A meta-analysis took place in 2021 that assessed the outcomes of several clinical trials, and concluded that omega 3 supplementation – particularly above 1g per day – increased the risk of developing atrial fibrillation.
Given this conflicts with everything we’ve been led to believe about omega 3s over the years – including numerous cardiovascular and neurological benefits – this evidence comes as quite a shock to most people.
I’ve even read some articles following this up with claims that the well-known cardiovascular benefits of omega 3 supplementation are not backed with clinical evidence – this part, is simply untrue.
While it is challenging to provide an exact count, I can assure you that there is a substantial body of research on this topic.
Cardiovascular Benefits include:
- – Cardiovascular Disease Prevention: Multiple studies have shown that omega-3 fatty acids have a protective effect against cardiovascular diseases, including coronary heart disease, heart attacks, and strokes. These studies include large randomized controlled trials such as the GISSI-Prevenzione trial and the REDUCE-IT trial.
- – Triglyceride Reduction: Omega-3 fatty acids have been shown to reduce triglyceride levels, which are associated with an increased risk of cardiovascular disease. This effect has been demonstrated in several studies, including the GISSI-Prevenzione trial and the JELIS trial.
- – Blood Pressure Management: Some research suggests that omega-3 supplementation may have a modest effect in reducing blood pressure levels, particularly in individuals with hypertension.
- – Anti-inflammatory Effects: Omega-3 fatty acids possess anti-inflammatory properties, which may contribute to their cardiovascular benefits. Chronic inflammation plays a role in the development of atherosclerosis and other cardiovascular conditions.
Neurological Benefits include:
- – Cognitive Function and Aging: Several studies have examined the potential cognitive benefits of omega-3 fatty acids, particularly in older adults. While results have been mixed, some studies suggest that omega-3 supplementation may have a positive impact on cognitive function and help protect against cognitive decline.
- – Mental Health Conditions: Omega-3 fatty acids have been investigated for their potential therapeutic effects in mental health conditions such as depression, anxiety, and bipolar disorder. Research in this area is ongoing, and while some studies have shown promising results, further investigation is needed to establish definitive conclusions.
So this new evidence really is quite contradictory to everything we once knew about Omega 3 fatty acids. Suddenly they’re now detrimental to cardiovascular health, and not beneficial?
Now, it’s important we dig into the claims of this new study a little further, to understand the real risk factors.
Let’s begin with the meta analysis itself – so we can see if we should be lending credibility to these claims in the first instance.
The analysis covered just five randomised controlled trials investigating the effects of omega-3 fatty acid supplementation on cardiovascular outcomes.
Participants of these 5 trials had elevated triglycerides and were either at high risk for cardiovascular disease or had established cardiovascular disease. This, is the most poignant piece of information when it comes to assessing the credibility of the study and its findings – all people, across these 5 trials, had either pre-existing cardiovascular issues or were at least at higher risk of experiencing cardiovascular issues. This likely skews the whole outcome when it comes to making generalised conclusions like ‘omega 3 can increase the risk of atrial fibrillation’. Not correct – at least not for the general population – and particularly not for those who are of good or reasonable health.
The people in these studies were likely to have been at higher risk of experiencing atrial fibrillation anyway, due to their pre-existing cardiovascular issues or higher cardiovascular risk factors. So it could be argued that, in fact, the doses of omega 3 may not have been HIGH ENOUGH, to combat their pre-existing conditions or risk, or that their other lifestyle choices or genetic predispositions meant that they would have incurred atrial fibrillation – omega 3 supplementation or not.
A total of 50 277 patients received fish oils or placebo and were followed up for between two and 7.4 years – so granted, this was a fairly large scale, long-term analysis. And the dose of fish oils varied from 0.84 to 4 g per day – so fairly significant dosages. I personally have a very high strength fish oil supplement, one of the most potent you can buy – and this delivers around 3.5g of total omega 3s daily. Anything above 1-2g could be considered pretty high dose.
So in summary, a pretty credible study insofar as scale, dosages and duration, but heavily skewed by the specific health condition and risk factors of the sample group. Bear this in-mind, and I really don’t think – as a result – that they should be concluding a sweeping statement of ‘omega 3s increase your risk of atrial fibrillation’ from this study. Not without making the context of the study sample very clear – which most media coverage, didn’t do. You have to dig into the meta analysis overview and papers themselves to decipher this critical piece of information.
Now even if, indeed, omega 3 supplementation led to increased risk of atrial fibrillation, what does this actually mean in terms of being a risk to your health and a mortality risk?
Atrial fibrillation in itself is not fatal. It’s simply the inefficient and/or abnormal beating of the heart.
In a normal heart rhythm, the electrical signals follow a coordinated pattern, allowing the atria to contract and pump blood into the ventricles (the lower chambers of the heart), which then pump blood to the rest of the body. However, in atrial fibrillation, the electrical signals become chaotic, resulting in a quivering or fibrillating motion of the atria instead of a regular contraction.
So, in and of itself, atrial fibrillation is not immediately dangerous in most instances. It’s the conditions that proceed to develop from atrial fibrillation over time, that can be extremely dangerous – such as strokes and heart-failure.
In the media, stroke risk is heavily covered alongside the ‘omega 3 increases risk of atrial fibrillation’ coverage – stating you can be 5 times more susceptible to stroke when you have atrial fibrillation. Again, scary to read on the face of it – but let’s dig further.
There are ultimately 2 different forms of stroke.
- 1. Ischemic Stroke: Ischemic stroke occurs when a blood clot or blockage obstructs the flow of blood to the brain.
- 2. Hemorrhagic Stroke: Hemorrhagic stroke is caused by bleeding in the brain, often due to a ruptured blood vessel.
The stroke that often occurs as a result of atrial fibrillation is most commonly an ischemic stroke. Now, here’s where the contradiction occurs regarding omega 3’s and available evidence – because, several studies have suggested that omega-3 fatty acids, particularly the long-chain types (eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA) found in fish and fish oil, may help reduce the risk of ischemic stroke. These omega-3 fatty acids have anti-inflammatory and anti-thrombotic properties, which can help prevent the formation of blood clots and improve blood vessel function.
This means that, even if we were convinced by the conclusion that ‘omega 3 supplementation increases your risk of atrial fibrillation’ – the most prominent mortality risk posed by this condition, is actually vastly reduced by supplementation of omega 3s – the things this study states is leading to the condition that precedes this mortality risk.
It’s almost self-remiadating in this respect, even if you were convinced by the highly-skewed evidence of the meta-analysis.
In summary, this relatively new study sits in direct contradiction with likely hundreds, if not thousands, of clinical studies that prove the benefits of omega 3 intake, and given what we’ve explored in this article, should be taken with a generous pinch of salt.