Patching up memory with nicotine

Nicotine may help improve mild memory loss in older adults, according to a new study – but experts are stressing that the findings are not a licence to self-medicate with patches or cigarettes.

A clinical trial, published today in the journal Neurology, examined the effects of low-dose nicotine in people with mild cognitive impairment, which is the stage between normal aging and dementia when people have mild memory or thinking problems but no significant disability.

In the study, non-smoking, elderly participants with memory impairment wore nicotine or placebo patches for six months. Memory testing the end of the trial revealed that the nicotine-treated group regained 46 percent of normal performance for age on long-term memory, whereas the placebo group worsened by 26 percent over the same time period.

But don’t go lighting up just yet, warn the researchers.

“People with mild memory loss should not start smoking or using nicotine patches by themselves, because there are harmful effects of smoking and a medication such as nicotine should only be used with a doctor’s supervision,” said study author Paul Newhouse, MD, of Vanderbilt University School of Medicine in Nashville in an accompanying release. “But this study provides strong justification for further research into the use of nicotine for people with early signs of memory loss. We do not know whether benefits persist over long periods of time and provide meaningful improvement.”

Our colleagues at the UK Science Media Centre collected the following expert comments on the research:

John O’Brien, Professor of Old Age Psychiatry, Newcastle University, said:

“This pilot study investigated the ability of nicotine patches to improve attention and memory in those with Mild Cognitive Impairment (MCI). Previous studies have shown that transdermal patches and nicotine administered by other routes can have mild beneficial effects on attention and cognition in people, including those with Alzheimer’s disease. The current study also showed significant but small improvements in measures of attention and memory over a 6 month period in those with MCI. However, effects were not seen on a global rating scale, meaning that the clinical impact of these improvements is unclear.  Nicotine administration was associated with an increased incidence of adverse events, as well as changes in weight and blood pressure, and further studies would be needed to ascertain the full benefits and risks of treatment. While findings are of interest, nicotine certainly cannot be advocated as a treatment for cognitive problems based on current evidence. “

Professor A. David Smith, Professor Emeritus of Pharmacology, University of Oxford, said:

“I have read the paper with interest. It is a carefully-performed study that confirms an earlier preliminary report. The effects on several cognitive tests are statistically significant but it has not been shown that they are clinically significant. The study confirms other reports that people with mild cognitive impairment are probably the most suitable for clinical trials in the Alzheimer field. It is important that the study was of short duration and did not produce any evidence that nicotine treatment slows down the disease process, but only relieved some of the symptoms, just as current drugs licensed for Alzheimer’s do. Thus, it is not justified to suggest, as the authors do: “CNS nicotinic acetylcholine receptor stimulation may be a promising strategy to ….slow progression to dementia.”

Dr Anne Corbett, Research Manager, Alzheimer’s Society, said:

“This is an interesting preliminary study that builds on previous evidence of the possible benefits of nicotine. While the findings indicate some limited improvements in memory, attention and mental processing, further studies are needed to establish whether the findings are clinically important.

“People should under no circumstances consider self-medicating with nicotine patches or cigarettes. A great deal more research is needed into this area, and the health risks of smoking massively outweigh any potential nicotine benefits. The best way to reduce your risk of developing dementia is to get regular exercise, eat plenty of fruit and vegetables, stop smoking and limit your alcohol intake.”

Professor Gordon Wilcock, Professor of Clinical Geratology, Nuffield Dept. of Medicine University of Oxford, said:

“We have known for some time that nicotine can have a positive effect on some types of memory function, but not enough to be a treatment for Alzheimer’ disease. This study shows a similar benefit for people with mild cognitive impairment, some of whom will have pre-clinical Alzheimer’s disease. We need more information on the improvements in daily life activities, and however good it proves to be, it does NOT justify cigarette smoking.”

Dr James Warner, Reader in Psychiatry, Imperial College London said:

“The conversion rate from MCI (a pre-dementia state in some people) to dementia is low and there are insufficient participants in the trial to observe a significant reduction in developing dementia over 6 months. In addition, saying some domains of cognition improve does not equate to reducing dementia.

“That said, there is quite a potent argument why nicotine should work in dementia.

“The most important thing is that people should not start smoking in the light of this research.”

Derek Hill, Professor of Medical Imaging Science, University College London, said:

“Developing new drugs that stop Alzheimer’s in its tracks is proving really hard, despite pharmaceutical companies investing billions in testing experimental new medicines.  In fact, it is looking increasingly likely that by the time a patient has full-blown Alzheimer’s Dementia, it will be too late to treat them. This small study produces some tantalizing evidence that treatment of people when they only have mild memory problems might be possible with relatively cheap drugs – in this case nicotine patches.  Larger and longer studies are now needed to really investigate whether this might be a viable approach to reducing the scourge of dementia in society.

“This study does not demonstrate that dementia can be cured. What it shows is that some people with mild memory problems can have the severity of those problems reduced over a 6 month period by using nicotine patches. This is potentially exciting, but longer and larger studies are now needed to fully assess the benefit, and whether these outweigh the potential risks.

“This study produces some exciting evidence that mild memory problems might be treatable before they develop into full blown dementia. Nicotine is just one of the existing or experimental drugs that could prove beneficial for this patient group. It should encourage more investment into research into possible treatments. It is quite likely that no treatment will help everyone – and so new diagnostic tests to match patients to treatments may be also needed to tackle dementia.”