June 10, 2012
Many people use a nicotine patch to help kick the smoking habit. But wearing a nicotine patch may also help to sharpen memory and thinking skills in those with mild cognitive impairment, a new study suggests.
Memory problems are a hallmark of mild cognitive impairment, a condition that sometimes progresses to full-blown Alzheimer’s. And nicotine is known to sharpen cognitive skills. Smokers who are given the drug, for example, do better on tests requiring attention skills. Some studies have suggested that nicotine – by patch or through injections – can boost memory in people with Alzheimer’s as well.
To test whether nicotine helps people with mild cognitive impairment, or MCI, researchers recruited 67 men and women with the condition. All were nonsmokers, and their average age was 76. Some wore a nicotine patch for six months, and others were a lookalike dummy patch. They were then given tests of memory and thinking.
Those who got the nicotine patch scored higher on tests of memory that required them to remember lists of words or what they read. They were also better able to pay attention and had faster reaction times. Those wearing the placebo patch, by contrast, did worse on these tests after six months. The patch, which was given at a dose of 15 milligrams per day, also appeared to be safe, with few side effects.
The researchers note that nerve cells involved in attention contain receptors for nicotine, which may in part explain the findings. People with Alzheimer’s disease show diminished nicotine receptors, though in those with MCI, the receptors are often intact.
One interesting finding was that nicotine appeared to have greater benefit in those who carried the APOE-E4 gene. People with this gene are at increased risk of developing Alzheimer’s, though carrying the gene does not mean you will get the disease.
Still, experts caution that it’s too soon to recommend that those with MCI start wearing a nicotine patch to help keep the memory sharp. The study was relatively small, so larger tests would need to be conducted to confirm the findings. It’s also not known how the patch might affect smokers or former smokers with memory problems. And one study in mice suggested that nicotine could lead to increased production of tau, a protein that builds up in the brains of those with Alzheimer’s.
Still, the scientists believe that the results provide strong justification for further research into the effects of nicotine on those with memory problems. They note that nicotine or similar drugs could be “a promising strategy to ameliorate symptoms of MCI and slow progression to dementia.”
Source: P. Newhouse, MD: K. Kellar, PhD; P. Aisen, MD; et al: “Nicotine Treatment of Mild Cognitive Impairment: A 6-Month Double-Blind Pilot Clinical Trial.” Neurology 2012, Vol. 78, pages 91-101.