How long you live has a lot to do with your
environment and lifestyle, but exceptional longevity may have even more to do
with your genes. For the first time, researchers have identified a genetic
recipe that accurately predicts who may live to 100 and beyond. Scientists led
by Dr. Thomas Perls at the Boston University School of Medicine conducted a
genetic analysis of more than 1,000 centenarians and their matched controls and
found 150 genetic variants-or bits of DNA-that differed between the two groups.
These variants identified people who lived to a very old age (past 100)
with 77% accuracy, researchers found.
Further analysis
identified 19 distinct genetic profiles associated with extremely long life; 90%
of participants who lived to 100 possessed at least one of the signature genetic
clusters. Each profile appeared to confer a different tendency to develop common
age-related chronic diseases, such as heart disease or brain disorder. "We
realize this is a complex genetic puzzle," Perls said. "We’re quite a ways away
still in understanding how the integration of these genes-not just with
themselves but with environmental factors-are playing a role in this longevity
puzzle."
Perls has studied many factors that contribute to
longevity, and he is the first to acknowledge that living longer isn’t likely to
be simply a matter of genes. His previous work has shown, for example, that
among most elderly people who live into their 70s and 80s, about 70% of their
longevity can be ascribed to environmental factors such as not smoking; eating a
healthy, low-fat, low-calorie diet; and remaining socially engaged and
intellectually active throughout life.
Still, it seems clear
that those who live to an exceptionally ripe old age are benefiting from a
special DNA boost. In fact, Perls believes that the older a person gets, the
more likely it is that his or her genes are contributing to those extended
years. His current genetic findings support that theory: the 19 most common
genetic profiles that distinguished the exceptionally long-lived appear to be
correlated with lower incidence of certain diseases. For example, some profiles
were associated with lower rates of high blood pressure and diabetes, while
another was linked to a reduced risk of brain disorder.
Although most of us can’t expect to become centenarians, Peris is hoping that
his work will lead to better ways-perhaps through pharmaceutical interventions
based on the genetic clues to longevity-to help more of us live like
them. By analysing the genes of centenarians, scientists found that
A. environment and lifestyle contribute much to longevity.
B. centenarians’ genes are the same as other people.
C. many genetic variants may identify centenarians.
D. 19 genetic profiles of centenarians are different from others.