NEW YORK, Oct 27 (Reuters Health) -- High daily intake of dietary fiber may be an effective means of reducing obesity, high blood pressure and other heart disease risk factors, according to a major study published in the October 27th issue of The Journal of the American Heart Association.
In fact, "fiber may play a greater role in determining cardiovascular disease risk than total or saturated fat intake," report a team of researchers led by Dr. David S. Ludwig of Children's Hospital in Boston, Massachusetts.
Dietary fiber -- from fruits, vegetable, and grains -- remains largely undigested in the gastrointestinal tract. However, experts believe that fiber slows the progress of food through the gut, reducing the absorption of food, and keeping insulin secretion at low or moderate levels.
In their study, Ludwig's team examined the diets and cardiovascular risk factors of over 2,900 individuals between 18 and 30 years of age.
They found that high-fiber diets were associated with lowered "insulin levels, weight gain, and other risk factors for cardiovascular disease in young adults."
"Individuals eating the most fiber gained less weight than those eating the least fiber," they write. Subjects ranked in the highest 20% in terms of fiber intake weighed 8 pounds less, on average, than did those in the lowest 20%.
High fiber intake was also associated with lowered blood pressure, especially among whites, according to the researchers.
Ludwig and colleagues believe that the health benefits of fiber stem largely from its ability to reduce insulin secretion. High insulin levels are associated with increased fat absorption, hypertension, and other heart disease risk factors.
In a related statement from the American Heart Association (AHA), Nutrition Committee member Dr. Alice Lichtenstein notes that the findings "are consistent with the heart-healthy dietary guidelines of the AHA," which now recommend that individuals consume at least 25 to 30 grams of dietary fiber per day from food.
According to Lichtenstein, the study does not confirm a direct cause-and-effect relationship between fiber and improved cardiovascular health. "The subjects in this study with the highest fiber intake smoked less and exercised more," she points out. "Therefore, one shouldn't conclude that adding a dietary fiber supplement, without adapting a heart-healthy lifestyle, will decrease an individual's risk."
