Study Finds Early Hearing-Aid Use Associated With Large Reduction in Dementia Risk

Adults with hearing loss who reported wearing hearing aids before the age of 70 had a substantially lower risk of developing dementia than those with untreated hearing loss, according to a study published in JAMA Neurology.

Researchers reported that participants with hearing loss who used hearing aids had a 61% lower risk of "incident all-cause dementia" compared with participants who had hearing loss but did not use hearing devices. The study also found that people under age 70 without hearing loss had a 29% lower dementia risk compared with those who had untreated hearing loss. The same protective association for hearing-aid use was not observed among participants who were 70 or older at the time of hearing assessment.

The analysis drew on data from 2,953 participants in a long-standing observational cohort and was conducted by investigators affiliated with the University of Texas, the University of Pittsburgh, Boston University and other institutions. The authors framed hearing loss as a potentially modifiable risk factor for dementia and highlighted the temporal relationship between the onset of hearing impairment, timing of hearing-aid use and later cognitive outcomes.

The study used clinical hearing assessments and self-reported use of hearing devices. Investigators categorized participants by hearing status and device use and tracked incident dementia over follow-up. The reported 61% reduction refers to the relative difference in rates of dementia onset between hearing-impaired participants who used hearing aids before age 70 and those who did not use hearing aids.

Experts who have studied sensory impairment and cognition say the mechanisms linking hearing loss to dementia risk may include social isolation, increased cognitive load from straining to hear, and downstream effects on brain structure and function. Prior research has shown associations between hearing impairment and cognitive decline, but randomized trials testing whether hearing-aid treatment prevents or delays dementia have been limited.

The authors and commentators emphasized that the findings are observational and cannot by themselves prove that hearing-aid use prevents dementia. Observational analyses can be affected by residual confounding, differences in health care access, socioeconomic factors, general health status and other behaviors that influence both hearing-aid uptake and dementia risk. The study relied in part on participants' reports of hearing-aid use, which may be subject to reporting errors.

Nevertheless, the magnitude of the association and the age-dependent pattern reported in the paper add to a growing literature suggesting that treating hearing loss earlier in life could be an actionable strategy to reduce dementia risk at a population level. Public health advocates have noted that hearing-aid adoption remains low among older adults despite increases in availability and efforts to lower costs.

The study's authors called for further research, including randomized controlled trials, to test whether interventions to correct hearing impairment can causally reduce dementia incidence and to determine the optimal timing of intervention. In the interim, clinicians and public health officials may consider screening for hearing impairment and discussing treatment options as part of comprehensive strategies to address cognitive health in aging populations.