Page 96 - LCNL Diwali Magazine

RAGHUVANSHI 2023 - 2024 HAPPY DIWALI

Hearing loss and dementia: How are they linked?

Introduction

More than 11 million people in the UK are affected by hearing loss and the Royal National Institute for Deaf People
(RNID) estimates that the number is likely to increase to 14.2 million by 2035. Hearing well is an important part
of healthy ageing and cultivates easier engagement with family and friends, promotes stronger connections, and a
more positive outlook on life. Dementia presents a significant risk to brain health and cognition and is not typical
of the ageing process. Hearing loss and dementia can often occur together as we get older, and have an impact on
each other. Addressing a hearing loss promptly can help maintain cognition in later life.
How Hearing works?

When you hear sounds, it is the result of a complex process. Sound waves travel through the ear canal. The ear
drum vibrates and sends these sound vibrations to the cochlea, where they are transformed into electrical signals
which then travel up the neural pathways and into the brain.

Figure 1. Diagram of the ear
Hearing loss as a risk factor for dementia

There is strong evidence to show that:
 hearing is an essential part of brain health

 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.

A recent review (Livingston et al, 2017) has suggested that mid- and late-life hearing loss is the greatest risk factor (of
nine) for the development of dementia ahead of other health and life style factors including type 2 diabetes mellitus,
smoking, obesity, depression, and social isolation. Hearing loss is also recognised as one of the few modifiable risk
factors for dementia which if treated early on, may reduce/delay the onset of any cognitive decline.

Currently, the underlying mechanisms connecting dementia and hearing loss are poorly understood and further
research into this area is still required. A few theories have been proposed:

1) Cognitive Load
Age-related hearing loss increases the listening effort required to understand speech and overloads the brain, leaving
depleted resources for other cognitive tasks.

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