I've repeatedly heard the claim, often from anti-fructose advocates, that there is a skyrocketing prevalence of two formerly rare disorders: non-alcoholic fatty liver disease (NAFLD) and juvenile type 2 diabetes:
- Study Reveals Sizable Increase in Diabetes Among Children - New York Times
- New data show non-alcoholic fatty liver disease will reach epidemic status in the US - ScienceDaily
- A Global Effort to Address the Epidemic of Fatty Liver Disease - Medscape
I don't know if the historical data on these conditions is comparable to the data we're getting today. If screening methods became more sensitive, testing became more frequent, or diagnostic criteria changed, you could see more cases even if the underlying health conditions hadn't changed. This would be similar to the ostensible "autism epidemic" which turned out to mostly reflect change in diagnostic practices. It seems especially possible for NAFLD, since it is mostly asymptomatic. Type 2 diabetes, while it has more effects on health, can also be missed during the early stages if doctors don't think to look for it.
There's plenty of primary source material on these claims, but I haven't reviewed enough to know whether the methods used are reliable. I'd like to know if there's solid evidence for these four claims:
- Incidence of juvenile type 2 diabetes is increasing.
- Incidence of NAFLD is increasing.
- Juvenile type 2 diabetes was, until recently, very rare.
- NAFL was, until recently, very rare.
(these are logically distinct claims, but I'm putting them in the same question because I expect much of the same evidence to apply.)