Researchers have long been aware that fewer smokers get Alzheimer's and Parkinson's diseases than non-smokers. Up to April l992, of the 17 studies on Alzheimer's and smoking which had been published in peer-reviewed journals, 13 reported a reduced risk for smokers and only four found no difference between smokers and non-smokers. Similar findings have been published on the effect of smoking and Parkinson's disease.

In an article in The Times of London (9/7/93), Dr. James Le Fanu provided an examination of the research on smoking and its apparent protective effect for certain diseases. Dr. Le Fanu stated unequivocally: "Smokers have a 50 per cent reduced risk of developing Alzheimer's--and the more smoked the greater the protection." He also noted that emerging research points to a similar effect of smoking on Parkinson's disease.

So striking was the apparent protective effect of smoking on Alzheimer's and Parkinson's that increasingly biomedical researchers are experimenting with nicotine to treat the symptoms of these dread disease in-patients who have been diagnosed as having them. Results from these experiments have all showed promise in alleviating the symptoms of these diseases with the administration of nicotine.

The mechanism by which the nicotine in tobacco works to protect smokers is that it increases the number of so-called "nicotinic" receptors in the brain, which in turn influence the production and release of the neurotransmitter acetylcholine. Those who come down with Alzheimer's show a marked loss of "nicotinic" receptors in their brains and thus have reduced levels of acetylcholine, which is necessary for memory and other brain functions.

Research has shown that tobacco smoke (and the nicotine therein) inhibits the activity of monoamine oxidase B (MAOB). Experiments on mice which were genetically engineered to be without the gene for MAOB "were resistant to the neurodegenerative effects of MPTP, a toxin that induces a condition reminiscent of Parkinson's disease," (Dr. Jean C. Shih researcher at the University of Southern California, as reported in Reuters, 10/7/97, "Isoenzyme Inhibited by cigarette Smoke May Have Role in Aging and Neurodegeneration"). The findings of Dr. Shih and her colleagues point to a protective effect from smoking on the aging of the brain.

Other diseases for which smoking and nicotine appear to be protective are ulcerative colitis, Tourette's Syndrome, and possibly rheumatoid arthritis and colorectal cancer.

Below are excerpts from some recent articles and studies on nicotine, Alzheimer's, Parkinson's, cognitive abilities, Tourette's and ulcerative colitis.

"In human studies, reported performance improvements with post-trial administration of nicotine have all involved associated learning (Mangan and Golding l883; Colrain et al, l992; Warburton et al, l992).... Nicotine improves performance by increasing the attentional resources available for such strategic processing," [Rusted JM, et al, "Facilitation of memory by post-trial administration of nicotine: evidence for attentional explanation," Psychopharmacology, 108(4):452-5, l992].

"1. Nicotine improves attention in a wide variety of tasks in healthy volunteers. 2. Nicotine improves immediate and longer-term memory in healthy volunteers. 3. Nicotine improves attention in patients with probable Alzheimer's Disease," [Warburton D M, "Nicotine as a cognitive enhancer," Progress in Neuro-Psychopharmacology and Biological Psychiatry, 16(2): 181-91, Mar l992]

"Researchers observed lessening of tic frequency and severity 3 minutes after subjects chewed [nicotine] gum, even more so at 10 minutes." [Rickards E H, "Nicotine gum in Tourette's disorder," American Journal of Psychiatry, 149(3):417, Mar l992. Note: the subjects were all children with Tourette's disorder].

"In humans, nicotine-induced improvement of rapid information processing is particularly well documented.... Preliminary studies have found that some aspects of the cognitive deficit in Alzheimer's disease can be attenuated by nicotine." [Levin E D, "Nicotinic systems and cognitive function," Psychopharmacology, 108(4):417-31, l992]

"Improvement in attention, learning, reaction time, and problem solving have been reported.... Different processes, including attention, stimulus evaluation, and response selection, appear to be involved in the effect of nicotine on human information processing." [Le Houezec J, Benowitz N L, "Basic and clinical psychopharmacology of nicotine," Clinics in Chest Medicine, 12(4):681-99, Dec l991].

"Despite the absence of change in memory functioning, these results demonstrate that DAT [Alzheimer's disease] patients have significant perceptual and visual attentional deficits which are improved by nicotine administration." [Jones G M, Sahakian B J, et al, "Effects of acute subcutaneous nicotine on attention, information processing and short-term memory in Alzheimer's disease," Psychopharmacology, 108(4):485-94, l992].

"When you look at people who smoke, and people who don't find those who smoke cigarettes are about half as likely to get Parkinson's disease." [Dr. David Morens of the University of Hawaii School of Public Health as quoted in "Stunned docs discover cigarettes stop Parkinson's," by Roger Field, New York Post, 6/15/95. Dr. Morens and colleagues examined 34 studies on smoking and Parkinson's. Their study was published in the June, l995 issue of Neurology].

According to a study conducted at Surrey University and published in the journal Psychopharmacology, smokers are more mentally alert at night than non-smokers. Rosemary Brook, spokeswoman for Surrey University's psychopharmacology unit, said, "The results showed that smokers were subsequently able to perform various tests of reaction, memory recall and other related tasks consistently better than the non-smokers," [Reported on the BBC News, 4/8/98, "Cigarettes 'keep you sharp after dark'."

In a presentation at the 151st annual meeting of the American Psychiatric Association (June 8, l998 in Toronto), Dr. Paul Newhouse of the University of Vermont reported on his research on treating Parkinson's disease with nicotine. "Preliminary analysis shows improvements after acute nicotine administration in several areas of cognitive performance." These areas included reaction time and central processing speed. The researchers also reported that after chronic use of nicotine on Parkinson's patients, motor function and the ability to move also improved. [Reported by Reuters, 6/8/98, "Nicotine patch promising for Parkinson's"].

"The influence of smoking on the risk of developing ulcerative colitis is well documented. Compared with lifetime nonsmokers, the risk is reduced in smokers...." [Tysk C, Jarnerot G, "Has smoking changed the epidemiology of ulcerative colitis?" Scandinavian Journal of Gastroenterology, 27(6):508-12, Jun l992].

"When association between cigarette smoking and UC [ulcerative colitis] are examined, never-smokers are approximately three times more likely to develop UC than smokers. A consistent finding from study to study is that quitters have a mildly increased risk of developing UC which suggests that cigarette smoking may have a protective effect," [Lashner B A, "Inflammatory bowel disease: family patterns and risk factors," Comprehensive Therapy, 18(8):2-4, Aug l992].

"It is beyond doubt that smokers are protected against ulcerative colitis, and the more that is smoked the greater the protection--so those on 25 cigarettes a day or more have a risk as little as one-tenth that of non-smokers," (Dr. Martin Osbourne, surgeon at the Royal Free Hospital in London, as quoted in the Daily Telegraph, 9/7/93).