A few cups of coffee a day may be all that is needed to reverse the effects of Alzheimer's disease, new research suggests.
They plan to follow up the initial results from animal experiments with human patient trials. Leading researcher, the US neuroscientist Gary Arendash said: "The new findings provide evidence that caffeine could be a viable 'treatment' for established Alzheimer's disease, and not simply a protective strategy. 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."
A key aspect of Alzheimer's is sticky clumps of abnormal protein in the brain called beta amyloid plaques. Mice with a rodent equivalent of the disease showed a 50 per cent reduction in levels of amyloid protein in their brains after scientists spiked their drinking water with caffeine. The change was reflected in their behaviour as the mice developed better memories and quicker thinking.
Dr Arendash's team, from the Florida Alzheimer's Disease Research Centre in Tampa, studied 55 mice, genetically engineered to develop dementia symptoms identical to those of Alzheimer's. At the age of 18 to 19 months, about 70 in human years, the mice were showing signs of memory impairment. The researchers then gave half the mice water containing caffeine while the other half continued to drink ordinary water.
Humans receiving an equivalent dose for their body weight would be consuming two cups of strong "coffee shop" coffee, 14 cups of tea, or 20 cola drinks a day.
At the end of the two-month study, the caffeine-drinking mice performed far better on tests of memory and thinking than mice given "straight" water. Their memories were as sharp as those of healthy older mice without dementia. Almost half the abnormal protein previously seen when the brains of Alzheimer's mice were examined had vanished after two months. The study was published online in the Journal of Alzheimer's Disease.
But the scientists found no evidence that caffeine boosted the mental performance of healthy young brains. Normal mice given caffeinated drinking water throughout their lives had memories no better than those raised on regular water when they reached old age.
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