These blue zones are hot spots of longevity around the world. People not only live a long life here but also tent to grow old without health problems like heart disease, obesity, cancer or diabetes.
The five blue zones are:
1. Ikaria, Greece
2. Okinawa, Japan
3. Ogliastra region, Sardinia
4. Loma Linda, California
5. Nicoya Peninsula, Costa Rica
What those people have in common is most rise and set with the sun, spend their days working, eating and playing in equal measure. Almost all spend a significant amount of the day active, either working in the farmland or fishing or walking around the neighbourhood to visit friends or family. So being outside during the day is a huge common factor.
Being outside so much means that these happy people are daily exposed to good light, light that is beneficial for synchronizing their biological clock. And it is known that this improves sleep, fitness and mood.
Of course this not the only thing they have in common, also very healthy local diet, deep social networks and genetics might have something to do with it.
Sources:
https://www.vpro.nl/programmas/the-mind-of-the-universe/kijk/wetenschappers/poulain.html