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Among older adults, hearing loss and dementia are both highly prevalent and thought to be related. In a new study, a team of international researchers has tried to determine how the two are linked.
It is predicted that, by 2050, dementia will affect 150 million people worldwide. Hearing loss equal to or greater than 20 dB affects 10% of people aged 40 to 69 years, 30% of people aged 65 and over, and 70% to 90% of people aged 85 and over. For context, the whisper heard 1.5 meters away produces a sound of 20 dB.
One study A previous study had already demonstrated a relationship between the two conditions, suggesting that hearing loss is a risk factor for dementia. One report of the Lancet Commission on Dementia, released in 2020, concluded that the loss of hearing may be linked to 8% of cases of the disease worldwide.
Few studies have analyzed the relationship between the use of hearing aids and dementia. In new research, a team of international researchers examined the relationship between hearing aid use and dementia among middle-aged and older adults.
Evidence has shown that hearing can be the strongest risk factor for dementia, but the effectiveness of hearing aid use in reducing the risk of dementia “has remained unclear”said Dongshan Zhu, one of the authors of the study, published recently in The LancetPublic Health and quoted by New Atlas.
“Our study provides the best evidence to date” and suggests “that hearing aids can be a cost-effective, minimally invasive treatment to mitigate the potential impact of hearing loss on dementia,” he said.
The researchers used the UK Biobank to analyze data from 437,704 people aged between 40 and 69. About three-quarters of the participants had no hearing loss. The rest had some hearing loss and 11.7% used hearing aids.
The researchers found that, compared to participants with normal hearing, those with hearing loss who did not use hearing aids had an increased risk of dementia. They did not find an increased risk among people with hearing loss who used hearing aids.
This means that people with hearing loss who do not use hearing aids have an approximately 1.7% risk of dementia, while the risk for individuals with normal hearing or who use hearing aids is 1.2%.
“Nearly four-fifths of people with hearing loss do not use hearing aids in the UK. Hearing loss can start as early as the 40s, and there is evidence that the gradual cognitive decline before a diagnosis of dementia can last 20 to 25 years”explained Dongshan Zhu.
“Our findings underscore the urgent need for early introduction of hearing aids when someone begins to suffer from hearing impairment,” continued the researcher.
The study also examined how other factors, such as loneliness, social isolation and depression may have an impact on the relationship between hearing loss and dementia. Data suggest that about 8% of the association between the two conditions could be eliminated by addressing psychosocial problems.
According to the investigators, this indicates that the decrease in the risk of dementia comes mainly from the use of hearing aids and not from indirect causes.
Although the study has some limitations, the researchers believe that its conclusions highlight the need for an effort to raise society’s awareness of hearing loss and its potential links to dementia, in addition to increase access to hearing aids.
More research is needed to determine the link between hearing loss and dementia.
ZAP // 
