Coffee drinkers have yet another reason to relish their favorite drink - it can protect against Alzheimer's disease, say researchers.
The research team from University of South Florida has revealed that five cups of coffee not only helps reverse the effects of the disease but can treat it too.
They showed that caffeine significantly decreased abnormal levels of the protein linked to Alzheimer's disease, both in the brains and in the blood of mice exhibiting symptoms of the disease.
"That's important because caffeine is a safe drug for most people, it easily enters the brain, and it appears to directly affect the disease process."
During the study, the researchers gave half the mice caffeine in their drinking water. The other half got plain water.
At the end of the two-month study, the caffeinated mice performed much better on memory tests and thinking skills.
Mice genetically induced to develop the disease also showed a 50 per cent reduction in levels of amyloid protein in their brains.
Their memories were as sharp as those of healthy older mice without dementia.
"These are some of the most promising Alzheimer's mouse experiments ever done, showing that caffeine rapidly reduces beta amyloid protein in the blood, an effect that is mirrored in the brain, and this reduction is linked to cognitive benefit," said Dr Huntington Potter, director of the Florida Alzheimer's Disease Research Centre in Tampa.
Neil Hunt, chief executive of the Alzheimer's Society, said: Previous research into caffeine and dementia has suggested that it could delay Alzheimer's disease and even protect against vascular dementia.
"This research in mice suggests coffee may actually reverse some element of memory impairment," Hunt added.
The study is published in the Journal of Alzheimer's Disease.