Scientists are studying how to battle ageing, and if you live to be 100, you fall into the special group being studied. What are the factors that lead to their longevity? Is it because they are immune to the diseases – heart problems, diabetes, arthritis, kidney failures and more, or is there some other factor? Scientists believe those who reach 100 have an anti-ageing secret that shields them against the effects of ageing because they have just as many genes that contribute to disease as those with an average life span.
However, another paper published by PLOS Genetics, researchers led by Stuart Kim, professor of developmental biology and genetics at Stanford University, has concluded differently. He found that cenetarians have fewer of the genes that contribute to major chronic diseases, which means they don’t experience as much disease of people who live shorter lives. They don’t possess any anti-ageing genes.
Kim’s team came to the conclusion after conducting a novel type of genetic analysis. Most attempts to look for genes related to ageing and compare the genomes of ceneterians and one’s with average life spans, picking out the regions where the maps differ. Kim says, “Because you search through hundreds of thousands, and now millions of variants, there is a lot of noise. So it makes it difficult to see the signal amidst all the noise.”
Kim made the assumption that disease genes can reduce the chances of someone reaching their 100’s and focussed on known disease-causing genes in his analysis. “With that, we can make better guesses about what is really bad for becoming a centenarian,” he says.
Five major regions of interest for longevity were found. Four are familiar. They involve the gene connected to Alzheimer’s, an area involved with heart disease, the genes responsible for the A-B-O blood type and the immune system’s HLA region that needs to be matched for organ transplants to avoid rejection.
The fifth region was one which had not been linked to longevity before and not much is known how it contributes to longevity.
“It seems intuitively obvious, that avoiding disease is part of the strategy of becoming a centenarian,” says Kim. “But there is a really, really strong dogma in the field that there was no depletion of disease genes in centenarians, and that all of their survival benefit was coming from protection from anti-ageing genes. I think they were wrong.”
“We found that, at least in part, they live longer because they don’t get sick,” he says. Although he does admit that they may have added benefits from other ant-ageing factors that haven’t been discovered yet.