The oldest among us seem to have chosen their parents well. Researchers closing in on the impact of family versus lifestyle find most people who live to 100 or older share some helpful genes.
But don’t give up on diet and exercise just yet.
In an early step to understanding the pathways that lead to surviving into old age, researchers report in Thursday’s online edition of the journal Science that a study of centenarians found most had a number of genetic variations in common.
That doesn’t mean there’s a quick test to determine who will live long and who won’t – a healthy lifestyle and other factors are also significant, noted the team led by Paola Sebastiani and Thomas T. Perls of Boston University.
Nevertheless, Perls said the research might point the way to determining who will be vulnerable to specific diseases sooner, and there may be a possibility, down the road, to help guide therapy for them.
The team looked at the genomes of 1,055 Caucasians born between 1890 and 1910 and compared them with 1,267 people born later.
By studying genetic markers the researchers were able to predict with 77 percent accuracy which gene groups came from people over 100.
“Seventy-seven percent is very high accuracy for a genetic model,” said Sebastiani. “But 23 percent error rate also shows there is a lot that remains to be discovered.”
The centenarians could be fitted into 19 groups with different genetic signatures, they found.
Some genes correlate with longer survival, others delayed the onset of various age-related diseases such as dementia.
“The signatures show different paths of longevity,” Sebastiani said.
In general, the centenarians remained in good health longer than average, not developing diseases associated with old age until in their 90s, according to the study.
The researchers were surprised, Sebastiani said, that they found little difference between the centenarians and the control group in genetic variations that predispose people to certain illnesses.
“We found that what predisposes to a long life is not lack of disease associated variants, but the presence of protective variants,” she said at a briefing.
In addition, 40 percent of “super-centenarians” aged 110 and over had three specific genetic variants in common.
While this study, begun in 1995, focused on Caucasians, the researchers said they plan to extend it to other groups, including studying Japan, which has large numbers of elderly.