9.14.2006
Caffeine Protects Against Alzheimer's?
>
In a study just published in Neuroscience, Caffeine appears to impact onset of Alzheimer's Disease -if you think that your daily cups of coffee only provide you with alertness after you wake up or during the day, think again. Long-term intake of caffeine, the major constituent in coffee and tea, has been shown to reduce the risk of Alzheimer’s in mice that develop the disease. In a study just published on-line in the journal Neuroscience, researchers at the Byrd Alzheimer’s Institute in Tampa, Florida, are reporting that caffeine intake equivalent to five cups of coffee a day in humans, protects Alzheimer’s mice against otherwise certain memory impairment and reduces Alzheimer’s pathology in their brains.
An earlier study in humans hinted that caffeine was protective against Alzheimer’s disease by showing that Alzheimer’s patients consumed markedly less caffeine during the 20 years preceding disease diagnosis compared with age-matched individuals without Alzheimer’s disease.
"We wanted to test the ability of dietary caffeine intake to protect against Alzheimer’s disease in a highly controlled study in Alzheimer’s mice where the only variable that was different between groups was whether caffeine was in their drinking water or not," says Dr. Gary Arendash, Ph.D, lead researcher in the study. "We were surprised to find that Alzheimer’s mice given caffeine in their drinking water throughout adult life performed much better than Alzheimer’s mice not given caffeine and very similar to normal mice without the disease," adds Arendash.
Not only was the memory of Alzheimer’s mice protected by the human equivalent of five cups of coffee per day (500 mg/day), but levels of an abnormal brain protein that most researchers believe causes the disease were reduced. This abnormal protein, called beta-amyloid, is formed by the actions of two enzymes on a much larger protein called APP, which extends through the cell membrane of brain cells. The two enzymes (BACE and PS1) cut APP in specific places, resulting in beta-amyloid formation. Once formed, beta-amyloid molecules aggregate into "plaques" within the brain, causing death and dysfunction of cells, especially in brain areas important for learning and memory. The researchers found that caffeine reduces the level of both BACE and PS1 enzymes, thus resulting in much less of the dangerous beta-amyloid protein.
