You research telomeres. What's the CliffsNotes version on why they are so important?
The chromosomes are where all our genetic material is packaged, in the form of DNA. Telomeres are very special caps at the ends of each chromosome that protect against deterioration.
The protective end deteriorates?
It wears down and has to build back up again. My colleagues and I discovered an enzyme, telomerase, that adds back DNA to the ends as they wear down.
And that's a good thing?
We've found that the better your telomeres are protected, the less chance you'll have of getting any of the big diseases. A beautiful study came out recently showing that if your genes urge your telomeres to be better maintained, your chances of getting Alzheimer's disease will be somewhat low. It's not 100 percent protection, but it's an underlying factor.
What can a person do to stop the erosion?
Exercise, do really interesting activities, don't have long-term chronic stress.
You've done a lot of studies on stress. What did you learn?
We've studied moms of children who were chronically ill and postmenopausal women who were taking care of a family member. In both groups, the worse the stress was — and the longer they felt it — the more their telomeres wore down.
Is there a key to effective exercise?
A big study categorized people: Do you do vigorous exercise? Do you do moderate exercise? Do you cycle or walk to work? Do you do weight-bearing exercises? It was simply additive; the more types of exercise you did, the better the results.
So what do you do?
I use the gym and an elliptical trainer at home. I was very cunning. I put the elliptical in front of the TV so I could watch episodes of The Big Bang Theory. And I'm happy to tell you: I now walk to work.
What have you learned about meditation and aging?
It's a fairly small number of studies so far, but they've all indicated that telomere maintenance improved. We knew that when the stress got worse, the telomeres got worse. The question was: Could you get better, with real improvements? It was good to see that it extended not just in the bad direction but also in the good direction.
How has your work changed your thinking about aging?
Well, it's all about the quality of your life. I used to think that aging was an inevitable march toward getting these debilitating diseases, but it doesn't have to happen. One idea of aging was that you might like to take it easier and easier, but what I've found personally is that what I really needed was purpose , which is actually why I took this job at the Salk Institute.
What's the big unanswered question that's driving you now?
People come up to me and say, "Stress is having terrible effects on my telomeres." They're using the word personally. But could it be extended to a lens through which to look at broader societal issues? That's the interesting question.
Hugh Delehanty is a freelance journalist and former editor in chief with AARP Publications.