I don't disagree, but to add I think the retirement culture probably helps a lot for longevity too.
The Japanese retirement attitude is "I've worked my ass off all my life. Contributing to the society all my life. Finally I have some time to spend on my hobbies! I should be active!" and they pick up quite active hobbies: if you go hiking mountains you'll see many old retired people with serious gears. Also still trains.
Contrast it to ime, western retirement which is more "finally I can relax" and people become sedentary. Hanging around in parks, cafe, or focus more on socializing and diet. And starts to rely more on cars and other senior services.
Yes. My Japanese wife’s father and mine are the same age. FIL had a heart attack last year and almost died. Yet he’s still the president of the rotary club, travels every two weeks across the country to attend events or give lectures. Recently hosted an international student exchange at his workshop and is still making new pieces of art to be exhibited.
My father spends all day watching football or horses and has visibly started going senile.
Feels like a much more likely explanation. Heard my parents talk a lot about people who retire, make their primary activity be vegging out, and then health issues start popping up. Japanese also seem to have a big culture of everyone needing to have hobbies.
Germany is rather like that. Never try to keep up with a German granny going up a hillside.