Keep an ear out for the risk of dementia

What would you guess is the best thing you can do to reduce the worldwide burden of dementia?

I’m not talking about an individual person’s risk of developing the condition – though the answer may well be relevant to you personally – but about something that would prevent or delay most cases around the world.

You might be thinking exercise, diet, or looking after your heart health, and all of these would be reasonable choices, but the number one intervention may come as a surprise – avoiding or treating hearing loss.

This finding comes from a 2020 commissioned report in The Lancet, a prestigious medical journal, that looked at a number of modifiable risk factors for dementia. This report suggested that 8 per cent of cases of dementia could be avoided or delayed by addressing hearing, more than any other intervention.

Research has found a correlation between poor hearing and an increased risk of developing dementia. While hearing loss may not directly cause dementia, it can contribute to cognitive decline in several ways.

One possibility is that hearing loss may lead to social isolation and loneliness, which are risk factors for dementia.

When individuals have difficulty hearing, they may withdraw from social activities. Lack of social stimulation can lead to reduced cognitive function and increased risk of dementia.

Another possibility is that the brain must work harder to process and interpret sound when hearing loss is present. This increased cognitive load can lead to cognitive fatigue and can impact cognitive performance in other areas as well.

There is also evidence to suggest that hearing loss can lead to changes in brain structure and function. Specifically, when the brain does not receive input from the ears due to hearing loss, the areas of the brain responsible for processing auditory information can become less active.

This can impact the brain’s ability to perform other cognitive functions, potentially contributing to the development of dementia.

It’s important to note though that while there is a correlation between hearing loss and dementia, not everyone with hearing loss will develop dementia, and not everyone with dementia has hearing loss.

Positively, there is also some evidence to suggest that correcting hearing loss can reduce the risk of cognitive decline and dementia.

For example, a study published in the Journal of the American Geriatrics Society in 2018 found that older adults who used hearing aids had a lower risk of developing dementia or depression compared to those who did not use hearing aids.

Some studies have also suggested that treating hearing loss with hearing aids may improve cognitive function in individuals who already have mild cognitive impairment or early-stage dementia. However, other studies have not come to the same conclusion. One reason may be that hearing loss is only one of many factors that can contribute to cognitive decline and treating hearing loss alone may not be enough to improve cognition in advanced dementia.

So, while there is evidence to suggest that treating hearing loss may help reduce the risk of cognitive decline and dementia, evidence for whether treating hearing loss can improve cognition in individuals who have dementia, is less clear.

Ultimately, although there is some uncertainty about the link between hearing loss and dementia, doing so is usually straightforward and has no associated risks.

In my opinion, it is low hanging fruit when it comes to promoting brain health.

Kailas Roberts is a psychogeriatrician and author of Mind your brain The Essential Australian Guide to Dementia now available at all good bookstores and online. Visit yourbraininmind.com or
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