DNA diagnostics of caffeine metabolism efficiency
The AHR gene controls how much of cytochrome CYP1A2 and cytochrome CYP1A1 enzymes will be produced in your body. The AHR gene, along with the CYP1A2 gene, determines the amount of caffeine that circulates in your blood and its exposure time. If you metabolize caffeine quickly, caffeine does not retain long enough to significantly affect your brain centers, so you can consume more caffeine-containing products. But if your body produces a small amount of the enzyme, the caffeine will stay in your system longer and may cause adverse side effects. The G/G genotype ― the fast caffeine metabolizer; and A/A and G/A ― slow caffeine metabolizers.