Oxford study finds social hearing issues precede dementia

People who have trouble hearing in busy public venues could be at greater risk of developing dementia, an Oxford University study has revealed.

The inability to hear in noisy environments, such as train stations, restaurants or parties, could be linked to dementia, the study published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, found.

Researchers studied data from more than 82,000 people aged 60 and above, and found that difficulty hearing spoken conversation is associated with up to a 91 per cent increased risk of dementia.

The jury is still out on whether the hearing problems are causing the dementia or an early symptom of the condition.

“Dementia affects millions of individuals worldwide, with the number of cases projected to treble in the next few decades,” said study senior author Dr Thomas Littlejohns, senior epidemiologist in the Nuffield Department of Population Health.

“However, there is growing evidence that developing dementia is not inevitable and that the risk could be reduced by treating pre-existing conditions. While preliminary, these results suggest speech-in-noise hearing impairment could represent a promising target for dementia prevention.”

The study found that, over 11 years of follow ups, 1,285 participants were identified as developing dementia based on hospital inpatient and death register records.

Insufficient and poor speech-in-noise hearing were associated with an increased risk of developing dementia of between 61 and 91 per cent, compared to normal speech-in-noise hearing, respectively, the study found.

David Curtis, honorary professor of University College London genetics’ institute, said the new research seems to confirm the association between hearing problems and dementia, but not that the hearing issue is the cause of dementia or that tackling the hearing issue could stop the dementia.

“I think this confirms the association but it remains much more plausible that people who are going to develop dementia will have a bit of dementia that has not been clinically diagnosed yet.

“They have problems deciphering speech when there’s background noise because it’s a very, very demanding cognitive task to decipher speech over background noise, and if there’s any impairment at all to your cognitive function that will be a place to pick that up.”

“The idea that you can stimulate your brain out of dementia is probably a little but optimistic,” Prof Curtis said.

The study also found that the risk of dementia remained similar when restricting the analysis to dementia, which developed after nine years as well as within three years.

“Many people with dementia will experience difficultly following speech in a noisy environment – a symptom sometimes called the cocktail party problem,” said Dr Katy Stubbs from Alzheimer’s Research UK.

“This study suggests that these hearing changes may not just be a symptom of dementia, but a risk factor that could potentially be treated.”

“Large studies... are powerful tools for identifying genetic, health and lifestyle factors linked to conditions like dementia, but it is always difficult to tease apart cause and effect in this type of research,” she said.