In fact, after two months on caffeine, the Alzheimer's mice scored just as well as normal mice on memory tests.
The studies also found caffeine cut the animals' levels of beta amyloid, the protein linked to plaque found in human Alzheimer's patients.
"Caffeine is the most widely used psychoactive drug in the world and it might protect against Alzheimer's," said Gary Arendash, a researcher at the Byrd Alzheimer Institute in Tampa, Fla..
Forgetfulness is a possible sign of the onset of Alzheimer's, and researchers say the study indicated caffeine could protect the brain from small changes in one's memory capability.
The study found that Alzheimer's disease strikes nearly 50 percent of Americans 85 years old and older.
The study is published in the Journal of Alzheimer's Disease.