The link between hearing loss and dementia

Published on 4 October 2021

Hearing loss and dementia are usually associated with the elderly, and recent studies have brought to light a connection between the two conditions, stating that hearing loss is a potential indicator of dementia development. 

The 2020 Lancet Commission study has identified hearing loss as one of the nine potentially modifiable risk factors for dementia, which in combination contribute to between 30% to 40% of the risk.

Dementia, a condition that is marked by memory loss, difficulties with communicating and problem-solving, as well as carrying out other mental tasks, affects about 5.2% of Singaporeans aged 60 and above. 

“Dementia becomes more prevalent with age. Degeneration of the brain and its connections account for the majority of dementias in the elderly,” explained Dr Tan Chin Kwok, Consultant, Geriatric Medicine, Ng Teng Fong General Hospital (NTFGH). 

Hearing loss affects more than 60% of Singaporeans above the age of 60. The condition spans different levels of severity, ranging from mild to profound. 

These recent findings offer a significant forewarning to individuals to seek early treatment for hearing impairment to offset their higher chances of cognitive decline. 

How are they linked? 

While the exact correlation between hearing loss and dementia is still undetermined, research points to three possible theories: 

• The brain has to work harder to process sound in the presence of a hearing disability, burning resources that could have been used for other important functions.

• If less auditory information reaches the brain, that part of the brain becomes underused, shrinks in volume, and eventually declines. 

• Hearing loss can lead to social isolation, resulting in reduced personal interactions and mental stimulation which can negatively impact mental health.

While it doesn’t mean that all individuals who experience hearing loss will develop dementia, it certainly increases the odds of developing it. The more profound the hearing impairment is, the higher the risk of developing dementia; individuals with mild hearing loss are twice as likely to develop dementia compared to those with normal hearing, whereas people with severe hearing loss are five times as likely to develop dementia.

What can you do? 

Dr Liu Jiaying, Consultant, Otolaryngology – Head & Neck Surgery, NTFGH, said that the early treatment of hearing loss can help to prevent the onset of dementia by enhancing brain health and functions and reducing the possibility of social isolation. 

To first confirm hearing loss, Dr Liu recommends that individuals should visit an Ear Nose Throat (ENT) specialist to be professionally assessed. “After a painless 15 minute hearing test, the doctor would be able to explain your level of hearing loss. Based on the test results, hearing rehabilitation options like hearing aids can be recommended,” said Dr Liu.

For individuals already diagnosed with dementia, seeking treatment for hearing loss may help to reduce the severity of their condition as well as improve their day-to-day lives. “Once dementia has set in, it is irreversible and rehabilitating peripheral hearing loss will not cure or reverse dementia. However, improving hearing in someone who already has dementia helps to reduce the cognitive burden from deafness with the hope of preventing deterioration of their dementia,” said Dr Liu.

In consultation with Dr Tan Chin Kwok, Consultant, Geriatric Medicine, NTFGH and Dr Liu Jiaying, Consultant, Otolaryngology – Head & Neck Surgery, NTFGH.