Pubdate: Thu, 24 Feb 2005
Source: Guardian, The (UK)
Copyright: 2005 Guardian Newspapers Limited
Author: Ben Sills in Madrid and Ian Sample
Bookmark: (Cannabis - Medicinal)


Scientists at one of Spain's leading research centres claimed yesterday to 
have found evidence that cannabis helps prevent the memory loss experienced 
by people suffering from Alzheimer's.

The potential breakthrough in understanding a disease that affects nearly 
half a million people in Britain, and around nine million worldwide, was 
made by a team led by Marma de Ceballos at the Cajal Institute in Madrid.

Their study seems to show that THC, the main active ingredient in cannabis, 
inhibits the activity of cells that cause damage to neurons in the brain.

Although the study is preliminary, it was welcomed by patient groups.

"Right now, there are no good drugs for Alzheimer's. There are some that 
treat symptoms but nothing that halts the disease," said Susanne Sorensen, 
head of research at the Alzheimer's Society.

While the beneficial effects of cannabis looked promising, Dr Sorensen 
cautioned that people with Alzheimer's should not start using the drug to 
help their memories, because of side effects.

Memory loss in Alzheimer's patients is not fully understood, but part of 
the problem is thought to lie with cells called microglia that surround 
neurons in the brain. In Alzheimer's, the activity of microglia gets out of 
control, damaging neurons and killing off parts of the brain. Dr de 
Ceballos's team conducted two separate experiments using human brain tissue 
and rats which showed that THC inhibits the activity of microglia, thus 
reducing memory loss.

Dr de Ceballos said the results showed that THC could help prevent memory 
loss in Alzheimer's patients, although the reasons why this might happen 
are still to be explored.

The next stage, she said, would be to test the rats using a synthetic 
equivalent of THC which inhibits the activity of microglia without 
intoxicating the rats as well.

"There's a long way to go before we will know if it is actually possible to 
stop the progression of Alzheimer's," she said. 
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MAP posted-by: Richard Lake