Should You Avoid Grains?

Word on the street (or at least on the internet) is that grains—all grains—are bad choices. But research consistently associates higher intake of whole grain foods with better health outcomes. We asked some experts to help us understand who might need to avoid these ubiquitous foods, and how the rest of us can enjoy them in good health.

The Anti-Grain Game. Many arguments against grains seem to boil down to concerns that humans did not evolve eating grains, and that these carbohydrates therefore have negative health effects. “Anthropologists who study the evolution of diet and human biology tend to dismiss this ‘mismatch’ hypothesis,” says Ellen Messer, PhD, a biocultural anthropologist and visiting associate professor at the Friedman School. “Human populations evolved in diverse environments with very diverse diets. Many of these diets included seasonal nuts and seeds, among them species related to maize (corn), wheat, rice, and millets—all of them ‘grains’ that were later domesticated and cultivated as staple cereals that nourished diverse human populations.”

When Avoidance is Necessary. According to John Leung, MD, director of the Center for Food Related Diseases at Tufts Medical Center, there are a few medical conditions that require people to cut out some, if not all, grains. These include fructan intolerance, celiac disease or non-celiac gluten sensitivity, food allergies, and some rare genetic conditions. Grains in general, and gluten specifically, have not been shown to have inflammatory effects in people who do not have these conditions.

Good Grains. “Evidence from large observational studies shows that eating more whole grains is associated with lower risk of obesity and diseases like cardiovascular disease, diabetes, cancer, and hypertension, compared to eating little or no whole grain,” says Caleigh Sawicki, PhD, a post-doctoral research fellow at Harvard University who studied carbohydrate quality and cardiometabolic health at the Friedman School. These positive effects are largely attributed to the dietary fiber in whole grains, along with the wide array of nutrients they provide.

When whole grains are processed into refined grain—be it wheat, corn, rice, or other white flour—the fiber is removed, along with much of the nutritional value. “A few nutrients, notably iron and the B vitamins thiamin, riboflavin, niacin, and folate, may be added back through enrichment or fortification,” says Sawicki, “but others, such as numerous phytochemicals, cannot be replaced.” These refined grains are used to make all manner of white breads, breakfast cereals, crackers, cookies, cakes, pretzels, and other processed goods (including gluten-free products, made with rice and other non-wheat flours). “Since refined grains lack dietary fiber, they are digested more rapidly than whole grains,” Sawicki explains, “which can lead to a rapid increase in blood glucose levels. This can stress the body and even lead to food cravings.” Additionally, refined grain products usually include added sugar, salt, or both. “Ideally, choosing minimally processed whole grains in your diet—for example oats, barley, or wheat berries—is the best option,” Sawicki says

“Traditional cuisines incorporate diverse varieties of grains, with nutritionally advantageous processing methods that, in combination with other traditional foods, produce healthy diets,” says Messer. “In contrast, modern diets are high in very refined carbohydrates (including grains) that may be easily digestible but unhealthy.” While excluding all grains is rarely necessary, we could all benefit from strategically including some less processed whole grain products in our diet. This tends to squeeze out less healthy options and helps us move toward an overall healthy dietary pattern.