[xkcd-sucks]

The first one I head of was https://academic.oup.com/ageing/article/46/2/245/2654230, which did not consider income but did consider other typical biomarkers of health (HDL/LDL, BP/HR, smoking, etc)

Emerging evidence suggests a plausible mechanism is the "heat-shock response", which upregulates a lot of crap related to cleaning up misfolded (= aggregatey) proteins, like protein degradation and chaperone protein expression. Where most of these neurodegenerative diseases AD, PD, some dementias, CTE, prion diesases etc. involve protein aggregation at some point whether necessary-and-sufficient or just along for the ride. Like at this point if some kind of degenerative disease isn't thought to relate to protein aggregation, it's more likely nobody's bothered to look for it

Anecdotally/personally, it seems like there's kind of a step response going from "not cooked" to "cooked", the good stuff doesn't happen until you get "cooked" (ideally remaining that way for a while), and this seems to happen around a body temperature of 38.5-39C.