Key Findings:
This is a controversial paper as it reports that higher membrane levels of ALA are positively associated with sudden cardiac death especially in those with higher body weight. Most of the literature in fact has found that ALA reduces the risk of coronary heart disease. Studies on the effect of ALA on sudden cardiac death are few. Dietary ALA has been associated with lower risk of sudden cardiac death in women with low intake of DHA and EPA in the Nurses’ Health Study. Further work is needed to confirm the study findings in other populations. The association of dietary ALA with sudden cardiac death may be modified by different variations in metabolic processes, which should be explored in future work.
ABSTRACT:
Higher levels of long chain n3 polyunsaturated fatty acids in red blood cell membranes are associated with lower risk of sudden cardiac arrest. Whether membrane levels of alpha-linolenic acid (ALA), a medium chain n3 polyunsaturated fatty acid, show a similar association is unclear. We investigated the association of red blood cell membrane alpha-linolenic acid with sudden cardiac arrest risk in a population based case-control study. Cases, aged 25 to 74 years, were out of hospital sudden cardiac arrest patients, attended by paramedics in Seattle, Washington (n of 265). Controls, matched to cases by age, sex and calendar year, were randomly identified from the community (n of 415). All participants were free of prior clinically diagnosed heart disease. Blood was obtained at the time of cardiac arrest (cases) or at the time of an interview (controls). Higher membrane ALA was associated with a higher risk of sudden cardiac arrest: after adjustment for matching factors and smoking, diabetes, hypertension, education, physical activity, weight, height and total fat intake, the odds ratios corresponding to increasing quartiles of alpha-linolenic acid were 1.7 (95% confidence interval [CI] 1.0 to 3.0), 1.9 (95% CI 1.1 to 3.3), and 2.5 (95% CI 1.3 to 4.8) compared to the lowest quartile. The association was independent of red blood cell levels of long chain n3 fatty acids, trans fatty acids, and linoleic acid. Higher membrane levels of ALA acid are associated with higher risk of sudden cardiac arrest. (Authors abstract)