The answer, it seems, is not the magic of technology or powerful new drugs, but, as CBS News Correspondent Elizabeth Kaledin reports, it's something much simpler: food - a lot less food.
For 15 years researchers have compared monkeys fed normal diets to those fed 30 percent less. The monkeys eating fewer calories have lived much longer and avoided disease.
"There's no question that diet contributes to aging and disease," says Dr. Donald Ingram, of the National Institutes of Health. "We have determined that several markers of potential age-related disease have been reduced in monkeys on calorie restriction."
How eating less affects the aging process is still unclear. One theory is that, simply put, when the body has fewer calories it has to decide more wisely how to use them, and they tend to be invested in self-preservation.
In animal studies cells that might have become cancerous were the first to die. Experts on aging are intrigued.
"If we can begin to understand what it is that relates to this extension of life and then put it in a bottle and have it as a medicine, that might be fantastic," says Dr. Robert Butler, of the International Longevity Center.
Dean Pomerleau isn't waiting for any medicine. Convinced by the animal studies, he and a small group of people are already practicing calorie restriction in the hopes of living longer.
Ideally, he'd like to shoot for 120 years.
Pomerleau wakes up at 4:30 every morning to prepare and package huge portions of salad, which he consumes three times a day.
"I eat about six pounds of vegetables a day," he says.
He also eats sprouts home grown in his basement, fruit and small quantities of lean protein, like fish.
"The bulk of the diet I eat keeps me from getting hungry ever."
In two and half years Pomerleau has lost 45 pounds. The extreme thinness has meant more brittle bones and a decreased libido, but his health, he says, is better than ever:
"I haven't had a cold that's lasted more than a half a day," he says. "I think my mood and sense of well being have improved substantially since being on the diet."
Pomerleau admits it's extreme, but "I see it as worth it to experience more of life to give up a slice of pizza."
That is unlikely to be a view shared by most Americans notorious known for loving their food. So even if calorie restriction does work in extending human years, scientists may find their biggest challenge is convincing people to trade in quality of life for quantity of life.