As people get older it’s common for their hearing to decline and studies show that hearing loss, for some, is associated with the onset of dementia. But researchers are beginning to identify who may be able to prevent or delay the onset of dementia by wearing hearing aids, and when they should start wearing them.
Age-related hearing loss happens when the tiny inner ear sensory cells called hair cells, as well as the nerve that innervates those hair cells, begin to degenerate, according to Andrew McCall, MD, associate professor of head and neck surgery at the David Geffen School of Medicine at UCLA. This is called sensorineural hearing loss, Dr. McCall says, and it’s permanent because the tiny hair cells cannot regenerate. “Once you lose them, they don't come back,” he says.
Several studies have shown the connection between hearing loss and dementia, including one recently published in the Journal of the American Medical Association Otolaryngology Head and Neck Surgery suggesting patients who have hearing loss and wear hearing aids have a reduced risk of dementia compared with those have hearing loss without wearing aids.
Exactly how hearing loss and dementia are related is unknown. “The linkage is largely based on associational studies, so there's a high coincidence of the two problems, of having dementia or cognitive decline and having hearing loss,” says Dr. McCall.
He relates two thoughts on the possible cause of this connection.
“If you have less hearing, the brain has less inputs to be able to process, and that can result in the brain not functioning as well as it used to,” he says. “Another hypothesis would be that it's pretty common if you have fairly severe hearing loss to become more socially isolated. And people think it's the social isolation that leads to cognitive decline because the individual's not interacting with others as much. Again, those are hypotheses. Nobody really knows for sure, but there is a pretty strong association between the two conditions.”
Risk factors for dementia
Dementia affects more than 6 million Americans, according to the National Institutes of Health, with women at a slightly higher risk than men. Risks for dementia include high blood pressure, lack of physical activity, smoking, alcohol use and uncontrolled diabetes.
People who have a number of these risk factors and are experiencing hearing loss may benefit most from wearing hearing aids, according to a large three-year study published in The Lancet in 2023. This study set out to determine if treating age-related hearing with hearing aids can delay onset of dementia or slow a person’s cognitive decline.
“What they found is that patients with higher risk factors for dementia in the hearing aid group were less likely to either progress or go on to develop dementia in the study period,” explains Dr. McCall. However, he says, “They didn't see a difference in lower-risk individuals in their lower-risk group.”
Should healthy, older adults who have mild hearing loss start wearing hearing aids to prevent developing dementia? There is no definitive answer at this time, says Dr. McCall, adding that many of his patients face this dilemma.
How hearing aids might help
Hearing aids have clear benefits for many older adults, he says. “Although there's not really evidence to say that hearing aids would stave off or prolong the course until dementia sets in, I think it's certainly unlikely to make them worse. And, by the way, the hearing aids may help people hear better during their day-to-day interactions with others.”
Hearing aids can be purchased over-the-counter (OTC) at retail stores or be fit by an audiologist. Dr. McCall says the advantage of obtaining hearing aids through an audiologist is that they can precisely adjust the devices to individual hearing needs and can treat more severe levels of hearing loss than can OTC aids.
Some people are reluctant to wear hearing aids out of embarrassment. Doubting the value of hearing aids and not finding them comfortable to wear also keep some adults from utilizing them, according to a 2013 study reported in the International Journal of Audiology.
“There is some hesitancy out there,” says Dr. McCall, “and we try to work with individuals the best we can to just give them the facts and let them make their informed decision about what they want to do.
“I want to emphasize that even if a person doesn't carry a diagnosis of dementia, but either they or their friends or loved ones notice that they're struggling with hearing loss to any degree, they should go have their hearing checked,” he says. “And if there are concerns raised on hearing testing, they should be evaluated and consider addressing it with hearing aids.”
