It's difficult to ignore the fact that people with Parkinson's Disease eat more chocolate. Were they doing that before their diagnosis?
It is as difficult to ignore as the odd fact that shortly before dying most people have been touched and poked by doctors and nurses.
As to why 'people with PD eat more chocolate', if true, maybe to self-medicate via chocolate induced dopamine boost. Or because of any other among myriad known and unknown correlations and connections between phenomena. To make a causal inference, you need a randomized study or animal experiment using doses of chocolate (or cocoa or PEA) comparable to what humans would consume.
How did this article get published, if its speculations are completely without merit? The authors go so far as to recommend that people limit their consumption of PEA-rich foods.
Medical research is
mostly PR material dressed up as science. The same goes for other fields with strong financial incentives to deceive and a slow or ineffective punishment feedback. Science has had great press after the WWII Manhattan project, then in 1960s with space exploration and Moon landing. Like anything of value, all that good buzz has attracted a thick layer of parasites by now.
Why Most Published Research Findings Are False, PLoS Med. 2005 August; 2(8): e124.
Majority of Landmark Cancer Studies Cannot Be Replicated (re: Nature 483, 531-533 (29 March 2012))
Why are these guys out to blame chocolate for PD? Among other possibilities, there are pesticide and cosmetic companies which might benefit from muddying the waters on PD since their products, unlike cocoa, can cause PD in animal experiments without requiring massive overdoses as done in the the PEA "research" that is worrying you.
Another possibility in this case is the general
competition for control of your dopamine circuits by various networks/intelligent systems at different levels (companies, nations, people, churches, plants, pets, memes such as songs, movies, TV shows,...), seeking to extract some gains from controling your reward mechanisms. Hence the wars on masturbation, on commercial sex, on pornography, on some drugs, on anything pleasurable,... If someone can scare you away from cocoa and chocolate with junk science like the cited materials, that's another potential customer for antidepressants, cough syrups, yoga classes,...
