytate levels,” Jones said.
Fiber in grains is not the same as the fiber in other foods.
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.