Table 1.

Findings of caffeine effects on main neurodegenerative diseases.

Drug Type (Adenosine Receptor Subtype)	Known Effects on Neurodegenerative Diseases
	Parkinson’s Disease	Alzheimer’s Disease (AD)
Caffeine (adenosine receptor antagonist)	Improves motor activity [7, 134].	Prevents the accumulation of amyloid-β- peptide (Aβ) in and around cerebral blood vessels [135].
	Down-regulates neuroinflammatory responses and nitric oxide (NO) production [136, 137].	Reverses cognitive impairment and decreases brain Aβ levels in AD mice [138].
	Reduces both motor and nonmotor early onset symptoms [139].	Consumption of 3-5 cups/day of coffee at midlife is associated with a decreased risk of dementia/AD by about 65% in later life [129].
	Prevents the loss of nigral dopaminergic neurons [140].	Protects against oxidative stress and AD-like pathology in rabbit hippocampus [141].
	Protects against disruptions of the blood-brain barrier in animal models [142].	Increases mitochondrial function and blocks melatonin signaling to mitochondria [143].
		Men in the highest quartile of caffeine intake are less likely than men in the lowest quartile to have any lesion type [144].