Yeah, it does show that for some of the areas, but not others. The problem with these population studies is they do not give you answers, only new variables. In my view, the whole blue zone study is moot, at least in the way it is typically applied. What it does give us are new variables to study. Those smaller studied can control for variables that the population level cannot. They can also apply those studies to populations of different decent (genetics).

The glass of wine recommendation has had many studies done and the results are conflicting.

The eating guidelines like heavy in plants, mederteranian, eating to 80% full all have multiple studies showing benefits over the typical western diet and especially the typical American diet. It's a no brainer that if you want to live a long life you have a better chance of doing that if you have a reduced risk of heart attack, stroke, diabetes, etc.

Most of these guidelines are based on the same sort of flawed population-level studies that can't control for many other aspects. For example, the "Mediterranean diet" is consumed in countries that have all sorts of other specific lifestyle differences that are just as likely to influence health and longevity - siesta, a general tendency not to stress or work in exaggerated amounts, a month or more of vacation per year, significant sun exposure, good social healthcare, and many others. All of these together have certain (mild) effects on longevity and health, but there is virtually no way to isolate any one from all of the others.

There are also many studies that suggest other kinds of diets are beneficial, and many populations that consume significantly different diets and have even better health than the average person around the Mediterranean. For example, inuit populations also display generally low obesity and risks of heart attack, stroke, diabetes etc - while consuming almost the opposite of a Mediterranean diet or of plant heavy diets.

"For example, inuit populations also display generally low obesity and risks of heart attack, stroke, diabetes etc - while consuming almost the opposite of a Mediterranean diet or of plant heavy diets."

That doesn't seem to be true.

https://pubmed.ncbi.nlm.nih.gov/30578133/

The studies backing up specific diets are not population level, but rather specific study groups. And yes, there are other healthy diets too.

Right, I have no problem with dietary recommendations that are inspired by "blue zones" and then validated with research in other populations.