There has been scientific evidence recently that has found an association between hearing loss and dementia. The most well-known of this has been research carried out by Dr. Frank Lin of John Hopkins School of Medicine in Maryland, United States. His work has been featured in The Telegraph, The Guardian, The Mirror and The Daily Mail and looks set to change the way hearing loss is perceived and possibly the way dementia is treated. He has said “I think many clinicians typically perceive hearing loss as being an inevitable, and hence inconsequential, part of ageing.” He suggests there are three possible explanations for why hearing loss has an association with dementia.
This is when so much effort is spent trying to make out what somebody is saying, that not much “brain power” is left for anything else. If somebody with a hearing loss is in a conversation, they’re not thinking about what is being said and connecting it to thoughts, feelings and memories. They’re straining to just make out the words themselves. When you have a hearing loss, you’re not trying to think back to some anecdotal story connected to whatever the other person is talking about nor picking out a witty reply from memory, all of which exercise different parts of the brain.
The second part to this is what happens to those parts of the brain we usually use for speaking and listening when they fall out pf use. Brain scans from 2014 show that those with hearing loss for longer than six years had decreased grey matter in the areas used for spoken language and semantic memory. Dr Lin says on John Hopkin’s website that “The middle and inferior temporal gyri, for example, also play roles in memory and sensory integration and have been shown to be involved in the early stages of mild cognitive impairment and Alzheimer’s disease.”
Isolation is a known risk factor in dementia and is also one of the major effects of hearing loss. The story is a familiar one. People start getting a hearing loss, they have difficulty hearing while out in a noisy restaurant, or a family get together and eventually they stop socialising. They have to keep asking people to repeat themselves until eventually communication is no longer easy and they retreat into isolation. Often, those with hearing loss are physically present at family gatherings but sit silently as socialising becomes difficult. This isolation then puts them at risk from dementia.
11 million people, that’s one in six in the UK have a hearing loss and the majority of those will wait ten years before seeking help for it. With an aging population, by 2035, that figure will rise to 15.6 million: one in five people in the UK. Dr Lin says “If you want to address hearing loss well, you want to do it sooner rather than later. If hearing loss is potentially contributing to these differences we’re seeing on MRI, you want to treat it before these brain structural changes take place.”