How long you live has a lot to do with your environment and lifestyle, but exceptional long life may have even more to do with your genes. For the first time, researchers have discovered a genetic recipe that accurately predicts who may live to 100 and beyond. Analysis shows that 90% of the participants who lived to 100 had at least one of the signature genetic clusters . Dr. Thomas Perls at the Boston University School of Medicine said, "We realize this is a complex genetic puzzle. There is a long way for us to go to understand how the integration of these genes--not just with themselves but with environmental factors--is playing a role in this long life puzzle." Perls has studied many factors that contribute to long life, and he is the first to acknowledge that living longer isn't likely to be simply a matter of genes. His previous work has shown, for example, that among most elderly people who live into their 70s and 80s, about 70% can owe their long life to environmental factors such as not smoking; eating a healthy, low-fat, low-calorie diet; and remaining socially engaged and mentally active throughout life. It seems clear that those who live extremely long are benefiting from a special DNA. In fact, Perls believes that the older a person gets, the more likely it is that his or her genes are contributing to those extended years. Perls may most likely agree that  _  .
most people living extremely long benefit from not smoking living longer just depends on certain genetic recipes environmental factors play an important role in long-living being mentally active has nothing to do with living an old age