07/17/2012 11:26 am ET Updated Sep 16, 2012

The Luck in Longevity

In 2005, Doctors Bradley Willcox, Craig Willcox and Makoto Suzuki's book The Okinawa Diet was published and rose to become a New York Times best-seller. Modeled after the lifestyles of Okinawans, the world's longest-living people, these doctors presented a formula for weight loss and longevity that focused on social, spiritual and dietary health. Later that same year, National Geographic's "The Secrets of Longevity" elevated Okinawans as examples of people who live long lives because of their low-meat/high-vegetable diet, active lifestyles and social networks. But over the past decade, the New York Times and The Telegraph have published articles questioning the health of Okinawans given their adoption of western eating habits since the American occupation between the end of World War II and 1952. These articles cited surprising statistics about meat and fat consumption in Okinawa -- Japan's most obese administrative prefecture today.

My curiosity to witness this change in Okinawan health led me to Naha, Okinawa, in February. In my mind I saw the oldest Okinawans -- centenarians -- as lean people eating piles of veggies and living in small, tight-knit communities. I guessed that the post-war generation under 65 would be less healthy because of the introduction of foreign meat products and fast food during the American occupation.

On my first day in Naha, I met with Professor and Doctor Craig Willcox in his office at Okinawa International University. To my surprise, Willcox explained that, in Okinawa specifically, longevity could be attributed not only to healthy lifestyles, but also to luck. Today's generation of Okinawan centenarians started life off on the right foot with a vegetable-heavy diet and strong social networks, but these could only take them so far. Once a healthy person hits their 60s and 70s, age-associated diseases invariably enter the picture. Luckily, today's Okinawan centenarians got access to a good health care system just when they needed it in post-war Japan. On top of that, Doctors Todoriki, Suzuki, Curb and Bradley and Craig Willcox completed tests that strongly suggest that calorie restriction contributes to longevity, and findings show that many of today's Okinawan centenarians likely experienced food shortages in Japan between 1949 and the late 1960s. Okinawa's centenarians are the product of years of traditional eating and social habits, well-timed food shortages, and modern health care -- factors that would be very hard to reproduce in the right doses for post-war born Okinawans.

Everywhere I went in Okinawa I was reminded that big, modernizing cities are often not compatible with traditional diets and lifestyles. Although much of the elder population still follows the traditional Okinawa diet, I saw countless people in downtown Naha licking soft-serve cones, savoring hamburgers and speeding by in cars. It appears that Okinawa's chance of maintaining its position at the top of the longevity charts is slim.

For a real-life example of the effects of changing diets on Okinawans, I went to the University of the Ryukyus Hospital see Toyo Mayahara, a 90-year-old woman hospitalized due to heart disease. When the nurses woke her, she lifted her head and her eyes opened wide behind her thick glasses. Her stark white, frizzy hair stuck out in every direction. When I asked her what her secret to a long life was, she said, "Eating! I love food, especially meat!" Her doctor turned to me and said, "Yes, in fact that's actually why she's here: for overeating." But relatively speaking, the doctors estimate that she is likely eating one-tenth the amount of meat that an average American eats. It's a miracle that she is in the hospital at 90 and not 50, which would likely be the case with the average meat-loving American or Okinawan born post-war.

But what of the centenarians themselves? We read studies about them, admire them, and want to live as long as them. Rest assured, based on Willcox's reports and National Geographic's article, there are many healthy centenarians in Okinawa. But what of those who cannot live independently? I decided to visit Shurei-no-sato Nursing Home to find out, and was disturbed by what I saw. During my tour, I found most of the centenarian residents bedridden and uncommunicative, barely able to move from bed to chair, chair to toilet, and back again. Yes, they have lived the longest lives on earth, but quality of life is severely lacking for those without independence and support.

"I think we're pushing people way past their biologically warranty periods," Craig Willcox told me. "There's only so far you can push biology." From what I witnessed at the hospital, an awful lot of technology is needed to keep people alive, and at the end of the day a big portion of the oldest population has serious difficulty functioning independently. How does their quality of life factor into the medical decisions made to keep them alive? As Willcox said, "Are we just driving these people?"

On my flight back to Tokyo I immersed myself in reading life expectancy debates, and I realized that these conversations often ignore the crucial difference between a long life and a productive and healthy long life. At the end of the day, for all the luck that the perfectly timed factors of healthy eating, social networks, calorie restriction and health care produced, countless Okinawan centenarians are finding themselves living out the last of their record-breaking lives alone in sterile nursing homes. And as Okinawa continues to modernize, the natural conditions, diet, lifestyle and luck needed for healthy and productive long lives are only becoming harder to find.