Nicotine is the highly addictive substance found in tobacco that gives users a buzz. It may also have some health benefits. See more drug pictures. Photographer: Sascha Dunkhorst | Agency: Dreamstime

By now the health hazards of smoking and tobacco use are well known. Smoking is the chief preventable cause of death in the United States and a major contributor to many types of cancer, heart disease and other serious or potentially fatal conditions. Cigarettes are also expensive, addictive and they leave a bad odor. However, medical researchers have begun to show interest in one of the most reviled components of cigarettes -- nicotine. And they're interested in this potent, powerfully addictive substance for its health benefits.

Over the past decade, new research has taught us more about how nicotine affects the brain and the body. Some of it is good news -- for example, a lower incidence of Alzheimer's disease in smokers. Research has pointed to a compound called acetylcholine as the reason. Nicotine is structurally similar to acetylcholine, a naturally-occurring compound that serves as a neurotransmitter. Nicotine binds to nerve receptors and makes nerve cells fire more frequently. In one study, a group of Alzheimer's patients were given nicotine patches, while another received a placebo. Those with nicotine patches maintained their cognitive abilities longer and sometimes even recovered lost cognitive function. A follow-up study indicated that nicotine may also boost cognitive abilities in elderly people who aren't suffering from Alzheimer's but who are experiencing the typical mental decline associated with old age.



­The transformation with nicotine happened when the nicotine patch was introduced. Intended to help smokers quit, the nicotine patch also opened up a whole new way of studying the drug. Suddenly scientists had a reliable delivery system -- one without the numerous carcinogens found in cigarettes -- that could be standardized across various studies. A 1982 study revealed that patients with ulcerative colitis had fewer flare-ups when taking nicotine. However, side effects proved nicotine to be a poor long-term treatment.

In 2000, a study performed at Stanford revealed surprising results about nicotine's effects on blood vessels. Contrary to popular opinion, the study showed that nicotine actually boosts the growth of new blood vessels. The discovery may lead to new treatments for diabetes. Many people with severe diabetes experience poor circulation, which can lead to gangrene and ultimately, limb amputation.

Researchers from the Scripps Research Institute published a study in 2002 that revealed a connection between nornicotine -- a chemical found in tobacco and also created when the body breaks down nicotine -- and a reduction of Alzheimer's symptoms. However, nornicotine is toxic, pointing to the need for a nontoxic substitute.

­­­­In 2006, Duke scientists found that people with depression who were treated with nicotine patches reported a decrease in their depressive feelings. The results were perhaps not surprising for a drug associated with imparting a "buzz." However, the research also showed a direct link between nicotine and an increase in the release of dopamine and serotonin, two vital neurotransmitters. A lack of dopamine or serotonin is a common cause of depression.

These studies point to potentially positive aspects of nicotine, but what can we do with this information? Surely people shouldn't start smoking for their health. Read on to find out about drug research associated with nicotine.

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