When it comes to longevity, Okinawans wear the crown. You can go out and read a bunch stuff on the internet as to why. You'll find snippets like the fact that they only eat until they're 80 percent full; and they eat a wide variety of vegetables and soy products.
I went to Okinawa in 1999. When I was there, I was a little obsessed with why they live so long. I had a number of translators, so I could ask lots of them why. Most of them told me it was dietary. They all said that seaweed is a big reason, and that it's imperative to eat small amounts of pork.
What may be imperceptible to them is the fact that their lifestyle is so relaxed. Okinawa is like a Japanese version of Hawaii, so you can imagine it's very beautiful and cushy. The Okinawans don't have words for lying, cheating, stealing and rape; and they certainly do not do those things. By the time I left and landed in Taiwan, white people freaked me out.
The longevity reign of Okinawans is only questionable in my mind because we can't research the Chinese in the same way. China is closed-off, enormous, and lots of its people live high in the mountains or way out in BFE.
The Chinese use the word "immortality" to mean "live longer than yer sposta, and live well in your old age."
Behold, Li Ching-Yuen! He is known as "the 250-year old man."
http://en.wikipedia.org/wiki/Li_Ching-Yuen
Li was an herbalist and a martial artist. There are records in China from 1827 congratulating Li on his 150th birthday. In 1927, General Yang Sen was said to be impressed with Li's youthfulness, strength and prowess. Li died May 6, 1933-- immortal.
In my experience, I've learned there are three real keys to longevity:
1. Diet
Don't eat too much. Live with hunger, it's good for you. Be sure to eat Onion, Garlic, Ginger, & Cilantro as often as you can. These things are very good for your health. Also, eat Greens, Small Amounts of Pork, Fish Oil and Green Tea. I highly recommend you take vitamins; and when you feel your energy running low, read up on the different kinds of Ginseng.
2. Healing Exercise
Li Ching-Yuen was a Chinese martial artist. If you don't believe me, believe him-- practice of proper martial arts will extend the usable life of your body well into your golden years. Fu Tai Chi is the best exercise there is.
3. Relaxation
Li's secret of long life was:
- Tranquil mind
- Sit like a tortoise
- Walk sprightly like a pigeon
- Sleep like a dog
All four of these points mean to say, "relax, loose the tension." This echoes what I know of Okinawans, and also exemplifies an important principle of Fu Tai Chi.
Live long and prosper.