Diet and exercise can certainly help you to live a long, healthy life, but that might not be the whole story.
- Scientists have found 150 genetic markers associated with longevity.
- Computer programs analyzed relevant genetic markers and picked out participants who were at least 100 years old.
- Longevity genes associated with disease-fighting and slow aging trumped predispositions for age-related disorders, such as Alzheimer's.
People who live to 100 share an array of genes that boost immunity, slow aging and resist disease, a finding that may lead to new, personalized treatments for staying healthier longer.
A study comparing about 1,000 centenarians with random individuals showed that genes associated with warding off disease and boosting longevity were key to the senior citizens' staying power, even overriding genetic predispositions for age-related disorders such as Alzheimer's disease and cancer.
"This result, (which) is very surprising, suggests that what makes these people live a very long life is not a lack of genetic predisposition to diseases, but rather an enrichment of longevity-associated (genetics traits)," said Paola Sebastiani, professor of biostatistics at Boston University's School of Public Health.
"This analysis suggests that if you want to calculate the risk for a disease based on simply (genetic predispositions), your calculation may be incomplete if the overall genetic background is ignored," Sebastiani added.
Researchers found 150 genetic markers that pegged 77 percent of the study's centenarians, an accurate enough result to prompt the creation of a free web-based computer program to assess the relevant genetic markers of anyone who wants to know if he or she has the genetic potential for long life. The program is expected to be posted on the New England Centenarian Study website next week, Sebastiani said.
Anyone not genetically blessed shouldn't give up hope for a long and healthy life. The study showed 23 percent of the participants lived 100 years or longer despite less-than-stellar genetics.
In Western industrialized countries, reaching your 100th birthday is rare, with about 1 in 6,000 people living to 100. Only one in 7 million live 110 years. The average lifespan for an American is 78 years, according to the Centers for Disease Control.
Researchers found that the genetic markers for longevity are distributed throughout the 23 chromosome pairs that comprise the human genome, confirming suspicions that long lifespan rests on a complex interplay of genetics involving different biological processes. Environmental factors and lifestyle choices, such as not smoking and maintaining a healthy weight, also play key roles in how long a person lives, the scientists said.
"I look at the complexity of this puzzle and feel very strongly that this will not lead to treatments that will get a lot of people to become centenarians, but rather to make a dent in the onset of age-related diseases like Alzheimer's for example," said study director Tom Perls, an associate professor of medicine and geriatrics at Boston Medical Center.
The research appears in this week's issue of Science