Living near main road increases dementia risk by 12 per cent ‘with traffic pollution triggering one in 25 cases’
Researchers think exhaust fumes cause inflammation in the brain, which leads to memory loss and aggressive behaviour
LIVING on a busy road significantly raises the risk of dementia, a major study warns.
Experts claim traffic pollution can trigger the brain-wasting disease and may be to blame for up to one in every 25 cases.
It means 34,000 cases in the UK could be due to poor-quality air.
The study found people living within 50 metres of main roads were up to 12 per cent more likely to develop the devastating illness.
Scientists blamed two common pollutants, nitrogen dioxide and diesel fumes called particulates.
They are thought to trigger inflammation in the brain, which then leads to memory loss and aggressive behaviour.
And they said other chemicals and traffic noise may also play a role.
But the study found vehicle smog had no impact on diseases such as Parkinson’s or multiple sclerosis.
There are 850,000 Brits with dementia – and there is currently no effective treatment.
But current medications can help to slow down the symptoms.
The Lancet study followed 6.6 million Canadian adults for 11 years.
Lead researcher Dr Hong Chen, from Public Health Ontario in Canada, said “roughly one to two in every 50 cases can be attributed to road pollution”.
He said: “Given that UK is a more densely populated country and likely as many people are living close to major roads, the impact of traffic exposure on dementia is likely similar, or even higher.
“Our findings show the closer you live to roads with heavy day-to-day traffic, the greater the risk of developing dementia.
“With our widespread exposure to traffic and the greater tendency for people to live in cities these days, this has serious public health implications.”
Around one in five people in the study lived near busy roads.
Compared with those whose homes were more than 200 metres away from a busy street, those living within 50 metres of heavy traffic had a seven per cent higher risk of developing dementia.
And being a city-dweller appeared to boost the effect, with those on main roads seeing their chances rise by up to 12 per cent.
British experts said the findings could help cut future dementia cases.
Professor Martin Rossor, NIHR National Director for Dementia Research at University College London Hospitals, said: “This is an important paper that adds to the evidence that air pollution is bad for health.”
Professor Tom Dening, director of the Centre for Old Age and Dementia at the University of Nottingham, said: “Interesting and provocative findings. It is certainly plausible that air pollution from motor exhaust fumes may contribute to brain pathology that over time may increase the risk of dementia.”
And Dr David Reynolds, Chief Scientific Officer at Alzheimer’s Research UK, said: “This study has identified major roads and air pollutants from traffic as possible risk factors for dementia, a finding which will need further investigation before any firm conclusions can be drawn.”