1. Don’t Oversleep

Here’s a reason not to hit the snooze button anymore: Sleeping too much can reduce life expectancy, according to a February 2002 study in the Archives of General Psychiatry. The study found that people who sleep more than eight hours per night had a significantly higher death rate than normal. But late-night-party-goers shouldn’t rejoice: researches say that sleeping less than four hours also increases death rates. People who sleep between six and seven hours per night were shown to live the longest.

2. Be Optimistic

Researchers at the Mayo Clinic in Rochester, Minn., found that optimistic people had a 50% decreased risk of early death compared with those who leaned more toward pessimism. The results, published in the August 2002 issue of Mayo Clinic Proceedings, make sense: Those with a positive outlook on life are probably less stressed, better equipped to deal with adversity and, consequently, healthier. Optimists also tend to have lower blood pressure than pessimists, which, again, is most likely related to how positive thinkers respond to stress.

3. Have More Sex

No complaints here. There’s decent evidence that sex helps keep us healthy, and thus increases longevity. But according to researchers, it’s not necessarily an actual biological response generated by sex that makes us live longer. What’s more likely is that having intimate sex means you are less stressed, happier and better rested–all factors that can lower blood pressure and protect against stroke and heart disease. A study published in the April 2004 Journal of the American Medical Association found that “high ejaculation frequency was related to decreased risk of total prostate cancer.”

4. Get a Pet

People who own pets, especially dogs, have been shown to be less stressed and require fewer visits to their physicians than non-owners. Survival rates for heart-attack victims who had a pet have been shown to be 12% longer than for those who did not have one, according to one of the first studies dealing with the impact pets can have on our health, led by researcher Erica Friedmann. Pet owners have also been shown to have lower blood pressure. The reasons are most likely related to an array of psychological factors, such as the facts that owning a pet decreases loneliness and depression, encourages laughter and nurturing, and stimulates exercise.

5. Get a VAP

It’s estimated that about half of the people with heart disease–the No. 1 killer in the U.S.–have normal cholesterol levels, which raises serious doubt about the ability of traditional cholesterol tests to detect risk. But more advanced cholesterol tests, like the VAP test, made by the Birmingham, Ala.-based lab Atherotech, may remedy that. VAP measures important metrics that traditional tests miss. Regular tests only detect half of the people with heart disease, while the VAP has been shown to detect 90% of heart disease patients. That’s important because lipid abnormalities can most often be rectified with medication and dietary changes. And the sooner you start making changes, the better.

6. Be Rich

According to the National Center for Health Statistics, 24% of Americans whose family income is less than $20,000 are “limited” by chronic disease, whereas only 6% of people with an income of $75,000 or more have this problem. In general, population groups that suffer the worst health have the highest poverty rates and the least education. One possible explanation: Higher incomes permit access to better food and housing, safer neighborhoods and increased medical care. Higher incomes also increase the opportunity to engage in health-promoting behaviors. Of course, being a chief executive certainly exposes you to a high level of stress that can decrease life expectancy. But according to the data, striving to be financially comfortable is a good goal for aspiring centenarians.

7. Stop Smoking

To say that smoking is bad for your health is, of course, not revelatory. But it still cannot be denied that quitting can significantly improve your prospects for a long life. Middle-aged men who are long-term, heavy smokers face twice the risk of developing more aggressive forms of prostate cancer than men who have never smoked, according to findings that appeared in the July 2003 issue of Cancer Epidemiology, Biomarkers and Prevention. According to a recent study in the Archives of Gerontology and Geriatrics, cigarette smoking has been clearly linked to the most common causes of death in the elderly.

8. Chill Out

A study led by the Johns Hopkins University School of Medicine in 2002 found that men classified as having the highest level of anger in response to stress were over three times more likely to develop premature heart disease than men who reported lower anger responses. They were also over six times more likely to have a heart attack by the age of 55. One possible explanation is the correlation between anger and high blood pressure, a condition that commonly develops in highly stressed individuals. The lesson is simple: Try as much as you can to let unavoidable, everyday stresses roll off your shoulders.

9. Eat Your Antioxidants

Antioxidants, substances that are found in foods ranging from cinnamon to blueberries, can scavenge free radicals, compounds whose unstable chemical nature accelerates the effect of aging on our cells. Until these excess free radicals are quenched by antioxidant molecules, cellular damage accumulates. This contributes to an array of degenerative diseases, including atherosclerosis, Alzheimer’s and cancer. Research shows that certain types of beans (kidney, pinto, black) are among the best sources of antioxidants, while blueberries and other berries follow close behind.

10. Marry Well

While the phrase “marry well” is typically used to describe people who marry someone rich, we are talking about something entirely different: genetics. Apparently, longevity genes can be inherited. According to a February 2005 study in Mechanisms of Aging and Development, exceptional longevity and healthy aging is an inherited phenotype across three generations. So, for the single people out there, pick a spouse whose grandparents are still alive. This won’t make you live longer, but it might help your children.

11. Exercise

Get up and start moving. Not only does exercise help us maintain our weight, it improves our cardiovascular health, strengthens the bones and increases endorphins in the body–hormones that give us energy, make us happier and help ward off stress and disease. “If you don’t use it, you lose it,” says Dr. Merl Myerson, director of cardiovascular prevention at St. Luke’s/Roosevelt Hospital in Manhattan. “We find that active people will do better, live longer.”

12. Laugh a Little

Laughter reduces levels of stress hormones like adrenaline and cortisol. It also releases endorphins that work as pain killers and gives your blood circulation a boost. Not to mention it relaxes blood vessels and keeps a person from being angry–a significant predictor of heart disease. “The higher you score on anger and hostility, the greater the likely hood you’ll have a heart attack,” says Dr. David Fein, medical director at Princeton Longevity Center in New Jersey.

13. Lose Weight

For people who are overweight or obese, life is a ticking time bomb. They have increased risk of heart disease and several types of cancer, along with higher risk of developing Type 2 diabetes–a condition that is becoming an epidemic in the U.S. “The real way to lose weight is to cut back on food intake,” says Dr. David Fein, Medical Director at Princeton Longevity Center in New Jersey. “People are under the impression that they can exercise weight off, but exercise is a means to maintain weight.

14. Manage Stress

Everyone has stress to a certain degree, but not everyone knows how to manage it. The key is to recognize what the big factors are in your life and how to mitigate them. Constant stress produces high levels of cortisol, which has been shown to impair cognitive functioning and weaken the immune system. “I think stress kills more people than just about anything else,” says Dr. David Fein, medical Director at Princeton Longevity Center in New Jersey.

15. Meditate

According to Dr. Woodson Merrell of Beth Israel Hospital in New York City, the most powerful healing tool for stress and prolonged life is meditation. It clears the mind of thought and lets a person concentrate on tranquility. Fifteen minutes of meditation has been shown to produce a much more relaxed state of mind than one hour of the deepest sleep. Even starting the day with just two minutes of meditation can be beneficial. Sit with your spine erect and try to quiet your thoughts; it may help to concentrate on one word.