Dietary intakes of monounsaturated fatty acids and risk of mortality from all causes, cardiovascular disease and cancer: A systematic review and dose-response meta-analysis of prospective cohort studies

Background: Findings on the link between dietary intakes of monounsaturated fatty acids (MUFA) and risk of mortality are conflicting. This study aimed to summarize existing literature regarding the association between MUFA intake and risk of mortality from all causes, cardiovascular diseases (CVDs), and cancer. Methods: PubMed, Scopus, and ISI Web of Science was systematically searched up to December 2020. Prospective cohort studies which investigated MUFA intake in relation to mortality from all causes, CVD, or cancer were eligible for this systematic review. Publications that had reported risk ratios (RRs) or hazard ratios (HRs) and 95% confidence intervals (CIs) as effect size, were considered. Results: A total of 17 prospective cohort studies were included. These studies included 1022,321 participants aged >= 20 years in total, and 191,283 all-cause deaths, 55,437 CVD deaths, and 64,448 cancer deaths were totally reported. Combining 15 effect sizes from 11 studies, MUFA intake was inversely associated with risk of all cause mortality (RR: 0.94; 95% CI: 0.90, 0.98; I-2 =55.5; P = 0.005). Based on 17 effect sizes from 11 studies, we found no significant association between MUFA intake and risk of CVD mortality (RR: 0.95; 95% CI: 0.89, 1.01; I-2 =37.0; P = 0.06). Combining 10 effect sizes from 6 studies, MUFA intake was not significantly associated with cancer mortality (RR: 0.99; 95% CI: 0.96, 1.03, I-2 =13.3%, P = 0.32). Also, an additional 5% of energy from MUFA was associated with a 3% reduced risk of all-cause mortality (RR: 0.97; 95%CI: 0.96, 0.98), but not with CVD (RR: 0.98; 95%CI: 0.95, 1.01) and cancer mortality (RR: 0.99; 95%CI: 0.97, 1.01). Conclusions: MUFA intake was found to be inversely associated with risk of all-cause mortality. However, no link was found between MUFA consumption and mortality from CVD or cancer.