Abstract
SCOPE: To compare the effects of supplementary eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) versus α-linolenic acid (ALA) administered as capsules on lipid profiles, inflammatory status, and fatty acid composition of peripheral blood mononuclear cells (PBMCs) in hypercholesterolemic adults. METHODS AND RESULTS: We conducted a randomized, controlled, double-blind trial. A total of 123 hypercholesterolemic subjects aged 53.3 ± 5.2 years were randomly divided into 5 groups to receive (1) control oil; (2) low ALA, 4.2 g/d; (3) high ALA, 7.2 g/d; (4) low DHA+EPA, 1.8 g/d; or (5) high EPA+DHA, 3.6 g/d for 12 weeks. Lipid profiles were detected, and the fatty acid composition of PBMCs was measured. In vitro production of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) by PBMCs was also determined. After the intervention, subjects who received a low and high dose of DHA+EPA experienced a 11.99% and 15.78% decrease in triglycerides. This change was significantly different from that of the control group (P < 0.05). The in vitro study indicated that supplementation of high-dose DHA+EPA induced the greatest decrease of IL-6 production by PBMCs relative to other groups (P = 0.046). ALA intervention significantly increased the PBMCs composition of ALA but not EPA/DHA. CONCLUSION: EPA+DHA, but not ALA improved lipids and inflammation status in hypercholesterolemic adults. Supplementation of ALA did not increase the PBMCs composition of EPA/DHA in middle-aged to elderly Chinese.
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Key Points
This study conducted in China, determined whether 12 weeks of enrichment of the habitual diet with two doses of ALA or EPA+DHA would have differential effects on cardiometabolic markers in volunteers with hypercholesterolemia. In addition, their effects on PBMCs fatty acid composition and the production of inflammatory markers were evaluated. The results indicated that EPA+DHA intervention could decrease the TG level, whereas supplementation of ALA did not reveal any effects on metabolic markers. High-dose EPA+DHA induced a significant decrease in IL-6 production by PBMCs. Supplementation of ALA did not elicit any changes in EPA or DHA composition in PBMCs, suggesting a low conversion efficiency of ALA to the long-chain metabolites in Chinese subjects. The beneficial effects of ALA supplements on cardiovascular disease (CVD) risk factors are less well documented than EPA/DHA. Although the targeted intake of the High-ALA group was 7.2 g/d, the actual consumption might be lower, because not all of the cooking oil was consumed. Thus, the effects of ALA might be underestimated. The length of the treatment regimens was only 12 weeks. The study enrolled only middle-aged to elderly Chinese subjects. Further studies in larger populations with various clinical characteristics are needed to clarify the relationship between PUFA and cardiovascular disease.