DNA Test Tells a Fat Man That He Can't Hide Behind His Mom's Genes
Tuesday, February 24, 2009
I'm fat. And while I don't think of myself as particularly vain, I avoid looking at my profile in the mirror: The protruding belly is dismaying. But head-on, my body looks more like the image in my mind -- of the slightly pudgy 5-7, 160-pound college student who played basketball three times a week.
I've always taken solace in the fact that my mother was heavy, as was her mother. "It's not my fault," I'd tell myself. "It's in the genes."
But I'm over 40 now and closer to 210 pounds, and my long-term health is starting to concern me. I'm still active, though I gave up basketball after I tore up my knee a few years ago. I have a border collie who demands a busy lifestyle. I like to hike and garden. And I want to be able to continue to do those things well into my autumn years.
I've already taken two steps toward that goal: Regular exercise keeps my energy up and decreases the aches and pains that crept up on me in the past decade; and whole grains such as brown rice and whole-wheat bread seem to prevent the afternoon energy crash that used to wipe me out and send me on a desperate hunt for a sugary snack.
Still, it seems like there should be more I can do. So I was excited when I heard that such companies as 23andMe and Navigenics offer genetic screening services to predict your odds of developing various diseases and medical conditions.
If I were to find out, for example, that I am at heightened risk for, say, adult-onset diabetes, then I should keep an even closer watch on my sugar intake. Or if I learned that my genes predispose me to arthritis, maybe I should take supplements in the hope they might help stave it off.
What's more, I secretly hoped that genetic screening might provide some scientific evidence to back my belief that I could blame my weight on my genes.
So I was pleased when Navigenics offered me a complimentary test, one of the occasional perks of being a freelance writer. (The service usually costs about $2,500.) The company sent me a spit kit with instructions on how to collect a sample of saliva and a prepaid overnight envelope to send it back. My saliva would allow the company to identify markers in my DNA that researchers think may be associated with particular conditions.
A few weeks later, my results were ready. From a laptop in my home office, I signed in and perused the risk estimates for a variety of conditions, including macular degeneration, lupus, Alzheimer's disease, stomach cancer and restless legs syndrome.
Navigenics told me I was indeed at heightened risk for diabetes. But only one result made a strong impression: It informed me that the average person has a 34 percent chance of becoming obese. Based on the company's analysis, my risk was just 25 percent.
"Oh, man!" I shouted. "I can't blame my genes anymore!" When my wife heard, she laughed. And in truth, I suppose I was half-joking.
But I was half-serious, too. I've always known I could make choices that should affect my weight, but they got me only so far. A few years ago, I dropped from 190 pounds to 170 by counting calories. After a few months I stopped counting, and my weight stabilized for about six months. But then I took an overseas trip, and when I returned, it began to creep upward. I eventually ballooned to about 210, where I've remained since.