Back in the day, when I first started dabbling in nutrition more seriously, I gave out ALOT of fish oil.

I heard about the omega 3:6 ratio (or EPA:AA ratio more correctly), and how it was the balance of inflammation.

Cue me and many others, piling 2.5g – 10g of fish oil (EPA & DHA) daily into my patients (and me).

The results?

Did patients’ pain and poor health disappear and inflammation balance out?


In fact, not that much really happened.

A few had improvements in mental health, especially in older people, and I hope I helped a few females have babies with lovely fatty brains.

But none of the promised miracles.

In hindsight, I simply did not understand the basics of inflammation.

If the omega 3-6 ratio is valid, then an out-of-balance ratio (ideally, you aim for no more than 1:3 in favour of omega 6 in the form of arachidonic acid AA) is going to be due to excessive intake of seed oils like sunflower and canola (rapeseed).

These are ubiquitous in processed/pre-made foods, so a small amount of those will upset your ratio, even if you are eating fish x1-2 a week.

So it is not an omega 3 deficiency per se but an excess of omega 6 starting as linoleic acid (LA) and converting eventually into AA which turns into PGE2, which is inflammatory.

As it turns out eating loads of LA doesn’t push AA up, but it is still a nice theory.

Another nutritional myth I swallowed.

Those delicate double bonds are vulnerable to oxidative damage, ironically created by inflammation, the very thing you are trying to reduce.

It is a real possibility that taking fish oil leads to the oil going rancid inside you, oxidised.

Bear in mind also from an evolutionary point of view, where would tribes on the plains of Africa get fish from?

Yes, there is coastline and lakes, but when did we get skilful enough to catch little fish?

Hunter-gatherers prize large land animals for the volume of food and the saturated fats they contain.

Remember, saturated fat is solid at room temperature because it has no double bonds.

It is “saturated” with hydrogen.

This makes it more stable, hence solid at room temperature.

It also makes it, therefore, less likely to go rancid inside you, as it is less vulnerable to oxidative damage from free radicals.

In my one-to-one clients, who are often very metabolically poorly, I actively encourage them to reduce their poly-unsaturated fat from all sources initially and increase saturated fat to reduce the oxidative stress from rancid fats.

Hunter gatherers can get omega 3 from grass-fed animals but not in huge volumes like fish.

Note here the difference in fat content between grass-fed and grain-fed animals.

EPA content is wayyyy higher.

But check the omega 3-6 content and ratio.

8.99 in favour of omega 6 for grain-fed vs 1.77 for grass-fed – WOW.

One other issue is that omega 3 supplements are now directly linked to increasing the risk of atrial fibrillation, especially with higher doses.

“Considered together, the data from the 4 trials suggest, but do not prove, that there may be a dose-related risk of AF with omega-3 fatty acid intake.

At a dose of 4.0 g/d, there was a highly statistically significant increase in risk (nearly a doubling).

With an intermediate dose of 1.8 g/d, the increase in risk (hazard ratio, 1.84) did not achieve statistical significance, and with a standard daily dose of 840 mg/d, there was no apparent increase in risk (although the data were consistent with as much as a 24% increase in risk).

Patients who choose to take omega-3 fatty acids, especially in high doses, should be informed of the risk of AF and followed up for the possible development of this common and potentially hazardous arrhythmia. “

Overall, I would suggest getting your omega 3 from small wild fish if wanted, once or twice a week max.

Is there heavy metal like mercury in the fish?


Have I seen mercury toxicity from daily fish eating, especially tuna?


But on balance, if we eat smaller ones, wild, the selenium, iodine and other nutrients along with the modest omega-3 doses, it is a net benefit.