Study: Fish Oil Supplement May Reduce COVID Severity

A new preprint study suggests that regularly taking a fish oil supplement may help reduce the severity of the symptoms of COVID-19.

Fish oil is of interest to researchers because it has the potential to support the immune system. As a source of DHA and EPA omega-3 fatty acids, fish oil is thought to produce fewer proinflammatory mediators, which could ultimately reduce the symptoms of an infection.

Since the study has not yet been peer-reviewed, experts say that more research is needed to understand the possible benefits of taking fish oil for the health of your immune system.

The recent study isn’t the first time researchers have looked at whether fish oil could help COVID patients. Past studies have shown that omega-3 fatty acid supplementation might be linked to better outcomes for critically ill patients with COVID.

Hao Chen, an associate professor at the Department of Gastroenterology at Guangdong Provincial People’s Hospital in China and an author of the study, told Verywell that “the results from previous studies on the association between fish oil supplements and COVID-19-related outcomes remain controversial.”

Specifically, Chen said that while past studies have suggested the protective role of fish oil supplements against COVID infection, “the statistical power of previous studies was limited, resulting from their defects of small sample sizes or insufficient study designs.”

Fish Oil: A Natural Way to Reduce COVID Symptoms?

For the study, Chen and researchers at the Guangdong Academy of Medical Sciences looked at whether taking omega-3 fatty acid-rich fish oil supplements was linked to better outcomes for people who got COVID.

The researchers reviewed data on more than 110,000 adults in the UK Biobank cohort. They checked to see if the participants reported taking a fish oil supplement and also went over the results of their health exams at the start of the study.

Over a 12-year follow-up, the researchers looked at the participants’ health. Specifically, they looked at how many people got COVID and what their outcomes were (e.g., how sick they got and whether they died from the infection).

The findings showed that the participants who regularly took a fish oil supplement appeared to be less likely to get COVID.

Among the participants who got COVID, those taking fish oil seemed to have a lower risk of needing to be hospitalized for or dying from COVID.

However, taking fish oil supplements was not linked to a reduced risk of being infected with COVID.

It’s important to note researchers collected data before the Omicron strain emerged, which could have influenced the results.

Could Other Protective Effects Be at Play?

Aside from taking a fish oil supplement, there were some other factors about the participants that the researchers had to consider and adjust for in their analysis.

For example, they noted that the participants who regularly took fish oil supplements were also more likely to be women, older, past smokers, and have chronic health conditions like high blood pressure.

According to Chen, fish oil may be more protective in people with chronic conditions because they experience more complications related to inflammation, which omega-3 fatty acids can modulate.

There was no significant difference seen between the fully-vaccinated group and the group that was partially vaccinated or unvaccinated for COVID-19.

Could Fish Oil Help With Other Infections?

As we head into flu season, COVID is certainly not the only viral illness we have to worry about. Could fish oil protect us against other infections, too?

“Several pieces of evidence have demonstrated that fish oil supplementation, with its powerful immunomodulatory function, is potentially beneficial in preventing many respiratory diseases, including asthma and common colds,” Chen said.

However, Chen also cautioned that fish oil’s anti-inflammatory properties may suppress the inflammatory responses necessary to combat viral infection—which is one reason why we need more research to really know for sure what fish oil can—and cannot—do.

Should You Take Fish Oil?

Should you be taking a daily fish oil supplement to help prevent serious COVID illness?

“It’s a good idea to take a daily EPA and DHA supplement, just for your overall health,” Elana Natker, RD, a registered dietitian and the Director of Consumer and Health Professional Communications at the Global Organization for EPA and DHA Omega-3s, told Verywell. “Aim for at least 500 milligrams of EPA and DHA combined. If there are any additional benefits related to COVID-19, that’s the cherry on top!”

However, Natker emphasized that before starting any supplement, including fish oil, you should talk to your provider about your medical history, medications, and diet.

If you follow a vegan diet or want to avoid fish oil, an algae-based omega-3 DHA supplement can be an alternative.

“The body doesn’t care where the omega-3s come from,” said Natker. “It just knows how and where to use them.”