A group of researchers has set up a foundation to study the members of a rare and exclusive club: people who live to be older than 110.

The Supercentenarian Research Foundation hopes to identify why these people live so long, develop strategies to help combat the effects of aging and improve the quality of life of the very old.

It is estimated that there are about 300 people worldwide who are 110 years old or older, but not all of those people have had their ages verified through public documents.

As of this week the foundation, based in Pittsburgh, reported that there were 76 people in the world -- 66 women and 10 men -- who were verified to be 110 or older.

"The longer we wait, the more they're going to die and we will lose that information," said Dr. Stephen Coles, the foundation's treasurer and a researcher who has studied the elderly as part of the Los Angeles Gerontology Research Group.

Coles said demographers have shown that the number of people reaching 100 years old is growing exponentially, while few people live to be older than 110. Researchers are turning to science to try to explain why.

The oldest person ever whose age was authenticated was Jeanne Louise Calment, who lived to 122 years and 164 days, the foundation said. She was born on Feb. 21, 1875, and died at a nursing home in Arles in southern France on Aug. 4, 1997.

Stanley R. Primmer, the foundation's president, said there have only been seven autopsies of supercentenarians that the group knows of. He said the foundation is in the process of gathering tissues from the very elderly so they can look for clues to longevity.

"We want to know why it is they're able to live longer than the rest of us, and what is the limit to our life span," Primmer said.

The foundation began after several experts on aging met at an anti-aging conference in Las Vegas in 2004, and decided that so-called "supercentenarians" needed to be studied.