There's probably more truth in your sushi and rice comment than you realize. Epigenetics is the study of how different biological and environmental signals affect gene expression. Instead of changing DNA itself, epigenetic signals can change the number of methyl chemical groups attached to a gene, which turns that gene on or off. A person’s diet is an important source of epigenetic signals, and that's why the author of the book I was referring to examined the diets and environmental factors of all the world's longest living people to see what they're doing and we're not.
Aside from diet and excercise, another important epigenetic signal is exposure to extreme temperature. It seems that when the body is exposed to extreme conditions like a sauna on the hot side or cryotherapy on the cold side, it activates certain pathways in the body that have a direct effect on longevity. So the more you put stress on the body in that way, the tougher the body becomes which is beneficial for living longer. You can view exercise as being a beneficial stressor in the same way.
So it seems that a combination of limiting caloric consumption, daily exercise or hard work, combined with occasional exposure to extreme temperature is where the magic happens for living longer.
Of course, but doesn't the inherent genetic change happen over time (generations of family)?
