You'll have to do a genetic test. Nebula, 23andme, etc.
Then look at CYP1A2, see if you have the C/C genotype.
Definitely read the Genetic Life Hacks article that I linked to above.
Then look at CYP1A2, see if you have the C/C genotype.
Definitely read the Genetic Life Hacks article that I linked to above.
Your DNA is worthless[0] and impossible to hide. If someone did want your DNA there is nothing you could do to stop them. You leave it everywhere you go.
[0] except to your children you don't know you have
They sell it to GlaxoSmithKline and others:
https://en.wikipedia.org/wiki/23andMe
not to mention the recent data breach
This seems to be the original paper. I don't find this paper particularly meaningful, but the effects they did observe showed A/C and C/C to be about the same, and both different than A/A.
This is based on a 5 hour after caffeine ingestion blood test in smokers. They found no differences in the non-smokers, but those were urine tests taken at variable times (whenever they peed), which seems sketchy to me.
Based on this study, subsequent studies (e.g. https://pubmed.ncbi.nlm.nih.gov/16522833/) seem to group A/C and C/C together, and not look at them independently. C/C is rare enough that studies have trouble getting many individuals from that group.
Marker rs762551, as another poster noted above.
For 23andme customers: https://you.23andme.com/tools/data/?query=rs762551
Groan, I'm A/C!!