There are some 70,000 of them in the U.S. alone - people 100-plus years old, who make up the fastest-growing age group of Americans and whose numbers have tripled in just the last two decades.
Clearly, these "centenarians" can safely be called "over the hill," but how did they survive the mountain of age-related threats to reach the 100-year milestone?
Thomas Perls, M.D., founder of the New England Centenarian Study, has been working to unlock the secrets of the very old. "We have ingrained in us the idea that the older you get, the sicker you get, and so people would think these 100-year-olds must have every age-related disease under the sun and must certainly be on death's doorstep," says Perls. In fact, he explains, quite the opposite is true: These oldest Americans are still alive because they avoided these lethal age-associated diseases, such as cancer, heart disease and Alzheimer's.