How to Live to 100

Want to live to 100?

According to the Centers for Disease Control and Prevention, the average American lives about 78 years. But what if there were ways to extend your longevity?

There are!

On "The Early Show," CBS News Medical Correspondent Dr. Jennifer Ashton discussed ways to live -- and enjoy -- a century of life.

Special Section: Dr. Jennifer Ashton
Video Series: Dr. Ashton's Health and Wellness

Ashton said the U.S. is 49th in the world in terms of life expectancy. Macau is No. 1, according to the CIA Factbook. People in that country, located in the South China Sea, live about six years more than people in the U.S.

Why?

Ashton said, "We can do better. It's not only what they're doing there. It's what we're not doing here, or in some cases, what we are doing here. And the theory as to why we don't do so well compared to other parts of the world has to do with how we live. Higher rates of obesity, smoking, death from motor vehicle accidents, homicide, that all takes its toll. And then, of course, they tend to have a more active, outdoor lifestyle. And they do some of the things that we're going to talk about and hopefully, we can do some of them, too."

"Early Show" co-anchor Maggie Rodriguez said, "Probably they're more stress-free, too. I'm sure stress is a big contributor."

Ashton replied, "It can be. And we have a lot of stress here. But there's a lot of things that are in our control. Some things are not in our control."

Ashton discussed these "longevity boosters":

Marriage can enhance your life, based on age: "If you're already married, obviously, there's nothing you can do about this. But men tend to do better in marriage, if you will, than women. In other words, some studies have found that men, if their wives are younger, as it happens in my household, tend to live a little longer. The cougars, the women who marry younger men, don't do as well. Their risk of death goes up by 20 percent."

Why?

Ashton said, "It's really unclear. This is one of those things that's an association. Maybe for men, if your wife is a little younger you tend to be more active, and have a healthier lifestyle."

Light drinking: "Very controversial. This needs to be individualized. One study has shown that people who drink less than one ounce a day extend their life span by two years. Again, wine and other forms of alcohol all seem to be equally protective. But it's a very individualized. It's not good for everyone."

Higher education: "Ironically, a study done at Harvard shows that people who have 12 or more years of higher education live around 80 years, which is significant, in thinking there that they might have less high risk behaviors such as smoking. Again, ironically, done at Harvard. But again, another reason to stay in school."