Thanks, Georgios, for yourthoughtful input and questions.

The issue of disentangling keto.dieters vs. plant-based, or Mediterranean diets, is indeed a difficult one.

Epidemiological studies can tell us only so much. That "so much" is predominantly association, not causation. So, epi data can only be the basis for hypothesis generation. In one of my next articles I will highlight the surprising facts about trying to derive causative conclusions from epi studies, particularly in the domain of nutrition. It is quite a bit like reading tea leaves.

Your reference to the Icaria and other so-called blue-zone areas is an importatn one.

My personal suspicion is that what we observe in these geographical clusters is a coincidentally perfect match between genetic predisposition and lifestyle habits.

This match is the objective of my work: to develop means that help people find in a trial-and-error fashion the lifestyle that perfectly matches their predisposition. We can't know the latter (simply reading out the genetic profile doesn't tell us much), so we need to "feel" our way towards that perfect match. The biomarker of vascular age is the one that I use as the benchmark of how well a person is doing.

For some, a plant-based diet might do the trick, for others a different diet and exercise approach will be better. We know, for example, that people with certain gene variants do find it easier to stick to purely plant-based diet, because they process plant-based fats differently.