Abstract P209: Dose-Response Relationship Between Dietary Intake of Alpha-linolenic Acid and Risk of Coronary Heart Disease: A Meta-analysis of Prospective Studies
Introduction: Previous studies show that alpha-linolenic acid (ALA) is associated with reduced risk of coronary heart disease (CHD). However, it remains unclear whether and how dietary ALA doses are related to CHD.
Hypothesis: We hypothesized that higher dietary ALA intake is associated with a greater reduction in risk of CHD.
Methods: We searched PubMed, EMBASE, and Web of Science for prospective studies examining the association between dietary ALA intake and CHD risk. Dietary ALA intake was assigned or measured by self-report. Outcomes were reported as total and fatal CHD and/or myocardial infarction, which were obtained from blinded endpoint assessments or medical records. Two-stage fixed-effects dose-response meta-analyses were conducted to estimate the association between increasing ALA intake (relative to study-specific referents) and CHD.
Results: Fifteen published articles were identified and included in the meta-analysis (13 cohort studies and 2 randomized controlled trials). The pooled analysis was based on 310,768 individuals with 12,049 events with a mean length of follow-up of 9.6 years. The analysis showed a J-shaped curve between ALA intake and relative risk of total CHD (Chi-square=21.08, p<0.001). ALA intake from 0.3-1.4g/day showed reduced risk of total CHD, while intake ≥2.5g/day was associated with increased risk of CHD, compared to people without ALA intake (Figure 1A). Approximately 1g/day of ALA intake was associated with the lowest risk of total CHD. ALA intake was linearly associated with fatal CHD - every 1g/day increase in ALA intake was associated with an 11% decrease in fatal CHD risk (95% CI: -0.16, -0.05) (Figure 1B).
Conclusion: The J-shaped dose-response relationship based on our pooled analysis suggests that 1g/day of dietary ALA may be optimal for total CHD prevention. Though a higher dietary ALA intake was associated with reduced risk of fatal CHD, the excess total CHD risk at higher ALA intakes warrants further investigation, especially through randomized controlled trials.
Author Disclosures: J. Wei: None. Y. Xi: None. R. Hou: None. A. Kowalski: None. H. Sun:None. E.K. Chandrasekar: None. M.K. Ali: None.
- © 2017 by American Heart Association, Inc.