[Note: high blood triglyceride levels have been associated with atherosclerosis even when cholesterol levels are not high.]
Background: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) [rich in fish and krill oils] have been shown to reduce cardiovascular mortality at a dose of about 1 gram [1000 mg] per day. Studies using higher doses have shown evidence of reduced inflammation and improved endothelial function. Few studies have compared these doses.
Objective: The objective of this study was to compare the effects of a nutritional dose of EPA+DHA (0.85 gram [850mg] per day) with those of a pharmaceutical dose (3.4 grams [3,400 mg] per day) on serum triglycerides, inflammatory markers, and endothelial function in healthy subjects with moderately elevated triglycerides.
Design: This was a placebo-controlled, double-blind, randomized, 3-period crossover trial (8 wk of treatment, 6 wk of washout) that compared the effects of 0.85 and 3.4 grams EPA+DHA per day in 23 men and 3 postmenopausal women with moderate hypertriglyceridemia (150-500 mg/dL).
• The higher dose of EPA+DHA lowered triglycerides by 27% compared with placebo (173 ± 17.5 compared with 237 ± 17.5 mg/dL; P = 0.002), whereas no effect of the lower dose was observed on lipids.
• No effects on cholesterol (total, LDL, and HDL), endothelial function [as assessed by flow-mediated dilation, peripheral arterial tonometry/EndoPAT (Itamar Medical Ltd, Caesarea, Israel), or Doppler measures of hyperemia], inflammatory markers (interleukin-1beta, interleukin-6, tumor necrosis factor-?, and high-sensitivity C-reactive protein), or the expression of inflammatory cytokine genes in isolated lymphocytes were observed.
Conclusion: The higher dose (3.4 g/d) of EPA+DHA significantly lowered triglycerides, but neither dose improved endothelial function or inflammatory status over 8 wk in healthy adults with moderate hypertriglyceridemia. The trial was registered at clinicaltrials.gov as NCT00504309.
Source: American Journal of Clinical Nutrition, Dec 15, 2010. PMID: 21159789, by Skulas-Ray AC, Kris-Etherton PM, Harris WS, Vanden Heuvel JP, Wagner PR, West SG. Departments of Nutritional Sciences, Pennsylvania State University, University Park, PA, USA.