If you like a mystery, you're going to love this.
In 2005, Dr. Luis Rosero-Bixby, a Costa Rican demographer trained in the United States, presented a paper at an international conference claiming to have discovered that 60-year-old Costa Ricans have the longest life expectancy of anyone in the world. In other words, if you are middle aged and live in Costa Rica, you are more likely to reach, say, a healthy age 90 than your counterparts worldwide.
The academics at the conference did not believe Rosero-Bixby. After all, Central America is still considered "Third World," a place of poverty, tropical disease, and, during the 1990s, terrible wars. How could the people here live longer than "First World" countries like those in Europe and the United States?
Centenarians and Census Records
In August, thanks to a grant from National Geographic and Allianz Life, I traveled with a world-renowned longevity expert, Dr. Michel Poulain, to meet Rosero-Bixby and examine his data. We interviewed 90-to-100-year-olds to verify their ages, and then doubled-checked in the archives (Costa Rica has an excellent record-keeping system that has recorded everyone born since 1888) to make sure our subjects weren't lying or misguided about their dates of birth.
We found that not only was Rosero-Bixby's data accurate, but in looking at it more closely we noticed something extraordinary -- a Blue Zone: In northwestern Costa Rica, residents live even longer than people in the rest of the country.
This area -- the Nicoya Peninsula -- is about 70 miles long and 30 miles wide. Surfer beaches and upscale resorts hem the peninsula's western edge. But inland, forest-covered hills and cow pastures blanket most of the terrain.
For the 75,000 or so people who live here, life proceeds much the way as it has for hundreds of years. Nicoyans make their living as small farmers, laborers or sabaneros -- cowboys who work the area's huge cattle ranches. Judging by the dusty villages where neighbors hang out on porches, or the rural homes where women still cook on ancient wood-burning stoves, you'd never guess that the Nicoya is the longest-life place in the Americas.
We've recruited a world-class team of scientists and media to unravel the mystery as to why people here are living so long.
Genetics vs. Lifestyle
Scientists generally agree that less than 25 percent of how long we live is dictated by genetics -- how long our parents and grandparents lived. The other 75 percent or so is determined by our lifestyle -- our habits day-in and day-out. Over the next three weeks, our team will be carefully examining the culture of Nicoya, searching for clues in their habits and behaviors that may explain how long they live.
So here's your briefing. We've already uncovered several leads. For example, we know that Nicoya is the driest part of Costa Rica, that it used to be part of Nicaragua, and that more Indians intermarried with the Spanish who began settling here in 1510.
We know that the diet here is different than that of the rest of the country, and that the character of the people here is unique in the world.
Finally, we know that there is literally something in the water.
All in all, we have about 20 clues that we're going to pursue. Each day, we'll search for new evidence. The secret of longevity is not a magic pill or supplement, it's an a la carte menu. Over the next couple of weeks, we will hope to identify some of the entrees…
NOTE: Dan Buettner is a writer, adventurer and entrepreneur who is working to identify 'longevity Blue Zones' -- places in the world where people live longer, and in better health, than most of the population around them.
His goal: to understand what in these people's lifestyles protects them against the diseases of old age, so that others may learn from them.
We reported on his work as he was preparing to leave with a team of scientists to go to Costa Rica, and invited him to tell us what he was finding.
Dan Buettner has written for National Geographic, and is posting more details at http://www.bluezones.com.