"This study suggests that centenarians may possess additional longevity genes that help to buffer them against the harmful effects of an unhealthy lifestyle," said senior author Nir Barzilai, director of the Institute for Aging Research at Yeshiva University's Albert Einstein College of Medicine.

　　The study involves 477 Ashkenazi Jews between the ages of 95 and 122, of whom 75 percent are women.

　　According to the study, Ashkenazi Jews are chosen as subjects because they are more "genetically uniform than other populations, making it easier to spot gene differences that are present."

　　The study also found that the long-lived Ashkenazi Jews drank slightly more and exercised less than their average counterparts.

　　But Barzilai also warned: “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," He added.