A coffee grower displays beans at his farm shop in Sao Domingos do Norte, Brazil. (Alexandre Meneghini/Reuters) A new study seems almost too good to be true: Drinking coffee may help prevent dementia.

An apple a day keeps the doctor away, but your morning java might keep you sharp. While the scientific opinions on life's greatest pleasures -- coffee, alcohol, dark chocolate -- seem to be in a constant state of flux, researchers in Cambridge, Massachusetts, this week are giving your caffeine addiction the thumbs-up, saying that it might actually be good for long-term cognitive function.