There are a variety of common, everyday habits and lifestyle tendencies that are scientifically proven to reduce lifespan-an MIT professor explains.

Question: What are the five worst things people can do in terms of aging?

Leonard Guarente: Well, I would say smoking would be one. Eating to caloric excess would be another. Being sedentary, not moving around, not exercising would be a third. We didn't talk about exercise, but there's ample evidence that exercise is beneficial. I think the other thing is what we were just talking about: your attitude and mindset. I think, you know, being focused on negativity would be a fourth. And I think the last one, which again would be more or less in this lifestyle area, would be stress level, level of stress that you maintain on a day-to-day basis. So I believe, and others believe, in something called hormesis. What hormesis means is that a lot of stress is a bad thing, but no stress is also a bad thing. And the optimum is something in the middle, so that you're engaged on a daily basis, you're revved up, you're functioning, okay, but you feel as though you're in control. And I think finding that balance, that hormesis, is probably very important in maintaining mental health and physical health. So that would be my big five.

 Well, I mean I think a low-calorie diet is probably a good thing. I think in humans we don't know; there's no data on what a low-calorie diet does in terms of diseases and longevity, as I said before. By analogy to rodents, you would think it would be a good thing. On the other hand, if it made you really miserable to eat 1,000 calories a day -- and people who are on that diet tend to be cold; they tend to have very low sex drive; they tend to in some cases be irritable -- and so if you're not happy, then that gets back to what we were saying earlier. You may be undoing some of the good that that diet would otherwise produce. So my feeling is to live sensibly.

I mean, a word of advice that I think is good -- it's hard to follow -- but I think what everybody should do, if everybody could do this, it's the best you can do right now -- is decide what is your perfect weight, body weight. What's perfect for you? And I think what most people do is rifle through the past and decide on when they were most happy with themselves -- and do everything possible to get to that weight and keep to it. And I think that that would necessarily make you healthier, most people healthier than they are now. Beyond that, I, you know, I take a vitamin supplement, a general supplement. I take Vitamin D. I do not take resveratrol, though a lot of people do. And the reason is, I'm waiting for a 100 percent pure and reliable source of it, and then I will take it. And I drink a little wine, and all the data says, again, there's an optimum. I think the data says that too much wine is bad, but no wine is not optimum. The right amount of wine is optimum.

Recorded on November 9, 2009