Eicosapentaenoic Acid Versus Docosahexaenoic Acid as Options for Vascular Risk Prevention: A Fish Story

Vascular inflammation is a key component involved in the process of arthrosclerosis, which in turn increases the risk for cardiovascular injury. In the last 10 years, there have been many trials that looked at omega-3 fatty acids as a way to reduce cardiovascular risk. These trials observed the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the traditional lipid panel and found that both EPA and DHA reduce triglyceride (TG) level and increase high-density lipoprotein cholesterol (HDL-C) levels but also increase the low-density lipoprotein cholesterol (LDL-C) levels. In the 2 more recent trials, the MARINE and ANCHOR, EPA was given as an adjunct therapy to high-risk patients and not only was the traditional lipids measured but also examined the vascular inflammatory biomarkers. The results of these 2 trials not only showed reduction in cardiovascular risk because of reduction in vascular inflammation and reduction in the lipid panel but also showed that one of the MARINE-derived omega-3 fatty acid is superior to the other. Data search for omega-3 fatty acids and cardiovascular risk was performed, and articles were selected for review from 2006 to date. The research studies were all double-blind randomized trials except for one, which was a single-blind and focused on the effects of omega-3 fatty acids on the entire lipid panel. The participants received DHA/EPA and compared with a placebo group on the effect seen in the lipid panel. The first 7 studies looked at the effects of omega-3 fatty acids on TG, LDL-C, and HDL-C; of the 7, 1 directly compared DHA and EPA, 2 focused on EPA, and 4 were directed towards DHA alone. The MARINE and ANCHOR trials were more recent and also looked at the same parameter but also monitored vascular inflammatory biomarkers and how they were affected by omega-3 fatty acids. A second data search was performed for vascular biomarkers and cardiovascular risk, and articles that focused on high-sensitivity C-reactive protein and oxidized low-density lipoprotein were selected for review. Omega-3 fatty acids have shown to decrease TG level in multiple trials, but they have also shown to increase LDL and HDL levels, likely because omega-3 fatty acids promote TG conversion into HDL/LDL. The older data suggested that the benefits of omega-3 fatty acids are nullified by their effects on LDL levels. The data from the MARINE and ANCHOR trials have shown that EPA alone at 4 g per day has shown to decrease TG and total cholesterol without affecting the LDL levels. The earlier data showed that both EPA and DHA decreased TG level and increased levels of HDL-C, but that the DHA alone and direct comparison of DHA/EPA showed that DHA has more undesirable effects on LDL. Furthermore, the MARINE and ANCHOR trials have both shown that not only does EPA improve the lipid panel but also helps to decrease the levels of the vascular inflammatory biomarkers, thus further helping to decrease cardiovascular risk. The use of EPA as an adjunct therapy for high-risk patient has shown to help decrease cardiovascular risk. The reduction in risk is performed not only by decreasing TG but also by reducing vascular inflammation. Although because there are no randomized double-blind study looking at this, the research is inconclusive and requires further investigation.