Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective observational cohort studies.
PubMed 25161045 · doi:10.1161/CIRCULATIONAHA.114.010236
What was done
Authors conducted a systematic review and fixed-effect meta-analysis of prospective cohort studies from MEDLINE and EMBASE (searched through June 2013) plus unpublished data from a previous pooling project. They calculated pooled multivariate-adjusted relative risks (RRs) for coronary heart disease (CHD) events and CHD deaths comparing highest versus lowest categories of dietary linoleic acid (LA) intake and modeling isocaloric substitution of saturated fat with LA.
What was found
Across 13 cohort studies including 310,602 individuals with 12,479 total CHD events (5,882 CHD deaths): - Comparing highest to lowest LA intake category, LA was associated with a 15% lower risk of CHD events (pooled RR 0.85, 95% CI 0.78-0.92; I² = 35.5%) and a 21% lower risk of CHD deaths (pooled RR 0.79, 95% CI 0.71-0.89; I² = 0.0%). - A 5% energy substitution of saturated fat with LA was associated with a 9% lower risk of CHD events (RR 0.91, 95% CI 0.87-0.96) and a 13% lower risk of CHD deaths (RR 0.87, 95% CI 0.82-0.94).
Why it matters
These findings provide quantitative epidemiological support for nutritional guidelines advising the replacement of saturated fats with polyunsaturated fats like linoleic acid for primary CHD prevention.
Limits
The analysis is restricted to observational cohort studies, which are subject to residual dietary confounding and measurement error in self-reported dietary intake. The abstract does not detail specific food sources of linoleic acid or report findings on non-fatal cardiovascular outcomes separately.
Cited by
- supports Observational dietary survey data show that higher dietary intake of linoleic acid is associated with lower risk of coronary heart disease.