Does poor hearing increase my risk of developing dementia?

Poor hearing increases your risk of dementia, but not dramatically. Large cohort studies and meta-analyses consistently find a hazard ratio between 1.07 and 1.28: a modest but reproducible elevated risk. An older study suggested a risk up to five times higher for severe hearing loss, but that has not been confirmed by more recent, larger studies.^1,2,3

The more severe the hearing loss, the higher the estimated risk. However, the majority of people with hearing loss do not develop dementia. The association is just that - an association, not a proven cause. Other factors that affect both your hearing and your brain may explain part of the relationship.^3,1

At the population level, hearing loss in middle age is one of the larger modifiable risk factors for dementia. Estimates attribute roughly 9% of all dementia cases worldwide to it. The elevated risk begins before age 65, which means that early intervention is theoretically worthwhile.^4,5

Whether a hearing aid genuinely prevents dementia remains unclear. Observational research suggests that hearing aid users are at lower risk than people with hearing loss who do not use one. However, in the largest randomised trial to date, the ACHIEVE study with 977 participants, a hearing aid intervention did not reduce cognitive decline over three years in the overall group. Only older adults who already had more risk factors appeared to derive any benefit. A hearing aid is therefore not a proven means of broadly preventing dementia.^1,6

Why the association exists is not yet certain. It is possible that the brain has to work harder to process sounds, or that sensory input diminishes. Hearing loss also tends to co-occur with social isolation and depression, both of which independently raise the risk of dementia. This makes it difficult to determine what is a direct cause and what is a consequence.^4,7