In the Better Hearing Blog we have posted several articles discussing why older adults with hearing loss are more likely to develop problems thinking and remembering than older adults whose hearing is typical.
Researchers have three main theories about why there is a link between hearing loss and dementia. The first is social isolation, notable because isolation has already been proven to be a risk factor for Alzheimer’s disease. Studies by John Cacioppe, a professor at the University of Chicago, on the effect of isolation on health have shown that “perceived isolation” (or simply feeling lonely) may have a greater effect then actual objective isolation.
The second is cognitive load: The effort of your brain trying to understand and translate sounds may deplete brain power needed elsewhere, such as for memory. “Shouting Won’t Help” author Katherine Bouton says this effort feels more like “cognitive overload.”
Third, there may be a pathological link between hearing loss and dementia, a genetic or environmental factor that leads both conditions. Researchers at the U.K.’s University of Cardiff, reported on the link between hearing loss and dementia in the journal Neurology in October 2012, hypothesized that hearing loss could lead to dementia, or the other way around. The early stages of dementia, what is called a prodromal effect, may have an effect on auditory threshold.
While the research by Frank Lin, M.D., Ph.D, an assistant professor at the Johns Hopkins University School of Medicine and the university’s Bloomberg School of Public Health, shows that hearing aid usage does not seem to lower the risk for cognitive impairment, he is planning further study about whether the use of hearing devices has any effect on cognitive decline and impairment. This will help eliminate the potential unreliability of self-reported hearing aid usage. Lin will examine the specifics of hearing aid usage: when they were adopted by an individual, how well they were fitted, how frequently they were used, whether and how often counseling and follow-up visits were implemented, and whether other assistive technology was used.
The hope is that treated hearing loss – which can help decrease isolation as well as cognitive load – may help prevent cognitive decline.