Unfair as it may seem, people who live to be 100 are just as likely to smoke, drink and pile on the pounds as the rest of us, according to new research.

A study of hundreds of centenarians found that when it came to living to a ripe old age, the genetic make-up of the lucky appears to stave off the harm caused by an unhealthy lifestyle.

A team of researchers at the Albert Einstein College of Medicine in New York studied the lifestyles of nearly 500 Ashkenazi Jews, both men and women, aged between 95 and 109. As Ashkenazi Jews are descended from a small founder group, it means there is less genetic variation in the population, making it easier spot any gene differences that may be present.

The elderly group of people answered questions about their weight, height, diet, alcohol consumption, smoking habits and normal physical activity.

The results were then compared with data from more than 3,000 people who had been born around the same time as the centenarians, but who had average lifespans.

DNA

The study found that the lifestyles of those in the long-lived group were no healthier than those in the general population, as the centenarians were just as likely to drink, smoke, not exercise enough and have a poor diet as their normal aged counterparts.

However, although both male and female centenarians were just as likely to be overweight, those in the general population were more likely to become obese as a result.

It appears that nature rather than nurture has helped the long-lived survive to such an age.

“This study suggests that centenarians may possess additional longevity genes that help to buffer them against the harmful effects of an unhealthy lifestyle,” said Dr Nir Barzilai at the college’s Institute of Ageing Research.

“Although this study demonstrates that centenarians can be obese, smoke and avoid exercise, those lifestyle habits are not good choices for most of us who do not have a family history of longevity.”

“We should watch our weight, avoid smoking and be sure to exercise, since these activities have been shown to have great health benefits for the general population, including a longer lifespan.”

The researchers also asked the long-lived group why they believed they had lived so long. The group cited family history as the most important factor, followed by physical activity, drinking or smoking less, having a positive attitude, luck and religion.