Effect of omega-3 fatty acid supplementation on the arachidonic acid:eicosapentaenoic acid ratio

Study Objectives. To determine the baseline arachidonic acid:eicosapentaenoic acid (AA:EPA) ratio in patients with coronary artery disease and healthy subjects, and whether supplementation of omega-3 fatty acids, administered as fish oil capsules, affects this ratio. Design. Prospective, open-label trial. Setting. University-affiliated cardiology clinic. Subjects. Thirty patients with stable coronary artery disease (CAD) and 30 healthy subjects. Intervention. All participants received omega-3 fatty acids 1.5 g/day for 4 weeks, followed by 3 g/day for an additional 4 weeks. Measurements and Main Results. For each participant, a lipid profile was determined at baseline and after 4 weeks of treatment with each dose. Other laboratory results analyzed were serum AA:EPA ratios, high-sensitivity C-reactive protein (hs-CRP) levels, and blood glucose levels. Mean ± SD baseline AA:EPA ratios were 39.6 ± 19.0 in healthy subjects and 23.7 ± 12.5 in patients with CAD. These ratios decreased significantly in both groups after treatment with 1.5 g/day of omega-3 fatty acids: 9.0 ± 4.2 in healthy subjects and 10.3 ± 8.8 in patients with CAD. After treatment with 3 g/day, the ratios were further reduced: 5.1 ± 3.2 in healthy subjects and 4.9 ± 2.6 in patients with CAD. Supplementation with omega-3 fatty acids did not significantly affect hs-CRP, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, or blood glucose levels. Triglyceride levels were not reduced in patients with CAD but were significantly decreased in healthy subjects (by 20% decrease with omega-3 fatty acids 1.5 g/day and by 32% decrease with 3 g/day). Conclusion. Treatment with omega-3 fatty acids significantly reduced AA:EPA ratios in both healthy subjects and in patients with stable CAD. The treatment had no effect on hs-CRP levels in either group, and it reduced triglyceride levels in healthy subjects but not in patients with CAD.