Abstract P225: The Associations of Dietary and Biomarkers of Linoleic Acid Intake and All-cause and Cardiovascular Mortality: A Systematic Review and Meta-analysis

Abstract

Background: Previous studies on intake of linoleic acid (LA), a predominant n-6 fatty acid, and risk of mortality from all-cause and cardiovascular disease (CVD) have generated inconsistent results. We performed a systematic review and meta-analysis of prospective cohort studies to summarize the evidence regarding the relation of LA and all-cause and CVD mortality. Methods: We searched MEDLINE and EMBASE databases through June 2017 for prospective cohort studies reporting association of LA (assessed by dietary survey or biomarker in blood or adipose tissue) with all-cause and CVD mortality. In addition, unpublished data from pooling projects were included. We pooled the multivariate-adjusted Hazards ratios (HRs) using random-effect meta-analysis, which allowed for between-study heterogeneity. Results: 27 studies covering 37 prospective cohorts were identified; these included 274,565 individuals with dietary assessment (34,597 all-cause and 10,636 CVD deaths) and 54,794 individuals with biomarker measurements (6,767 all-cause and 5,311 CVD deaths). Comparing the highest category with the lowest, dietary LA intake was associated with a 14% lower risk of all-cause mortality (95% confidence interval [CI], 2%-25%, I 2 =71%) and a 20% lower risk of CVD mortality (95% CI, 13%-26%, I 2 =0). Baseline health status (i.e. general population, CVD/high risk for CVD, or cancer) might be a main source of heterogeneity for the association of dietary LA intake with all-cause mortality. As for biomarkers, 1 SD increment in LA was associated with a 9% lower risk of all-cause mortality (95% CI, 4%-14%, I 2 =61%) and a 10% lower risk of CVD mortality (95% CI, 5%-14%, I 2 =13%). Heterogeneity was presented across tissue types and between genders. Conclusions: In prospective cohort studies, LA intake, assessed by either dietary survey or biomarkers, was inversely associated with all-cause and CVD mortality in a dose-response manner. These data support the current recommendations on polyunsaturated fat intake for prevention of CVD and early death.