I recall looking at a map of average life expectancy in Japan and the difference between Okinawa and the worst area was just a year. Also the gap between men and woman is fairly big though. Men tend to eat more. Though things like natto / fermented soy (Vitamin K2) and better fiber sources may make a difference I expect the largest factor is calorie control. The Japanese like many Asians have a belief in eating until you just start to feel full and stop. Women particularly follow this.