New study finds hearing loss a stronger predictor of dementia risk than previously thought

It’s common for our senses to diminish over time, and many of us are at a higher risk of hearing loss as we age. However, scientists are now emphasising that hearing loss may also be a sign of cognitive decline or dementia.

A new study has revealed that hearing loss or reduced hearing could be a stronger predictor of dementia than we initially thought. In fact, scientists believe that nearly one-third of older adults living with dementia experienced hearing difficulties before showing any signs of the disease.

Published in the AMA Otolaryngology—Head & Neck Surgery journal, the study followed a group of almost 3000 people aged 66 to 90 without dementia and living in community housing.

The research team collected data for the participants from 2011 to 2019, and conducted one hearing assessment using pure tone audiometry and self-report from the participants themselves.

They also determined which participants developed dementia by using a standardised algorithm incorporating neuropsychological testing, informant interviews, and medical records.

Strikingly the team found that significant hearing loss was present in over 66 per cent of cases, while during the follow-up period almost ten per cent of participants with hearing loss developed dementia compared to less than five percent for those with normal hearing.

Using population-level modeling, the study showed that approximately 32 per cent of all dementia cases were linked with audiometric hearing loss, while about 31 per cent of dementia cases could be linked to hearing loss for participants aged 75 years or older.

Though previous studies have shown a link between hearing loss and dementia in anywhere from two percent to 19 percent, many of those studies used different measures for hearing loss and sometimes relied on participants reporting their own level of hearing impairment.

Still, self-reported hearing loss in this study was likened to a lower, though not significant, risk of dementia.

Additionally, it should be mentioned that the study did not track hearing or hearing loss over time but it does show how different hearing loss testing can lead to vastly different estimates of dementia risk and why future research using standardised assessments could help us better understand why hearing loss foreshadows dementia.

The findings come as advocates say many of us are still unaware of the link between hearing and dementia, urging all Australians to prioritise their brain health and its vital role in preventing the disease.

According to new data from Dementia Australia, many Australians are unaware that common health issues- such as hearing loss, depression, and high cholesterol are all risk factors for developing dementia.

Dementia Australia CEO Professor Tanya Buchanan said that dementia is the second leading cause of death for all Australians and there are currently 433,300 Australians living with the condition.

“Dementia is on track to become the country’s biggest cause of death within the next five years. While we cannot change getting older, genetics or family history, scientific research shows that looking after our brain health can make a big difference to reducing or delaying the risk of developing dementia,” Professor Buchanan said.

A recent Ipsos survey of Australian attitudes toward dementia revealed a surprising gap in awareness. Many Australians still don’t realise that making proactive lifestyle changes can help reduce the risk of developing dementia.

Last year, the Lancet Commission identified 14 modifiable risk factors that, if addressed, could reduce global dementia incidence by a remarkable 45 per cent. These factors include smoking, obesity, physical inactivity, and conditions such as hearing loss, high cholesterol, and depression.

“In fact, people with mild-severe hearing loss are two to five times as likely to develop dementia than those with normal hearing,” Professor Buchanan said.

Hearing Australia says hearing loss in older people can begin by affecting high frequency sounds first and mean that a person will often be able to detect some sound but unable to understand everyday noises or speech. If you or your loved one are concerned, you can contact your GP for further assistance.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.