02/07/2026
Cod Liver Oil: Remember That Spoonful? Well… Science Has Been Hard at Work.
Okay, let's face it.
If you grew up in the 70s or 80s, chances are someone chased you around the kitchen with a spoonful of cod liver oil.
Your mom. Your nan. Or both.
In those days, nobody asked if you liked it.
You took it because it was good for you.
End of story.
And you know what?
No one questioned it for years.
Then something interesting happened.
Science did what science was supposed to do. It kept asking questions.
Because unlike your uncle on Facebook, science doesn't marry its opinions.
It changes them when new evidence comes to light.
Now before anyone freaks out and throws their fish oil capsules in the bin...
Chill.
This is not one of those everything-you've-ever-known-is-a-lie stories.
It’s actually a lot more interesting than that.
So, what's changed?
For years, omega-3 was the golden child.
> Healthy heart? Take omega-3.
> Healthy brain? Take omega-3.
> Joints? Omega-3.
> Mood? Omega-3.
> Bad haircut? Someone probably suggested omega-3 for that as well.
Then researchers carried on doing what researchers do.
They did bigger studies. Longer studies. Better studies.
And they found something unexpected.
Among those taking high doses of omega-3 supplements, there appeared to be a slight increase in the odds of developing atrial fibrillation, an irregular heart rhythm.
Notice what I didn't say.
I never said fish is dangerous. I didn't say cod liver oil is poisonous.
And I never said your mum was trying to ruin your childhood.
Here's what I said:
Sometimes even things that are generally good for us are not entirely without risk.
Especially at high doses.
Funny, eh? We understand this perfectly with chocolate. Too much? Not so great. Coffee? Same story. Sunshine? Lovely... unless you stay out all day without suncream.
But when it comes to supplements people suddenly think:
If one capsule is good.....surely four must be brilliant.
That’s not the way biology works. That’s the way marketing works.
Does this mean omega-3 is useless?
Of course not.
That's another extreme. And people absolutely love extremes.
Yesterday:
Omega-3 cures everything.
Today:
Omega-3 is dangerous.
Tomorrow:
Someone on social media will likely tell you celery juice cures both.
In reality, it is less dramatic.
The health benefits of Omega-3 are still known.
Oily fish is still recommended in a healthy diet.
There are people who benefit from prescribed omega-3 treatment.
The important bit is this:
Benefits and risks can exist at the same time. Life is awkward like that.
Here's what really interests me...
We spend so much time looking for that one magic pill.
One magic exercise. One magic diet. One magical massage. One magic something.
Meanwhile the body continues to react to the same boring habits that it always liked:
* Move regularly.
* Sleep properly.
* Eat real food.
* Manage stress.
* Don't smoke.
* Maintain a healthy weight.
Hardly front-page stuff, is it?
But that’s the annoying thing about being healthy. It's not much of a thrill.
So what's the lesson?
It wasn’t that cod liver oil was a mistake. It’s not that omega-3 has suddenly become the bad guy.
The lesson is much simpler.
When someone tells you they’ve found the one thing that will change your health…
Wait. Smile. Then ask:
What is the latest evidence actually showing?
Because good science isn’t about proving that we were right.
It’s about getting a bit closer to the truth.
And unlike marketing...
Science is pretty comfortable with not having all the answers.
Disclaimer: This article is for educational purposes only and should not be taken as individual medical advice. If you have atrial fibrillation, cardiovascular disease, or are taking omega-3 supplements on medical advice, do not stop treatment without discussing it with your GP or cardiologist.
References:
Bhatt, D.L., Steg, P.G., Miller, M., Brinton, E.A., Jacobson, T.A., Ketchum, S.B., Doyle, R.T., Juliano, R.A., Jiao, L., Granowitz, C. and Tardif, J.C. (2019) Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia. New England Journal of Medicine, 380(1), pp.11–22.
Jia, X., Gao, F., Pickett, J.K., Al Rifai, M., Birnbaum, Y., Nambi, V., Virani, S.S. and Ballantyne, C.M. (2021) Association Between Omega-3 Fatty Acid Treatment and Atrial Fibrillation in Cardiovascular Outcome Trials: A Systematic Review and Meta-analysis. Cardiovascular Drugs and Therapy, 35(4), pp.793–800.
Lombardi, M., Carbone, S., Del Buono, M.G., Chiabrando, J.G., Vescovo, G.M., Camilli, M., Montone, R.A., Vergallo, R., Abbate, A., Biondi-Zoccai, G., Dixon, D.L. and Crea, F. (2021) Omega-3 fatty acids supplementation and risk of atrial fibrillation: an updated meta-analysis of randomized controlled trials. European Heart Journal – Cardiovascular Pharmacotherapy, 7(4), pp.e69–e70.
Medicines and Healthcare products Regulatory Agency (MHRA) (2024) Omega-3-acid ethyl ester medicines (Omacor/Teromeg 1000 mg capsules): dose-dependent increased risk of atrial fibrillation in patients with established cardiovascular diseases or cardiovascular risk factors. Available at: GOV.UK Drug Safety Update (Accessed: 27 June 2026).
Nicholls, S.J., Lincoff, A.M., Garcia, M., Bash, D., Ballantyne, C.M., Barter, P.J., Davidson, M.H., Kastelein, J.J.P., Koenig, W., McGuire, D.K., Mozaffarian, D., Ruotolo, G., Uno, K., Borgman, M. and Nissen, S.E. (2020) Effect of High-Dose Omega-3 Fatty Acids vs Corn Oil on Major Adverse Cardiovascular Events in Patients at High Cardiovascular Risk (STRENGTH Trial). JAMA, 324(22), pp.2268–2280.