Mounting evidence shows hearing aids can help prevent dementia and possibly even slow the progression of existing cognitive decline. A new study presented at AAIC turns up the volume on the conversation.
Some 65 percent of adults over the age of 60 live with hearing loss — and mounting research shows it is a controllable risk factor for dementia. But according to a Johns Hopkins study, only about 14 percent of people actually pursue the solution of getting a hearing aid. In a new study presented at the Alzheimer’s Association International Conference 2023 in Amsterdam this week, researchers behind a study called ACHIEVE bring more findings that support hearing aids as a means of protecting cognitive health — particularly in people who already have higher risk factors for dementia (i.e. older age, high blood pressure, and early signs of cognitive decline.)
The science on hearing aids, cognitive decline and dementia risk
For years, scientists have been probing this link between hearing loss and cognitive decline, linking eight percent of all dementia cases to hearing loss, and finding that hearing loss is one of 12 modifiable risk factors key to dementia prevention on a population-wide scale.
According to Dr. Sarah A. Sydlowski, the audiology director of the Hearing Implant Program and former president of the American Academy of Audiology, checking for hearing loss is key for healthy brain aging.
“If you aren’t hearing well, you tend not to participate in those activities that stimulate your brain, through conversation or through challenging listening environments,” Sydlowski told Being Patient. “When you identify hearing loss early and start using appropriate well fitted hearing aids, you’re giving your brain access to those sounds that keep it sharp and keep it active.”
In December of 2022, a study followed more than 137,000 adults for a 25-year period and found that not only did people who started using hearing aids show small improvements on cognitive tests in the short term: They were almost 20 percent less likely to develop cognitive decline or dementia in the long term. In other words, hearing aids reduced the risk of dementia by one fifth.
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The new study presented at AAIC takes this a step further. The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study, was a different type of study: a randomized, controlled clinical trial of hearing aids. Beginning in 2017, ACHIEVE followed 977 adults over the course of three years. Participants were aged 70 to 84, who were living with untreated hearing loss and who were free from substantial cognitive impairment, providing the study group with hearing aids, a hearing “toolkit” to assist with self-management, and ongoing instruction and counseling with an audiologist. The goal: to understand specifically whether hearing aids would reducing long-term cognitive decline in older adults.
AAIC 2023’s ACHIEVE study: What did the research team actually find?
News outlets covering the study will be quick to point out that the simple act of getting hearing aids appeared to slow down cognitive decline in by almost half. However, the study did not find that this was the case overall: Hearing aids did not generally slow cognitive decline in comparison to the control group in the total study population, nor in a subset of the 977 study participants called the community population.
But, in a specific segment of the study — 238 people participating in an ongoing observational study of heart health — the researchers found something different. According to the ACHIEVE researchers, this particular group generally had higher risk factors for dementia, lower baseline cognitive scores, and a faster rate of three-year cognitive decline during the study than the other three quarters of ACHIEVE study participants. The heart health observational study had been called “Atherosclerosis Risk in the Communities” (ARIC), for a condition that involves thickening or hardening of the arteries due to build-up of cholesterol and other substances. (According to STAT News, further risk factors for the ARIC group also included that this group skewed older, they tended to be lower-income, these participants generally had higher blood pressure, and they were more likely to be living alone.)
In this group with higher dementia risk, the research team found that hearing intervention did make a serious difference, appearing to slow cognitive decline in this group by 48 percent, or as much as half.
“The positive results with the hearing intervention in the ARIC subgroup analysis are encouraging and warrant further investigation,” Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer, said in a press release. “Previous research has identified hearing loss as potentially the single largest dementia risk factor that can be addressed or modified with existing tools that remain underutilized.”
According to co-primary investigator of the ACHIEVE study Dr. Frank Lin, of Johns Hopkins University School of Medicine and Bloomberg School of Public Health, there were other benefits too.
“In both the ARIC group and the new group of community volunteers, we also found that the hearing intervention improved communication abilities, social functioning and loneliness,” Lin said in a press release. “Until we know more, we recommend for general health and well-being that older adults have their hearing checked regularly and any hearing issues properly addressed.”
The bottom line on hearing aids for older adults
If you’re starting to experience hearing loss as an older adult — especially if you’re already concerned about brain health issues or cognitive decline — it’s worth consulting with your doctor and speak to a hearing health specialist. There is enough scientific evidence at this point to indicate that it has longer-tail health benefits. And besides, it can be a boost to quality of life.
“Hearing loss is very treatable in later life, which makes it an important public health target to reduce risk of cognitive decline and dementia, along with other dementia risk factors such as less education in early life, high blood pressure, social isolation and physical inactivity,” Lin said in a press release.
However, audiology experts point out that some hearing aids, when used incorrectly or mismatched with the user, can actually make hearing issues worse. Sydlowski recommends visiting an audiologist for advice rather than purchasing a hearing aid on one’s own.
“Studies that are just now starting to emerge suggest that if you start using appropriate hearing aids, or cochlear implants, when it’s a more significant hearing loss, you can improve the cognitive decline that you’re experiencing,” Sydlowski told Being Patient in a previous interview. “So not only can you perhaps help stave it off, you can also help to mitigate it.”