Study Suggests Eating Whole Grains May Affect Cardiovascular Health

Eating whole grains has been linked to an abundance of positive health outcomes, including prebiotic gut effects1, healthier body weight2, and prevention of major diseases3 like type 2 diabetes and certain cancers (colorectal, pancreatic, and gastric). If that wasn't enough, a recent study4 just gave us one more reason to love whole grains: your heart health. 

Whole grains contain the entirety of the grain kernel—the bran, germ, and endosperm. Along with energy (calories) from carbohydrate, protein, and fat, you'll find additional nutritional bioactives in whole grains like fiber, an array of micronutrients, and even phytochemicals5. 

For example, one large whole wheat pita6 delivers about 220 calories, 47 grams of carbohydrate, 8 grams of protein, 1.5 grams of fat (mostly unsaturated and polyunsaturated), 5 grams of fiber, and 18 unique vitamins and minerals.

The findings from a recent study published4 in the Journal of the Academy of Nutrition and Dietetics give us more motivation to improve whole-grain intake: cardiovascular disease (CVD). The investigation was led by Skye Marshall, Ph.D., APD, who is scientific and education director at Nutrition Research Australia and assistant professor of nutrition and dietetics at Bond University in Queensland, Australia. This robustly designed4 systematic review and meta-analysis of randomized controlled trials (RCT) examined the effect of whole grains (vs. refined grains or placebo) on CVD risk factors in adults. 

Marshall explains the impetus for her study, sharing that, "Although there is really convincing observational evidence for the effect of whole grains on improved cardiovascular health, we do need interventional evidence to establish a cause-and-effect relationship." (RCT studies are the cream of the crop for determining causality/effect. Meta-analyzing multiple RCTs for a holistic perspective is even better.)

When you combine those findings, it suggests that in adults, swapping out refined grains with whole grains may improve major CVD risk factors—lipids, blood glucose, and inflammation. The potential public health impact is massive, as heart disease is the No. 1 cause of death in Australia and the United States7. Marshall elaborates on the significance of the study's findings, sharing that "In the long term, your cardiovascular health may be improved if you regularly choose whole-grain foods instead of refined (i.e., 'white' bread, rice, pasta, etc.)." 

But, practicing moderation in nutrition and life is also important. Marshall shares that, "eating some refined grains is OK. You shouldn't feel guilt while eating refined grains, especially foods important to your culture and social life."

Marshall and I then chatted about the popularity of low-carb diets and how carbs have gotten a bad rap in recent years in the U.S. She said the same trends have occurred in Australia and warns people of "the negative psychological effect of restrictive eating." She adds that the anti-carb camp "is being balanced by a counterculture of people really enjoying their carbs. A focus on healthy eating patterns can help, like the Mediterranean diet, which allows all food groups including those high in carbs." In fact the Mediterranean diet, which incorporates whole grains and other carb sources like fruits, vegetables, and legumes, is impressively linked to reductions in coronary heart disease, ischemic stroke, and total CVD.

With the benefits of whole grains mounting, it's a wonder more people don't eat them. "I think it's the taste!" says Marshall. "Most people choosing whole grains do so because they are aware of the superior nutrient profile. But whole grains have so much flavor and texture, which can really improve a meal. Perhaps it's a learned appreciation like coffee, chili, or beer."

As for the top whole grains Marshall recommends for cardiovascular health: "It does look like whole rolled oats and brown rice have the best evidence, currently, but the overall diet is what counts. Choosing whole grains of any type regularly is what matters," she says. "For example, I eat whole-grain oats and wheat two or three times a day but rarely eat rice of any kind. Someone could be the opposite, and that's OK too."

When shopping for whole grains, some products will have a whole-grain stamp to help you quickly identify them. When in doubt, flip the product over and check the ingredient list. If the first ingredient mentions the word "whole," that's a good sign that you're buying a whole grain.