Hearing loss and dementia can often occur together as we get older, and have an impact on each other. We know they are linked in several ways, but we don’t know exactly how. We’re funding vital research to find out more.
Hearing loss as a risk factor for dementia
There is strong evidence to show that:
- mild hearing loss doubles the risk of developing dementia
- moderate hearing loss leads to three times the risk
- severe hearing loss increases the risk five times.
But can steps be taken to reduce or avoid this risk? An international review in medical journal The Lancet, published in 2017, suggested that hearing loss is one of nine key risk factors for dementia that are possibly modifiable (factors that can be changed to reduce dementia risk).
The review suggested that one in three cases of dementia could be prevented if more people looked after their health throughout their lives. Other key risk factors for dementia include social isolation, smoking and depression.
Unaddressed hearing loss in mid-life was predicted to be the highest potentially modifiable risk factor for developing dementia. It is potentially responsible for 9% of cases. This is hugely important. Can addressing hearing loss – for example, by using hearing aids – reduce this risk? It’s vital we find out.
Misdiagnosis and further links
Hearing loss can sometimes be misdiagnosed as dementia. People with dementia can have difficulty communicating with others, including finding the right words, or signs, for what they want to say. They may have difficulty processing what they’ve heard, particularly if there are distractions. According to some researchers, this difficulty in processing information (when there is competing information) can be one of the first signs of cognitive impairment.
We also know that hearing loss can speed up the onset of dementia, or make the symptoms of dementia appear worse, and dementia can heighten the impact of hearing loss.
In addition, hearing loss can sometimes be misdiagnosed as dementia
To investigate the links between hearing loss and dementia more closely and help find the answers that so many people are desperate for, we’re funding three important research projects.
Dr Piers Dawes at the University of Manchester is testing whether hearing loss causes dementia, either directly or indirectly (for example, hearing loss may lead to social isolation, which in turn causes an increased risk of dementia). He will also identify if using hearing aids can help promote cognitive health and reduce the risk of dementia.
Dr Chris Hardy at University College London aims to understand how hearing loss and brain function are linked to different types of dementia and how this impacts on someone’s daily life.
He hopes to develop new tests to diagnose hearing loss in people with dementia. He also hopes to detect changes in hearing that may drive changes in the brain, cognitive decline and impact how badly dementia affects the daily life of older people with cognitive impairment.
Dr Brian Allman at the University of Western Ontario in Canada will be studying if inflammation in the brain could be the link between hearing loss and dementia. He will study whether the inflammation in the brain caused by exposure to loud noise speeds up the normal decline in cognitive abilities that occurs with age, and if this underlies the link between hearing loss and dementia, specifically Alzheimer’s disease.
This will be one of the first investigations into the biological processes linking hearing loss, age-related cognitive decline, brain inflammation and Alzheimer’s disease. Ultimately, this knowledge may lead to treatments that can reduce the risk of dementia associated with hearing loss, which would be life-changing for millions.
None of this crucial and groundbreaking research is possible without our amazing supporters
We need to keep up momentum with this vitally important research. Please donate today and help fund important research like this. Any donation you can make could change the future for all of us.
Looking for information, support or advice about dementia? Call the National Dementia Helpline on 0300 222 11 22.
To find out more about hearing loss and tinnitus, see our ear health information or contact our Information Line.