Hearing Impairment and Dementia Linked?
If you suffer from some type of hearing loss, do you ever notice that listening to people talk is work, and that you need to try really hard to understand what people are saying? You aren’t the only one. The feeling that listening and understanding is tiring work is typical among people with hearing impairment – even those that use hearing aids.
As though that wasn’t bad news enough, it may not be just your hearing that is impacted, but also cognitive functions. In the latest studies, researchers have found that hearing loss significantly raises your chances of contracting dementia and Alzheimer’s.
A 16-year study of this connection from the Johns Hopkins School of Medicine included 639 participants between the ages of 36 and 90. At the end of the research, investigators found that 58 people (9 percent) had been diagnosed as suffering from dementia, and that 37 of them (5.8 percent) had developed Alzheimer’s disease. Moreover, the more significant their degree of hearing loss, the greater was the chance of developing dementia; for every 10 decibels of hearing loss, the odds of dementia went up 20%.
A different research study of 1,984 people, also 16 years in duration, demonstrated comparable results linking dementia and hearing loss. In this second research study, investigators also found degradation of cognitive functions among the hearing-impaired over the course of the data gathering. Compared to individuals with normal hearing, those with hearing loss developed memory loss 40 percent faster. An even more startling conclusion in both studies was that the connection between dementia and hearing loss held true even if the individuals wore hearing aids.
The connection between hearing impairment and loss of cognitive functions is an active area of inquiry, but researchers have proposed a few hypotheses to explain the results observed to date. Researchers have coined the term cognitive overload in conjunction with one specific hypothesis. The cognitive overload hypothesis states that the hearing-impaired individual expends so much brain power working to hear, that the brain is tired and has a reduced capacity to understand and assimilate verbal information. This may lead to social isolation, which has been linked to dementia risk in other research studies. A second theory is that neither hearing loss nor dementia is the cause of the other, but that both are caused by an unknown mechanism that could be genetic, vascular, or environmental.
Even though these study results are a little depressing, there is hope that comes from them. For those who use hearing aids, it is crucial that you have your aids re-fitted and re-programmed on a consistent basis. You shouldn’t make you brain work harder than it has to work in order to hear. The less you have to strain, the more cognitive capacity your brain has in reserve to understand what is said, and remember it. Also, if the 2 symptoms are linked, early detection of hearing loss may at some point lead to interventions that could delay dementia.