A "longevity gene" credited with long life may also help older people think clearly and preserve their memories – offering new clues about the aging process.
A new study looking at people aged 95 to 107 showed those who had the gene were twice as likely to have good mental function, with fewer signs of dementia, than those without it.
Also, in another study group, with people aged 75 to 85, the researchers found the longevity gene was five times more likely to be present in those who did not develop dementia.
"Without good brain function, living to age 100 is not an attractive proposition," says researcher Nir Barzilai, MD, director of the Institute for Aging Research at the Albert Einstein College of Medicine of Yeshiva University in the Bronx, N.Y.
"We've shown that the same gene variant that helps people live to exceptional ages has the added benefit of helping them think clearly for most of their long lives," he said in a news release.
Longevity Gene Tied to Longer Life, Better Memories
Researchers say the gene variant, known as CETP VV, alters the cholesterol ester transfer protein, which affects the size of "good" HDL and "bad" LDL cholesterol.
Previous studies have linked the gene to exceptionally long life.
In this study, researchers looked at whether the gene was also linked to preserving memory and brain function in two different groups of older adults.
The first group included 158 people of Ashkenazi (Eastern European) Jewish descent who were 95 or older. Researchers found 29% of those with the gene had good mental function and memory, compared with 14% of those without the gene.
In the second group -- 124 Ashkenazi Jews between 75 and 85 -- those who did not develop dementia were five times as likely to have the CETP VV gene (21% vs. 4%). Those with the gene had higher HDL cholesterol levels and larger cholesterol particle size.
Barzilai says the gene's effect on cholesterol particle size may help protect against dementia and Alzheimer's disease as well as promote longevity.
Researchers believe larger cholesterol particles are less likely to lodge in blood vessels, lowering the risk of dementia, stroke, and heart attack.
"In studying these centenarians, we hope to learn why they're able to resist diseases that affect the general population at a much younger age," says Barzilai. "This knowledge should greatly aid our efforts to prevent or delay the onset of age-related diseases."
SOURCES: Barzilai, N. Neurology, Dec. 26, 2006; vol 67: pp 2170-2175. News release, Albert Einstein College of Medicine of Yeshiva University.
Reviewed by Louise Chang