Markers / Gene
between CYP1A1 and CYP1A2
One position in this gene is readable from a home DNA test.
How much coffee you actually drink
rs2472297 · chr15:75,027,880 · C/T · evidence: established
This is not about whether caffeine affects you. It is about how much coffee people with this version end up drinking, which turns out to be one of the most reliably replicated findings in the whole of behavioural genetics. People who clear caffeine faster drink more of it to get the same effect.
| If you carry | What it means |
|---|---|
| No copies | Typically lower coffee intake |
| One copy | Typically higher coffee intake |
| Two copies | Typically highest coffee intake |
| Ancestry group | T (the effect version) | |
|---|---|---|
| African | 1.4% | |
| American | 8.9% | |
| East Asian | 0.0% | |
| European | 21.5% | |
| South Asian | 3.3% |
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.
Where this gene fits
If you have taken a home DNA test, these positions are already in your file.
Read my file