National Geographic On Assignment
The ageless search for the secrets to long life has inspired recent studies that overturn myths and offer promising clues.
In New York City, Nir Barzilai, director of the Institute for Aging Research at Albert Einstein College of Medicine in New York, has led a study of more than 200 centenariansAshkenazi Jewsand their families, looking for potential "longevity genes" that may modify aging.
"When we asked people why they thought they lived so long, we got two answers," Barzilai said. "The first was that they had a mother who lived till 102 or a grandfather who lived till 108."
"The second answer was that they had 'something' protecting them. These were not people who exercised, they weren't vegetarians, some smoked heavily, some were very obesebut they could do anything and get away with it."
The protective "something" may be lipoproteins, Barzilai and his colleagues discovered. High- and low-density lipoproteinsthe so-called "good" and "bad" cholesterolsboth play a role in carrying fats throughout the body.
Among the centenarians, about 80 percent had lipoprotein molecules 30 percent larger than the control group. Barzilai's team also identified a form of gene that boosted the size of the lipoproteins in 26 percent of the long-lived group.
Large lipoproteins are associated with less cardiovascular disease, less hypertension, and reduced rates of metabolic syndrome.
A drug that increases the size of lipoproteins in the body might help prevent the onslaught of age-related diseases, Barzilai speculates in a study published in the October 15 issue of Journal of the American Medical Association.
Human Life ExpectancyPushing the Envelope
"Barzilai's results are interesting but lipoproteins are just one factor among many," said Bernard Jeune, director of the Aging Research Center and of the Danish Centenarians Project at the University of Southern Denmark in Odense. "Reaching 100 is dependent on many factors."
Apparently longevity and good health don't always go together. "Some [centenarians] have delayed age-related diseases, some have escaped [them] but most have survived [them]," Jeune said.
Jeune's study has followed 300 people who reached their 100th birthday in 1995. Two of the remaining three died last week. "They were at opposite extremes," Jeune said. "The man had the fewest number of diseases in the entire study group; the woman, the mostshe had 20 hospitalizations and six major operations."
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