Whole-Grain Intake and Mortality from All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies

Abstract

No conclusive information is available about the relation between the consumption of whole grains and the risk of mortality. We aimed to conduct a meta-analysis of prospective cohort studies to summarize the relation between whole-grain intake and risk of mortality from all causes, cardiovascular disease, and total and specific cancers. A systematic search of the literature published earlier than March 2015 was conducted in Medline and PubMed, SCOPUS, EMBASE, and Cochrane Library to identify relevant articles. Prospective cohort studies that examined the association of total whole-grain intake or specific whole-grain foods with risk of mortality from all causes, cardiovascular disease, and total and specific cancers were considered. Twenty prospective cohort studies were included in the systematic review: 9 studies reported total whole-grain intake and 11 others reported specific whole-grain food intake. In a follow-up period of 5.5 to 26 y, there were 191,979 deaths (25,595 from cardiovascular disease, 32,746 from total cancers, and 2671 from specific cancers) in 2,282,603 participants. A greater intake of both total whole grains and specific whole-grain foods was significantly associated with a lower risk of all-cause mortality in the meta-analysis. The pooled RR for all-cause mortality for an increase of 3 servings total whole grains/d (90 g/d) was 0.83 (95 CI: 0.79, 0.88). Total whole-grain intake (0.84; 95 CI: 0.76, 0.93) and specific whole-grain foods (0.82; 95 CI: 0.75, 0.90) were also associated with a reduced risk of mortality from cardiovascular disease. Each additional 3 servings total whole grains/d was associated with a 25 lower risk of mortality from cardiovascular disease. An inverse association was observed between whole-grain intake and risk of mortality from total cancers (0.94; 95 CI: 0.91, 0.98). We found an inverse association between whole-grain intake and mortality from all causes, cardiovascular disease, and total cancers.