Markers / Gene
FADS1
One position in this gene is readable from a home DNA test.
Turning plant fats into the ones your brain runs on
rs174546 · chr11:61,569,830 · C/T · evidence: established
Your brain needs long-chain omega-3 and omega-6 fats. You either eat them ready-made, from fish and organ meat, or you build them from the short ones in plants. FADS1 does the building, and the efficient version swept through farming populations that ate mostly plants. Populations that kept eating fish never needed it, and Greenlandic Inuit carry a different version entirely, adapted the opposite way.
| If you carry | What it means |
|---|---|
| No copies | You have the slower-converting version on both copies |
| One copy | You carry one efficient copy |
| Two copies | You have the efficient version on both copies |
| Ancestry group | C (the effect version) | |
|---|---|---|
| African | 97.8% | |
| American | 41.4% | |
| East Asian | 43.4% | |
| European | 65.3% | |
| South Asian | 86.3% |
1000 Genomes Project phase 3, via Ensembl, retrieved 2026-09-23. These groupings are coarse and flatten a great deal of internal diversity, particularly within Africa. A variant being common somewhere tells you where a piece of your ancestry probably comes from, and nothing else.
If you have taken a home DNA test, these positions are already in your file.
Read my file