The Straight Times - Asia
MAY 15, 2002
Proof smoking makes you stupid
FRENCH scientists say they have found the first biological evidence that smoking can make one stupid and forgetful.
The harmful nicotine contained in cigarettes, they found, destroys brain cells and impedes production of new ones.
At the National Institute for Health and Medical Research in Paris, scientists Pier-Vincenzo Piazza and Djoher Nora Abrous gave three groups of rats intravenous jolts of nicotine while a fourth group was not given any, as a test comparison.
The three nicotine doses were either low (0.02 mg per kilogram), medium (0.04 mg per kilogram) or high (0.08 mg per kilogram).
In all three nicotine-receiving groups, the rats suffered a major fall in production of PSA-NCAM, a protein with a vital role in the 'plasticity' of the brain, which is related to the ability to learn and memorise.
Rodents which received the medium and higher doses suffered a 50 per cent greater loss in the production of new brain cells than the non-nicotine group, as well as a significantly higher rate of brain-cell death.
'These results raise an important additional concern for the health consequences of nicotine abuse and open new insight on the possible neural mechanisms of tobacco addiction,' the scientists report in the specialist American publication, The Journal of Neuroscience.
The work focused on the dentate gyrus, part of the hippocampus region of the brain, which produces PSA-NCAM as well as new brain cells throughout an individual's life.
The rats absorbed the nicotine for one hour a day for 42 days before they were dissected for examination.
The authors say their findings counter headline-making studies of the 1990s that suggested smoking could boost cognitive performance.
These studies even contended that nicotine could help prevent the onset of Alzheimer's disease because the chemical boosted neurotransmitters, which get damaged by dementia.
Later research rebutted those contentions, but it was notably based on population research or cognitive tests with smokers and non-smokers rather than on biological tests on the brains of living creatures. --AFP
Copyright @ 2002 Singapore Press Holdings. All rights reserved.
News of this new study was first presented here at Freedom in a post by JFX in a May 13 post entitled MORE Reasons!. I'm posting this May 15th Asian spin on the story both because it strikes a chord in me and because I wanted to index this piece under the Reasons to Quit message board. The title chosen by Asia's Straight Times.