Q. I just turned 77 and I was wondering what my chances are of getting to 100. What do you think?

If you want some idea about your life expectancy, you can check out a table provided by the United States Social Security Administration.

The table indicates that someone who is 77 can expect to live another 11.26 years. Of course, if you are a "healthy geezer," you can do better than the average.

If you want to reach 100, you should know that there are three major characteristics that seem to enable you to become a centenarian.

First, be a female.

Second, have fabulous genes.

Third, maintain an optimistic outlook.

About 85 percent of centenarians are women. Scientists still don't know why women tend to outlive men.

Researchers are increasingly finding evidence that genes play an important role in pushing lifespan beyond 90. Longevity is known to run in families, which suggests that genes are responsible for long lives.

There have been many studies that suggest that optimistic people live longer, and are less likely to develop diseases. One study that included more than 1,000 men and women found that those who described themselves as optimistic had a 55 percent lower risk of death than pessimists.

Lynn Peters Adler, who runs the National Centenarian Awareness Project, cites the following attributes common to centenarians:

A positive but realistic attitude;

A love of life;

A sense of humor;

Spirituality;

Courage; and

An ability to handle losses.

"Centenarians are not quitters," she says.

Carmel B. Dyer, director of the Division of Geriatric and Palliative Medicine at the University of Texas Medical School, says she has seen dramatic effects from a positive outlook. Dyer adds:

"I've been practicing geriatric medicine for almost 20 years, and I've noticed that my patients make the best of everything. When there are lemons, they make lemonade. I think if you're more optimistic, you're going to feel better."

According to the U.S. Census Bureau, America's population of centenarians, already the largest in the world, has doubled in the past 20 years to around 72,000. The bureau's lowest estimate for 2050 is 265,000 centenarians. Its highest projection puts the number at 4.2 million.

"They have been the fastest-growing segment of our population in terms of age," says Thomas Perls, director of the New England Centenarian Study at Boston University.

Perls says the rise in 100-year-olds is attributed largely to better medical care. He said centenarians also have good genes and have made common-sense health decisions, such as not smoking and keeping their weight down.

However, according to researchers at Albert Einstein College of Medicine, New York, regular exercise, drinking in moderation and watching what you eat makes no difference to your chances of reaching the century mark.

Researchers studied nearly 500 people between the ages of 95 and 109 and compared them with more than 3,000 others born during the same period. They found that those who lived long lives ate, drank and smoked just as much as those who hadn't lived as long. The centenarians also did just as little exercise and were as likely to be overweight as their long-gone counterparts.

Order "How to be a Healthy Geezer," a 218-page compilation of published "Healthy Geezer" columns, at: www.healthygeezer.com.

Have a question? Email: fred@healthy-geezer.com

All Rights Reserved

&Copy; 2012 Fred Cicetti