Tuesday 7 July 2009

A simple drug for Alzheimer's disease?

Alzheimer's disease is the most common form of dementia, affecting 1 in 10 people over the age of 65 and 1 in 5 over the age of 80. This truly debilitating disease gradually reduces the patient to living in the past without the ability to make new memories, and is not only devastating for the patients and their families, but is also a heavy burden on our health system.

Researchers at the Florida Alzheimer's Disease Research Center may have found that one of the most harmless and commonplace 'drugs', caffeine, may have a positive effect on the cognitive abilities of patients who suffer from the disease. The research group studied 55 mice that were genetically modified to develop Alzheimer's disease. After the mice had developed the disease, half of the group was given 500 milligrams of caffeine – the equivalent of 5 cups of regular coffee - in their drinking water every day. The other half did not get any caffeine. The researchers showed that caffeine improved memory and thinking abilities significantly after only two months of treatment, and were able to perform as well as healthy mice of the same age. The mice that had not received treatment continued to deteriorate.

The main cause of Alzheimer's disease is the formation of tangles and plaques in the brain, causing brain cells to die and communication pathways to be disrupted and destroyed. Broadly speaking, there are two enzymes responsible for the formation of the plaques and tangles, tau and amyloid beta/β. Plaques are formed by large clumps of amyloidβ in the spaces between cells. Tangles are formed by tau. Tau, normally a building block of the transport system of a cell, starts to disintegrate this transport system as a result of a chemical change, causing damage to the cell's nutrition- and communication, eventually leading to the death of the cell.

In patients with Alzheimer’s disease, an abnormally high level of amyloidβ is found in the blood. The study published in the Journal of Alzheimer's Disease this week shows a remarkable decrease – nearly 50% – in the abnormal levels of this protein in the blood and brains of mice treated with caffeine. Thus, the improvement in memory and thinking thus seems to be related to the decrease of tangles and plaques in the brain.

Although mice, needless to say, are quite different from humans – and the development of the disease is different in both species – these results are really promising. The first very preliminary results from tests in elderly people indicate that levels of amyloidβ decrease rapidly after treatment with caffeine.

But don’t think you will be able to boost your memory by drinking coffee; when healthy mice drank 500 milligrams of coffee each day, their memory did not improve. So though we may have a wonder drug to cure one of the most debilitating diseases of our time, alas, we still haven’t found a way to become smarter.

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