Only about 1 in 6,000, or about 15% of the population, will live past 100. Most centenarians attribute their longevity to clean living, but researchers have found that they also have good genes, the kind that may actually cancel out the risks caused by disease-linked genes such as those for dementia and high blood pressure.
"It's an important stepping stone towards helping us understand the complex genetic and environmental factors that lead to a healthy, long life," said Winifred Rossi, deputy director of the National Institute on Aging's Division of Geriatrics and Clinical Gerontology, which funded the study.
Tom Perls, director of the New England Centenarian Study at Boston Medical Center, used a statistical method called genome-wide association to look at gene variants from more than 1,000 people who have lived beyond 100. They found 150 markers, grouped into 19 different profiles, which were either associated with many years of life or with late onset of debilitating disease.
They also found that 40% of the “super-centenarians”, or those who live to be at least 110, had three genetic signatures in common.
Using the markers, they were able to create a computer model able to predict the likelihood of living past 100 with 77% accuracy. "Seventy-seven percent is a very high accuracy for a genetic model, which means that the traits that we are looking at have a very strong genetic base," said Paola Sebastiani, a professor of biostatistics at the Boston University School of Public Health and lead author of the study.
Exactly what role the markers play remains unclear. Some reside within known genes, but many do not. Some appear to be genetic editors, affecting how and when other genes are activated. Further study is planned.
The researchers also stress that having good genes is not an automatic free pass to a long life. Perls says that most humans have genetic variations to “allow us to get to 88, which is eight years longer than average.” To achieve this, you must live a healthy lifestyle with exercise, weight management, nutritious diet, and avoidance of tobacco.
The study “Genetic Signatures of Exceptional Longevity in Humans” is published in the 1 July online issue of Science.