Book excerpt: Centenarians, once a rarity, are the world's fastest growing age group: there are currently about 50,000 people over 100 in the United States alone, almost three times as many as there were in 1980. Centenarians are setting the gold standard for healthy aging. What can we learn from these pioneers? How can people decades younger apply the centenarians' longevity lessons to their own lives? These are the questions Harvard scientists Thomas Perls and Margery Hutter Silver set out to answer when they launched the New England Centenarian Study.As they probed beyond disease to identify the parameters of an energetic later life, Perls and Silver realized that the key to preserving health and vitality lies not in learning how people stay young, but in understanding how they age well. By identifying lifestyle patterns, vitamins, and medications that contribute to aging well—and may even help slow down the aging process—they show how all of us can maximize the healthy portion of the life-span.Filled with personal profiles, informational sidebars, and quizzes, Living to 100 offers inspiration and solid scientific information to the more than seventy-five million people alive today who can look forward to their ninth and tenth decades.