Today, 21 September, marks World Alzheimer’s Day, part of World Alzheimer’s Month — a moment when charities and researchers around the globe come together to raise awareness of dementia and the ongoing search for better treatment and, ultimately, a cure. At The Hearing Clinic, one question we’re asked more and more often is about the connection between hearing loss and dementia. So what’s the latest thinking?
What we already know
Since 2017, when the Lancet Commission published its first report on dementia prevention, hearing loss has been recognised as one of the modifiable risk factors linked to a higher likelihood of developing dementia later in life. Since then, mounting evidence has pointed to a correlation between untreated hearing loss and cognitive decline. But a correlation isn’t the same as a cause, and one crucial question has remained stubbornly unanswered: does hearing loss actually speed up the progression of Alzheimer’s disease, or does the disease itself cause the hearing problems in the first place?
A five-year study to find out
That’s exactly the question a major new study, led by Dr Jay Buckey Jr at Dartmouth’s Geisel School of Medicine, together with Dr Pedro Rosa-Neto of the Douglas Research Center at McGill University, is hoping to answer. Backed by a $6 million grant from the US National Institute on Aging, and also involving researchers from Northwestern University and Creare LLC, the five-year project will follow three groups: 70 older adults with mild cognitive impairment, a group of cognitively unimpaired older adults, and a group of young, healthy adults for comparison.
What the researchers will measure
Participants will undergo PET brain imaging at three points over the course of the study to track amyloid plaques and tau tangles — two of the hallmark features of Alzheimer’s disease — alongside blood and cerebrospinal fluid samples, detailed neurocognitive testing, and comprehensive hearing assessments.
As Dr Buckey explains it: “What we’re wondering is, is this relationship between hearing and Alzheimer’s a ‘bottom-up’ process…or is it more of a ‘top-down’ process?” In other words: does hearing loss, by depriving the brain of stimulation, help drive the disease process, or does the disease itself damage the parts of the brain that process sound?
Why the answer matters
Getting a clear answer matters enormously. If hearing loss does turn out to accelerate cognitive decline, then treating it promptly, with hearing aids or other support, could become a genuinely important tool for protecting brain health in later life, not just for helping people hear better day to day. If the relationship runs the other way, that would point research in a different, equally important direction.
What you can do now
The study’s final results are still years away, but the advice we give our patients doesn’t need to wait for them. We already know that untreated hearing loss can make everyday life harder, more isolating and more tiring, whatever its relationship with dementia turns out to be. This World Alzheimer’s Day, if you or a loved one has noticed changes in hearing, please don’t put off getting it checked. Book a comprehensive hearing assessment with our team in Hitchin, Radlett or Welwyn, and we’ll talk you through what we find, and what support is available.
