The Influence of CYP1A2 Genotype on Caffeine Consumption Habits and Athletic Performance Enhancement in Collegiate Distance Runners

The liver enzyme CYP1A2, which is responsible for metabolizing caffeine, is a member of the cytochrome P450 family. CYP1A2 activity is highly variable across individuals, depending on factors such as gender, personal habits (e.g., smoking status and diet), and genotype. A single nucleotide polymorphism (A/C) in intron 1 of the CYP1A2 gene leads to differences in gene inducibility, with AA individuals reportedly having higher activity than C-allele carriers. Several reports have suggested that genotype can modulate the physiological effects of caffeine. For example, “fast metabolizers” with the AA genotype benefit more from caffeine supplementation before cycling time trials than C-allele carriers. We investigated whether CYP1A2 genotype influences self-reported caffeine consumption and performance effects in collegiate distance runners. DNA samples and questionnaires were collected from 65 subjects. PRC-RFLP was performed to determine genotype. Preliminary statistical analysis based on the questionnaires ...