Could air pollution cause dementia?

We brought together neurologists, epidemiologists and experts on the effects of toxins in the brain to help us make sense of the research on air pollution and dementia so far.

Research to date has linked air pollution to a wide range of health conditions, in particular respiratory and cardiovascular disease but also to certain forms of cancer and developmental disorders. Polluted air has also been implicated in impaired brain function and potentially dementia.

While there’s a lot of hot air and foggy reasoning out there, we at Alzheimer’s Society wanted to get a clear view of the facts. We brought together a panel of experts in neurology, epidemiology, environmental risk, and how metals behave in the brain, to advise us within a new report.

What is air pollution?

Air pollution refers to substances that are present in the air, or have entered the air, which have harmful effects. Air pollution can come from many sources and travel across distances, and it can interact with other molecules with various consequences.

Most research into whether air pollution is linked to dementia has been through studies of large populations, and there are limitations to them. Many base their findings on where a person is currently living, without taking into account the level of pollution at any previous addresses or at their workplace.

These studies are often also retrospective – they look back on what has happened in a person’s life, rather than recruiting them and seeing how their health then changes over time. The latter gives researchers a better chance to observe cause and effect and ability to rule out coincidence.

An indirect link?

Though research to date has not shown how air pollution could directly cause dementia, evidence does point towards an indirect cause.

It is likely that the effect of air pollution on our respiratory and cardiac health has a knock-on effect on brain health, increasing our risk of developing dementia.

More research is required

There is some evidence that particles from air pollution might be able to enter a person’s brain. If these triggered a toxic response in the brain, this might cause damage that in turn increases the risk of dementia. However, we need more research to find out if this is really the case. 

We do know that air pollution has a negative effect on our health, and it is encouraging to see more political engagement with this topic.

The infographic suggests how we can limit our exposure to air pollution on an individual level.

Does air pollution increase risk of dementia?

Read the full report

Our report shows that the experts agreed evidence to date supports several possible ways that pollution could be indirectly associated with dementia.

Learn more

Care and cure magazine: Summer 19

Care and cure is the research magazine of Alzheimer's Society is for anyone interested in dementia research.
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Care and cure is the research magazine of Alzheimer's Society is for anyone interested in dementia research.
Subscribe now
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What about air quality in air craft, also travelling at the speed and height for so long, does this have any thing to do with dementia. When you thing about it, the number of people affected by dementia is growing so much. My wife has dementia, I look after her at home this is about 8 years, but I won't put her in care as long as I stay healthy.

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Hi John, I’m afraid there’s limited research in this area but we do know that in the majority of cases of dementia it’s very rare that one single factor will cause the condition. You can find out about what research has told us about the causes of dementia here:
Alzheimer's Society research team

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What a brilliant website! Easy to read, absorbs and understand. Very informative

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