Sometimes while looking for the better of two options you find out you actually need both. That’s what happened when researchers at Tufts University were looking for the better of two forms of omega-3 fatty acids from fish oil when it comes to fighting chronic inflammation. Scientists found EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) work differently on inflammation and each plays an important role in immune system function.
A 34-week double-blind study was conducted with a small group of obese older adults suffering from chronic low-grade inflammation and the results were recently published in the journal Atherosclerosis. The participants were randomly divided into two groups and each received supplements of either EPA or DHA twice a day.
EPA and DHA in fish oil have been linked in previous studies to a lower risk of heart disease as well as a reduction in inflammation. This study showed DHA possesses stronger anti-inflammatory properties but both were important.
DHA lowered the genetic expression of four types of pro-inflammatory proteins while EPA lowered one. DHA lowered white blood cell secretion of three types of pro-inflammatory proteins while EPA lowered one. And DHA reduced levels of an anti-inflammatory protein that EPA did not.
However, EPA improved the balance between pro- and anti-inflammatory proteins. And EPA produced by-products associated with immune function regulation and worked differently than those from DHA.
"The jury has been out, so to speak, on how the two major components of fish oil work—and whether one might be better than the other,” said researcher Stefania Lamon-Fava. “These results suggest that DHA is the more powerful of the two on markers of inflammation in the body, but that's not the end of the story."
"In our bodies, there is always this balance between pro-inflammatory and anti-inflammatory proteins, and we found EPA was better than DHA at enhancing that balance,” said fellow researcher Jisun So. “For the prevention of cardiovascular disease, previous research tells us that balance is very important."
Researchers said the latest recommendations for adults is to get at least two servings of at least four ounces of seafood a week in order to get the recommended amounts of EPA and DHA. Fish high in EPA and DHA include salmon, cod, sardines, trout and tuna.
"Our study gives us a snapshot of how EPA and DHA may work to reduce chronic inflammation, and how each has distinct effects," Lamon-Fava said. “Our results provide insight for future research to explore why that is the case and who would benefit from one or both of these healthy fats.”