Blue zone Dan Buettner

Japan has some of the longest-living citizens in the world -87 years for women and 81 for men , according to the country's Ministry of Health, Labor and Welfare. Could this concept of ikigai contribute to longevity?

Author Dan Buettner believes it does. He's the author of Blue Zones: Lessons on Living Longer from the People Who've Lived the Longest, and has travelled the globe exploring long-lived communities around the world, which he calls " blue zones ".

One such zone is Okinawa, a remote island with a remarkably high number of centenarians. While a unique diet likely has a lot to do with residents' longevity, Buettner says ikigai also plays a part.

According to Hasegawa, the origin of the word ikigai goes back to the Heian period (794 to 1185). " Gai comes from the word kai ("shell" in Japanese) which were deemed highly valuable, and from there ikigai derived as a word that means value in living."

There are other wo...