January 9th, 2012
04:00 PM ET
It's hard to escape the warnings of the dangers of smoking, but one component of cigarettes - nicotine - might actually have a therapeutic use, preliminary research suggests.
A small study, published Monday in the journal Neurology, finds that using a nicotine patch may help symptoms of mild cognitive impairment, a condition characterized by a noticeable memory problem. Many, but not all, patients with mild cognitive impairment will go on to develop Alzheimer's disease; scientists are still working on predicting who is most at risk.
A nicotine patch releases nicotine slowly over a number of hours. It gets into the blood stream, travels to the brain and interacts with receptors on nerve cells. In particular, it seems to activate receptors on nerve cells important for a circuit involved in attention, learning and memory.
Dr. Paul Newhouse of the University of Vermont Medical School and colleagues studied 74 people and saw improvement in measures of attention, memory and mental processing among those who received the nicotine patch treatment over six months. But it's hard to say whether these patients recovered fully because they were not tested before developing memory problems.
"I think nicotine could be one of the answers we end up with" for memory decline, Newhouse said. Multiple strategies will be needed to combat Alzheimer's disease; nicotine "may not be the only answer, but could be one of the answers," he said.
But Bill Thies, Chief Medical and Scientific Officer of the Alzheimer's Association, urges caution. Certain drugs that are approved for Alzheimer's disease, called anticholinesterase drugs (such as Aricept), slow the breakdown of the brain chemical acetylcholine. Acetylecholine in memory circuits works on nicotinic receptors. So it's not surprising to Thies that nicotine would show similar benefits.
"The course of the disease eventually overwhelms the effect of the medications, so they work for a few months and then they start to drop off," he said. It's possible that the same decline in effectiveness would also occur with nicotine after a matter of months.
The study did not address what impact nicotine would have in combination with these anticholinesterase drugs, he said.
And nicotine is not entirely innocuous. Studies have shown that smoking is a risk factor for Alzheimer's. Researchers do not recommend smoking to get the benefits of nicotine described in this study, nor do they advocate using nicotine patches for the purposes of cognitive benefits.
Also, if a person uses a nicotine patch for years at a time, there may be side effects including in cardiovascular disease, although this is not proven, Thies said.
All 74 participants in this study were nonsmokers. The only consistent side effect observed was a small amount of weight loss, which isn't surprising since nicotine is an appetite suppressant.
Nicotine patches retail about $2.30 to $2.85 per patch on Amazon.com, depending on which company and quantity per box you choose. For the purpose of smoking cessation, nicotine patch regimens usually involve using one patch per day for eight to 10 weeks (although they may help more with withdrawal then staying away from cigarettes, a new study shows).
Memory loss isn't the only area where nicotine is being considered, such as Tourette syndrome. Newhouse presented a pilot study on Parkinson's disease back in 2000. There has been pharmaceutical interest in using nicotine-like drugs for pain control and bowl disease
Delivering nicotine by way of a patch is more efficient than through a pill, since the patch doesn't affect the liver or stomach, which would suffer side effects, Newhouse said.
Newhouse's group is going to propose a larger trial for a longer period of time. The scientists want to get at the issue of whether this improvement effect would last - specifically, how much longer than the six months reported in this initial study.
Nicotine patches are not approved by the U.S. Food and Drug Administration for this purpose of treating patients with mild cognitive impairment. For that matter, there is no FDA-sanctioned treatment for mild cognitive impairment at all.
There is the potential for nicotine to protect against further deterioration, but so far nothing has been found to slow the progression of Alzheimer's. Experts agree that whatever intervention works will probably have to be given as early as possible in the course of the disease.
If people or their families are noticing memory problems, they should seek an evaluation from a doctor, Newhouse said.
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