People who smoke throughout their lives may be more likely to develop dementia, according to a new study.
Research carried out at the University of Edinburgh for Age UK's Disconnected Mind project - which aims to provide better understanding of the causes of mental health and degenerative conditions - shows that while smoking may trigger the onset of dementia, quitting the habit can allow the brain to recover.
The study found that long-term smoking accelerates the thinning of the cortex, which is the brain's outer layer. This usually happens as a person ages and can adversely affect their ability to plan, make decisions and solve problems.
Therefore, if this thinning takes place prematurely, degenerative conditions such as dementia and Alzheimer's disease may come on sooner than in non-smokers.
However, it was also found that study participants who beat the habit many years ago tended to have a thicker cortex than more recent quitters, which suggests that the brain can recover if people stop smoking early on in life. But the research paper authors recognised that further investigations would be needed to assess the full extent of this.
Previous research has hinted at a link between smoking, brain decline and the development of dementia, but the findings of this latest study show the connection to be significantly larger than previously thought.
Alongside causing degenerative mental conditions, smoking is also known to cause potentially life-threatening heart and lung diseases, but research has shown these do not worry people as much as the threat of dementia.
Professor James Goodwin, head of research at Age UK, commented: "With research suggesting that older people's fear of developing dementia outweighs that of cancer, it is important we inform people about the simple steps they can take to safeguard against this horrible and distressing disease.
"Brain decline is not an inevitable part of ageing, it is something we can protect ourselves against by making changes to our lifestyle - with avoiding smoking being one of them."
Find out about dementia care and support services at Barchester care homes.