Hearing loss is about more than hearing what your spouse is saying. (The difference between hearing and listening is another subject.) Losing aural function over time can also raise your chances of getting dementia, according to new studies.
Hearing loss is no minor issue. Research now suggests it's a top modifiable risk factor: Hearing loss alone is responsible for an estimated 7% of all dementia cases worldwide. Of the roughly 10 million people diagnosed with dementia each year, as many as 700,000 of the diagnoses may have resulted from hearing issues.
Now, scientists are asking whether treating hearing loss can help prevent dementia, and the results are promising. The research suggests there may be things you can do to reduce your risk of mental decline, such as wearing hearing aids. The sooner you identify and manage your hearing loss, the better are your chances of avoiding dementia.
How Are Hearing Loss and Dementia Connected?
About one in six people have some kind of hearing loss. That number rises with age to two in three adults 70 and older. Not everyone with hearing loss gets dementia. But if you have hearing loss, you have greater odds of losing your mental sharpness. One study found that people with mild, moderate, and severe hearing loss were two, three, and five times more likely to develop dementia over a 12-year span, compared to those without it.
Hearing loss is one of the top treatable risk factors for dementia, says researcher Frank Lin, MD, PhD, who is director of the Cochlear Center for Hearing and Public Health at Johns Hopkins University. A review of the research shows that hearing loss causes more dementia cases than diabetes, smoking, and high blood pressure combined.
Although experts aren't certain of the exact link, they think there are three main reasons why hearing loss can pave the way for cognitive decline (a loss in thinking, memory, and other brain functions).
- It competes for brain space. If you can't hear clearly, your brain has to work harder to understand noises, says Alejandra Sanchez-Lopez, MD, an assistant clinical professor of neurology and geriatric medicine at the University of California, Los Angeles. That comes at the expense of the parts of your brain in charge of memory and thinking.
- It may make your brain shrink more quickly. Hearing loss can speed up the rate you lose brain tissue. The part of your brain that controls hearing doesn't receive as much stimulation, which may lead to atrophy, Sanchez-Lopez says.
- It can make you less social. People with hearing loss may talk less to others or withdraw socially, says Ozama Ismail, PhD, the director of scientific programs at the Alzheimer's Association. This can lead to social isolation, which also raises the chances of dementia.
Can Hearing Aids Protect Against Dementia?
If you have hearing loss, getting treatment – such as wearing hearing aids – may protect against dementia. In one study led by Lin, people with mild to moderate hearing loss received either hearing aids and instruction on how to use them or simply general health counseling. In people at an increased risk of dementia, those who wore the hearing aids had nearly 50% less cognitive decline over the next three years, compared to those who didn't.
In theory, this slower mental slide can delay or even fend off dementia. "That's the hope," Lin says. "More research is needed. We're going to follow more people for many more years."
It makes sense: Wearing hearing aids allows you to hear more clearly, and that may improve your brain function over the long term. The aids also help you communicate better so you're more social, Lin says.
Wearing hearing aids gave Jan Correll of Hilton Head, South Carolina, more confidence in social situations. "It was annoying and embarrassing to ask people to repeat themselves," she says. "Trouble hearing can really cut you off from conversations and inhibit you from speaking up." But now that she hears clearly, Correll doesn't hesitate to speak and socialize with others.
Does this mean that wearing hearing aids can reverse a loss of mental skills to make you sharper? Probably not, Lin says. "It's more difficult to improve cognition compared to reduce a decline," he says. That's why it's important to detect and treat your hearing loss early on. Many people with hearing loss (more than 75%) don't wear hearing aids.
If You Have Hearing Loss, How Can You Lower Your Risk?
The first step to protect your cognitive health is to catch your hearing loss as soon as possible. "The signs can be subtle," Lin says. For example, "you may find yourself leaning in a bit more to hear at a noisy restaurant."
Donna Resnick of Milton, Delaware, noticed that it was harder to hear the dialogue on television. "I was frequently turning up the volume and asking people to repeat themselves," she says. "That's when I realized that something was off."
The following steps can help you detect hearing loss in its earliest stages.
- Keep tabs on your hearing. You can test your own hearing with the Hearing Number app, which was created by researchers at Johns Hopkins Bloomberg School of Public Health. Or take note when it's a little harder to hear, or when you're often asking people to repeat themselves.
- Get your hearing checked regularly. Experts recommend getting your hearing checked once every 10 years, and then every three years after age 50.
If you have hearing loss, ask about hearing aids – and don't be afraid to get them. It used to be that hearing aids cost thousands of dollars. But over the past several years, they have become more affordable and accessible, Lin says.
If you have severe hearing loss, you'll need an audiologist to prescribe hearing aids tailored to your ears. For mild to moderate cases, you may be able to use an over-the-counter hearing aid. Talk to your health care provider about which option is best for you.
"The most surprising part about hearing aids is that no one has ever noticed that I have them," Correll says. "They're so comfortable that they're part of my routine, and I forget that I'm wearing them."
