If it's the secret to longevity you're after, you should be interested to learn that the Okinawans are no longer "the longest living people in the world".
People from other parts of Japan have overtaken them.

https://en.m.wikipedia.org/wiki/List...ife_expectancy

I understand that there have been locally led promotions in different prefectures to tweak and change traditional diets (less salt is an example) and lifespans are extending throughout Japan as a result - particularly with regards to Japanese Men.

https://www.japantimes.co.jp/life/20.../#.XWi_nYHRbYU