What’s the secret to living longer? Eating lots of superfoods? Exercising regularly? Meditation? Many ideas have been thrown around in the past, and while nobody seems to really know, many scientists believe that the answer could lie within our genes. That’s for several main reasons. First, studies of twins have suggested that up to a third of the variation in human lifespan is determined by genetic factors. Second, close relatives of centenarians (those who live to be over 100) also tend to live longer than the average person. And finally, studies comparing centenarians with controls didn’t find significant differences between their lifestyle choices, such as smoking and drinking alcohol.
A few studies have delved into the genomes of centenarians with the hope of identifying some of these predicted genetic secrets to longevity, whatever they may be. Although certain variations in their genetic code often popped up, these were also found to be relatively common in the general population. Still convinced that there must be something that these studies missed, scientists from Stanford University decided to scrutinize the DNA of an even more remarkable bunch of people: supercentenarians.
Supercentenarians are people that live to 110 years or more, making them the world’s oldest people. Currently, there are 74 of them living across the globe, 22 of whom reside in the US. 16 women and 1 man were enrolled into the Stanford study, ranging in age from 110 to 116. Despite their age, they were in pretty good physical and cognitive shape and had escaped many age-related conditions such as cardiovascular disease or stroke. One even continued to practice as a doctor until the age of 103.
The researchers hoped that by scouring their genomes, they might be able to figure out how these individuals “slow down the aging clock,” according to study author Stuart Kim. Eventually, it may be possible to use this information to create therapies that delay aging or extend life.
For the study, which has been published in PLOS ONE, the team compared the genomes of the 17 supercentenarians with 34 controls between the ages of 21 to 79. Much to their surprise, they didn’t find any gene variants that seemed to be associated with extreme longevity. In fact, one individual actually had a variant associated with a rare heart muscle disease that can lead to sudden death through irregular heart rhythms.
While this investigation may not have revealed any genetic clues to living longer, the researchers still believe that there are differences waiting to be discovered, so they have made the DNA sequences available to assist future studies. It’s also possible that the sample size was too small to detect differences, or that the differences themselves were too small to be picked up by traditional methods. Therefore, the researchers are extending their work by examining more supercentenarians and using more complex analyses.
[Via PLOS ONE, New Scientist and Live Science]
