Associations of alpha-linolenic acid and linoleic acid with risk factors for coronary heart disease

Abstract

Background: Prevention of coronary heart disease (CHD) in high-risk subjects. Objective: To investigate the associations of dietary intake of alpha-linolenic acid (ALA) and linoleic acid (LA) as assessed by food frequency questionnaire and in the plasma cholesteryl ester (CE), with CHD risk factors. Design: Baseline data of a double-blind, randomized placebo-controlled trial. Subjects have hypercholesterolemia (6.0 ± 8.0 mmolal) and at least two other CHD risk factors (n 266). Results: The reported dietary ALA and LA intakes and the LAaALA ratio were associated with the contents in the CE (r 0.37, r 0.21, and r 0.42, respectively; P`0.01). In multivariate analysis, CE ALA was inversely associated with diastolic blood pressure (r 7 0.13; P`0.05) and positively with serum triacylglycerol (r 0.13; P`0.05), and CE LA was inversely associated with serum triacylglycerol (r 7 0.32; P`0.01). The CE LAaALA ratio was strongly inversely associated with CE ALA (r 7 0.95; P`0.01). In the lowest quintile of CE ALA, mean dietary intake was 0.4 energy % ALA (1.2 gaday), 8.4 energy % LA and an LAaALA ratio of 21, and in the highest quintile 0.6 energy % ALA (1.7 gaday), 6.8 energy % LA and 12 (ratio). In the lowest quintile of CE ALA the diastolic blood pressure was 4 mmHg lower (P trend`0.05), and the serum triacylglycerol 0.3 mmolal higher (P trend NS) when compared with the top quintile. Conclusions: In a CHD high-risk population with LA-rich background diet, these cross-sectional data suggest that replacing LA in the diet by ALA may decrease diastolic blood pressure, and may increase serum triacylglycerol concentration. Sponsorship: Dutch Prevent fund grant no. 28-2757; Unilever (margarine). Descriptors: alpha-linolenic acid; linoleic acid; plasma cholesteryl ester; CHD risk factors; blood pressure; serum triacylglycerol European Journal of Clinical Nutrition (2000) 54, 865±871 IntroductionThe MARGARIN study is a prevention project of coronary heart disease (CHD) through a high-risk approach. The study group is composed of 266 hypercholesterolemic subjects with at least two other CHD risk factors. Our project was inspired by the Lyon Diet Heart Study. In this secondary prevention trial among patients who had a myocardial infarction, a 70% reduction in CHD events was observed in the experimental group on an alphalinolenic acid (ALA; 18 : 3n-3) rich Mediterranean diet. In the ®nal report, plasma ALA content was associated with improved prognosis (de Lorgeril et al, 1994(de Lorgeril et al, ,1999. Also, several large observational studies have reported on the preventive effect of dietary ALA on CHD events (Ascherio et al, 1996;Hu et al, 1999).ALA is the vegetary precursor of the marine long chain n-3 fatty acids eicosapentaenoic acid (EPA; 20 : 5n-3) and docosahexaenoic acid (DHA; 22 : 6n-3). ALA competes with its n-6 counterpart linoleic acid (18 : 2n-6) for desaturation and chain-elongation. Linoleic acid (LA) is in this pathway converted to arachidonic acid (AA; 20 : 4n-6).In recent years, hypercholesterolemic subjects have b...

Increased α-linolenic acid intake lowers C-reactive protein, but has no effect on markers of atherosclerosis

“…Consumption frequencies were reported per day, week or month. At baseline, Pearson's correlation coefficient of ALA intake as assessed by the questionnaire and the content of ALA in the cholesteryl ester was 0.37 (Po0.01) (Bemelmans et al, 2000). Hence, the questionnaire assesses intake of ALA reasonably well.…”

Dose effect of alpha-linolenic acid on lipid metabolism in the hamster

“…However, the rationale of replacing n-3 long-chain PUFA (LC-PUFA) by their precursor ALA is still under debate, especially concerning their respective efficiency and mechanisms of action [8]. Indeed, ALA and its long chain derivatives exhibit similar positive effects on etiologic factors of CVD such as hemostasis, thrombogenesis [9], and blood pressure [10]. In contrast, the effects of ALA on lipid metabolism are still controversial.…”

Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients

“…Results from these surveys have indicated that dietary ALA intake is not related (Bemelmans et al, 2000;Djousse et al, 2001;Djousse et al, 2003) or negatively associated (Salonen et al, 1987;Salonen et al, 1988;Djousse et al, 2005) with blood pressure levels. Others have used instead the content of ALA in plasma lipids or adipose tissue and, likewise, reported either an inverse association (Berry and Hirsch, 1986;Bemelmans et al, 2000) or no relationship (Riemersma et al, 1986;Simon et al, 1996;Grimsgaard et al, 1999). Another approach has been the supplementation of the diet with ALA and the prospective monitoring of blood pressure.…”