caffeine metabolism

Genes and caffeine metabolism

Perhaps it’s not news to you that genes affect caffeine metabolism. It makes intuitive sense as we all know that person who can have coffee right before going to bed and still sleep like a baby.

A little while ago I got an email announcing a new report derived from my myDNA genetic testing.

Which caffeine metabolism genes are tested?

myDNA analyses three genes (ADORA2A, CYP1A1-CYP1A2, CYP1A2 and AHR) to derive information about caffeine effect on the brain, caffeine metabolism and whether inducers (foods that boost caffeine metabolism) help or not.

My reaction to caffeine

I know from experience that whenever I drink coffee in the afternoon, my sleep suffers. Falling asleep might or might not be a problem, but my sleep quality is crap. I wake up multiple times during the night and usually find it hard to go back to sleep. Therefore, as a general rule, I usually have one cup of coffee between 8 and 9am and then switch to tea.

What do my genes say?

I was pleased to learn that, looking at the big picture, my genetic testing proved to be very accurate:

  • My caffeine metabolism is normal (~45 minutes to process caffeine)
  • I’m unlikely to get anxious from moderate caffeine consumption (<4 cups of coffee per day)
  • The effects of caffeine should last 6-8 hours in my body
  • I have high likelyhood of sleep disturbance if drinking > 4 cups of coffee
  • Inducers (such as cruciferous vegetables, tobacco smoke, certain drugs, charcoal-grilled meat) do nothing to boost caffeine metabolism in my case

The takeaway is that my last cup of coffee should be about 8-12 hours before going to bed, which is exactly what I know from experience.

Bottom line

The way our bodies metabolise particular substances, including caffeine, is highly individual. You don’t need to run genetic testing to find out how you react to caffeine, you can find out by observing how you react to different levels and timing of intake.

Want to know more?

If you are curious about what your genes say, you can invest in genetic testing by companies such as myDNA. The report will also tell you the percentage of the population that shares your alleles (e.g. your particular variation of the tested genes), how many kilojoules/calories, fat and sugar are in different types of coffees and the caffeine content in different beverages. You will also find the scientific evidence behind the analysis and recommendations.

Finally, the folks at Examine.com have also recently released an article entitled Caffeine consumption: how much is safe?. Note that these are general recommendations and don’t take into account individual variations. They include caffeine content for popular drinks, too. Worth a read.

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