Whole Grains Consumption Linked to Lower Body Fat

Experts recommend eating whole grains to reduce risk of heart disease, stroke, cancer, diabetes and obesity. And a new study has uncovered part of the reason: People who consume several servings of whole grains per day while limiting their intake of refined grains appear to have less of a certain type of fat tissue believed to play a key role in generating cardiovascular disease and type 2 diabetes.

Researchers at the Jean Mayer USDA Human Nutrition Researcher Center on Aging (USDA HNRCA) at Tufts University examined diet questionnaires submitted by more than 2,800 adult men and women enrolled in The Framingham Heart Offspring and Third Generation study cohorts. The scientists observed lower volumes of visceral adipose tissue (VAT) in people who ate mostly whole grains instead of refined grains.

“VAT volume was approximately 10% lower in adults who reported eating three or more daily servings of whole grains and who limited their intake of refined grains to less than one serving per day,” says lead author Nicola McKeown, PhD, a scientist with the Nutritional Epidemiology Program at the USDA HNRCA. “For example, a slice of 100% whole wheat bread or a half cup of oatmeal constituted one serving of whole grains and a slice of white bread or a half cup of white rice represented a serving of refined grains.”

Visceral fat surrounds the organs vs. subcutaneous fat, which is found beneath the skin. “Prior research suggests visceral fat is more closely tied to the development of metabolic syndrome, a cluster of risk factors including hypertension, unhealthy cholesterol levels and insulin resistance that can develop into cardiovascular disease or type 2 diabetes,” explains co-author Paul Jacques, DSc, director of the Nutritional Epidemiology Program at the USDA HNRCA and a professor at the Friedman School of Nutrition Science and Policy at Tufts. “Not surprisingly, when we compared the relationship of both visceral fat tissue and subcutaneous fat tissue to whole and refined grain intake, we saw a more striking association with visceral fat. The association persisted after we accounted for other lifestyle factors such as smoking, alcohol intake, fruit and vegetable intake, percentage of calories from fat and physical activity.”

The researcher also found that those who consumed, three daily servings of whole grains on average, but continued to eat a high volume of refined grains did not show a lower VAT volume.

Whole grains contain all the essential parts of the grain, including the bran, germ and endosperm, and the naturally occurring nutrients of the entire grain seed.