Brazilian study highlights the need to treat auditory issues early
New research has strengthened the link between hearing loss and cognitive decline in middle age, a connection that could reshape how hearing health is viewed around the world.
While the Brazilian study focused on low- and middle-income countries, its findings are increasingly relevant for ageing populations in wealthier nations too, where access to routine hearing care is far more attainable but often underutilised.
The longitudinal study, published in the Journal of Alzheimer's Disease, tracked 805 Brazilians in their 50s over an eight-year period. Those with hearing impairments experienced significantly faster cognitive decline than their peers.
Lead author Claudia Suemoto, professor at the University of São Paulo’s medical school, said the findings underscore the urgent need to treat hearing health as a frontline defence against dementia.
A modifiable risk – but only if addressed early
Hearing loss is one of the few known modifiable risk factors for dementia. That means it’s both measurable and treatable, provided individuals have access to proper care.
Yet many people wait years before seeking help. The Brazilian findings reflect wider concerns about how middle-aged adults, regardless of location, often delay treatment, increasing their risk of long-term cognitive issues.
The study is part of the ELSA-Brasil project, which has monitored the health of 15,000 public servants since 2008. Participants completed audiometry and cognitive tests covering memory, language and executive function. The performance of those with hearing loss was found to deteriorate more quickly across all categories.
Suemoto explained that hearing loss deprives the brain of crucial stimulation and increases the likelihood of social withdrawal, another leading contributor to dementia risk. “To talk to them, you have to speak louder, repeat sentences … they end up being excluded from conversations,” she said.
Wealthier nations must also pay attention
Although the study was conducted in Brazil, researchers say its relevance is universal. Cognitive decline in middle age is not confined to any one part of the world. The difference is that, in higher-income countries, preventative steps are more readily available. In spite of their availability, these essential steps remain sadly untaken by most.
Irene Wong, a Clinical Audiologist at Hearology®, which provides hearing tests, hearing aid fittings and microsuction earwax removal, said: “One of the great advantages for people in more economically developed countries is the access to services like ours. When hearing loss is picked up early and properly managed, it’s possible to slow down any further decline of auditory function and communication capability. But the biggest challenge remains awareness – most people don’t realise the long-term risks of leaving hearing problems untreated.”
A growing body of global evidence
The Brazilian findings echo other recent studies. A review in JAMA Otolaryngology linked age-related hearing loss to cognitive impairment and dementia. The Lancet has also identified hearing loss, along with high cholesterol, as one of the biggest mid-life risk factors for dementia. And research from the National Institutes of Health in America found that using hearing aids cut the rate of cognitive decline by nearly half in older adults at high risk of dementia.
The ELSA study also identified 11 other modifiable risk factors, including hypertension, low education, depression and air pollution. These often intersect with social and economic inequality, making it even more urgent to embed hearing care within broader public health strategies.
A call for early action
The evidence is clear: hearing loss is not just a benign feature of ageing – it’s a gateway to accelerated cognitive decline, and potentially dementia. Addressing it in middle age offers one of the most promising avenues for prevention. Whether in São Paulo or Southampton, timely access to hearing services could change lives.
References
- Hearing loss and cognitive decline in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) during eight years of follow-up – Demonstrates faster cognitive decline in middle-aged adults with hearing loss.
- Association of Age-Related Hearing Loss With Cognitive Function, Cognitive Impairment, and Dementia – Links age-related hearing loss to cognitive impairment and dementia.
- Hearing impairment is associated with cognitive decline, brain atrophy and tau pathology.
- High cholesterol critical factor in development of dementia, study finds – Reviews The Lancet Commission’s findings on modifiable dementia risk factors.
- Hearing aids slow cognitive decline in people at high risk – Shows hearing aids reduce dementia risk by nearly 50%.
