Smokers face a 20 per cent greater risk of developing dementia when they reach old age, a study has found.
Fears that cigarettes lead to people being slowly robbed of memories have grown over the past decade, on the back of several trials.
And the new South Korean research, based on data from thousands of people, adds to the mounting evidence.
Seoul National University researchers also said kicking the notoriously bad habit will protect millions from getting dementia later in life.
Fears that cigarettes lead to people being slowly robbed of memories have grown over the past decade, on the back of several trials
Dr Sang Min Park, who led the study, said: ’Smoking cessation was clearly linked with a reduced dementia risk in the long term.’
He added this indicates ‘that smokers should be encouraged to quit in order to benefit from this decreased risk’.
The scientists were unable to determine why smoking was linked to such an elevated risk of dementia from their observational study.
However, trials over the past decade have showed smoking and boozing can shrink grey matter in the brain, the cells that crunch information.
The new study tracked the lives of 46,000 men over the age of 60 for around 11 years, on average, to make the conclusion.
They found those who had never smoked had a 19 per cent lower risk of being struck down with dementia, compared to smokers.
It also revealed former smokers who had quit the habit for at least four years faced a 14 per cent lower risk.
Dementia is the umbrella term for a range of neurological disorders. The biggest known risk factor is age.
In terms of Alzheimer’s – the most common form of dementia, the risk was 18 per cent lower in never smokers, compared to smokers.
While for vascular dementia – caused by a lack of blood flow to the brain, the risks were around 30 per cent lower for both long-term quitters and never smokers.
Dr Park and colleagues published their findings in the medical journal the Annals of Clinical and Translational Neurology.
There are 850,000 people living with dementia in the UK, with numbers set to rise to more than one million by 2025 and two million by 2051.
In the US, it’s estimated there are 5.5 million Alzheimer’s sufferers. A similar percentage rise is expected in the coming years.
Currently, there is no cure for dementia. But drugs can slow down its progression and the earlier it is spotted the more effective treatments are.
Smoking is known to cause almost 90 per cent of lung cancers, and can also trigger tumours in the kidney, pancreas, mouth and stomach, among others.
Inhaling carbon monoxide – found in cigarette smoke – also decreases the ability of blood to carry oxygen, putting a strain on the heart.
But giving up smoking would see the blood improve, and the body become rid of the harmful poisons which cause major damage to the body.