• Posted April 14, 2023

Hearing Aids Might Help Lower Risk for Dementia

Can treating hearing loss lower your chances of developing dementia down the road?

Maybe, claims new research that found that folks who are experiencing hearing loss and don't use a hearing aid may have a higher risk of developing dementia than people who use hearing aids and those without hearing loss.

The study wasn't designed to say how untreated hearing loss may up the risk for memory problems in later life.

"The underlying pathways which may link hearing aid use and brain health are unclear,"said study author Fan Jiang, of the Centre for Health Management and Policy Research at Shandong University in Jinan, China.

However, the brain works hard to listen when there is hearing loss, and hearing aids may lighten its load, allowing the brain to focus on other tasks related to memory and learning. "We encourage the public to seek adequate assessment and treatment of hearing loss in the early stages, such as fitting hearing aids," Jiang suggested.

In the United Kingdom, where the study took place, hearing aids are free from the National Health Service. In the United States, hearing aids became available over the counter in late 2022, which has lowered prices and should encourage more people to use these devices.

The new study included slightly more than 437,700 people in the UK Biobank (a database of genetic and health information from a half-million people in England, Scotland and Wales). Folks were asked about hearing loss and whether they used a hearing aid. Researchers then compared this information to dementia diagnoses using hospital records and death registry data.

Around 75% of the people in the study reported no hearing loss, and the remaining group said they had some hearing loss. Among those with hearing loss, 11.7% used hearing aids.

Compared to people with normal hearing, those with hearing loss who didn't use a hearing aid had a 42% higher risk of developing dementia. By contrast, there was no increased risk in people with hearing loss who used hearing aids.

Still, the absolute risk was small: People with hearing loss who are not using hearing aids have a 1.7% risk for dementia, compared to 1.2% among those without hearing loss or those who are experiencing hearing loss but use hearing aids.

Researchers controlled for other factors, such as loneliness, social isolation and symptoms of depression, which could affect the link between hearing loss and dementia. These factors account for less than 8% of the association between hearing loss and dementia risk.

The findings, published April 14 in The Lancet Public Health journal, was not funded by the hearing aid industry.

Hearing aids may allow for more mental stimulation, and may lower the risk for depression and social isolation, said Gill Livingston, a professor of psychiatry at the University College London who specializes in older people.

She said that there could be a coming decrease in dementia rates now that hearing aids are available over the counter in the United States.

Her advice? "Get your hearing tested and persevere with hearing aids,"said Livingston, who co-wrote an editorial accompanying the new study. "Your brain takes time to get used to them and for them to work well. "

Other experts were also cautiously optimistic about the role that addressing hearing loss can play in offsetting dementia risk.

"There appears to be a protective effect of hearing aids, but a large, long, randomized controlled trial of people with hearing aids and those without them is needed before drawing any conclusions,"said Nicholas Reed, an audiologist at the Cochlear Center for Hearing and Public Health at Johns Hopkins Medicine in Baltimore.

Such a study is ongoing at Hopkins.

Even though hearing aids are free in the United Kingdom, there are often long wait lists and many people don't take advantage of this benefit. Hearing aid use may be a marker for other factors contributing to better health and lower risk for dementia, such as having a caregiver or a higher socioeconomic status, Reed said.

"There are no late-life interventions that show strong prevention from dementia, and hearing loss comes on later in life, so to have a late-life modifiable risk factor for dementia is a huge deal,"Reed said.

The new findings are in line with other studies, said Betsy Mills, assistant director of aging and prevention at the Alzheimer's Drug Discovery Foundation in New York City.

"In the absence of sound stimulation, [brain] cells can die off,"she explained. "Because there are less brain cells to process sound, the brain must work harder and is less efficient."

Hearing aids may help prevent the brain cells from degenerating by maintaining auditory stimulation and allowing the brain to process sound more efficiently, Mills said. In addition, hearing aid use may allow people to remain engaged in social activities, which may also help lower the risk of developing dementia.

"Individuals concerned that they may be experiencing hearing loss should consult a physician to have their hearing tested and to get a hearing aid as soon as possible,"Mills said.

There are other things to do to protect hearing, she said.

"Minimizing exposure to loud sounds by not blasting music in earbuds, and wearing ear plugs in loud environments, such as concerts and construction sites, are important steps everyone can take to protect their hearing,"Mills advised.

More information

The U.S. National Institute on Deafness and Other Communication Disorders provides more on hearing aids.

SOURCES: Fan Jiang, PhD, Centre for Health Management and Policy Research, Shandong University, Jinan, China; Gill Livingston, PhD, professor, psychiatry of older people, University College London; Nicholas Reed, AuD, audiologist, Cochlear Center for Hearing and Public Health, Johns Hopkins Medicine, Baltimore; Betsy Mills, PhD, assistant director, aging and prevention, Alzheimer's Drug Discovery Foundation, New York City; Lancet Public Health, April 14, 2023