Sioux Falls, SD—Research published in the American Journal of Clinical Nutrition (AJCN) explored whether omega-3 fatty acids might be protective against contracting and/or suffering adverse outcomes of COVID-19 infection. As explained in an announcement from the Fatty Acid Research Institute (FARI),  researchers compared the risk for three COVID-19 outcomes:

  1. testing positive
  2. hospitalization
  3. death as a function of baseline plasma DHA levels

About the research on omega-3s and COVID

The COVID-19 outcomes were assessed between January 2020 and March 2021. DHA levels (% of total fatty acids) were measured by Nuclear Magnetic Resonance (NMR) spectroscopy but were converted to Omega-3 Index (red blood cell EPA+DHA%) for this analysis, FARI shared. The three outcomes and relevant covariates were available for 110,584 subjects (hospitalization and death) and for 26,595 ever-tested subjects (positive COVID-19 PCR test result) via the UK Biobank prospective cohort study. 

Findings on omega-3 levels and COVID outcomes

  • In the fully adjusted models, subjects in quintile 5 (highest Omega-3 Index levels) were 21% less likely to test positive than those in quintile 1.
  • Risk for a positive test was 8% lower for each 1-SD (standard deviation) increase in plasma DHA%. 
  • Quintile 5 subjects were 26% less likely to be hospitalized than those in quintile 1.
  • Risk for hospitalization was 11% lower per 1-SD increase in DHA%.
  • Risk for death with COVID-19 was monotonically lower through quintile 4.
  • In quintile 5, the risk reduction was partially attenuated and became non-significant. 
  • Estimated Omega-3 Index values across the five DHA quintiles ranged from 3.5% (quintile 1) to 8% (quintile 5).
The researchers concluded: "These findings suggest that nutritional strategies to increase the circulating n-3 PUFA levels, such as increased consumption of oily fish and/or use of n-3 FA supplements, may reduce the risk of adverse COVID-19 outcomes."

Dr. William S. Harris, PhD, FASN, President of FARI and corresponding author of the study, commented, "This study confirms previous findings that low omega-3 status is associated with increased risk for hospitalization with COVID-19. We extended these findings by also showing reduced risk for testing positive with the infection and by providing evidence that the risk for death may also be reduced. Furthermore, we identified the Omega-3 Index levels associated with the least (<4%) and greatest (>8%) protection from COVID-19. Altogether these results support the practice of increasing consumption of oily fish like salmon or omega-3 fish oil supplements as a potential risk reduction strategy when it comes to COVID-19."

Philip Calder, BSc(Hons), Ph.D., DPhil, RNutr, FSB, FAfN, Professor of Nutritional Immunology within Medicine at the University of Southampton, UK, wrote an 
editorial accompanying this publication titled Bioactive omega-3 fatty acids are associated with reduced risk and severity of SARS-CoV-2 infectionHe said the findings suggest that consuming more long-chain omega-3 fatty acids (EPA and DHA) should be encouraged as a strategy to reduce the impact of the ongoing SARS-CoV-2 pandemic and of future respiratory virus infection outbreaks.

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