Hearing AIDS may cut risk for cognitive decline by half

A landmark clinical trial found that for some older adults, wearing hearing aids may cut the risk for cognitive decline by nearly half. The July 2023 study published in The Lancet has major implications for millions of people.

Hearing loss affects about 1 in 3 U.S. adults between the ages of 65 and 74 and nearly half of those older than 75, according to the National Institutes of Health. And hearing loss is tied to dementia or accelerated mental decline. One study that followed 639 adults for more than a decade estimated that mild hearing loss doubled someone’s odds of developing dementia, and the risks increased from there. Moderate hearing loss tripled the risk, and those with severe hearing loss had five times the risk.

It’s estimated that hearing loss accounts for 8 percent of dementia cases—or 800,000 of the nearly 10 million new cases diagnosed each year.

How hearing loss affects dementia risk

Hearing loss has long been associated with increased brain atrophy, or the loss of brain cells and their connections. Research is ongoing but it’s also theorized that hearing loss forces the brain to work harder, which can interfere with the mental processing required for other tasks. Another explanation is that the social isolation associated with hearing loss, reduces brain stimulation and hastens mental decline.

Hearing aids may help protect the brain

The July 2023 randomized, controlled trial investigated whether hearing aids could help protect the brain function of 977 cognitively healthy older adults with mild to moderate hearing loss typically associated with aging. Of this group, however, 238 people had a higher risk of cognitive decline.

The participants were followed for three years. During that time, one group received hearing aids, a hearing “toolkit” to assist with self-management, and ongoing instruction and counseling with an audiologist. A separate control group received talk sessions with a health educator about chronic disease prevention. At the end of the study period, both groups underwent comprehensive neurocognitive testing.

The researchers found that hearing aids had a significant benefit for the subgroup of older adults at high risk for dementia, slowing the rate of cognitive decline by 48 percent.

“The positive results with the hearing intervention in the ARIC subgroup analysis are encouraging and warrant further investigation,” said Maria C. Carrillo, Ph.D., Alzheimer’s Association chief science officer in a July 18 news 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.”

A separate January 2023 study from the Johns Hopkins Bloomberg School of Public Health published in JAMA also found that older adults with more severe hearing loss were more likely to have dementia. The researchers found, however, that the likelihood of dementia was lower among people who used hearing aids than those who didn’t.

For their study, researchers collected data from a nationally representative group of 2,413 people through in-home testing and interviews. They found the prevalence of dementia was 61 percent higher for those with moderate or severe hearing loss than those with normal hearing. But for the 853 people with moderate or severe hearing loss who wore hearing aids, the prevalence of dementia dropped to 32 percent when compared to those who did not wear hearing aids.

“This study refines what we’ve observed about the link between hearing loss and dementia,” said the study's lead author Alison Huang, PhD, MPH, a senior research associate in the Bloomberg School’s Department of Epidemiology and at the Cochlear Center for Hearing and Public Health in a January 10 news release. Huang added these findings help build support for public action to improve hearing care access.

Hearing aids are more affordable and easier to get

Nearly 29 million Americans would benefit from wearing hearing aids, the NIDCD notes. But only about one-fifth of those people actually get them. In a move that could help address this issue, on September 12, the U.S. Food and Drug Administration (FDA) authorized the first over-the-counter (OTC) hearing aid software device, Hearing Aid Feature (HAF). The mobile medical application was designed for use with certain versions of Apple’s AirPods Pro. The HAF is set up using an iOS device, such as an iPhone or an iPad. Users can personalize the software and adjust tone and volume setting to their individual hearing levels on their own—without the help of a hearing professional.

Hearing aids can also be expensive, but in August 2022 the U.S. Food and Drug Administration (FDA) took action to improve access. The agency finalized an historic rule, establishing a new category of over-the-counter (OTC) hearing aids. As a result, these OTC hearing aids are available at retailers across the country. Adults with mild-to-moderate hearing loss can buy a pair a store or online at a lower cost without a prescription, medical exam, fitting by an audiologist fitting.

The decision makes hearing aids easier to buy and more affordable for millions—something that could have a dramatic impact on their well-being and quality of life.

Timing matters. Many people delay the decision to get hearing aids, which may come at a cost. Changes in the brain and hearing pathways resulting from hearing loss may be irreversible. A person’s response to hearing aids may also be better if they get them closer to the onset of their hearing loss.

If you need or want to learn more about hearing aids, talk to your healthcare provider about the options that are best for you.