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The potential role for omega-3s in COVID-19

The potential role for omega-3s in COVID-19.jpg
A small pilot study examined a possible connection between omega-3 EPA and DHA levels and well-being in subjects affected by the pandemic.

The pandemic of 2020 has garnered global attention for nearly a year. Even though news about vaccines and improved treatments is beginning to appear, a need remains to find simple, ideally nutritional approaches to reduce the susceptibility to or the severity of the infection.

Much has been said about vitamin D and zinc, but a major nutrient that has been largely overlooked is the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Found mostly in oily fish like salmon, albacore tuna, sardines and herring—as well as dietary supplements (fish oil, krill oil, algal oils)—these fatty acids may also play a potential role in the fight against COVID-19.

The science behind omega-3s

Scientific discoveries about the mechanisms of action of EPA and DHA indicate the omega-3s are very effective in slowing and even resolving inflammation.1 Cytokine levels may have something to do with it.

The word “cytokine” comes from combining two Greek words—“cyto” means cell and “kine” means movement. Cytokines are certain proteins secreted by some immune cells that attract or activate other immune cells. Cytokines come in many different forms—e.g., interleukin (IL), tumor necrosis factor (TNF), interferon—and affect the function of many different types of cells, such as macrophages, monocytes, mast cells and more. An excessive production of these proteins can cause excessive inflammatory reactions like swelling, pain and fever, which can ultimately cause organs (and the entire body) to cease functioning.

Omega-3 levels have shown a relationship to cytokines. People who have chronically higher blood levels of EPA and DHA (hereafter referred to as the “Omega-3 Index”) have chronically lower blood levels of many cytokines.2 Further, when people are given supplements of omega-3, cytokine levels slowly drop, meaning that the immune and inflammatory cells are making and secreting fewer cytokines.3

Omega-3s have shown to support some autoimmune issues, such as arthritis4 and lupus,5 and other more benign conditions—like dry eye, which has an inflammatory basis—can also be improved.6 Studies have shown how the omega-3s interfere with cytokine biology. First, the body can turn EPA and DHA (if they are present) into a suite of molecules that actively resolve inflammation once it starts.7 These are called inflammation-resolving mediators (resolvins, maresins and protectins), and they put the brakes on inflammatory reactions.

EPA and DHA can work at the other end as well, preventing the initiation of an inflammatory response by making subtle changes to cell membrane architecture which, in very complex ways, serves to quiet cells and make them less responsive to inflammatory forces in the body.8

Finally, the omega-3s EPA and DHA can also be converted into other compounds that oppose the actions of some of the pro-inflammatory compounds made from arachidonic acid, a major omega-6 fatty acid.9 Having a high (versus low) Omega-3 Index is a soothing balm to the body in general, calming down the body’s sometimes overly eager attempts to protect itself from infections and injury.

Testing the Omega-3 Index with COVID-19

Knowing what omega-3s can do in cells is nice, but it’s much more important to know what they actually do in real life. Current ongoing studies are exploring whether supplementing people with omega-3 at the first signs of COVID-19 infection will help decelerate the disease and possibly save lives. Clinical studies take time, but other ways of exploring a potential link between omega-3 and COVID-19 exist, such as a recently published pilot study that has inspired optimism regarding omega-3s.

The study was undertaken between research scientists at the Fatty Acid Research Institute (FARI) and physician scientists at Cedars-Sinai Medical Center. Led by Arash Asher, M.D., the study took advantage of the fact that Cedars-Sinai—like many research institutions around the country—has a “biobank,” a place where leftover blood samples are stored from patients admitted to the hospital. The purpose of biobanks is to allow research to be done on diseases like COVID-19 in an expeditious manner that strictly protects the private health information of patients.

In this case, FARI obtained blood samples from 100 patients who had been admitted to Cedars-Sinai with COVID-19, along with information about age, sex and importantly, how they did in the hospital. The Omega-3 Index in the samples was analyzed, and the results studied in answering the question, “Is a higher Omega-3 Index associated with a lower risk for death from COVID-19?”

Bearing in mind this was a pilot study with a modest number of subjects, the findings suggested high levels of omega-3 corresponded with lower death risk.

Of the 14 patients who died in the pilot study, only one was in the highest “quartile” (i.e., among the 25 patients with the highest Omega-3 Index, a value of 5.7% or greater). The other 13 were in the group with an Omega-3 Index below 5.7%. When analyzing the data statistically, the group with the highest Omega-3 Index was found 75% less likely to die from COVID-19 compared to those with an Omega-3 Index below 5.7%. Although not “statistically significant” by the usual standards, as a pilot study, the findings were sufficient to demand that further, larger studies be undertaken to confirm or refute the observations.

Larger study on tap

FARI is anxious to conduct a larger study, obtaining hundreds of blood samples from the biobank to see if a higher Omega-3 Index really is linked with survival from COVID-19.

Omega-3 fatty acids are nutrients that have many health benefits. A steady diet high in EPA and DHA—which will raise the Omega-3 Index well above 5.7% if maintained consistently—may end up being a powerful nutritional shield people can wield against the scourge of 2020.

William S. Harris, Ph.D., is the founder and president of the Fatty Acid Research Institute (FARI). He has been a leading researcher in the omega-3 fatty acid field for 40 years, with over 300 scientific papers on fatty acids and health. Harris has been on the faculty of three medical schools (Universities of Kansas, Missouri (at Kansas City) and South Dakota), and has received five National Institutes of Health (NIH) grants to study omega-3. He was the co-author on three American Herb Association (AHA) statements on fatty acids and heart health. As the co-inventor of the Omega-3 Index and founder of OmegaQuant Analytics, Harris has been a leader in raising awareness of the importance of omega-3 fatty acids in optimizing health.


1 Calder PC. “Omega-3 fatty acids and inflammatory processes: from molecules to man.” Biochem Soc Trans. 2017;45:1105-1115.

2 Fontes JD et al. “Red blood cell fatty acids and biomarkers of inflammation: A cross-sectional study in a community-based cohort.” Atherosclerosis. 2015;240:431-436.

3 Li K et al. “Effect of marine-derived n-3 polyunsaturated fatty acids on C-reactive protein, interleukin 6 and tumor necrosis factor alpha: a meta-analysis.” PloS one. 2014;9:e88103.

4 Dawczynski C et al. “Docosahexaenoic acid in the treatment of rheumatoid arthritis: A double-blind, placebo-controlled, randomized cross-over study with microalgae vs. sunflower oil.” Clin Nutr. 2018;37:494-504.

5 Wright SA et al. “A randomised interventional trial of omega-3-polyunsaturated fatty acids on endothelial function and disease activity in systemic lupus erythematosus.” Ann Rheum Dis. 2008;67:841-848.

6 Park J et al. “Effects of the re-esterified triglyceride (rTG) form of omega-3 supplements on dry eye following cataract surgery.” Br J Ophthalmol. 2020. DOI:10.1136/bjophthalmol-2020-317164.

7 Serhan CN et al. “Resolvins in inflammation: emergence of the pro-resolving superfamily of mediators.” J Clin Invest. 2018;128:2657-2669.

8 Calder PC. “Marine omega-3 fatty acids and inflammatory processes: Effects, mechanisms and clinical relevance.” Biochim Biophys Acta. 2015;1851:469-484.

9 De Roos B et al. “Long-chain n-3 polyunsaturated fatty acids: new insights into mechanisms relating to inflammation and coronary heart disease.” Br J Pharmacol. 2009;158:413-428.

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