Arguably, preliminary evidence that fish oil fatty acids were effective in coronary heart disease prevention came from Danish physicians Jörn Dyerberg and Hans Olaf Bang. The two physicians discovered that Greenlandic Inuit had lower mortality rates from coronary heart disease than Americans and Danes due to a diet rich in omega-3 fatty acids.
Fish oil is an essential source of omega-3 fatty acids, which function in regulating biological processes, brain function and metabolic signaling pathways. The oil is also an important source of vitamins A and D.
Several clinical trials provide evidence of the benefits of fish oil in supporting our heart health, as it may increase levels of good cholesterol by up to 30 per cent, reduce blood pressure and prevent arterial plaques.
Besides potentially reducing risk factors associated with heart disease, fish oil may also have health benefits related to improving cognitive functions, alleviating joint swelling and autoimmune inflammation and even may help manage symptoms of certain mental health conditions.
Because of this, fish oil supplements are one of the most commonly used dietary supplements in recent times, contributing to a global market valued at more than US$2 billion.
University of Manitoba physiology professor Peter Zahradka has worked extensively on the components of fish oil and highlighted its benefits — specifically on individuals with slower metabolisms. His research work focuses on therapeutic approaches using dietary interventions, identifying new approaches in treatment and prevention of vascular complications.
Although SARS-CoV-2-, the virus that causes COVID-19, is a respiratory virus, it also affects the cardiovascular system, with higher COVID-19 mortality in patients suffering from pre-existing health conditions like cardiovascular disease.
Angiotensin converting enzyme 2 (ACE2) — a protein found on the outside of multiple cell types — serves as a receptor for SARS-CoV and SARS-CoV-2 virus in entering human cells. This protein is in multiple regions of the body.
“By reducing the amount of ACE2 on the surface of the cells, there are fewer anchor points for the virus to attach to, and therefore the ability to infect those cells is reduced too,” Zahradka explained.
“The change caused by fish oil actually would reduce the ability of the virus to infect cells.”
Attachment of SARS-CoV-2 via the ACE2 receptor leads to the infection, and as such, it is an object of focus as a potential target for anti-viral therapeutics.
Through his research, Zahradka has found that fish oil also has benefits for the cardiovascular system.
“Because COVID seems to have some nasty effects on the cardiovascular system, we thought it might be interesting to see if there was something that changed in animals that had been given fish oil for a period of time,” he said.
Zahradka and his team discovered that animals that had ingested fish oil for an extended period displayed reduced levels of ACE2 on the outside their cells.
Additionally, they found a reduction of over 50 per cent of ACE2 after experimental treatment with a SARS-CoV-2-like virus in human cells with fish oil, with low infectivity and limited entry of the virus into cells.
Zahradka proposes further investigation and clinical applications in humans to determine the actual effectiveness of fish oil in protecting against COVID-19 infection.
“It will take a study where somebody actually does an intervention with giving some people fish oil to see whether they become less infected before it is possible to actually tell people to take fish oil for this purpose,” he added.
Zahradka hopes that clinical trials involving fish oil takes place soon.
“It would be very useful because it could be used alongside vaccines to protect people,” he said, as fish oil could potentially serve as an additional layer of protection against COVID.
“If you’re vaccinated and using fish oil, you should be extra protected against infection.”