People who consumed higher amounts of fiber, particularly from grains, had a significantly lower risk of dying over a nine-year period compared to those who consumed lower amounts of fiber, according to a new National Institutes of Health study. Fiber, found in whole grains, beans, nuts, vegetables and fruits aids the body with bowel movements, lowers blood-cholesterol levels and improves blood glucose levels. The study involved about 388,000 people who are part of a larger NIH-AARP diet and health study who were between ages 50 and 71 years old when the study began. Specifically, researchers analyzed data from 219,123 men and 168,999 women who had completed a detailed food questionnaire in 1995 and 1996 to figure out the amount of fiber consumed on a daily basis. People with diabetes, heart disease and most cancers were excluded, as well as those who reported “extreme” intakes of fiber. Researchers, led by the National Cancer Institute, concluded that “a diet rich in dietary fiber from whole plant foods may provide significant health benefits.”
Participants’ fiber intake ranged from 12.6 to 29.4 grams per day in men and from 10.8 to 25.8 grams per day in women. Current U.S. dietary guidelines recommended people consume 14 grams of fiber per 1,000 calories consumed per day—or about 28 grams a day for a typical adult diet of 2,000 calories.
Researchers divided study participants into five groups ranging from the lowest to highest dietary intake of fiber. There were significant reductions in the risk of death from cardiovascular disease, infectious and respiratory diseases among both men and women, with the greatest benefit seen among those who consumed the largest amount of fiber. The study also looked at the type of fiber consumed and found that the most significant health benefits in both men and women came from whole grains, as well as beans. There also appeared to be a benefit from eating vegetables, but improvements didn’t result in statistically significant increases in lifespan. Researchers controlled for other factors that impact health such as smoking, exercise and body weight.
The findings will appear in the June 14 print issue of Archives of Internal Medicine.