In 2004, Michel Poulain, a demographer at Belgium's University of Louvain, along with Gianni Pes, a physician and epidemiologist at Italy's University of Sassari, published an article in the journal Experimental Gerontology that identified an unusual phenomenon that came to be called "Blue Zones".
Blue Zones are areas of the Earth where people live the longest, often reaching well beyond 100 years of age - compared to an approximate average of 73 years.
Blue Zones got their name from the colour which Poulain and Pes used to highlight the first such area identified, which was located in the province of Nuoro on the Italian island of Sardinia.
In 2005, American author and National Geographic Fellow Dan Buettner wrote an article entitled "Secrets of Long Life" for the November 2005 issue of National Geographic magazine, and it became one of the best-selling issues ever. In 2006, Buettner collaborated with Michel Poulain to identify a second Blue Zone, located on the Nicoya Peninsula of Costa Rica. By 2008, Buettner and Poulain had identified a third Blue Zone on the Greek Island of Ikaria.
That same year, Buettner published his book, The Blue Zones: Lessons for Living Longer From the People Who've Lived the Longest, and it became a New York Times Best Seller. In September 2009, Buettner gave a TED talk entitled, "How to live to be 100+" which has been viewed over four million times.
By 2015, Buettner had identified a total of five Blue Zones around the world. They are:
Sardinia, Italy
The islands of Okinawa, Japan
Nicoya Peninsula, Costa Rica
Ikaria, Greece
Loma Linda, California
When scientists examined the DNA of residents living in Blue Zones, they found nothing to indicate that it had anything to do with the residents' longevity. Rather, what set Blue Zones apart was that they were geographically isolated from the rest of the world. That meant it took longer for fast food, processed foods, and diets containing more meat to reach those areas.
You may have spotted that Loma Linda, California, is a bit of a weird one - being only 60 miles from Los Angeles. What is it that makes Loma Linda so different? Well, it has a high population of Seventh Day Adventists who believe the human body to be the temple of the Holy Spirit, and that it should be protected. Seventh Day Adventists believe in a Sabbath day of rest, and they eat a plant-based diet that is rich in whole foods and avoid taking narcotics and stimulants, including alcohol and caffeinated beverages. Loma Linda residents tend to remain physically active into their 80s and 90s, and many are actively involved in their faith and the church community.
Besides diet, scientists have identified other factors that lead to a longer life. These include:
Having a purpose in life and goals
Having a social support network of family and/or friends
Reducing stress
Stopping eating when you're 80 percent full
Enjoying wine or alcohol moderately
Keeping physically active
Buettner has established the Blue Zones Project to advise other communities on how to achieve greater longevity and, as the website says: 'to live better, longer.'