Not only can coffee make you smarter in the short term, it may also protect your brain in old age. Alzheimer's disease is the most common neurodegenerative disorder in the world and a leading cause of dementia. In prospective studies, coffee drinkers have up to a 60% lower risk of Alzheimer's and dementia. Parkinson's is the second most common neurodegenerative disorder, characterized by death of dopamine-generating neurons in the brain. Coffee may lower the risk of Parkinson's by 32-60%.