Attention all java junkies…there may be less pressure to kick the habit now. That’s because new research suggests caffeine significantly decreased abnormal levels of the protein linked to Alzheimer's disease in mice. The aged mice bred to develop symptoms of Alzheimer's disease saw their memory impairment reversed when they were given a lot of caffeine—the equivalent of five cups of coffee a day—according to University of South Florida researchers at the Florida Alzheimer's Disease Research Center.

Published recently in the Journal of Alzheimer's Disease, two studies show 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. The researchers say that both studies build upon previous research that revealed caffeine in early adulthood prevented the onset of memory problems in mice bred to develop Alzheimer's symptoms in old age.

"The new findings provide evidence that caffeine could be a viable 'treatment' for established Alzheimer's disease, and not simply a protective strategy," says lead author Gary Arendash, a USF neuroscientist with the Florida Alzheimer's Disease Research Center. "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."

Researchers at the Florida Alzheimer's Disease Research Center and Byrd Alzheimer's Center at USF hope to begin human trials to evaluate whether caffeine can benefit people with mild cognitive impairment or early Alzheimer's disease, says Huntington Potter, director of the Florida Alzheimer's Disease Research Center and an investigator for the caffeine studies. The research group has already determined that caffeine administered to elderly non-demented humans quickly affects their blood levels of β-amyloid, just as it did in the Alzheimer's mice, researchers say.

"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," Potter says. "Our goal is to obtain the funding needed to translate the therapeutic discoveries in mice into well-designed clinical trials." The highly controlled studies using Alzheimer's mice allowed researchers to isolate the effects of caffeine on memory from other lifestyle factors such as diet and exercise, researchers say says.

The study included 55 mice genetically altered to develop memory problems mimicking Alzheimer's disease as they aged. After behavioral tests confirmed the mice were exhibiting signs of memory impairment at age 18 to 19 months—about age 70 in human years—the researchers gave half the mice caffeine in their drinking water while the other half got plain water, the researcher say. Meanwhile, the Alzheimer's mice received the equivalent of five 8-oz. cups of regular coffee a day. The researchers say that the amount is equivalent to the 500 milligrams of caffeine contained in two cups of specialty coffees like Starbucks, or 14 cups of tea, or 20 soft drinks.

At the end of the two-month study, the caffeinated mice performed much better on tests measuring their memory and thinking skills, researchers say. In fact, their memories were identical to normal aged mice without dementia, they add. The Alzheimer's mice drinking plain water continued to do poorly on the tests.

What’s more, the brains of the caffeinated mice showed nearly a 50 percent reduction in levels of beta amyloid, a substance forming the sticky clumps of plaques that are a hallmark of Alzheimer's disease, the researchers say. Other experiments by the same researchers indicate that caffeine appears to restore memory by reducing both enzymes needed to produce beta amyloid. The researchers also suggest that caffeine suppresses inflammatory changes in the brain that lead to an overabundance of beta amyloid, they add.