There is a large body of scientific evidence that has been confirmed in randomized controlled trials indicating a cardioprotective effect for omega-3 fatty acids from fish. For alpha-linolenic acid (ALA), which is the omega-3 fatty acid from plants, the relation to cardiovascular health is less clear. We reviewed the recent literature on dietary ALA intake, ALA tissue concentrations, and cardiovascular health in humans. Short-term trials (6–12 weeks) in generally healthy participants mostly showed no or inconsistent effects of ALA intake (1.2–3.6 g/d) on blood lipids, low-density lipoprotein oxidation, lipoprotein(a), and apolipoproteins A-I and B. Studies of ALA in relation to inflammatory markers and glucose metabolism yielded conflicting results. With regard to clinical cardiovascular outcomes, there is observational evidence for a protective effect against nonfatal myocardial infarction. However, no protective associations were observed between ALA status and risk of heart failure, atrial fibrillation, and sudden death. Findings from long-term trials of ALA supplementation are awaited to answer the question whether food-based or higher doses of ALA could be important for cardiovascular health in cardiac patients and the general population.
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•• Campos H, Baylin A, Willett WC: Alpha-linolenic acid and risk of nonfatal acute myocardial infarction. Circulation 2008, 118:339–345. In this study, 1819 patients who survived an MI and 1817 matching controls provided adipose tissue for analysis of ALA and completed a validated food questionnaire. ALA in adipose tissue ranged from 0.36% in the lowest decile to 1.04% in the highest decile. The corresponding median ALA intakes were 1.1 to 2.4 g/d. The risk of nonfatal MI was strongly reduced to adipose tissue ALA levels of about 0.7%, which corresponds to an intake of about 1.8 g/d. Further increases in intake were not associated with increased protection. CrossRefPubMed
• Dai J, Ziegler TR, Bostick RM, et al.: High habitual dietary alpha-linolenic acid intake is associated with decreased plasma soluble interleukin-6 receptor concentrations in male twins. Am J Clin Nutr 2010, 92:177–185. In this cross-sectional study, habitual ALA intake was examined in relation to plasma inflammatory markers, including IL-6 and sIL-6R, in 353 middle-aged male twins. ALA intake ranged from 0.2 to 2 g/d and was significantly inversely associated with plasma sIL-6R, but not with plasma IL-6 or other inflammatory markers. A major strength of this study is the use of twins who share genetic factors and who generally have similar lifestyles and diets. CrossRefPubMed
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•• Lemaitre RN, King IB, Sotoodehnia N, et al.: Red blood cell membrane alpha-linolenic acid and the risk of sudden cardiac arrest. Metabolism 2009, 58:534–540. Previous population-based case-control studies of this research group showed strong inverse associations of dietary intake and erythrocyte membrane levels of marine n-3 fatty acids with the risk of sudden cardiac death. In this article, data from a similar case-control study of ALA in erythrocyte membranes and sudden cardiac arrest are reported. Blood was obtained at the time of cardiac arrest (cases) or at the time of an interview (controls). Against expectations, higher membrane ALA was associated with a increased risk of sudden cardiac arrest, with an odds ratio of 2.5 (95% CI, 1.3–4.8) for the upper versus lower quartile. CrossRefPubMed
- Alpha-Linolenic Acid: Is It Essential to Cardiovascular Health?
Johanna M. Geleijnse
Janette de Goede
Ingeborg A. Brouwer
- Current Science Inc.
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