Here's a story about growing older that has nothing to do with wrinkles or plastic surgery -- it's about how physical activity may influence aging. As a contrast to the article in last week's New York Times titled "Does Exercise Really Keep Us Healthy," a study reported on here by HealthDay News found that among 2,401 white twins, the people who were more physically active had longer leukocyte telomeres than those of their couch-potato peers.
What does that mean, exactly? Leukocyte telomeres are sequences at the end of white blood cells that, as the article explains, shorten over time and may serve as markers of a person's biological age. The scientists doing the study reported that the most active individuals had telomeres that were "up to 10 years younger, on average."
That's fine and good -- and does suggest that exercise is indeed beneficial. But there are still potential confounding variables -- for example, are the active people's telomeres longer because they exercise? Or do they exercise more because they have longer telomeres? (I'd bet that most people would have more energy if they were 10 years younger than their current age.) Also, as with any uncontrolled trial, especially one that relies on participants' own reports of their activity (rather than activity monitored and measured by researchers to make sure the information is accurate), there is plenty of room for error, or for additional factors that could contribute to what scientists refer to as "residual confounding." Nonetheless, considering how good exercise can make you feel (even if actually motivating yourself off the couch is difficult), it certainly can't hurt. And if does turn out to help my telomeres? All the better.