A new Finnish study reveals that the omega-3 fatty acid eicosapentaenoic acid (EPA) from fish oil affects metabolism differently in each person, with benefits appearing quickly but fading soon after supplementation stops. Researchers observed significant variations in blood lipid profiles among healthy adults taking high doses. The findings emphasize the role of personalized approaches in cardiovascular health.
Scientists at the University of Helsinki and the Wihuri Research Institute conducted a study on how EPA, an omega-3 fatty acid found in fish oil, influences metabolism and blood lipid levels in healthy adults. While EPA is known to lower cardiovascular risk in people with high cholesterol or heart disease, its effects in healthy individuals remained unclear, particularly regarding incorporation into lipoproteins that transport fats in the bloodstream.
The research involved 38 volunteers who received unusually high doses of EPA supplements. Blood samples were taken before, during, and after the supplementation period to track changes. Results showed efficient absorption of EPA, leading to a sharp rise in blood concentrations, but levels dropped quickly once supplements ended. The strongest effects occurred in participants with lower baseline EPA levels.
Notably, EPA improved blood lipid profiles and reduced lipoproteins' tendency to attach to artery walls, a key factor in preventing atherosclerosis. However, individual responses varied widely. "The samples taken during supplementation clearly show the effect of EPA on all participants. Having said that, all samples were different among the group. In other words, each individual has a unique lipoprotein lipidome in their circulation, a 'lipid fingerprint', if you will, that persisted despite EPA supplementation," explained Professor Katariina Öörni, a lead author from the Faculty of Biological and Environmental Sciences at the University of Helsinki and the Wihuri Research Institute.
The short-term study did not assess long-term outcomes but highlighted metabolism's importance in cardiovascular disease prevention. "The findings highlight the importance of metabolism in the prevention of cardiovascular diseases. EPA's effects varied more between individuals than we expected. We also demonstrated that these effects dissipate quickly, which is good to know in case EPA were to have adverse effects," noted Doctoral Researcher Lauri Äikäs.
Future research will explore EPA's impact on inflammatory cells and lipid mediators that control inflammation. "It's interesting to see how, for instance, dietary changes affect lipoprotein quality, or the individual lipid fingerprint," Öörni added.
The study was published in JCI Insight (2025; 10 (19), DOI: 10.1172/jci.insight.193637).