I’d note that the blue zone theory is not terribly rigorous.
Let’s say that we count how many people were killed by a falling meteorite - something completely random, geographically - and tabulate this per region (county, state, country, etc.). If you were to do that, you’d find that some regions are above average and some are below average. Even if you tabulate it on a per capita basis, this will still be true because random is…random.
Random things will cluster. If you flip a coin 20 times, 25% of the time, you’ll have at least one streak of 5 heads. Nature doesn’t try to smooth things out, ensure an even distribution, etc. Over an infinite amount of time, you’ll start to get things to converge but, looking at time spans of a few years or a few decades, you can get widely divergent results on the basis of simple random chance.
But let’s assume that there’s a lifestyle choice that causes meteorites to hit people. To see if this is true, we will compare regions on Earth that are on land, no larger than 100 square miles, and inhabited by at least 100 people.
If you were to do that, nearly all random selections would turn out to be rural land with small farms. Minus the 100 persons limit and your average result is going to be uninhabited land or a small slice of some mega-farm without enough residents to calculate anything from. We’re excluding those but, as a side effect of that choice, we end up only looking at the range of land between small farms and cities.
A city is going to have more people and thus a larger sample size. Larger sample sizes hew towards the average. Smaller sample sizes are going to be on the top of the scale and the bottom of the scale because we don’t have enough samples to pull things into the average. Cities aren’t going to appear in our output as a stand-out region.
If we take only the regions that are at the edge of the scale, then we will end up with some region that’s a small farm. Nearly all of our results, at the top of the meteorite hit scale and at the bottom, are going to be closer to the 100 person limit. That’s how you escape “average”. So, statistically, meteorites almost always hit in 100 square mile regions with about 100 inhabitants.
Now, other than the lifestyle choice of living inside of a region with about 1 person per square mile, the other lifestyle choices of people who get hit by meteorites is that they walk around a lot, farm, eat more whole produce, care for animals, etc.
These are also the lifestyle choices of people who are hit by the fewest meteorites per year.
To be sure, science does say that exercise, eating whole foods, etc. are beneficial to your longevity. But Okinawa may just have gotten the luck of the draw for having more 100+ year old people, and some other region had bad luck and a lot of early heart attacks. Maybe their main benefit is that the doctor who delivers most babies on the island was a big proponent of abortion and advised nearly all of his patients with weaker-looking fetuses, to abort. The end result is a above-average healthy population. Maybe their main benefit is that they were victims of WWII, and a lot of the elderly are those who survived a period of famine. Famine seems to trigger the sirt2 pathway to elongate the life of an organism. The end result is a large group of people who had a few years added to their life but, unless you want to replicate the experience of hiding in a cave for months, running away from soldiers and bombs, eating your own clothing and mud balls, you’re probably not going to take much from Okinawa that’s useful for life extension. Taking a supplement that affects sirt2 is a lot more practical.
Real, scientific research will generally run away from region-to-region comparisons. There’s too many confounding factors between history, local culture, environment, etc. to allow you to tease out what’s really affecting the output.
The blue zone journalist dude is not doing science. He’s selling books. His stuff sounds good and it’s fairly unlikely that he’ll identify a region that’s doing everything wrong and, yet, somehow getting a large number of centenarians. But you’re better to look at medical science than at Okinawa for tips on how to live longer.