By Virginia Hughes | April 4, 2011 | 12 Comments
On Friday I woke up too early with a splitting headache and chest pain. This was alarming. In the shower, I tried to come up with a list of plausible explanations, but my mind found only one: the four cups of coffee I drank the day before. I wondered, is this how a heart attack begins? For the first time in eight years, I sat down at my desk to work without a mug of jolt.
The rational part of my brain knew why I had jumped to the worst-case scenario. I recently bought a genetic testing kit from 23andMe. After the initial shock about my melanoma risk variants, I calmed down and started digging into the rest of the data. Turns out I carry a variant for a condition that is, in some ways, more unnerving than skin cancer: slow caffeine metabolism.
I should say a word about my coffee habits. I have coffee habits. I live in Brooklyn and buy micro-roasted (in the past three days, if possible) Guatemalan Gorilla from an adorable shop four blocks from my apartment. I grind it myself in small batches and put it immediately into a French press. If you know coffee, you know what all that means. If you don’t know coffee, you’re rolling your eyes but still get my point.
Since I started drinking coffee, in college, I’ve happily ignored the possibility that my ritual is actually an addiction that’s hurting my body and brain. Although some ingredients in coffee — antioxidants, magnesium — are good for us, the one we all know and love, caffeine, might not be. It makes my mind sharper, but it also spurs adrenaline release and raises blood pressure. There’s a huge scientific debate over whether habitual caffeine consumption causes (or prevents!) hypertension, heart attacks and diabetes.
So back to my genes. We metabolize caffeine thanks to a liver enzyme called cytochrome P450 1A2. The enzyme is produced by a gene dubbed CYP1A2.
23andMe found that I carry an ‘C’ variant in CYP1A2 that makes it difficult for the enzyme to do its job. We C people therefore metabolize caffeine more slowly than do people who carry an ‘A’ variant in the same spot. (How much slower? It’s too hard for me figure out, but I think the answer is somewhere in this paper. Or maybe this one. If you can decipher these, please leave a comment and enlighten me!)
A big study from 2006 found that C people under age 60 who drink two to three cups of coffee a day have a 1.87 times higher risk of having a non-fatal heart attack than A people do. C people who drink four or more cups a day (like me) have a 3.47 times higher risk.
These were the numbers swimming through my pounding head on Friday morning as I thought about a life without coffee. It was depressing. It occurred to me that I might be feeling like any other addict who knows, deep down, that a drug is killing me, but is unable or unwilling to give it up. But I also knew that I’m a neurotic worrywart.
A couple of hours later, I left my apartment to go to the dermatologist. It was my first time. Despite my family history of skin cancer, I had never really considered seeing one before getting the 23andMe test results. My doctor was lovely, and after a nice chat and thorough examination of my many, many moles, she gave me a clean bill of skin health and told me to come back in a year. I walked out of the office into pouring rain and barely noticed. My headache and chest pains had vanished. I got home, went straight to the kitchen, turned on the water and took out the French press.
I enjoyed a large cup, but that was it for the day. Everything in moderation, right?
Image courtesy of vissago, via Flickr