 |
 |
At 07:18 14/03/98 -0500, Mario A. Gonzalez wrote: >Has any of you heard anything about Parkinson's and Smoking. January 21, 1997 BY WARREN E. LEARY - New York Times It may sound like scientific blasphemy, but medical researchers have begun paying more attention to whether nicotine might have some beneficial effects. After years of quiet discussion among scientists, hints that cigarettes can protect against some diseases or improve the outcome of others have led to growing interest in finding out why. This has focused attention on nicotine, tobacco's most active ingredient, as a potential treatment for several major health problems, including Parkinson's and Alzheimer's diseases. Without question, researchers say, cigarette smoking does far more harm than any potential good and should be strongly discouraged. But some researchers say antismoking attitudes have discouraged research into the possible benefits of nicotine. "The problem with nicotine is that it is tied to cigarettes and therefore seen as 'bad,' " said Dr. Paul Newhouse of the University of Vermont College of Medicine. "Clearly, this affects getting funding and it makes life difficult for those of us interested in nicotine as a drug. A lot of people have difficulty in being convinced that nicotine is potentially valuable." Dr. John Baron, a professor of medicine at Dartmouth Medical School who has studied data on smoking and Parkinson's disease for over a decade, agrees there has been resistance to research. "The link between smoking and possible benefits is uncomfortable for many people," he said. "It's hard to accept, in an emotional sense, that an exposure so harmful in so many ways can have benefit. I detest smoking, but I also see evidence that research on nicotine could prove valuable and should be done." How nicotine works Dr. Zach Hall, director of the National Institute of Neurological Disorders and Stroke, said the federal government spends several million dollars a year on research related to nicotine. This work is mainly focused on learning how the chemical acts on the brain and why receptors in the central nervous system bind to it so strongly, he said. But, he added, "We are not currently funding research on using nicotine as a treatment." Part of the renewed interest in nicotine as a possible therapy is that the chemical has recently become available in non-tobacco forms; for example, in patches, gum and inhalers to help people stop smoking. Also encouraging nicotine research is a better understanding of how the chemical works. Throughout the body, on the surface of many types of cells, are protein units called nicotinic cholinergic receptors. Nicotine attaches to the receptors and stimulates activity in the cell. It especially stimulates the release of many types of neurotransmitters -- chemical messengers that carry signals from cell to cell -- including dopamine, acetylcholine and glutamate. Where it may help For more than 20 years, evidence has been accumulating that cigarette smokers have a reduced risk of developing Parkinson's disease. A similar effect has also been observed in studies of Alzheimer's disease and ulcerative colitis, an inflammatory bowel disease. Data from numerous studies suggest that smokers have half the risk of developing Parkinson's disease as those who have never smoked. The disease is characterized by the death of brain cells that make the neurotransmitter dopamine, and can be treated with drugs that replace the chemical. "Nicotine stimulates dopamine production in the brain, and this could be a reason smoking appears to be beneficial with Parkinson's," said Newhouse. Small studies suggest that nicotine patches or intravenous infusions may help treat Parkinson's symptoms, he said. The relationship between nicotine and Alzheimer's disease, a progressive brain condition that leads to dementia and loss of memory, is also spurring interest. Researchers at Case Western Reserve University found that nicotine appears to interfere with a major Alzheimer's process -- the formation of beta amyloid plaque deposits that block cell-to-cell communication. The researchers found in test-tube studies that nicotine kept certain chemicals from turning into plaques that are toxic to nerve cells. copyright 1997 Detroit Free Press [log in to unmask] (Judith Richards)