Secret Of Long Life - Diet, Interbreeding Or Faith

Okinawa (Japan), Ovodda (Sardinia) and Loma Linda (California), all have one thing in common. They are cited as three communities where the population live longer than most other places in the world. A recent report set out to examine the lifestyles and diets of these communities in an attempt to unearth the secrets that bring about this phenomenon.
Okinawa (Japan)
In the case of Okinawa diet appears to be the most significant factor in their longevity. Apparently, the Okinawan's have a tradition known as 'hava hatchi bu' which means 'eat until you are 80% full'. They eat more tofu and soya products than any other population in the world, their diet also includes a vast range of fruit and vegetables. Scientists refer to it as the rainbow diet. Could diet be the determining factor in their long life spans?
Ovodda (Sardinia)
The inhabitants of Ovodda, on the other hand, have a predominantly meat diet. A Professor Deiana concluded that this community owe their longevity to interbreeding. "Marriage among relatives is not the rule but there are some cases of it taking place" says Professor Deiana. This is brought about because the community lives in relative isolation, marrying into each others families.
Loma Linda (California)
The people of Loma Linda are thought to owe their longevity to their faith. A significant number of people in the town are Seventh Day Adventist's, a religion who's members live between five and ten years longer than fellow citizens. Regular churchgoers live longer than those who do not go to church and it is believed that is due to their faith counteracting stress. It must be said however, that Adventist's neither drink nor smoke and many have a vegetarian diet as advised by the church. So, do some or all of these factors ensure a long life, or do other influences also play a part?
As one wag said "Try Wokingham. You don't live longer, but it seems like it."