Alzheimer Scotland Dementia Research Centre team publish a review on the enviromental risk factors for dementia
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 – not smoke, avoid developing diabetes (or keep it well controlled), stay slim and active, and control blood pressure. These factors plus genetics probably explain about two-thirds of dementia risk – which means that a third of dementia risk remains unexplained!
Our study last year looking at geographical variation in dementia in Sweden (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4467562/) was able to factor out the genetic influences (because it was a twin study and we know how genetically related twins are) and the risk of dementia was still two-to-three times higher in the north of Sweden compared to the south. This must relate, at least partly, to something environmental and so environmental risk factors might well explain some of that unexplained dementia risk.
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 and we thought it would be helpful to produce a shortlist of environmental risk factors which have at least moderately good evidence already 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 adopt a healthy lifestyle.
The article is free for anyone to access and can be found here: https://bmcgeriatr.biomedcentral.com/articles/10.1186/s12877-016-0342-y
Media reports of the review: