In one of the largest studies of its kind, researchers have identified a link between high-fiber diets and lower risks of death not only from heart disease, but from infectious and respiratory illnesses as well. This government commissioned study also ties fiber with a lower risk of cancer deaths in men, but not women, possibly because men are more likely to die from cancers related to diet, like cancers of the esophagus. And it finds the overall benefit to be strongest for diets high in fiber from grains.
Figures reveal that most Americans do not consume enough roughage in their diets. The average American eats only about 15 grams of fiber each day, much less than the current daily recommendation of 25 grams for women and 38 grams for men, or 14 grams per 1,000 calories. For example, a slice of whole wheat bread contains 2 to 4 grams of fiber.
The researchers followed people for nine years and noted that those who met the guidelines were less likely to die. The men and women who ate the highest amount of fiber were 22 percent less likely to die from any cause compared to those who ate the lowest amount, said lead author Dr. Yikyung Park of the National Cancer Institute.
The study was published this Monday in Archives of Internal Medicine. It included more than 388,000 adults, ages 50 to 71, who participated in a diet and health study conducted by the National Institutes of Health and AARP. For the study the subjects had to fill a questionnaire in 1995 or 1996 about their eating habits. It asked them to estimate how often they ate 124 food items. Participants’ fiber intake ranged from 12.6 grams to 29.4 grams per day in men and from 10.8 to 25.8 grams per day in women. Researchers divided study participants into five groups ranging from the lowest to highest dietary intake of fiber.
After nine years, more than 31,000 of the participants had died. By gender, men with the highest fiber intakes had a 23% reduction in the risk of dying, while women had a 19% reduction compared to those who consumed the least amount of fiber. National records were used to find out who died and the cause of death. The researchers took into account other risk factors including weight, education level, smoking and health status and still saw lower risks of death in people who ate more fiber.
Dr. Frank Hu of the Harvard School of Public Health, an independent observer said in an accompanying editorial, “The results suggest that the benefits of dietary fiber go beyond heart health.” Lawrence de Koning of the Harvard School of Public Health, a co-author of the editorial added that whole grains were he real driving force. Whole grains also contain vitamins and minerals, which may play a role in reducing risk, he said. For that reason, supplements may not be as effective. “Nothing beats the original food,” he said. He suggested substituting whole wheat bread for white bread as a simple way to increase fiber from grains.
Experts recommend adding fiber gradually to allow your digestive system time to get used to it.
Eating more fiber supports growth of good bacteria and protects against gut infections