Cutting air pollution key to reducing dementia in the world
Air pollution is significantly associated with an increased risk of dementia in people aged 60 years and over, the study has concluded. The research is the first to both establish a link between air pollution and dementia, while accounting for other important factors such as fish consumption, and identify the most harmful pollutants to cognitive health and Alzheimer’s disease. “We found air pollution was significantly associated with dementia even after adjustment for environmental tobacco smoke (ETS) exposure and fish consumption,” explains Ruoling Chen, who coordinated the research at the University of Wolverhampton – UoW in the United Kingdom. The DEMAIRPO project was undertaken with the support of the Marie Skłodowska-Curie Actions. Professor of Public Health and Medical Statistics and the lead of Global Health and Epidemiology Research at the UoW, Chen concluded, using a new cohort study in China, that the risk of cognitive impairment increased with exposure to PM2.5 fine particulate matter, PM10 and sulfur dioxide. The air pollutants nitrogen dioxide, carbon monoxide and ozone gases were not significantly associated with increased risk.
Vital input to tackle dementia
Chen’s team carried out a cohort study of 7 311 people aged 60 years and over living in the rural and suburban areas of the Zhejiang province in China, interviewing them in 2014 for baseline information. Over the period of a 2-year follow-up, 23 % developed some form of cognitive impairment and 13 % were severe. Chen’s work through the DEMAIRPO project provides vital input for countries seeking to tackle dementia, which is forecast to affect 152 million people in 2050, according to the World Health Organization. “Strategies to target the most important air pollutants should be an integral component of cognitive interventions,” says the researchers, sharing some of their findings published in the Journal of Alzheimer’s Disease in ‘Impact of Air Pollution on Cognitive Impairment in Older People: A Cohort Study in Rural and Suburban China’.
Air quality and Alzheimer’s
The researchers also examined the risk of Alzheimer’s disease in relation to those six air pollutants and the air quality index (AQI) in the cohort and carried out a new case-control study to determine the independent association of air pollution exposure with dementia and its interaction effects with ETS exposure and fish consumption. The studies showed statistically insignificant interaction effects, suggesting the impact of air pollution on the development of dementia would be similar between people with and without ETS exposure, and among people who had different levels of fish consumption. These novel findings in population-based dementia research were greatly assisted by the UoW teaming with the Guangzhou Medical University as a collaborative partner. Chen intends to continue the research by investigating the pathways of the impact of air pollution exposure on dementia.
Keywords
DEMAIRPO, air pollution, dementia, environmental tobacco smoke, fish consumption
