BANGKOK, Thailand - Climbers over age 60 are three times more likely to die on Mount Everest than the average mountaineer, according to study results released Wednesday, as more older people try scaling the world's highest peak.
The age of the typical Everest climber is creeping higher, with records quickly being broken.
In May, retired schoolteacher Katsusuke Yanagisawa became the oldest person to make the 29,035-foot summit -- at 71 years, 2 months and 2 days old. He beat the previous record set last year by Japanese compatriot Takao Arayama, who was 70 years, 7 months and 13 days old.
"Before we did this analysis, we didn't know whether age would be important. Younger climbers have a physical advantage, but probably have less experience than older climbers," said University of Washington Prof. Raymond Huey, one of the study's authors.
"We used to refer to this advantage of age as the 'Kareem Abdul-Jabbar effect,' he said, referring to a U.S. basketball star. "As he got older, his physical skills declined but he was so smart and experienced that he was able to compensate and still play professional basketball at the highest levels."
"Unfortunately for older climbers, that effect does not apply on the world's highest mountain," Huey said.
The study met with some skepticism among the mountaineering community in Nepal's capital, Katmandu, where many climbers gather before attempting Everest.
"In general, older people have better adaptation to the environment in high altitude than younger climbers," said Ang Karma of the Nepal Mountaineering Federation. "They seem to perform better, and most of them come with experience."
The study found that many more people in general are trying to climb Everest than 30 years ago, and that their average age is rising. Nearly half of all climbers are at least 40, and one in 30 is 60 or older.
Huey attributed the phenomenon to a proliferation of guided expeditions, and to older climbers having more money to pay for such trips.
The study, published in Britain's Royal Society online journal Biology Letters, examined data from 2,211 mountaineers during the 1990-2005 spring climbing seasons.
It found that a climber's overall chances of reaching the summit were nearly 31 percent -- but dropped to 13 percent for climbers in their 60s.
The chances of dying on the mountain were 1.5 percent, but they more than tripled to 5 percent for climbers 60 and older.
Other authors of the study are Richard Salisbury, a database analyst and mountaineering historian in Ann Arbor, Michigan, and statisticians Jane-Ling Wang and Meng Mao at the University of California, Davis.
Huey said older climbers grapple not only with declining physical capacities, but also with a higher degree of caution.
"By the time you are 50 or 60, you've probably been banged up once or twice," he said. "You know it hurts, and you've seen consequences of losing fingers or toes to frostbite."
