A diet high in whole grain foods is associated with a significantly lower risk of developing cardiovascular disease, including heart disease and stroke, according to an analysis conducted by researchers at Wake Forest University School of Medicine.
"Consuming an average of 2.5 servings of whole grains each day is associated with a 21 percent lower risk of cardiovascular disease compared to consuming only 0.2 servings," said Philip Mellen, M.D., lead author and an assistant professor of internal medicine. "These findings suggest that we should redouble our efforts to encourage patients to include more of these foods in their diets."
The findings are based on an analysis of seven studies involving more than 285,000 people. By combining the data from these seven studies, researchers were able to detect effects that may not have shown up in each individual study. The studies were conducted between 1966 and April 2006.
Mellen said the findings are consistent with earlier research, but that despite abundant evidence about the health benefits of whole grains, intake remains low. A nutrition survey conducted between 1999 and 2000 found that only 8 percent of U.S. adults consumed three or more servings of whole grain per day and that 42 percent of adults ate no whole grains on a given day.
"Many consumers and health professionals are unaware of the health benefits of whole grains," said Mellen.
A grain is "whole" when the entire grain seed is retained: the bran, germ and the endosperm. The bran and germ components are rich in fiber, vitamins, minerals, antioxidants, and healthy fats. These are the parts removed in the refining process, leaving behind the energy-dense but nutrient-poor endosperm portion of the grain. Examples of whole grain foods include wild rice, popcorn, oatmeal, brown rice, barley, wheat berries and flours such as whole wheat.
In addition to protecting against cardiovascular disease, which accounts for one-third of deaths worldwide, there is evidence that whole grains also project against diabetes and other chronic conditions.
"Years ago, scientists hypothesized that the higher rates of chronic diseases we have in the West, including heart disease, are due, in part, to a diet full of processed foods," Mellen said. "Subsequent studies have born that out – especially with whole grains. Greater whole grain intake is associated with less obesity, diabetes, high blood pressure, and high cholesterol – major factors that increase the risk for heart disease and stroke."
According to nutritionists, consumers should look for "100 percent whole grain" on food labels or look for specific types of whole-grain flour as the main ingredient, such as "whole wheat."
Co-researchers were: Thomas Walsh, M.D., and David Herrington, M.H.S., M.D., both from Wake Forest.