The small pilot study, though not conclusive, may point the way to new treatments that delay the onset of Alzheimer’s disease and other forms of dementia.
Scientists carried out memory and thinking skill tests on 67 individuals with mild cognitive impairment (MCI) over a period of six months.
Half the participants, who had an average age of 76, were treated daily with 15 milligrams of nicotine administered via a skin patch. The others were asked to wear a “dummy” placebo patch containing no active medication.
By the end of the study the nicotine-treated group had regained 46% of normal long term memory for their age. Their ability to pay attention also improved.
However the authors of the research, published in the journal Neurology, were quick to scuttle any suggestion that smoking might stave off Alzheimer’s.
“People with mild memory loss should not start smoking or using nicotine patches by themselves, because of the harmful effects of smoking and a medication such as nicotine should only be used with a doctor’s supervision,” said lead scientist Dr Paul Newhouse, from Vanderbilt University School of Medicine in Nashville, US.
“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.”
Nicotine, the chemical that makes smoking tobacco addictive, is known to stimulate nerve cells in the brain.
Some of the affected cells play a role in preserving mental performance and cease to function properly in people with Alzheimer’s. This has led scientists to wonder if nicotine can help them find new ways of tackling the disease.
Dr Simon Ridley, from the charity Alzheimer’s Research UK, said: “This small study looks promising as people with MCI treated with nicotine patches showed improvements in several cognitive tests. Larger and longer-term studies will be needed to get a bigger picture of the potential of nicotine-based treatments in Alzheimer’s.
“As we know, nicotine is highly addictive and smoking can increase our risk of Alzheimer’s as well as other serious diseases, and so we must interpret the results sensibly.
“We hope that the findings can push scientists towards developing safe and effective therapies to tackle dementia, and with 820,000 people in the UK living with dementia, this need has never been greater.”
Dr Anne Corbett, research manager at the Alzheimer’s Society, said: “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 Derek Hill, an expert in medical imaging from 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 tantalising 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.”