This article is for general information only and is not medical advice. If you have concerns about your own or a family member’s memory or cognitive health, please speak with your GP.
Hearing loss is currently the largest single modifiable midlife risk factor for dementia, according to the 2024 Lancet Commission report on dementia prevention, accounting for an estimated 7% of dementia cases that could theoretically be prevented if addressed. This does not mean hearing loss causes dementia, or that everyone with hearing loss will develop it. It means hearing loss is one of several factors, alongside things like hypertension and physical inactivity, that consistently shows up as increasing risk across large studies, and treating it appears to help.
Concerned about your hearing? Book a free hearing test at Bridgnorth, Church Stretton, Kingswinford or Wombourne, or book online now. Call 01746 572572.
Contents
- What the 2024 Lancet Commission report says
- What the observational evidence shows
- What the ACHIEVE trial actually found
- Why might hearing loss and dementia risk be linked
- Peripheral and central hearing loss: an important distinction
- What this means for you
- FAQs
What the 2024 Lancet Commission report says
The Lancet Commission on Dementia Prevention, Intervention and Care is a standing group of international experts who periodically review the global evidence on dementia risk. Its 2020 report identified 12 modifiable risk factors for dementia across a person’s life, including hearing loss in midlife. The 2024 update reviewed the evidence again, added two further risk factors (untreated vision loss and high LDL cholesterol), and, based on new meta-analyses, confirmed hearing loss as the single largest modifiable risk factor from midlife onwards. Taken together, the Commission estimates that addressing all 14 identified risk factors could theoretically prevent or delay around 45% of dementia cases worldwide. Hearing loss alone accounts for roughly 7% of that population-level risk. The Commission also stated that the evidence that treating hearing loss reduces dementia risk is now stronger than in its previous report, particularly for people who already have other risk factors for cognitive decline.
What the observational evidence shows
Most of the evidence linking hearing loss to dementia comes from large observational studies, which track big groups of people over time rather than testing an intervention directly. A 2024 meta-analysis combining 50 such studies from the US, Europe, East Asia and Australia, covering more than 1.5 million people in total, found that adult-onset hearing loss was associated with increased risk of cognitive decline, mild cognitive impairment, dementia and Alzheimer’s disease, with each 10-decibel worsening in hearing linked to a 16% increase in dementia risk. Separately, data from the long-running Framingham Heart Study found that people with mild or greater hearing loss in midlife had a 71% higher risk of dementia over 15 years of follow-up compared with those with normal hearing.
It is worth being clear about what this type of evidence can and cannot tell us. Observational studies can show a strong and consistent association, but they cannot prove that hearing loss directly causes dementia, because people with hearing loss may also differ from people without it in other ways that affect their risk. This is exactly why researchers have also looked for evidence from randomised controlled trials, which can test cause and effect far more reliably.
What the ACHIEVE trial actually found
The most rigorous evidence to date comes from the ACHIEVE trial, published in the Lancet in 2023, the first large randomised controlled trial to test whether treating hearing loss actually reduces cognitive decline, rather than simply observing who develops dementia over time. Researchers followed 977 adults aged 70 to 84 with untreated mild to moderate hearing loss for three years, randomly assigning half to receive hearing aids and audiological support and the other half to a general health education programme.
Across the whole study group, hearing treatment did not produce a statistically significant reduction in cognitive decline overall. However, in a pre-specified subgroup of 238 participants who were already at higher risk of cognitive decline, due to older age and cardiovascular risk factors, hearing intervention slowed cognitive decline by 48% over the three-year period. A further analysis published in 2025 confirmed that the benefit of hearing treatment was not uniform across all older adults with hearing loss, but was concentrated in those already at greater risk of decline. In other words, treating hearing loss appears to matter most for the people who most need protecting.
Why might hearing loss and dementia risk be linked
The exact mechanism is still being researched, and several explanations are being investigated, likely working together rather than as a single cause.
Cognitive load – When hearing is impaired, the brain has to work harder to interpret incomplete or unclear sound. Some researchers believe this extra effort diverts mental resources away from memory and other thinking tasks over time.
Social withdrawal – Struggling to hear in conversation is tiring and frustrating, and can lead people to withdraw from social situations. Since social isolation is itself a separate, established risk factor for dementia, hearing loss may contribute to risk partly through this route.
Reduced brain stimulation – Less auditory input over time may mean parts of the brain involved in processing sound receive less stimulation, which some researchers believe could contribute to broader changes in brain structure.
Shared underlying causes – It is also possible that hearing loss and dementia share some common underlying biological causes, rather than one directly causing the other, particularly in the case of central hearing loss (see below).
Alzheimer’s Research UK and the Alzheimer’s Society both describe the relationship as complex and not yet fully explained, and are clear that hearing loss should be understood as a risk factor rather than a warning sign that dementia will definitely follow.
Peripheral and central hearing loss: an important distinction
Not all hearing loss is the same, and the distinction matters for this topic specifically. Peripheral hearing loss happens when the ear itself finds it harder to detect sound, most commonly due to ageing or noise exposure. This is the type that hearing aids are designed to help with, and it is the type most strongly linked to the research above. Central hearing loss is different: it happens when the brain has difficulty processing sound information it receives, even though the ears themselves are working normally. Hearing aids cannot correct this type of hearing loss, because the problem is not in the ear. In some cases, difficulty processing sound can be an early sign that the brain regions involved in hearing have been affected by neurodegenerative changes. It can be genuinely difficult to tell the two types apart without a proper assessment, which is one of several good reasons to have hearing changes checked by a professional rather than assumed to be “just” age-related.
What this means for you
None of this research means that hearing loss guarantees dementia, or that hearing aids are a proven way to prevent it outright. What it does show is a consistent, well-evidenced association, growing trial evidence that treatment helps at least some people, and no evidence that treating hearing loss causes any harm. Given that hearing aids also improve day-to-day communication, confidence and quality of life regardless of any effect on dementia risk, there is little reason to delay a hearing test if you have noticed changes.
Practical, evidence-backed steps include having your hearing checked from midlife onwards, even without obvious symptoms, protecting your hearing from loud noise throughout life, and addressing hearing loss promptly with properly fitted hearing aids if it is found, rather than waiting years as many people do.
Book your hearing test
- Book online
- Call us on 01746 572572 (Bridgnorth and Church Stretton) or 0800 644 6014 (Wombourne earwax and screening clinic)
- Find your nearest clinic: Bridgnorth, Church Stretton, Kingswinford, Wombourne, or a home visit
FAQs
Does hearing loss cause dementia? There is no proof that hearing loss directly causes dementia. Large studies show a consistent association between the two, and hearing loss is officially recognised as the largest modifiable midlife risk factor, but it is one of several contributing factors rather than a single direct cause.
Do hearing aids prevent dementia? No study has proven that hearing aids prevent dementia outright. The ACHIEVE randomised trial found hearing treatment significantly slowed cognitive decline in older adults already at higher risk of decline, though it did not show a significant effect across the whole study group.
How much does hearing loss increase dementia risk? Estimates vary between studies. A 2024 meta-analysis found each 10-decibel worsening in hearing was linked to a 16% higher dementia risk, while a separate long-term study found a 71% higher risk over 15 years for people with midlife hearing loss. These are associations from observational data, not fixed individual predictions.
Is all hearing loss linked to dementia risk in the same way? No. Peripheral hearing loss, caused by the ear itself, is the type most linked to this research and the type hearing aids can treat. Central hearing loss, caused by how the brain processes sound, cannot be corrected with hearing aids and needs a different kind of assessment.
Should I get a hearing test even if my hearing loss seems mild? Yes. Most of the research in this area involves mild to moderate hearing loss, not just severe cases, and treatment appears to matter most for people already at higher risk of cognitive decline. A hearing test is quick and can identify changes long before they become obvious.
How do I book a hearing test at Second Sense? You can book online through our booking page, or call us directly. Appointments are available at our Bridgnorth, Church Stretton, Kingswinford and Wombourne clinics, as well as home visits.
This article is for general information only and is not medical advice. If you have concerns about your own or a family member’s memory or cognitive health, please speak with your GP.
