Dementia risk found in air pollution and lack of vitamin D

Dementia risks have been in the headlines this week, thanks to our fascinating new study on how our environment influences the likelihood of developing the condition.

Here is Dr Tom Russ to explain how he learned that air pollution and unclean water can have lasting consequences to brain health …

Because the world is ageing, dementia is becoming a major global public health crisis. We know that there are several things that we can all do to reduce our risk of developing dementia – avoid cigarettes, stay slim and active, and control blood pressure and diabetes. These factors, plus genetics, probably explain about two-thirds of dementia risk. But this mean that a third of dementia risk remains unexplained.

Last year, we conducted research into geographical variation in dementia in Sweden and found that the risk of dementia is two-to-three times higher in the north of Sweden compared to the south. This must relate, at least partly, to something environmental.

This was why we wanted to see what had been published by other people about environmental factors and dementia. There have been a bewildering number of factors studied to date. We thought it would be helpful to produce a shortlist of environmental risk factors that have at least moderately good evidence linking them to dementia in order to guide where we should focus our research attention in the future. Our shortlist included air pollution, vitamin D deficiency, some pesticides, and electric and magnetic fields.

It is important to add that we could only show that these factors were associated with dementia. None of these studies are able to prove that any of the factors actually cause dementia. This is why we urgently need to do more research to provide this evidence. The best advice if you want to reduce your risk of dementia is still to follow the advice at the top – strive for a healthy, balanced diet, with plenty of exercise.

Our research paper is free for anyone to access and can be found here: Biomed Central .

Dr Tom Russ,
Academic psychiatrist
Centre for Dementia Prevention and Alzheimer Scotland Dementia Research Centre, The University of Edinburgh

For information on our previous work on geographical variation in dementia risk, go to: Epidemiology journal