A distinct version of the Mediterranean diet is followed on the Blue Zone island of Ikaria, Greece. It emphasizes olive oil, vegetables, beans, fruit, moderate amounts of alcohol and low quantities of meat and dairy products. Gianluca Colla/Courtesy of Blue Zones hide caption

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Regular nut consumers had about a 20 percent reduction in all-cause mortality, including lower death rates from heart disease and cancer, a study found. iStockphoto hide caption

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A mural in an ancient tomb in China shows a troupe of eunuchs. How long did they live? Wikimedia Commons hide caption

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A rhesus monkey eats watermelon, provided by zookeepers, at the Kamla Nehru Zoological Gardens in India in May 2012. Sam Panthaky/AFP/Getty Images hide caption

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