>> ^imstellar28:
Cancer, Heart Disease, Diabetes, Dementia, etc. were all virtually nonexistent several hundred years ago.

Oh come on, several hundred years ago people died if they got cut accidentally and their wound got infected. People didn't live long enough to get late onsetting illnesses like the ones you mentioned, for example cancer risk for most varieties increases with age.

Historically they were prevalent Hippocrates described several kinds of cancers. http://en.wikipedia.org/wiki/Cancer#History

Diabetes was coined by Aretaeus of Cappadocia, and has an extensive history as well http://en.wikipedia.org/wiki/Diabetes_mellitus#History

Human development has increased life expectancy and assurance of most people's survival over previously life threatening conditions like e.g. premature birth. Thus creating a situation where a larger proportion of the populace can get late life conditions.

I do agree with unhealthy living and consumption but thats another issue.