Omega-3/6 conversion efficiency

FADS1 controls how efficiently your body converts plant oils into long-chain omega-3 and omega-6 fats like EPA, DHA and arachidonic acid. Lower efficiency means dietary fish or algae matter more.

Possible results

Efficient omega-3 conversion. You have the efficient version of FADS1, so your body readily converts plant oils into the long-chain omega-3 and omega-6 fats (like EPA and DHA) your brain and heart use. You make these well from a normal diet.

Intermediate omega-3 conversion. You carry one copy of the less-efficient FADS1 variant, so you convert plant oils into long-chain omega-3s a bit less effectively than the most efficient type. Eating some fish or algae-based omega-3 helps cover the gap.

Lower omega-3 conversion. You have two copies of the less-efficient FADS1 variant, so your body is slower at turning plant oils (like those in flax or walnuts) into the long-chain omega-3s EPA and DHA. Getting omega-3 directly from fish or algae oil is a more reliable source for you.

Evidence & sources

Across global populations, about 11% of people carry two copies of this variant, and about 53% carry none.

This variant appears in 4 published genetic studies: PubMed 25646338 · PubMed 26584805 · PubMed 34503513 · PubMed 40545721.

Related

Adult lactose digestion · Alcohol response (flushing & dependence risk) · Caffeine metabolism speed · LDL cholesterol · Sweet tooth / carbohydrate preference (FGF21) · Total cholesterol · Vitamin D status (low-D genetic burden)