BOSTON (December 7, 2020, 9:00 a.m. EST)– The omega-3 fatty acids EPA and DHA have different effects on chronic inflammation, according to the results of a small randomized study, which suggests that each has its own important role in regulating the immune system.

The 34-week study led by researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University (HNRCA)compared the effects of the two omega-3s in a small group of older adults with low severity obesity and chronic inflammation. Participants were randomly given EPA or DHA supplements twice a day. The results are published today in Atherosclerosis.

EPA and DHA, which are found in abundance in fish and shellfish, have been linked in some studies to a lower risk of heart disease and are believed to have anti-inflammatory effects. The results showed that DHA had stronger anti-inflammatory effects than EPA:

  • DHA lowered the genetic expression of four types of pro-inflammatory proteins, while EPA lowered only one type.
  • DHA lowered white blood cell secretion of three types of pro-inflammatory proteins, while EPA lowered only one type.
  • DHA also reduced levels of an anti-inflammatory protein, while EPA didn’t.

However, EPA improved the balance between pro and anti-inflammatory proteins:

  • Once metabolized, EPA produced by-products associated with immune regulation that functioned differently than those derived from DHA.

“The jury argued, so to speak, about how the two main components of fish oil work – and whether one could be better than the other. These results suggest that DHA is the stronger of the two markers of inflammation in the body, but that’s not the end of the story, ”he said Stefania Lamon-Fava, a scientist on the cardiovascular nutrition team at the HNRCA.

Lamon-Fava is also Chair of the Department of Biochemical and Molecular Nutrition and Associate Professor at the Gerald J. and Dorothy R. Friedman School of Nutritional Science and Policy at Tufts.

“There is always this balance in our body between anti-inflammatory and anti-inflammatory proteins, and we have found that EPA improves that balance better than DHA. Previous research has shown that balance is very important in preventing cardiovascular disease, ”said first author Jisun So, who did this work as part of her doctoral thesis at the Friedman School in the HNRCA’s Cardiovascular Nutrition Team.

According to the 2015-2020 Dietary Guidelines for AmericansAdults should consume at least two servings of seafood (4 ounces per serving) weekly. Salmon, cod, sardines, trout, and canned light tuna are good sources of EPA and DHA.

“Our study gives us an overview of how EPA and DHA can reduce chronic inflammation and how they have different effects. Our results provide insight for future research to find out why this is the case and who would benefit from either or both of these healthy fats, ”said Lamon-Fava.


The study was a double-blind study, meaning that neither the participants nor the laboratory technicians or scientists knew which supplement each individual was receiving. The 21 participants received EPA or DHA supplements in an order that included supplement-free periods to create a blank board that could be used to measure the effects of each supplement. During an introductory phase, participants took dietary supplements that contained only high-oil sunflower oil (similar to olive oil and without omega-3 fatty acids) to provide a basis for comparison.

Authors and Funding

Other authors of the study are Dayong Wu, Alice H. Lichtenstein and Nirupa R. Matthan from the HNRCA; Albert K. Tai at Tufts University School of Medicine; and Krishna Rao Maddipati at Wayne State University.

This work was supported by the US Department of Agriculture’s National Institute of Food and Agriculture through a grant from the Agriculture and Food Research Initiative and from The Drs. Joan and Peter Cohn Research Fund. All opinions expressed in this paper are those of the authors and not the funders. None of the authors disclosed any conflicts of interest.


Also, J., Wu, D., Lichtenstein, AH, Tai, AK, Matthan, NR, Maddipati, KR and Lamon-Fava, S. (2020). EPA and DHA modulate the inflammatory response of monocytes in different ways

Patients with chronic inflammation partially specialized in plasma

Pro-Resolving Lipid Mediators: A Randomized, Double-Blind, Crossover Study. Atherosclerosis.


Via the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University

For four decades, the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University has studied the relationship between good nutrition and good health in aging populations. Tufts researchers work with federal agencies to establish the nutritional guidelines, nutritional reference intakes, and other important public guidelines.


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