Byrd Alzheimer's Institute researchers report in the online edition of the peer reviewed journal Neuroscience, that caffeine intake equal to five cups of coffee a day for humans protects mice against memory impairments and reduces Alzheimer's pathology in brains. The research follows an earlier study that hinted that caffeine might protect humans against Alzheimer's.
That study, focusing on humans, found that Alzheimer's patients consumed markedly less coffee in the 20 years prior to the disease diagnosis than did 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," 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."
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 beta-amyloid, an abnormal brain protein that most researchers believe causes the disease, were reduced.
The researchers administered caffeine to aged Alzheimer's mice, already with high levels of beta-amyloid, and caffeine intake resulted in lower beta- amyloid levels. This finding suggests that individuals living with the disease could benefit from a moderate daily intake of caffeine. The researchers began giving Alzheimer's mice caffeine in their drinking water at 4 months of age and continued treatment through 9 months of age - an age at which beta-amyloid levels are rapidly increasing in Alzheimer's mice.
During the final month of caffeine treatment, mice were tested in a variety of tasks involving learning, memory, and recognition. Across multiple behavioral measures, the Alzheimer's mice given caffeine performed much better than those that were given normal drinking water.
The study involved several laboratories and universities collaborating with the Byrd Institute. Other collaborators in the study include Dr. Jun Tan, Ph.D., of the University of South Florida College of Medicine and Dr. Ed Jackson, Ph.D., of the University of Pittsburgh School of Medicine.
For more information, visit Byrd Alzheimer's Research Center