Genes, rather than lifestyle, impact who lives 100 years.

Living a long, healthy life tends to run in families. If your grandparents and parents lived into their 90s and remained relatively healthy until the end, there's a pretty good chance you will, too.

So it's pretty clear genetics plays some role in longevity.

In this study, the research team developed a new statistical way of analyzing the genetic code of people who had reached age 100 as compared with people who had a more typical lifespan. Tom Perls, who heads the New England Centenarian Study, explains what they found.

"We discovered 150 or so genetic markers that can highly predict whether or not a person has the genetic propensity to live to extreme old age."

Using just that large number of genetic markers, the team was able to predict in almost four out of five cases whether a person would live to be 100.

Perls says the key to successfully predicting long life was the sophisticated statistical analysis of many different gene variations that each played some role.

"And that's what this method does - it captures the complexity of the puzzle and the interaction of all these genes together to produce exceptional longevity."

Perls and his colleagues publish their study in the online edition of the journal Science.

The Boston University researcher says this kind of analysis could play a role, not just in predicting who will live longest, but in actually helping people live longer and healthier lives.

In an interview via Skype, Tom Perls said the same technique used to predict long life may also be used to predict whether a person might eventually develop certain diseases. He gave the example of Alzheimer's Disease as one in which genetics plays a role.

"And we think that this methodology can very much be used to capture the bunch of genes that are playing an important role in one's susceptibility to that disease," he said. "And the same can be true, perhaps, for looking at adult-onset diabetes, or cardiovascular disease, or stroke. Again, where I think there is at least a moderate impact from genetic variation."

As the cost of the needed genetic tests continues to decline, he predicts doctors will be able to screen patients for diseases they may not develop until later in life, and recommend ways to avoid them.

propensity: a tendency to a particular kind of behaviour （行為方面的）傾向；習性

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（來源：VOA 編輯：陳丹妮）