By Morgan Nwanguma
A long-term research involving older adults with moderate hearing loss found that although hearing aids did not improve performance on standard tests of memory or thinking, they were associated with a lower risk of dementia over time. During the seven-year follow-up, individuals who were prescribed hearing aids were significantly less likely to develop dementia compared with those who were not.
The findings come from a newly published study in Neurology, which reported that among people with moderate hearing loss, receiving a hearing-aid prescription did not result in measurable gains on conventional cognitive assessments of memory and thinking.
“Hearing loss is more common as we age and previous research has found it may increase the risk of memory and thinking problems, including dementia, but less is known about how treating hearing loss with hearing aids may impact brain health,” said study author Joanne Ryan, PhD, of Monash University in Melbourne, Australia. “Our study followed people with hearing loss, some of whom were prescribed hearing aids and some who were not, and found cognitive scores were similar for both groups. However, we also found that hearing aids were associated with a lower risk of dementia.”
Who Was Included in the Research
The study tracked 2,777 adults in Australia with an average age of about 75 who did not have dementia at the start of the research. All participants reported moderate hearing loss defined as self-reported hearing difficulties, and none had previously used hearing aids. During the course of the study, 664 participants were prescribed hearing aids and were asked to report how often they used the devices.
Tracking Cognitive Health Over Seven Years
Participants were followed for seven years and underwent cognitive assessments annually. These tests measured abilities such as memory, language, and the speed of mental processing. By the end of the study period, 117 participants had developed dementia. Researchers compared results between those who received hearing-aid prescriptions and those who did not. On average, scores on memory and thinking tests remained similar in both groups, indicating that hearing-aid use was not associated with higher cognitive test performance.
Lower Dementia Risk Emerges
However, a different trend emerged when researchers examined the likelihood of developing dementia. After adjusting for factors such as age, sex, and health conditions including diabetes and heart disease, they found that 5% of participants who were prescribed hearing aids developed dementia during the study. In contrast, 8% of those who were not prescribed hearing aids developed the condition. This difference translates to a 33% lower risk of dementia among participants who received hearing-aid prescriptions.
Ryan noted that the contrast between unchanged cognitive test scores and the reduced risk of dementia was an unexpected finding. “One factor could be that most study participants had good cognitive health when the study started, reducing the potential for improvement with hearing aids.”
Cognitive Impairment and Hearing Aid Use
The researchers also examined rates of cognitive impairment, a category that includes both general cognitive decline and dementia. After adjusting for various factors, they found that 36% of participants who were prescribed hearing aids developed cognitive impairment, compared with 42% of those who did not receive hearing-aid prescriptions. This represented a 15% lower risk among those prescribed the devices.
Further analysis revealed that the more consistently participants used their hearing aids, the lower their risk of developing dementia, indicating a gradual decline in risk with regular device use.
What the Discoveries Suggest
“While we didn’t find a difference in cognitive scores, our study suggests that for older adults with hearing loss, using hearing aids may lower the risk of dementia and cognitive impairment, benefiting brain health,” said Ryan. “Further studies are needed to understand the ways hearing aids may support memory, thinking and brain health overall.”
The researchers stressed that the results demonstrate an association rather than definitive evidence that hearing aids directly prevent dementia.
Study Limitations and Funding
One limitation is that most participants were relatively healthy and had strong cognitive function at the start of the study. Because of this, the findings may not fully apply to people with poorer overall health or those who already have memory problems.
The research was funded by the National Institutes of Health, the National Institute on Ageing, the Australian Government, and Monash University.
English