Caffeine protects the brain. I’ve heard some clinicians vilify it or even tell people with Parkinson’s to avoid it; but look closely at this wiki.
Though it was recently discovered (lookup the Friedrich-Alexander-Universität study from 2017) that Parkinson’s is in part an autoimmune disease, almost no American clinicians address it as such. Though the primary drug used to treat Parkinson’s (l-dopa) accelerates the progression of the disease, in part through the increased expression of adenosine, almost no American clinician includes drugs which suppress adenosine (A2a receptor antagonists) for patients using l-dopa. I know. I’ve had several clients with Parkinson’s.
Caffeine is proven to suppress adenosine expression. That is, caffeine addresses several levels of the actual disease; whereas l-dopa addresses some symptoms while progressing the disease. Most researchers, however, fail to use effective (high enough) dosages of caffeine in Parkinson’s research. Odd.
More odd is that there are now drugs being developed for Parkinson’s specifically for their role in adenosine suppression. Here’s one, called “istradefylline.” Pay extra close attention to paragraph one, especially sentence 4.
When it’s caffeine, authorities tend to dismiss its effectiveness or vilify it. When it’s a vendable pharma drug, it’s an official therapy. Curious. I'm as skeptical as the next consumer when it comes to the specious claims made about supplements and essential oils. But when you hearken to the effectiveness of "official therapy" or "mainstream science" or "approved medications" simply because they're popular among official bodies of authority in the scientific or medical world you are not being skeptical and freethinking.