Air pollution possibly linked to dementia, London study suggests
A study shows a link between the condition and exposure to nitrogen dioxide (NO2) and toxic air particles.
Patients living within the M25 in areas with the highest NO2 levels were 40% more likely to develop dementia than those in areas with lowest levels, researchers said.
Alzheimer's Research UK said the results should be treated with caution (a trend is shown but is not necessarily the cause).
The study, published in journal BMJ Open, used anonymous patient health records from the Clinical Practice Research Datalink to collect data from 75 general practices within the M25.
The researchers, from the University of London, Imperial College and King's College London, said further work was "urgently" needed to confirm its findings.
Their work focused on 131,000 patients, aged between 50 and 79 in 2004, who had not been diagnosed with dementia. The health of each patient was tracked for an average of seven years until they were diagnosed, died or left their GP practice.
Those living in areas with the top fifth of nitrogen dioxide levels had a 40% increased risk of being diagnosed with dementia compared with those living in areas with the lowest fifth. A similar rise was seen in areas where the air had higher levels of the toxic air particles PM2.5, the study added.
"The cause of these neurodegenerative diseases is still largely unknown... while toxicants from air pollution have several plausible pathways to reach the brain, how and when they may influence neurodegeneration remains speculative." Alzheimer's Research UK has supported the idea of further research.
|Air pollution 'linked to dementia'
A study finds a link between the neurodegenerative condition and exposure to nitrogen dioxide.