Now keeping in mind this is not a matter of genetics. It is a matter of exercise and diet. The people of Japan simply exercise a lot more and healthier when compared to many other cultures around the planet.
It is very much a health-crazed culture which values eating healthy foods and regular exercise, and this is doubtlessly the biggest contributing factors to their long lifespan.
Japan's quality of health there is ranked number one in the world. Their life expectancy is also number one. If you live in Canada or the USA however it’s a different story, and not one to brag about.
America’s health score is the worst amongst all developed nations. Canada is significantly better, but it is dropping in recent years as a higher obesity rate starts to take grip in Canada. What is funny is that the USA spends more money on health care - billions of dollars more than any other country. The reason is because Americans get sick very easily, they get cancer very easily, and they get a huge variety of health problems very easily - and it is all due to low exercise and an unhealthy diet.
So what is Japan doing right and what is the USA doing wrong?
Infant Mortality Rate
Well lets start with infant mortality rate (IMR) as that can be a big contributor to life expectancy. For example if you have 100 babies and 50% die as infants and the rest live until 100 years old, then the average lifespan is 50 years old. Thus a country with a high IMR will have a lower life expectancy.
Japan's IMR is 2.17 per 1000 births.
USA's IMR is 5.9 per 1000 births.
So right from the very start America is killing their babies with bad food. Or maybe it is some other cause. (Such as a health care system driven by greed...)
Some people point the finger at America's tendency to vaccinate babies like crazy. Babies in the USA get 26 doses of vaccines. Japanese babies gets a mere 12. Now there is no proof that over-vaccination is tied to infant mortality in the USA, but there needs to be a study done on this sometime to see if a lower vaccination schedule would increase the number of babies who live past the first year. Because the IMR alone lowers life expectancy in the USA by a year or two.
Culture
Japanese people believe in being peaceful, calm, positive and to behave honourably. Especially in public. It is sort of a Zen Buddhist thing that they believe in. They believe in being patient, forgiving, kind and virtuous. For the vast majority of Japanese this is working really well because their culture is very low crime.
The murder rate in Japan is 0.4 per 100,000 per year.
The murder rate in the USA is 4.8 per 100,000 per year.
(Note: Japan's suicide rate is higher, but that is only because some of them believe in seppuku - Japanese ritual suicide when a person has dishonoured themselves so much they can no longer perform a role in society. Since seppuku is mostly a male thing it shows in the difference between life expectancy for women and men in Japan, where women live 7 years longer on average. So a quick way to raise your life expectancy is not believe in suicide.)
Exercise
Japanese people love hiking in the mountains. A long mountain climb burns a lot of calories and is a bit like weightlifting for the legs because you are going uphill so much. Many Japanese people also enjoy jogging, swimming, weightlifting and a huge variety of exercises.
Bathing
Now you might not think this is a factor, but many Japanese people swear by it. Soaking in very hot water - especially hot springs - is said to be very therapeutic for the skin. Whether this increase longevity is another topic, but I am mentioning it anyway. The extreme heat of the water does kill bacteria and that contributes to a lower rate of infectious diseases and illnesses.
In contrast most Americans take showers, which doesn't scrub off all the bacteria.
Green Tea
Unsweetened green tea is most common beverage in Japan is tea. Their green tea includes gyokuro, sencha, bancha, matcha (powdered green tea), konacha and hojicha. This may be the healthiest drink that exists and that is why the Chinese, Koreans and Japanese drink it as their main beverage. Green tea is very high in alkaline - and alkaline prevents cancer. When compared to other foods with high alkaline scores green tea has an acid binding score of 53.50 while spinach is only 28.01. (High blood acidity is a high contributor to cancer, so reducing the acid in your blood using alkaline makes a huge difference.)
Green tea also lowers blood pressure because it contains theanine, which helps relax a person. In contrast most Americans drink coffee - which raises blood pressure and makes you jittery.
Diet
Japanese people eat a wide variety of vegetables and also a lot of fish. This extra variety of greens, beans, nuts and berries, and even seaweed means that they get a wide variety of vitamins and minerals in their diet. In contrast most Americans go for "meat and potatoes", which doesn't give them much variety in their diet - and the only seaweed most Americans are eating is an additive to their ice cream.
Fish wise Japanese people eat a lot of tuna and salmon, which is very healthy for you because of the Omega-3 fatty acids in it. In contrast Americans eat a lot of pork, poultry and beef - which are high in bacteria. Fish is readily available all over the USA, but most Americans prefer farm animals for their meat.
Japanese people also eat a lot of soy - which has a long list of health benefits.
With respect to sugary foods Americans eat 3 times that of people in Japan. The average American consumes 153 lbs of sugar per year. That is almost half a pound of sugar per day.
Taken all together the obesity rate in Japan is 3.2%. In the USA it is 35%, so clearly Japan is doing something right and Americans are doing it horrifically wrong.
In an effort to lower obesity rates in Japan even further the Japanese government has reclassified obesity as anyone with a BMI over 25 (the global standard is 30 or more). This way they can scare more Japanese people into eating healthier.
The following is a list of popular foods in Japan:
Sweet potatoes/yam; Soy; Goya - a type of melon; Konnyaku - a Japanese jelly derived from the starchy tuber of the Konjac plant; Shiitake Mushroom; Gobo - a root vegetable; Hechima - a gourd or squash; Seaweed; Turmeric - this spice contains a powerful anti-inflammatory; Mugwort or fuchiba spice; Hihatsu - a type of pepper; Fennel or ichiba spice.