Less than perfect
Another deterrent to making their computer program available to the public is that currently its accuracy rate is only 77 percent. That’s a good score for a genetic model and shows that longevity does “have a very strong genetic basis,” says Sebastiani. But the 23 percent error rate also means that other genes, the environment and lady luck are having their say as well.
While only about 0.02 percent, or 1 in 6,000 people, live to age 100 in industrialized countries, about 15 percent of the study’s control group has the genetic signature of a centenarian, the team reports. This may suggest that more people than we thought “have the potential, at least genetically, to survive to an exceptional age,” they report.
Do the genes cause longevity?
The Boston team used statistical tools to tease out genetic variants common to long-lived people, but now the task is to see which of these variants may cause exceptional longevity, says geneticist S. Michal Jazwinski, director of the Tulane Center for Aging at the Tulane University Health Sciences Center in New Orleans.
His team’s approach is to study a few genes at a time that are known to have anti-aging functions. Using a “candidate gene approach,” he and his colleagues found three genes that interact to reduce age-related changes at the cellular level, they report in a paper published online June 21 in Aging Cell. Among study participants, the frequency of this three-gene combination continuously increased with age, including after age 100, Jazwinski reports.
Paving your own way to a long life
As we continue our wait for the fountain, or pill, of long life, what’s a person to do? Studies of long-lived groups, such as the Seventh Day Adventists, show that exercising, abstaining from smoking and heavy alcohol use, eating a healthy diet, staying engaged with others, and enjoying productive pursuits are all associated with a long and prosperous life.
Or you can listen to one of those lucky 1 in 7 million individuals. “I never had children—that’s the reason I reached 111!” says Bernice Madigan, laughing. She will celebrate her 111th birthday with a crowd on July 24 at her niece’s farm, where she now lives. She takes a daily walk, keeps her weight down and has always loved playing piano and reading. She also had a job for the federal government and a husband whom she loved. But really, she says, “I have no idea how I reached this age. I just feel normal, that’s all.”
Tina Adler is a freelance writer who covers health, science and the environment.