Omega-3: The Ratio Matters More Than the Amount

Omega-3 and omega-6 fats compete for the same enzymes and end up in the same membrane positions. That competition, not the absolute intake of either, is what determines the balance of signalling molecules the body produces from them.

Why supplementing alone rarely fixes it

The ancestral ratio of omega-6 to omega-3 was somewhere near 4:1. A modern Western diet runs closer to 15:1 or 20:1, driven almost entirely by industrial seed oils — sunflower, soybean, rapeseed, corn — in restaurant food, packaged food and anything fried.

Adding a fish oil capsule to that shifts the ratio slightly. Cutting the seed oil shifts it a great deal, and costs nothing. If you are only going to do one, do the second.

EPA and DHA do different jobs

• EPA is the one associated with resolving inflammation and with the cardiovascular signal in the trial literature
• DHA is structural — it makes up a large fraction of the fat in brain and retina, and it is what matters most in pregnancy and infancy
• ALA from flax and walnuts converts to EPA and DHA at a very poor rate in humans, often under five percent, and worse in men. It is not a substitute

Rancidity is the unglamorous problem

Long-chain omega-3 fats oxidise readily. A meaningful share of the fish oil on sale has been shown in independent testing to be oxidised beyond acceptable limits before it is opened. Oxidised fat is not neutral — it is the opposite of what you were buying.

If the capsule tastes fishy when you bite it, it has gone off. Fresh fish oil tastes of almost nothing.

Practical guidance

• Oily fish two or three times a week beats any capsule: sardines, mackerel, herring, wild salmon, anchovies. Small fish, low in the food chain, low in mercury
• If supplementing, look for combined EPA+DHA on the label rather than total fish oil, and aim for 1–2 g of the combined figure
• Keep it refrigerated, buy small bottles, check the expiry
• Triglyceride form is better absorbed than the cheaper ethyl ester
• Cod liver oil adds vitamins A and D, which is either a bonus or a reason to watch total vitamin A intake

Sardines deserve a particular mention: they are among the densest sources of EPA and DHA available, cheap, shelf-stable, and low enough in the food chain that mercury is not a concern. They are also the basis of one of the simplest fasting protocols on this site.