MONDAY, June 10, 2002 (HealthDayNews) -- Consider yourself lucky if you've got a really old person in the family.
The brothers and sisters of people who live past 100 have a lower risk of dying than the average person during every decade of their life -- not just in old age, new research shows.
The findings bolster the theory that what's known as "exceptional" longevity runs in families, says Dr. Thomas Perls, director of the New England Centenarian Study in Boston and lead author of the study.
"From my point of view, it intimates there is something scientifically special about these individuals that they can maintain half the mortality risk of the general population all the way into old age," says Perls, an associate professor of medicine at Boston University Medical School.
The study appears in the June 11 issue of the Proceedings of the National Academy of Sciences.
Perls and his colleagues analyzed mortality data from 444 families who had at least one family member who reached the century mark. They found the sisters of centenarians had about half the risk of dying at any given age compared to the national average. Brothers of centenarians had similarly low mortality rates, except during the teen-age years and young adulthood.
The low mortality rate means siblings of centenarians also have a greater chance of reaching age 100, Perls says. Brothers of centenarians were 17 times more likely to reach age 100, and sisters were eight times more likely to reach 100 than the general population, according to the study.
"What this implies is that they are either somehow more resistant to diseases -- or if they get them they are less likely to die from them, whether they are in young adulthood or elderly," says Dr. Evan Hadley, associate director of geriatrics and clinical gerontology for the National Institute on Aging in Bethesda, Md. "They carry this protection with them throughout their life."
Studies such as this one stoke the great debate among researchers on aging about the influences of genetics vs. lifestyle and environmental factors on life span and health.
This study lends credence to the idea that good genes are hugely important in life span, Hadley says.
Still, plenty of other research shows the influence of environmental factors -- things like diet, access to medical care, education, and smoking. These, too, are factors that family members may have in common.
"Families share a lot of other things besides genes," Hadley says.
The promise of a study such as this one is the potential of identifying the gene that contributes to longevity, and then passing along its good qualities to the rest of the population through new treatments or drugs.
For example, last year Perl and his colleagues found a region on chromosome 4 that is "highly suggestive" of genetic predisposition to exceptional longevity. And a study by University of Utah researchers found that brothers, sisters and other first-degree relatives of the long-lived had a greater chance of living extended lives than cousins and more distant relatives.
This leads researchers to conclude that a small number of genes might influence exceptional longevity.
"If you found out what those genes did, whether they affected the metabolism of sugar or the level of a hormone, then you could come up with a drug or a hormonal treatment or a change in lifestyle that would mimic what the gene did," Hadley says.
Unfortunately, there is likely no simple answer.
Researchers largely agree that exceptional longevity is probably due to a combination of factors: an absence of genes that predispose you to various diseases; longevity-enabling genes or genes that help you age more slowly; and a healthy lifestyle.
"This includes not smoking, not being obese, exercising and doing strength training, taking an aspirin every day, and maybe drinking a little bit of alcohol," Hadley says.
"We've all heard of centenarians who smoke two packs a day. These are probably people with the absolute best genes. Most of us don't have that so we have to be better about our health behavior," he says.
What To Do
The New England Centenarian Study is looking for people in their late 90s or older than 100 to include in their research into the secrets of long life.
The National Council on Aging has information and links to a variety of Web sites that can offer help with aging, from coping with Alzheimer's to a senior job bank.
