BOSTON — Greater intake of whole grains was associated with smaller increases in waist size in a study appearing online July 13 in The Journal of Nutrition. Among middle- to older-age adults, waist size over a four-year period increased by an average of more than 1 inch in participants who ate less than one-half serving per day of whole grains. Among those who ate at least three servings of whole grains a day, waist size increased by about a half inch. A greater association between whole grain intake and waist size was found in women.
Besides waist circumference, researchers from Tufts University in Boston examined the association between the intake of whole grains and refined grains on changes in fasting HDL (good) cholesterol, triglyceride and glucose concentrations as well as blood pressure. They used 3,121 subjects in the Framingham Offspring cohort study. Data were collected about every four years over a median 18-year follow-up. After accounting for changes in waist circumference, average increases in blood sugar levels and systolic blood pressure were greater in low-intake participants when compared to high-intake participants.
“Our findings suggest that eating whole grain foods as part of a healthy diet delivers health benefits beyond just helping us lose or maintain weight as we age,” said Nicola McKeown, PhD, senior and corresponding author and a scientist on the nutritional epidemiology team at the US Department of Agriculture’s Human Nutrition Research Center on Aging at Tufts University. “In fact, these data suggest that people who eat more whole grains are better able to maintain their blood sugar and blood pressure over time. Managing these risk factors as we age may help to protect against heart disease.”
Whole wheat bread and ready-to-eat whole grain breakfast cereal contributed the most whole grain intake among participants. Refined grain intake came mostly from pasta and white bread.
The USDA, the General Mills Bell Institute of Health and Nutrition, and the National Institutes of Health’s National Heart, Lung and Blood Institute all supported the study.