Summary: A Brazilian longitudinal study of 805 adults in their 50s found a strong link between hearing loss and accelerated cognitive decline. Over eight years, participants with hearing impairment experienced faster decreases in overall cognition, including memory, language, and executive function.
The researchers identify two main pathways that may explain this association: diminished auditory stimulation to the brain and increased social isolation. Both pathways are established risk factors for dementia. The findings highlight the importance of early hearing screening and timely interventions—such as hearing protection at work and use of hearing aids—to help preserve cognitive health, particularly in low- and middle-income countries where dementia prevalence is expected to rise.
Key facts:
- Faster cognitive decline: Adults with hearing loss showed a significantly faster decline in global cognitive scores over eight years.
- Two contributing mechanisms: Reduced sensory input to the brain and social withdrawal both contribute to increased dementia risk.
- Prevention potential: Routine audiometry and interventions like hearing aids and workplace noise protection may reduce the risk of cognitive deterioration.
Source: FAPESP
Study overview
Published in the Journal of Alzheimer’s Disease, this analysis used data from the São Paulo center of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). ELSA-Brasil has followed more than 15,000 public servants from six institutions since 2008. The present study evaluated 805 participants across three waves (2008–10, 2012–14, and 2017–19), combining objective audiometry with repeated cognitive testing to examine how midlife hearing loss relates to later cognitive change.
Claudia Suemoto, a professor at the University of São Paulo Medical School and lead author on the paper, emphasizes that hearing loss is a modifiable risk factor for dementia because it can be detected and treated. She notes that by 2050 more than 70% of people with dementia are expected to live in low- and middle-income countries like Brazil, reinforcing the need for locally relevant research and public-health action.
How hearing loss may accelerate cognitive decline
The study outlines two plausible mechanisms. First, hearing provides a primary sensory pathway for information that helps keep cognitive networks active. When auditory input is reduced, related brain regions receive less stimulation, which may accelerate decline. Second, hearing impairment often leads to social withdrawal: difficulties following conversations can prompt people to reduce social engagement, and social isolation is an established dementia risk factor.
The researchers point out that adults frequently adapt to gradual hearing loss without recognizing it, so objective tests such as pure-tone audiometry are essential for early detection. Corrective measures, including hearing aids and removing or reducing the auditory hazards that caused the loss (for example, occupational noise or excessive headphone volume), are practical steps to protect hearing and potentially slow cognitive decline.
Study methods and results
Hearing loss was defined as a pure-tone average above 25 dB in the better ear. Cognitive performance was assessed with six tests covering memory, verbal fluency, and executive function, which were combined into a global cognitive z-score. Linear mixed-effects models adjusted for sociodemographic, lifestyle, and clinical factors were used to assess the association between hearing loss and cognitive trajectory.
Of the 805 participants (mean age 51 ± 9 years; 52% women; 60% White), 62 individuals (7.7%) met the study definition of hearing loss. Over a median follow-up of eight years, hearing loss was associated with a faster decline in global cognitive performance (β = −0.012, 95% CI = −0.023; 0.000, p = 0.039). Declines were also observed across specific domains—memory, verbal fluency, and executive function—though estimates for these individual tests were less precise.
Implications for prevention and public health
This study reinforces hearing loss as one of several potentially modifiable midlife risk factors for dementia. The authors note that eliminating hearing loss could prevent an estimated proportion of dementia cases worldwide. Other modifiable risk factors identified include low education, hypertension, brain injury, diabetes, obesity, alcohol misuse, smoking, depression, physical inactivity, air pollution, and social isolation. Addressing hearing health—through workplace protections, safe listening practices, routine audiometry, and appropriate use of hearing aids—should be part of comprehensive dementia prevention strategies, especially in resource-constrained settings.
About this hearing loss and cognition research news
Author: Heloisa Reinert
Source: FAPESP
Contact: Heloisa Reinert – FAPESP
Image credit: Neuroscience News
Original research: Closed access. “Hearing loss and cognitive decline in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) during eight years of follow-up” by Claudia Suemoto et al., Journal of Alzheimer’s Disease.
Abstract
Hearing loss and cognitive decline in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) during eight years of follow-up
Background
Moderate or greater hearing loss becomes increasingly common with age, rising from roughly 12% at age 60 to more than 58% by age 90. Hearing loss in midlife is recognized as a potentially modifiable risk factor for dementia, and it has been estimated that removing this risk could prevent a meaningful share of dementia cases. Much prior research has focused on high-income countries, while low- and middle-income nations face growing dementia burdens.
Objective
To assess the association between hearing loss and cognitive decline over an eight-year period in a Brazilian cohort.
Methods
Participants from the São Paulo site of ELSA-Brasil were evaluated in 2008–10, 2012–14, and 2017–19. Hearing loss was defined by pure-tone audiometry >25 dB in the better ear. Cognitive function was measured using tests of memory, verbal fluency, and trail-making, combined into a global cognitive z-score. Linear mixed-effects models adjusted for demographic, lifestyle, and clinical variables were used to estimate the relationship between hearing loss and cognitive change.
Results
Among 805 participants (mean age 51 ± 9 years; 52% women; 60% White), 62 had hearing loss. Over follow-up, hearing loss was associated with a faster decline in global cognition (β = −0.012, 95% CI = −0.023; 0.000, p = 0.039).
Conclusions
In this Brazilian middle-income sample, hearing loss in midlife was significantly associated with a faster rate of global cognitive decline over eight years, underscoring the importance of hearing screening and intervention as components of dementia prevention efforts.