100 birthday candles? Thank longevity genes

[Guest guest]

http://ca.news.yahoo.com/s/capress/100701/national/longevity_genetics

100 birthday candles? Thank longevity genes

1 hour, 30 minutes ago

By Sheryl Ubelacker, Health Reporter, The Canadian Press

TORONTO - Researchers have identified a group of genetic signatures shared by

people with exceptional longevity — those rare folks whose lifespans reach the

century mark and beyond.

In a study published online Thursday by the journal Science, Boston University

researchers report that a spate of 150 genetic variants predicted with 77 per

cent accuracy those people who were 100-plus or close to reaching that ripe old

age.

The scientists compared the presence of the genetic variants in the genomes of

more than 1,000 Caucasians born between 1890 and 1910, with a median age of 103,

and almost 1,300 control subjects. The oldest in the first group died at 119.

They found that about 45 per cent of the oldest subjects — those 110 and older,

dubbed supercentenarians — had genetic signatures with the highest proportion of

longevity-associated markers.

" Centenarians are indeed a model of aging well, " said principal investigator Dr.

Perls, director of the New England Centenarian Study.

" A lot of people might ask who would want to live to 100, because they think

they have every age-related disease under the sun and are on death's doorstep

and certainly have Alzheimer's. But this isn't true. "

Previous studies of long-lived people have shown that about 90 per cent are

disability-free at the average age of 93, he explained.

" So they very much compress their diseases or their disability to the very end

of their lives. And supercentenarians compress both disability and disease even

further. "

Surprisingly, the researchers found that the centenarians and the control group

did not differ substantially when it came to genetic diseases that predispose

people to age-related illnesses such as heart disease and dementia.

" These results suggest that what makes these people live very long lives is not

a lack of genetic predisposition to disease, but rather an enrichment of

longevity-associated variants that may be protective, " added so-author Paola

Sebastiani, a professor of biostatistics at Boston University. " It may even

cancel the negative effect of disease-associated variants. "

" We think these analyses represent an important step forward in our

understanding of exceptional longevity as well as anti-aging, " she said.

However, the researchers cautioned that good genes aren't the only key to long

life — environmental and lifestyles factors also likely play significant roles

in whether a person will have a birthday cake topped with 100 candles or more.

And they caution that much more study is needed by their team and other research

groups to see if their findings hold up and just what they mean.

" Clearly we realize that this is a very complex genetic puzzle, " said Perls,

noting that the 150 markers involve 70 genes spread across the chromosomes.

" I feel very strongly that this will not lead to treatments that will get a lot

of people to become centenarians, but rather to make a dent in the onset of

age-related diseases like Alzheimer's. "

Still, the researchers concede that a " chip " could be made with the 150 genetic

variants that could test whether someone is likely to enjoy an exceptionally

long life, while other testing could look for those genes known to be linked to

dementia and other diseases of advancing years.

" Could these signatures tell a physician and their patients who's going to be at

increased risk for a particular disease sooner and can this lead perhaps to

interventions that might help them? " asked Perls.

" I think that that's a possibility down the road. That brings up that whole

field of personal genomics or medicine and being able to use genetic information

in the future to help guide therapy. "