I can see an awful lot of potential confounding factors there, though. Life expectancy in most countries in Africa, for instance, isn't even long enough for no

I can see an awful lot of potential confounding factors there, though. Life expectancy in most countries in Africa, for instance, isn't even long enough for non-early onset AD to develop. You'd expect less AD just because half or more of the population is going to die from other stuff at 65 or earlier. https://www.statista.com/statistics/1218173/life-expectancy-in-african-countries/ https://www.statista.com/statistics/1218173/life-expectancy-...