A new study by NeuRA has found a clear link between air pollution globally and an increased risk of developing dementia later in life.
Researcher Dr Ruth Peters found that rates of dementia in these regions were more likely when people were exposed to two specific air pollutants. She combined the findings of studies of people living in Canada, Sweden, Taiwan, the United Kingdom and the United States to create a global snapshot of how pollution is impacting dementia rates.
“This finding is concerning because 91% of the world’s population are exposed to pollution levels that exceed the World Health Organisation guideline limit,” said Dr Peters.
Two pollutants were found to be particularly problematic. The first is particulate matter 2.5 (PM2.5), which is an airborne mix of solid particles and liquid droplets. Each particle is less than 2.5 micrometres wide (the average human hair is 70 micrometres wide) and can be easily inhaled. The second pollutant is a group of gases known as nitrogen oxides (NOx). These chemical compounds of oxygen and nitrogen are responsible for the smog that clouds cities.
Researchers believe air pollutants may lead to an increased risk of dementia through two methods. Firstly, by increasing levels of inflammation in our bodies, and secondly by raising the risk of having a stroke. The rate of developing dementia is 50 times higher in the year following a major stroke.
“Unlike the majority of established dementia risk factors, it is very difficult for someone to reduce their exposure to air pollution, especially if they live somewhere where pollution levels are high,” Dr Peters said.
“Following this study, we now need extra investigations to better understand how these pollutants affect our brain health over the long term, and what levels of pollution pose the highest risk to us,” Dr Peters said.
“While it might be difficult to reduce our exposure to air pollution if we live in a city, people can still do quite a lot to reduce their risk of developing dementia. The easiest way to do this is to maintain a healthy lifestyle by eating well, getting enough sleep, and being physically active,” Dr Peters said.
The study has been published in the Journal of Alzheimer’s Disease as part of a special issue by the International Research Network on Dementia Prevention. This network is led by Professor Kaarin Anstey, who is co-author on the study with PhD student Nicole Ee.
For simple and practical steps on how to reduce your risk of dementia, download NeuRA’s free Ageing Well kit: foundation.neura.edu.au/ageing-well-tool-kit