Recent research has revealed a mechanism through which fish oil, which contains omega-3 fatty acids, might reduce inflammation. A study that tested an enriched fish oil supplement found that it increased blood levels of certain anti-inflammatory molecules. Share on Pinterest A new study sheds light on the inflammation-reducing properties of fish oil supplements. The anti-inflammatory molecules are called specialized pro-resolving mediators (SPMs), and they have a powerful effect on white blood cells, as well as controlling blood vessel inflammation. Scientists already knew that the body makes SPMs by breaking down essential fatty acids, including some omega-3 fatty acids. However, the relationship between supplement intake and circulating levels of SPMs remained unclear. So, a team of researchers from the William Harvey Research Institute at Queen Mary University of London in the United Kingdom set out to clarify the relationship by testing the effect of an enriched fish oil supplement in 22 healthy volunteers whose ages ranged from 19 to 37 years. The team conducted the Circulation Research study as a double-blind, placebo-controlled trial. Therefore, neither the participants nor those who gave them the doses and monitored them knew who received fish oil supplements and who received the placebo. “We used the molecules as our biomarkers to show how omega-3 fatty acids are used by our body and to determine if the production of these molecules has a beneficial effect on white blood cells,” says senior study author Jesmond Dalli, who is a professor of molecular pharmacology at the William Harvey Institute.

Enriched fish oil increased blood markers The trial tested three doses of enriched fish oil supplement against the placebo. The researchers took samples of the participants’ blood to test. Each participant gave five samples over 24 hours — at baseline and then 2, 4, 6, and 24 hours after taking their dose of supplement or placebo. The researchers found that taking the enriched fish oil supplement raised blood levels of SPMs. The results showed a “time and dose-dependent” increase in circulating blood levels of SPMs. The tests also revealed that supplementation led to a dose-dependent increase in immune cell attacks against bacteria and a decrease in cell activity that promotes blood clotting. Inflammation is a defense response by the immune system that is essential to health. Various factors can trigger the response, including damaged cells, toxins, and pathogens such as bacteria. Some of the immune cells that are active during inflammation can also damage tissue, so it is important, once the threat is over, for inflammation to subside to allow healing. Putting a stop to inflammation is where anti-inflammatory agents, such as SPMs, have a role. However, if inflammation persists and becomes chronic, then, instead of protecting health, it undermines it. Studies have linked inflammation to heart disease, rheumatoid arthritis, and other serious health conditions. Although it remains unclear whether those molecules reduce cardiovascular disease, a press release on the study notes that they do “supercharge macrophages, specialized cells that destroy bacteria and eliminate dead cells,” as well as making “platelets less sticky, potentially reducing the formation of blood clots.” Research has also shown the molecules to play a role in tissue regeneration. As Prof. Dalli notes, “These molecules have multiple targets.”