University of Manitoba researchers working at the Canadian Centre for Agri-Food Research in Health and Medicine (CCARM), St. Boniface Albrechtsen Research Centre, have discovered that animals consuming fish oil have fewer anchor points required for entry of the SARS-CoV2 virus into the heart, aorta and kidneys.
“This discovery represents a potential new tool for our medicine chest, a therapeutic that will not lose potency as vaccines do,” said Peter Zahradka, Principal Investigator, Molecular Physiology, CCARM, and Professor, Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba.
At the cellular level, scientists Shiqi Huang, Carla Taylor and Peter Zahradka have shown fish oil results in a 50 to 75 per cent reduction in a protein known as ACE2 that is present on the surface of certain cells. Since it acts as an anchor for SARS-CoV-2 to attach to cells, this reduction in ACE2 means these cells cannot be infected as easily by the virus responsible for COVID-19.
Why fish oil? Previous research conducted at CCARM has shown the beneficial effects of DHA, a fish oil component, on blood vessels in relation to cardiovascular disease. It was on that basis the team began to explore how DHA treatment might affect the number of ACE2 anchor points SARS-CoV2 uses to infect tissues.
“Treating animal models with DHA showed a strong reduction in ACE2 levels present in a variety of animal tissues, so we then extended the work to the cells that form the lining of blood vessels,” Zahradka explained. “From there, it was established that yes, DHA treatment significantly lowered ACE2 levels on these cells.”
Once it was confirmed that the ACE2 anchor points declined by 50 to 75 per cent on human cells treated with DHA, a model system was developed to measure the ability of SARS-CoV-2 to infect the cells. This experiment showed that the DHA treatment reduced entry of the virus into cells by more than 50 per cent. A paper describing these findings was published on Nov. 10, 2022, in the peer-reviewed International Journal of Molecular Sciences.
While further studies in people are needed, the team at CCARM believes it possible that the lowering of ACE2 levels and reduced viral entry should make individuals more resistant to SARS-CoV2 infection.
“Essentially, this treatment could enhance our body’s ability to defend against SARS-CoV-2 infection by making it more difficult to infect our cells. This means you would need to be exposed to higher amounts of virus for a longer period of time to actually get infected and experience symptoms. We also would like to explore the possible effects on long Covid, since DHA treatment may be able to reduce the severity of its symptoms,” he added.
To determine whether these potential therapeutic uses of fish oil are valid, the research team is in conversation with clinicians who deal with COVID-19 to determine which direction the research should take next.
Mario Pinto, UM vice-president (research and international), concurs that “it is important to verify whether these initial observations also apply to people. Consequently, the research team is now approaching clinician scientists who are studying the effects of COVID-19 in patients. Their goal is to examine the relationship between omega-3 levels, susceptibility to infection, and disease severity to determine whether fish oil has a potential therapeutic application in the management of COVID-19.”
A separate human study by Drs. Zahradka, Taylor and Harold Aukema, and graduate student Lisa Rodway and post-doctoral fellow Samantha Pauls, showed genes that strengthen immune function and provide resistance against infection are increased in persons taking fish oil supplements. Their results, to be published in the journal Biomedicine and Pharmacotherapy, indicate fish oil could work through other routes to help fight COVID-19 as well as help protect against other viruses.