hearing health and Alzheimer's

Over the summer, at the Alzheimer’s Association International Conference in Amsterdam, researchers presented a new study that indicated hearing aids could reduce the risk of cognitive decline by roughly half in older adults, particularly among those with other risk factors for dementia. Experts called the three-year study of the long-term cognitive effects of wearing hearing aids “truly groundbreaking.” It’s the latest evidence that hearing health and overall health are inextricably linked.

With World Alzheimer’s Month upon us, scientists have a lot to be optimistic about when it comes to treating Alzheimer’s disease. Still, Alzheimer’s disease — and by extension, dementia in general — is so far irreversible. Which makes preventing it as important as ever.

The theme of this year’s World Alzheimer’s Month is “Never too early, never too late,” with an emphasis on identifying risk factors and encouraging proactive measures to reduce them. As it becomes clearer that hearing loss can contribute to the onset of dementia, hearing care as preventative care is among the most critical, proactive measures.

Growing Risks

The numbers can seem overwhelming. The World Health Organization estimates that by 2050, nearly one in four people across the globe will experience hearing loss and about 700 million of those will need hearing care. In that same timeframe, more than 130 million people are predicted to suffer dementia. Hearing aids can certainly help, but it all starts with care — and the earlier the better.

Although Alzheimer’s disease and dementia typically manifest later in life — commonly diagnosed in people over 65 — research now indicates that hearing loss in middle age (45 to 65) is the most significant risk factor for dementia. Riskier than alcohol consumption, hypertension, and even traumatic brain injury. What’s more, there are signs that even mild hearing loss — typically considered borderline or  “subclinical” hearing loss — can also affect cognition. 

Beyond the age of 65, after which hearing loss has often already taken its toll, the greatest risks for dementia are smoking, followed by depression and social isolation. All three factors have their own links to hearing loss.

While scientists continue to explore the reasons that hearing loss contributes to cognitive decline, there’s a body of evidence that suggests those who experience hearing loss often withdraw from social situations. This withdrawal can negatively impact their cognitive health. Studies also show that having hearing loss alone could lead to changes in your brain chemistry. Therefore, research tells us that hearing loss can have an inherit, negative impact on cognitive function that’s only exacerbated by social isolation. 

Those with hearing loss struggle to hear what others are saying to them. Plus, they often strain to follow conversations among friends, family, or colleagues because the din of voices — or even background noise — makes it hard to pick up words or transitions. For example, there are millisecond gaps in group conversations that are part of conversational dynamics and encourage participation and engagement. People with hearing loss struggle to process these “turn-taking” gaps, especially in the presence of background noise. This makes it hard for them to follow and contribute.

All told, people with hearing loss, whether they’re at a performance, out to dinner, or in a business meeting, commonly end up fatigued by the experience. They avoid the fatigue by avoiding the situations that cause it, leading to social isolation and cognitive decline.

The Importance of Hearing Care

Hearing aids can help. Not only do modern hearing aids amplify sound, they also intelligently process the entire listening environment in order to make speech clearer and more natural, reduce the impact of background noise, and enhance the conversational dynamics that make participation and engagement easier. They can be tailored by a hearing care professional to a wearer’s particular hearing loss, with features that allow people to fine-tune even further and address other issues, like noise-induced tinnitus.

The challenge is getting more people who need them to wear hearing aids. Overall, less than one in five people who could benefit from hearing aids actually uses them (the figure is only a bit higher among adults 70 and older), and it typically takes seven years from diagnosis to adoption. With what we now know about the link between hearing health and cognitive health, any delay could have serious ramifications.

Global initiatives to make hearing aids more widely available and accessible will certainly help. For its part, HearUSA offers prescription and over-the-counter hearing aids through its networks of hearing care centers.

But going forward, access to hearing care is going to be paramount. At the 2023 Alzheimer’s Association International Conference, other experts presented findings on the impact of affordable, accessible, community-based intervention on people experiencing cognitive decline. In one study from Johns Hopkins University, subjects in Baltimore, Maryland, who received hearing care were compared with those who were placed on a temporary, control waitlist. Those who received hearing care saw significant improvement in their ability to communicate.

The fact is, there remains much we don’t know about the causes of dementia and Alzheimer’s disease. But we know social isolation impacts cognitive health. So, when there’s a risk factor we do know how to address, it’s incumbent on hearing care professionals, healthcare providers, and the public to take preventative steps. In this case, that means maintaining cognitive health by addressing hearing health.

At the Alzheimer’s conference, a researcher from the University of Western Australia presented, “The Role of Hearing Healthcare Professionals in Supporting Patients with Dementia Risk.” That role, she concluded, is “essential.”