YOU report that “smoking could prevent dementia (“Study claims nicotine could protect the ageing brain and help to prevent dementia”, The Herald, October 3). This is not what the research said, and actually the reverse is true.

The idea that nicotine has a role to play in dementia prevention is not a new one. However, to equate “nicotine” with “smoking” is fatally misleading. The authors of this latest research, which involved mice and pure medicinal nicotine administered orally in sweetened water, were at pains to say that smoking would cancel out any potential benefit of nicotine. At no point were these laboratory mice tested either with tobacco or with lit cigarettes – which deliver a range of poisons along with the nicotine. Nicotine alone was being researched as a plausible mechanism in protecting the ageing brain.

Research suggests that the risk of developing dementia is up to 70 per cent higher in current heavy smokers than in non-smokers, and smoking is implicated as a factor in age-related cognitive decline. Smoking and exposure to second-hand smoke increase the risk of heart disease, diabetes and stroke, which are themselves linked with developing dementia.

There may well be a place for nicotine in protecting brain health, but not through smoking.

Sheila Duffy,

Chief executive, ASH (Action on Smoking and Health) Scotland,

8 Frederick Street, Edinburgh.