What does a CYP1A2 genotype mean for lifestyle?

The CYP1A2 gene encodes the enzyme responsible for metabolizing ~95% of caffeine. Variants (mainly rs762551) classify individuals as 'fast' (AA) or 'slow' (C-allele) metabolizers. Slow metabolizers consuming high caffeine (>2–3 cups/day) face increased risks of hypertension, myocardial infarction, and sleep disruption due to prolonged caffeine exposure. Fast metabolizers tolerate caffeine better and may benefit from its ergogenic effects before exercise. Evidence is human-strong, supported by large cohort studies and meta-analyses (e.g., on blood pressure, heart attack risk). However, effect sizes are moderate and modifiable by lifestyle factors like smoking (which induces CYP1A2, accelerating metabolism) and medications. MyBody-X DNA tests may include this SNP, but the clinical utility for individuals is limited. A genetic result does not replace medical advice, especially for those with cardiovascular conditions. Conclusion: The genotype offers a clue, but caffeine tolerance and health outcomes should be assessed holistically, with moderation as a key principle.