A new study, using long-term data adds to a growing evidence base linking air pollution with increased risk of dementia and stroke.
Researchers collected health data on more than 413,000 people taking part in the UK Biobank project.
All of the participants were between 40 and 69-years-old and free of dementia, cancer or stroke at the start of the study.
Their health was tracked, focusing on the association between air pollution and the transition from being healthy to having a stroke, dementia or both. Data was also collected on their lifestyles, including smoking, exercise, alcohol consumption and diet, as well as their socioeconomic status.
Associations between multiple air pollutants and the dynamic transitions of stroke and dementia were estimated, and the impacts during critical time intervals were explored.
Over the course of 11 years, 6,484 people had a stroke, 3,813 developed dementia and 376 went onto develop comorbidities of stroke and dementia.
Having allowed for other risk factors, the researchers found relationships between long-term air pollution exposure and dementia, as well as developing dementia after a stroke.
The authors conclude: “Our findings suggested that air pollution played an important role in the dynamic transition of stroke and dementia even at concentrations below the current criteria. The findings provided new evidence for alleviating the disease burden of neurological disorders related to air pollution during critical time intervals.”
A previous report, published by the UK Health Security Agency (UKHSA) in 2022, highlighted how evidence of the link between air pollution and and negative impacts on the brain has grown in recent decades, with the authors concluding ‘it is likely air pollution does contribute to dementia and cognitive impairments’.
Speaking to the Guardian, Prof Frank Kelly of Imperial College London, who was part of the study team, said: “These new findings help to clarify how air pollution plays an important role in the dynamic transitions of stroke and dementia, even at concentrations below the UK’s current air quality standards.
“The target for particle pollution under the Environment Act is twice the World Health Organization guideline and is set to be achieved by 2040. Not meeting the WHO guideline as soon as possible means that thousands more people are on the path to developing serious illness such as stroke and dementia simply because they are unable to breathe clean air.”
