Omega-3
A family of essential polyunsaturated fatty acids (ALA, EPA, DHA) that the body cannot make, important for heart and brain health and for regulating inflammation.
Omega-3s come in three main forms:
- ALA (alpha-linolenic acid): the plant form (flax, chia, walnuts, rapeseed)
- EPA (eicosapentaenoic acid): a marine form (oily fish, algae)
- DHA (docosahexaenoic acid): a marine form, crucial for the brain and retina
A fresh angle (the biological chain): contrary to popular belief, fish do not “produce” the omega-3s EPA and DHA. It is marine micro-algae that synthesise them. Oily fish concentrate them because they eat these algae. In other words, the algae come before the fish in the chain. This is why algal oil supplements are a direct, sustainable vegan alternative that cuts out the fish.
The conversion trap: the body can convert ALA (plant) into EPA and then DHA, but this conversion is very low: often under 5-10% for EPA and barely 0.5-4% for DHA. It depends on sex, hormonal status (women convert better thanks to oestrogens) and, above all, the omega-6/omega-3 ratio.
So eating flaxseed is beneficial, but it does not guarantee optimal DHA status. For that, marine sources (fish, algae) remain essential.
The real role: EPA and DHA do not “suppress” inflammation. They promote its resolution by producing pro-resolving mediators (resolvins, protectins). Inflammation is not always bad; it is failure to resolve it that causes problems.