Greater Fiber Intake Lowers Coronary Disease Risk

Increased dietary fiber intake is associated with a lower risk of both cardiovascular disease and coronary heart disease, according to new research. Investigators from the University of Leeds studied dietary fiber intake and any potential dose-response association with coronary heart disease and cardiovascular disease. The group used data from cohort study publications meeting inclusion criteria—studies reporting associations between fiber intake and coronary heart disease or cardiovascular disease, with a minimum follow-up of 3 years and published in English between January 1, 1990 and August 6, 2013. Ultimately, researchers studied 22 cohort study publications that met the criteria, and reported total dietary fiber intake, fiber subtypes, or fiber from food sources and primary events of cardiovascular disease or coronary heart disease. Total dietary fiber intake was inversely associated with risk of cardiovascular disease and coronary heart disease. Researchers found evidence of some heterogeneity between pooled studies for cardiovascular disease (I2=45 percent (0 percent to 74 percent)), and coronary heart disease (I2=33 percent (0 percent to 66 percent)). Insoluble fiber and fiber from cereal and vegetable sources were inversely associated with risk of coronary heart disease and cardiovascular disease. In addition, fruit fiber intake was inversely associated with risk of cardiovascular disease. The study’s findings that link greater dietary fiber intake with a lesser risk of both cardiovascular disease and coronary heart disease are “aligned with general recommendations to increase fiber intake,” according to study authors, who note that “the differing strengths of association by fiber type or source highlight the need for a better understanding of the mode of action of fiber components.” “Physicians should be aware that, on average, intakes of dietary fiber in the United States are much lower than recommended goals—about half of what is advised,” says Victoria Burley, PhD, MSc, RPHNutr, a senior lecturer in nutrition at the University of Leeds and a lead study author. “Reaching the fiber goal is likely to have all sorts of health benefits, including reducing long-term cardiovascular disease risk.” “It’s straightforward to get 7 grams of fiber extra per day,” says Burley. “This can come from 1 serving of whole grain breakfast cereal and 2 servings of fruit or vegetables, for example. Drastic changes to the diet are often not necessary, and just exchanging refined carbohydrates for the higher fiber, less-refined versions as well as aiming for increased fruit and vegetable intakes will take the average patient a long way towards achieving the fiber goals.” She points out, however, that “the studies we looked at only provided information about fiber from foods, rather than from supplements. So we can’t say that fiber supplements would provide the same benefit as eating fiber-rich foods.” —Mark McGraw Reference Threapleton D, Greenwood D, et al. Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ. 2013.