The American Journal of Clinical Nutrition published an article online on May 30, 2012 which revealed the finding of an international team of researchers of a reduction in mortality during 12.7 years of follow-up among men and women who consumed higher amounts of fiber. The study included 452,717 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC), a prospective cohort study of different dietary patterns across ten European countries. The average age upon enrollment was 50.8 years. Questionnaires concerning diet, physical activity and other lifestyle factors completed upon recruitment were analyzed for total fiber intake (for which bread, vegetables and fruit were the most common sources). Over an average follow-up period of 12.7 years, 23,582 deaths occurred.
Subjects whose fiber intake was among the top 20 percent of participants at 28.5 grams or more per day had a 24 percent lower risk of dying from any cause over follow-up in comparison with those whose intake was among the lowest 20 percent at less than 16.4 grams daily. Each 10 gram per day increase in total fiber was associated with a 10 percent lower mortality risk. When deaths were examined by cause, a protective effect for fiber was observed for smoking-related cancers as well as circulatory, respiratory, digestive and inflammatory diseases. The greatest benefit was associated with digestive disorders, with men and women whose fiber intake levels were highest experiencing a 71 and 58 percent lower risk of dying from this cause than to those whose intake was lowest.
Fiber could promote health via several mechanisms, including helping to control weight, improving glycemic control, and aiding in the maintenance of a favorable intestinal environment. Fiber may help protect against circulatory diseases by lowering low density lipoprotein (LDL) cholesterol, which, when elevated, is a major risk factor for cardiovascular disease. Fiber intake has also been associated with a reduction in inflammatory markers including C-reactive protein, interleukin-6 and tumor necrosis factor-alpha. The authors note that greater total fiber intake could be a marker of an overall dietary pattern that benefits health.
"We observed inverse associations between total dietary fiber intake and mortality, and specifically mortality from circulatory, digestive, and non-cardiovascular disease, noncancer inflammatory diseases," the authors conclude. "These results show that high fiber intake, mainly from cereals and vegetables, may reduce the risk of death from these diseases."