[rc_hadoken]

Zimbabwean here but live in Canada now. There are numerous older people back in Zimbabwe who probably haven't seen a toothbrush aside from an ad in a newspaper (they are 70+ years of age). No Alzheimer's to speak of its possible this is an anecdote but I don't hear of its prevalence there or other non-north--american countries. But then again those countries don't have as big of a media footprint and research. I still think it's something westerners do (or do not do!) that causes its prevalence here.

[KMag]

At least in the mid-2000s, Zimbabwe had the lowest life expectancy in the world, according to the WHO. There are differences in distribution, particularly skewed due to infant and childhood mortality rates, but I'd still expect to see significantly lower rates of late-onset diseases in Zimbabwe. Even looking at the percentage of 70+ year-olds with a given disease, I'd expect significant survivor bias; if people don't live long once they get a given disease, the percentage of the population with that disease is low. You need to be much healthier in Zimbabwe in order to reach old age.

Differences in access to diagnosis can also skew statistics. We don't actually ever know prevalence of a given disease, only diagnosis rates (and perhaps gross estimates of underdiagnosis and false positive diagnostic rates).

Given the factors above, looking at any late-onset disease, I'd expect that the percentage of people living long enough to be diagnosed is much lower in Zimbabwe. Even when just looking at people over the age of 70, I'd expect the percentage living with any given disease that significantly affects life expectancy to be much lower in Zimbabwe.

Having a good healthcare system deceptively skews lots of health-related statistics.

As far as factors related to the article, Western diet is probably much higher in sugar and meat than an average Zimbabwean diet over the past 70 years. I have several dentist friends here in Hong Kong who mention patients being skeptical about modern dental practices because their grandparents never had problems, forgetting that their grandparents had diets much higher in plants and much lower in sugar.