Friday, Jan. 11, 2013
Jiroemon Kimura, who became the world's oldest man on record last week, can thank a combination of luck early in life and, later, good genes for surviving seven decades longer than most of his peers.
Kimura, a former postman who is 115 years and 258 days old and still greets visitors with a warm smile, dodged childhood killers such as tuberculosis and pneumonia that kept life expectancy in Japan to 44 years around the time he was born, in 1897.
As an adult living in the town of Kyotango, Kyoto Prefecture, he had no major illnesses, his granddaughter-in-law, Eiko Kimura, said in an interview.
He continued to follow sumo on television and read two newspapers a day until the last few years, she said.
As Kimura ages, his DNA is giving him an edge. Scientists say specific genes that protect against heart disease, cancer and other ailments of old age foster longevity. Knowing the biological mechanisms involved may provide clues to counter a rising tide of noncommunicable diseases predicted to cost the global economy $47 trillion over the next 20 years.
"Getting the right combination is like winning the lottery," said Thomas Perls, director of the New England Centenarian Study at Boston University. Some of Kimura's genes "are likely protective against damaging cellular processes that contribute to aging, and even protective against genetic variants that may not be good for him."
Genetic factors may account for about 30 percent of a person's chances of living to their late 80s, with behavior and the environment contributing the remainder, according to Perls. The reverse is true in people who survive to 105 years, when genetic influences become more significant, he said.
As people age, cells accumulate potentially harmful mutations as mechanisms to repair defective DNA become less efficient, said Dario Alessi, a cell biologist at the University of Dundee in Scotland. Kimura may have no major disease-causing mutations and/or a superior ability to repair defective genes, he said.
Scientists are making conclusions about Kimura based on the medical history of the centenarian and his relatives they haven't studied his genome.
Read more from the original source:
Oldest man ever won genetic jackpot