Alas, there are reasons to doubt that they’re unusually healthy. The paper Supercentenarians and the oldest-old are concentrated into regions with no birth certificates and short lifespans makes a decent case that they’re mostly just areas where ages have been overstated. There are some relatively unhelpful arguments about who’s right on Andrew Gelman’s blog and on Bluezones.com.
As a consequence, I’m slightly decreasing my opinion of some foods that I was encouraged to eat by the Blue Zone memes: whole grains, beans, olive oil, and sweet potatoes. Sweet potatoes still seem likely to be quite healthy compared to the average American food, but I’m now uncertain whether they’re better or worse than the average paleo food (I previously considered them one of the best foods available). The rest of those foods seem no worse than the average American food, but I’m less optimistic about the safety of the average American food than I previously was.
I’ve also become less confident in the safety of a diet with less than 10% of calories from protein (Blue Zone Okinawans in 1949 got 9% of calories from protein), but I’d already decided not to pursue a low protein diet.
H/T William Eden.