The truth about fish oils - are they really pointless?

Are fish oils not as protective as we’d hoped?

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Emma Thornton
Qualified Nutritionist (BSc, MSc, ANutr)
@EmmaThornton
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03 August 2018

What are the recent claims?

A recent Cochrane review (a large scale study and generally considered as quite a credible source) combined the results from 79 separate studies on fish oils and concluded that ‘fish oils may have little or no effect on heart related death’.1 

Unsurprisingly, this has rocked many of us who incorporate supplements into our daily regime and has made us question whether or not our current fish oil supplements are really worthwhile. Here I dissect the information, delve a little deeper and explain what the best approach is going forward!

Are there any flaws?

Firstly, no matter how good quality the research appears, there are always a few important considerations to be had. When it comes to this example, the other side of the story looks a little like this:

1 – Variety is good but harder to keep tracking of confounding factors 

Although the study is larger scale which suggests it is more reliable, there are still minor criticisms to make. Firstly when it comes to the health of the participants across all of the studies, not all included healthy people. Some had history of heart complaints already, understandably which could potentially skew the results. 

Next, factors such as lifestyle weren’t always taken into consideration. If people are living relatively unhealthy lifestyles, yet taking fish oil supplement, we shouldn’t be surprised if the results aren’t altogether favourable!

Finally, although there were many of them present, the quality of the studies included in the review must also be considered. Only 25 of the 79 studies were considered at ‘low summary risk of bias,’ and within them, some of the studies included as little as 11 participants which isn’t likely to be representative of our population as a whole. 

2 – Variety in the supplements too

As well as the study design, it’s important to look at what was actually tested. ‘Omega-3’ can be acquired from both plant sources (in the form of flaxseed oil normally) and from fish – from both the flesh of the fish (marketed as ‘fish oils’) and from the liver in the case of cod liver oil. These different sources may have different outcomes on health and there are different doses, strengths, plus the quality of the products to consider! We know that a good dose of EPA and DHA (the essential fatty acid components of good quality omega 3) is preferable and this is an important consideration is important when picking your omega-3 product. 

So, when we are combining the results from a number of studies there is bound to be a larger variety in the quality of the products being included and this may make it harder for us to assimilate conclusions from.

3 – Lots of other studies say the opposite!

Although this review doesn’t paint the most positive picture for the health benefits of omega-3, we know that many previous studies have2,3, hence the association with fish oils and heart health in the first place! Other studies have shown that cardiovascular events (meaning heart attacks, strokes, angina attacks, palpitations or arrhythmia) are less likely to crop up if you have the right balance of omega-3 oils in your system. 

There is also lots of ongoing research in this field which haven’t yet been included in studies such as the review in question, which may able to help create a clearer picture for us in the future.

Stressing the importance of the naturopathic approach 

As always, we must stress that a naturopathic approach is often best when it comes to optimal heath. In terms of these results and the conclusions that have been drawn from this study, when it comes to fish oils and other Omega-3 supplements, they simply shouldn’t be seen as an infallible remedy against any form of heart disease! However, they can of course be a sensible addition to a programme of healthy diet, moderate exercise, and stress management. 

Nothing is going to guarantee that you won’t experience a heart attack or stroke eventually, especially if you have questions lifestyle habits alongside your daily fish oil cap. However, there are of course many steps you can take that make it less likely and having the right oils in your diet or supplement regime is one of them.

Our guide to the best approach 

1 - First and foremost start with diet! 

When it comes to healthy oils (or most supplements for that matter), it’s important to look at your diet first. Many nutrients are ‘essential’ meaning we can’t manufacture them and we need to get them from our diet. This means, you should always start by looking at your diet rather than supplements. 

Omega-3 is most readily found in sources of oily fish including salmon, tuna, herring, kippers, sardines, mackerel and anchovies, to name a few! However, there are also various plant sources including flaxseeds, chia seeds and walnuts. My advice is to include 2-3 oily fish portions in your diet each week, habitually include your plant-based sources too, and if need be, you can top up your levels with a supplement.

However, let’s forget it isn’t just omega-3 that’s important for heart health and this is where the study in question may have fallen down as mentioned above.  Other protective components of our diet when it comes to heart health includes; other healthy oils including omega-9 rich olive oil, vitamin C found in fruit and antioxidants found in a variety of fresh fruit and vegetables. 

So, if we are including all of these in our diet, alongside a fish oil supplement, surely this could put is in much better stead than someone who lives off fast food, yet pops their daily fish oil capsule alongside it?

2 - Next, other important lifestyle factors to consider  

Although diet is always an important starting point, there are also other factors to consider when it comes to optimal heart health. Firstly, exercise. Sedentary lifestyles or the other end of the scale (extreme exercise), could put our cardiovascular system other pressure and we know that other factors such as stress, insufficient sleep, medication use, alcohol intake and even genetics could all have a significant impact on our risk of cardiovascular events. 

3 - Then, worry about the supplements!

Once we’ve appropriately addressed diet and lifestyle factors, then it might be time to consider adding a supplement in. Although this recent review has suggested that fish oils may not ‘significantly’ decrease our risk of cardiovascular events, we know that many other factors could be at play. However, having a favourable ratio of oils in our diet, with some good quality omega-3 supplement containing a beneficial dose of EPA and DHA, is most likely to put you in good stead for a healthy future! 

1Abdelhamid AS, Brown TJ and Branaird JS et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews 2018, Issue 7. Art. No.: CD003177. http://cochranelibrarywiley.com/doi/10.1002/14651858.CD003177.pub3/full

2Lee JH, O’Keefe JH and Lavie CJ et al. Omega-3 fatty acids for cardioprotection. Mayo Clin Proc 2008; 83 (3): 324-32

3Alexander DD, Miller PE and Van Elsewyk ME et al. A meta-analysis of randomised controlled trials and prospective cohort studies of eicosapentaenoic and docosahexaenoic longchain omega-3 fatty acids and coronary heart disease risk. Mayo Clinic Proceedings, 2017; 92 (1): 15-29

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