Secret of extreme old age remains secret

WASHINGTON—How do some people live past 110 years old? Is it superior genes, clean living, good luck or some combination of those?

Scientists studying these “supercentenarians” said on Wednesday they had sequenced the genomes of 17 people ages 110 to 116 to try to determine whether they possess genetic traits that may account for their membership

in this exclusive club that worldwide includes only 74 individuals, nearly all women.

“This marks the beginning of the search for key genes for extreme longevity,” said Stuart Kim, a professor of developmental biology and genetics at Stanford University whose study was published in the scientific journal PLOS ONE.

The answer was not so simple. The study did not identify a common genetic characteristic in them, and the findings underscored the idea that living to extreme old age may involve lots of factors, the researchers said.

The US scientists found no genetic secrets shared among the 17 supercentenarians.

“From this small sample size, the researchers were unable to find rare protein-altering variants significantly associated with extreme longevity compared to control genomes,” said the study.

People who live to age 100 and beyond are far less likely to get cancer—a 19-percent lifetime incidence compared to 49 percent in the general population—according to background information in the article.

Those who live more than a century also have lower rates of cardiovascular disease and stroke than controls.

74 alive worldwide

There are 74 supercentenarians alive worldwide, and 22 live in the United States.

The research involved 16 women and one man, all of whom lived in the United States. Fifteen were white, with one black and one Hispanic. All have died since the study began.

The 17 people had lived to age 110 and older.

Their average age at death was 112, and the longest living member of the group lived to age 116.

Fourteen had European ancestry; two were Hispanic and one was African-American.

Different clock

“Our hope was that we would find a longevity gene,” Kim said. “We were pretty disappointed.”

Kim believes there is a genetic underpinning to extreme longevity but it probably is not as simple as a single gene mutation that slows the aging process in certain people.

“These supercentenarians have a different clock where they are staying really highly functional for a long time. We wanted to know what they had. It’s pretty clearly genetic,” said Kim, who collaborated with Stephen Coles of the Gerontology Research Group and other researchers.

“The results indicate that the genetic effect must be complex. It must be many genes, or different genes in each supercentenarian, that gives them the edge to live an extremely long time,” Kim added.

Secret: Sushi and sleep

Kim said the 17 supercentenarians did not report obvious health habits that explained their longevity. As a group, he said, they did not have especially healthy eating or exercise habits.

“About half of them were smokers,” Kim added.

Even though no genetic clues emerged in this study, scientists said they would make their analysis available to the public as a resource for future research.

Misao Okawa, a 116-year-old Japanese woman born in 1898, is recognized as the world’s oldest person. At her birthday this year in Osaka, she credited sushi and sleep for her longevity.