Author Dan Buettner (The Blue Zones: Lessons for Living Longer from the People Who’ve Lived the Longest), in partnership with National Geographic and the National Institute on Aging, traveled the world to find out who lives the longest and what we can learn from them.
From the NPR story:
Buettner says one such zone, the Italian island of Sardinia, has the highest number of male centenarians in the world, while another, Okinawa, Japan, has the longest disability-free life expectancy. In Loma Linda, Calif., a community of Seventh Day Adventists has a life expectancy that’s nine to 11 years greater than that of other Americans. And middle-age mortality is lowest on Costa Rica’s Nicoya Peninsula — where Buettner says middle-aged residents have about a four-fold greater chance of reaching age 90 than people in the United States do.
Some commonalities which seem to correlate with long, healthy lives:
“One of the idiosyncrasies we discovered is that people who eat nuts four to five times a week, 2 ounces at a time, tend to live two to three years longer than people who don’t eat nuts. That was a big surprise for us,” Buettner says.
Some may think the secret to longevity lies in strenuous physical activity, such as running marathons or triathlons or pumping iron. But Buettner says he has identified four things people can do that can potentially increase life expectancy: Create an environment that encourages physical activity, set up your kitchen in such a way that you’re not overeating, cultivate a sense of purpose and surround yourself with the right people.
“These are long-term fixes that have been shown over and over to add not only more years of life, but better years of life,” Buettner says.
The weakness of this kind of research is that it only shows correlations (does not prove cause and effect) and suffers from the “cohort effect” — all the people studied, by virtue of their similar age, grew up under unique socio-cultural-historical conditions which may never occur again.