Higher Blood Levels of Omega-3 DHA Linked to Lower COVID-19 Risk and Severity

This is an expert commentary discussing a large UK Biobank study that measured blood levels of the omega-3 fatty acid DHA in over 100,000 people and tracked their COVID-19 outcomes during the pandemic. People with higher DHA levels in their blood were less likely to test positive for SARS-CoV-2 and less likely to be hospitalized with COVID-19, even after accounting for factors like age, smoking, diet, and health status.

The article also reviews several other studies with similar findings, including research showing that people who regularly took fish oil supplements had somewhat lower rates of testing positive for the virus, and that hospitalized COVID-19 patients with higher omega-3 levels tended to have better survival outcomes. One small randomized trial found that critically ill COVID-19 patients given EPA and DHA had improved 1-month survival compared to those who didn’t receive it.

The author discusses possible biological explanations, including omega-3s potentially interfering with how the virus’s spike protein binds to cells, slowing viral replication, and helping calm an overactive inflammatory response that can worsen COVID-19 severity. However, since most of the underlying evidence comes from observational data, it cannot prove that omega-3s directly caused the lower risk — other lifestyle factors linked to higher omega-3 status could be involved.