Regular use of fish oil supplements might increase, rather than lessen, the risk of first-time heart disease and stroke among healthy people.

On the other hand, these popular supplements “may slow progression of existing poor cardiovascular health and lower the risk of death”.

These are the main findings of a large long-term study.

Research into the benefits and safety of fish oil (omega-3 fatty acid) supplements is notoriously mixed.

Conflicting results

One study will find that fish oil is good for the heart or your diabetes nerve pain or your kidney disease or your immune system. Another will say it’s all hogwash.

Worse, in the past few years, evidence has emerged that these supplements – which tend to be of poor quality when bought over the counter – can hurt you.

In 2021, the European Society of Cardiology published a new analysis that went off like a bomb.

It found that omega-3 fatty acid supplements were associated with an increased likelihood of developing atrial fibrillation (Afib) in people with a high risk of, or existing, heart disease.

These findings were supported by previous studies.

Now, seriously confusing the issue is the new study published in the British Medical Journal.

The intention of the researchers was to “strengthen the evidence base”.

First, they tracked the dietary habits and health records of 415,737 UK Biobank study participants. Nearly a third regularly consumed fish oil supplements.

They then looked for associations “between fish oil supplements and new cases of atrial fibrillation; heart attack, stroke, and heart failure; and death from any cause in those with no known cardiovascular disease”.

They also assessed “the potential role of these supplements on the risk of progressing from good heart health (primary stage), to atrial fibrillation (secondary stage), to major cardiovascular events, such as a heart attack (tertiary stage), and death (end stage)”.

The findings

In short, for people with healthy hearts, supplements raised the risk of heart disease.

But for people with heart disease, the risk of a catastrophic cardiac event was lowered by regular supplement intake.

For participants with no known cardiovascular disease at the start of the monitoring period, it was found that “regular use of fish oil supplements was associated with a 13 per cent heightened risk of developing atrial fibrillation”.

They also had a five per cent heightened risk of having a stroke.

For those who had cardiovascular disease at the start of the monitoring period, regular use of fish oil supplements was associated with a 15 per cent lower risk of progressing from atrial fibrillation to a heart attack.

They also had nine per cent lower risk of progressing from heart failure to death.

Overall, the authors, who note that an observational study doesn’t prove causation, conclude: “Regular use of fish oil supplements might have different roles in the progression of cardiovascular disease.

“Further studies are needed to determine the precise mechanisms for the development and prognosis of cardiovascular disease events with regular use of fish oil supplements.”

For more detail about the study, see here.

What to do

Get your omega-3 fatty acids from food, not pills.

Small amounts of omega-3 fats are essential for good health.

They regulate the nervous system, blood pressure, hematic clotting, glucose tolerance, and inflammatory processes.

The main types of omega 3 fatty acids are:

• Alpha-linolenic acid (ALA), normally found in fats from plant foods, such as nuts and seeds. Walnuts and rapeseed are rich sources
• Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), collectively called long chain omega-3 fats. These are naturally found in fatty fish, such as salmon and fish oils, including cod liver oil.

Can’t afford salmon? The quality and taste of tinned sardines has improved enormously. They’re also very cheap at $2 a tin.