Determining your likelihood of living to 100 or beyond may soon be as simple as conducting a DNA test. American researchers have identified a set of genetic signatures that signal exceptional longevity in humans. The so-called “longevity genes” have been found to contribute to life spans well in excess of what the average individual can expect living in the developed world. The study, which examined a large sample of centenarians against a control group, found that it could predict “exceptional longevity” with 77% accuracy.
Dr. Thomas Perls, the lead author on the report, said that “It’s really quite revolutionary. With the accuracy we’ve demonstrated, companies are going to pick this up. We’ll see it on the market in a month.” The behavioral and social implications of such a test are exciting, unnerving, and unpredictable.
Anticipating the reactions of people intrigued by the possibility of discovering the likelihood of their longevity, Dr. Perls asked, “What do you do when you’re told you absolutely don’t have the [genetic] signature for exceptional longevity or you [do] have it? … Do you go and do a lot of risk-taking behaviours and say, ‘Well, I’m hanging it up,’ or does it give you impetus to take all the more better care of yourself?” He added, “What are people going to do with this, what health or financial decisions might they make?”
For one, you might reconsider the structure of your annuities and other elements of financial planning. You may even decide to eat more bacon. Before you do, however, the report reminds us that “studies of twins suggests that only 20-30% of the factors in surviving to 85 years of age is determined by genetics”, with environmental, and lifestyle, and unknown factors contributing the rest.
The report is also proving controversial in the scientific community. Shortly after the study was released Dr. Perls released an e-mail message that he had been “made aware that there is a technical error in the lab test” used on some of the centenarians. While Dr. Perls believes the “apparent error would not affect the overall accuracy of the model,” others are not so optimistic.
“I think it is very unlikely indeed that the findings in the Science paper are correct, or even mostly correct,” David B. Goldstein, a geneticist at Duke University, wrote last week in an e-mail message.
Whether the longevity genes are real and identifiable may be in dispute, but Dr. Perls does admit that much of longevity is due to lifestyle and other factors. He and his co-authors point out that it is not a coincidence that the average life expectancy of Seventh-day Adventists is several years higher than the North American average, “who by virtue of their religion have health-related behaviours conducive to healthy aging.”
Dr. Perls also warns us that the test is based solely on Caucasians, meaning that tests on other ethnicities might produce different results. The study also noted that some of the centenarians in the study did not carry any of the longevity genes, suggesting that environmental, behavioural, and other unknown factors can contribute to exceptionally long lives as well. Of course, the right set of genes does not protect you from accidents either. The key to a very long life may be a perfect cocktail of genes, lifestyle, and luck.