Dietary Fiber Intake and Mortality from All Causes, Cardiovascular Disease, Cancer, Infectious Diseases and Others: A Meta-Analysis of 42 Prospective Cohort Studies with 1,752,848 Participants

Results from observational studies on dietary fiber intake on total mortality and cause-specific mortality are inconsistent. The objective of the present meta-analysis was to investigate dietary fiber intake and mortality, and cause-specific mortality. Medline, EMBASE and web of science database was searched for cohort studies published from inception to February 2013.  Studies were included if they provided a hazard ratio (HR) and corresponding 95% CI for mortality in relation to fiber consumption. A database was developed on the basis of 25 eligible studies and 42 cohorts, including 1,752,848 individuals with an average 12.4 years of follow-up. Compared with those who consumed lowest fiber, for individuals who ate highest fiber, mortality rate was lower by 23% (HR, 0.77; 95% CI, 0.72-0.81) for cardiovascular diseases (CVD), by 23% (HR, 0.77; 95% CI, 0.73-0.81 ) for all-cause mortality, by 17% (HR, 0.83; 95% CI, 0.74- 0.91 ) for cancer, by 68% for digestive diseases, by 58 % for infectious diseases, 43 % for inflammatory diseases. For each 10 g/d increase in fiber intake, the pooled HR was estimated to be 0.89 (95% CI, 0.86-0.93 ) for all-cause mortality, 0.91 (95% CI, 0.88-0.94 ) for cancer, 0.80 (95% CI, 0.72-0.88 ) for coronary heart disease (CHD) mortality , and 0.66 (95% CI, 0.40-0.92 ) for ischemic heart disease (IHD) mortality . Dietary fiber and CVD mortality showed a strong dose-response relation. For each 10 g/d increase in fiber intake, the pooled HR of  CVD mortality was estimated to be 0.83 (95% CI, 0.80-0.87 ; P for trend=0.0 0 1). In conclusion, our meta-analysis results clearly show that h igh dietary fiber intake is associated with low all-cause mortality and mortality due to CVD, CHD, cancer, digestive disease, infectious diseases, and other inflammatory diseases.