When I played in a band in college, my roommate was talking with an earnest young man while I was doing my solo part of the set. He explained to me later that the gentleman was suggesting what we really needed to complete our band was a harmonica player. "Hey, that's really interesting. You don't happen to play the harmonica, do you?"
Yeah, it was more than a lucky guess.
Well, at least the BBC mentioned genes in this story of Okinawan longevity.
Let us consider the high-carb diet theory unproven. And not really all that intriguing, no. These studies all have an air of "gee, I don't really understand how all this gene stuff works and I don't have the training to get funded for a study like that. So it must be something else that's the cause, something other than genetics."