Does hearing loss increase your risk of dementia, and does a hearing aid help?
Hearing loss demonstrably increases the risk of dementia, and a hearing aid appears to help, but proven protection for everyone has not yet been established. Have hearing loss assessed in any case, if only because of the other health risks associated with it.
Hearing loss is consistently associated with a higher risk of dementia. In a large cohort study of more than 573,000 people, the risk among those with hearing loss was somewhat higher than among people with normal hearing (hazard ratio 1.07). A meta-analysis of 36 studies involving more than 20,000 participants found an odds ratio of 1.28 for dementia. The association is modest but robust. Epidemiological models estimate that hearing loss in middle age is responsible for approximately 9% of all dementia cases worldwide, making it one of the larger modifiable risk factors.
The more severe the hearing loss, the greater the risk. For every additional 10 decibels of hearing loss, the risk increases by a factor of 1.27. In cases of severe hearing loss, estimates are even higher, but those figures come from small studies and are therefore uncertain. Hearing impairment also proved to be a risk factor for dementia occurring before the age of 65, so the association is not confined to the very elderly.
Exactly how hearing loss contributes to dementia remains unknown. Researchers point to several possible mechanisms: shared brain pathology, cognitive overload when trying to understand speech, and an information-poor environment that provides less stimulation to the brain. Which mechanism carries the most weight also determines how large the benefit of a hearing aid can realistically be.
The findings on hearing aids are mixed. In a large Danish cohort study, people with hearing loss who wore a hearing aid had a clearly lower risk than those who did not (hazard ratio 1.06 versus 1.20). However, the only large randomised trial to date, involving 977 participants aged 70 to 84, found no significant difference in cognitive decline over three years in the overall group. Only among older adults who already had more dementia risk factors was there an indication of a beneficial effect. A hearing aid is therefore not a proven means of preventing dementia, although there are indications that it may help people at higher risk.
Apart from dementia, there are other reasons to address hearing loss. It is associated with social isolation, late-life depression, falls and a generally reduced resilience. If you are experiencing hearing loss, it is certainly worth having it assessed, even if the dementia benefit of a hearing aid has not yet been established.
Based on several large cohort studies and a meta-analysis of 36 studies (together involving tens of thousands of participants), plus one randomised study (ACHIEVE, n=977). The causal relationship has not yet been proven; associational research predominates. Reverse causality (early-stage dementia leading to missed hearing loss) cannot be fully excluded.
Does poor hearing increase my risk of developing dementia?
Poor hearing is associated with a modest but real increased risk of dementia. Have hearing loss assessed and treated promptly, but do not automatically count on direct protection against dementia from a hearing aid.
Is there a link between depression and a higher risk of dementia?
Depression is strongly associated with a higher risk of dementia, though it remains uncertain whether depression causes dementia or is sometimes an early sign of it. Treating depression appears to lower the risk, so if you or someone close to you is experiencing depressive symptoms, it is worth taking them seriously and discussing them with a doctor.
Does type 2 diabetes increase your risk of dementia?
Type 2 diabetes substantially increases the risk of dementia, and the younger you are at diagnosis, the greater that risk. Good blood sugar management and the choice of medication appear to be relevant; discuss this with your doctor if you have diabetes.
What can I concretely do to prevent dementia?
Various lifestyle choices demonstrably lower your risk, but no single approach guarantees that you will prevent dementia. Regulating blood pressure, exercising, not smoking and staying mentally active are the best-supported steps you can take.
Is there a link between your hormones and the risk of dementia later in life?
Does poor sleep cause dementia sooner?
Poor sleep probably increases your risk of dementia, but ordinary insomnia does not make dementia inevitable. One exception: if you physically act out your dreams while sleeping, discuss that with a doctor.