Scientists have tried for a long time to find out why do some people live much longer than they were expected. One of the big questions is if this depends on their lifestyle or does it have anything to do with internal reasons, inscribed in their DNA?
Until now, scientists would bet their money on lifestyle as being the secret of longevity, after many studies have shown that these people are just as predisposed to disease as any other person and also similar genes.
A paper led by Stanford University professor of developmental biology and genetcs Stuart Kim and published recently in PLOS Genetics comes to contradict those beliefs. Kim argues that people living over a century have fewer genes responsible for important chronic diseases.
The team of researchers led by Kim developed a new type of genetic analysis. Traditional analyses was comparing the genomes of people living over 100 years to those of people wih what are considered to be average life spans and then they were looking more closely at those regions of the maps where they found the biggest differences.
But Kim claims that there is a lot of misleading information in the genomes, since there are millions of variants that need to be analysed. Instead of doing such a Sisyphus work, Kim started from the assumption that the genes which could reduce someone’s chances of living a century were genes of chronic diseases.
Following these assumptions, Kim’s team focused its analyze on the genes known to be causing disease. Five major areas have been pointed out as being responsible for longevity. One of them is the Alzheimer’s gene, the second is connected to heart disease, the third is the one that gives the O blood type, the forth is related to the immune system’s HLA and the fifth is connected to neurological diseases.
Four of them were already known to influence the life span. For example the gene which causes Alzheimer is responsible for a shorter life span while the gene responsible for the O blood type is thought to give a longer life span.
The only area that has never been associated with the life span before was that related to neurological diseases.
Unfortunately, Kim admits that he doesn’t know yet how it might influence longevity so further research is needed. But at least future researches will have a starting point that was never revealed before.
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