Association of types of dietary fats and all-cause and cause-specific mortality: A prospective cohort study and meta-analysis of prospective studies with 1,164,029 participants

BACKGROUND: Associations between dietary fats and mortality are unclear.

METHODS: We evaluated the relationship between quartiles of total fat, mono-unsaturated (MUFA), polyunsaturated (PUFA) and saturated fatty acid (SFA) consumption, and all-cause, coronary heart disease (CHD), stroke, and type 2 diabetes (T2D)-associated mortality in 24,144 participants from the National Health and Nutrition Examination Surveys (NHANES) 1999-2010. We added our results to a meta-analysis based on searches until November 2018.

RESULTS: In fully adjusted Cox-proportional hazard models in our prospective study, there was an inverse association between total fat (HR: 0.90, 95% confidence interval 0.82, 0.99, Q4 vs Q1) and PUFA (0.81, 0.78-0.84) consumption and all-cause mortality, whereas SFA were associated with the increased mortality (1.08, 1.04-1.11). In the meta-analysis of 29 prospective cohorts (n = 1,164,029) we found a significant inverse association between total fat (0.89, 0.82-0.97), MUFA (0.94, 0.89-0.99) and PUFA (0.89, 0.84-0.94) consumption and all-cause mortality. No association was observed between total fat and CVD (0.93, 0.80-1.08) or CHD mortality (1.03 0.99-1.09). A significant association between SFA intake and CHD mortality (1.10, 1.01-1.21) was observed. Neither MUFA nor PUFA were associated with CVD or CHD mortality. Inverse associations were observed between MUFA (0.80, 0.67-0.96) and PUFA (0.84, 0.80-0.90) intakes and stroke mortality.

CONCLUSIONS: We showed differential associations of total fat, MUFA and PUFA with all-cause mortality, but not CVD or CHD mortalities. SFA was associated with higher all-cause mortality in NHANES and with CHD mortality in our meta-analysis. The type of fat intake appears to be associated with important health outcomes.