Nicotine found to have health benefits

The results, presented Sunday at a meeting of many of the 20,000 scientists worldwide who study the brain, hinted that nicotine-based drugs may one day provide relief for Alzheimer's and Parkinson's disease, schizophrenia and anxiety disorders.

The new research on animals explains anecdotal evidence that smoking helps schizophrenics function better, that smokers are less likely to develop the motor disorder Parkinson's disease and that people with Alzheimer's disease using nicotine patches focus better on tasks.

Nicotine itself, a natural substance found in tobacco and also in small quantities in tomatoes, eggplants and bell peppers, is probably not a good candidate to become a therapeutic drug because it affects so many of the body's systems.

In addition to stimulating the brain, nicotine can cause the heart to race dangerously, can cause nausea and can be highly addictive.

``Nicotine's a bit of a sledgehammer,'' said Darwin Berg, a professor of biology at the University of California at San Diego. ``You want drugs to be much more specific.''

In one study, rats given a molecule that mimics nicotine were smarter -- better at learning their way around mazes and at solving new problems. Other rats with symptoms of Alzheimer's disease had memory and learning problems ``completely reversed'' after being given the nicotine-like compound, said Edward Levine, an associate professor of toxicology at Duke University.

Researchers at R.J. Reynolds Co., who have long studied nicotine as an adjunct to cigarette development, also are looking at nicotine's therapeutic potential.

Two nicotine-like compounds developed in the company's Winston-Salem labs improved both short- and long-term memory in rats and even kept brain cells from dying when they were exposed to toxic chemicals that should have killed them.

``Traditional drugs have focused on ameliorating symptoms,'' said Patrick Lippiello, a neuroscientist with R.J. Reynolds who noted that current drugs available for Alzheimer's have only marginal effects. ``Now drugs can focus on delaying the onset of these diseases and perhaps get to the point where you can prevent the disease altogether.''

Lippiello and Levine are working to design molecules that have nicotine's beneficial effects without its drawbacks.

``You get clues from natural products, but you have to go on and improve on that theme,'' said Lippiello. R.J. Reynolds now is talking with pharmaceutical companies to develop drugs based on nicotine mimics, he said.

Our bodies do not produce any nicotine, but it exploits targets in our brains that normally respond to a chemical that we do produce naturally.

One study reported Sunday did use nicotine in its natural state to understand a paradox that's long surrounded smoking.

Nicotine itself causes a stress response -- a racing heart and higher blood pressure. ``On the other hand, people say they smoke because it relaxes them'' said Esther Sabban, a professor of biochemistry and molecular biology at New York Medical College.

Sabban compared the stress levels of nicotine-free rats with those given one shot of nicotine and those who had the constant levels of nicotine a person wearing a nicotine patch or smoking routinely would have.

Only rats receiving nicotine long term had the calmer responses, she said. Other studies have showed normally fearful rats given nicotine are less stressed and braver in their rodent explorations.

One interpretation of the animal findings is that chronic smoking can help block the body's stress response while nicotine given to a non-smoker wouldn't have the same relaxing effect.

Despite nicotine's apparent promise, researchers were quick to add that smoking, because many other chemicals in smoke are harmful, remains taboo. ``The relationship between lung cancer and smoking is clear,'' said Sabban. ``That's not the way you want to cure Alzheimer's disease.''

Slapping on a nicotine patch in an attempt to cure a disorder isn't advisable either, said Levine, because no studies have been conducted to determine if such use is safe.