Could Hearing Loss be an Indicator of Alzheimer’s?
For those of you who’ve suffered some form of hearing impairment, do you ever find yourself needing to work really hard to understand what’s being said to you or around you? This is a sensation that happens even to people wearing hearing aids, because in order for them to perform well you need to have them tuned and adjusted properly, and then get used to wearing them.
As if that was not bad enough, it may not be just your hearing that is affected, but also cognitive abilities. In newly released studies, scientists have discovered that hearing loss significantly increases your chances of developing dementia and Alzheimer’s.
A 16-year study of this relationship conducted by the Johns Hopkins School of Medicine involved 639 participants between the ages of 36 and 90. At the end of the study, researchers found that 58 participants (9 percent) had been diagnosed as having dementia, and that 37 of them (5.8 percent) had developed Alzheimer’s disease. On top of that, the greater their degree of hearing impairment, the higher was the likelihood of developing dementia; for every 10 decibels of hearing loss, the likelihood of dementia increased 20%.
In a related study, evaluating 1,984 participants, investigators found a similar relationship between hearing loss and dementia, but they also found that the hearing-impaired experienced measurable declines in their cognitive functions. In comparison to participants with normal hearing, those with hearing loss developed memory loss 40% faster. In each of the two studies, a far more depressing finding was that this association was not reduced by using hearing aids.
Researchers have suggested several hypotheses to explain the association between loss of hearing and loss of cognitive ability. Researchers have coined the term cognitive overload in association with one particular hypothesis. The cognitive overload hypothesis suggests that the hearing-impaired person expends so much brain energy trying to hear, that the brain is tired and has a diminished capacity to comprehend and assimilate verbal information. Having a two-way conversation requires comprehension. An absence of understanding causes interactions to break down and might result in social isolation. A second theory is that neither dementia nor hearing loss is the cause of the other, but that both are caused by an unknown mechanism that could be genetic, vascular, or environmental.
Although the individual with hearing loss probably finds these study results depressing, there is a good side with valuable lessons to be extracted from them.For those who use hearing aids, it is essential to have your hearing aids re-fitted and re-programmed on a regular basis. You don’t want to make you brain work harder than it has to work in order to hear. The less work used in the mechanics of hearing, the more brain power available for comprehension. And, if it ends up that hearing loss is an early indicator of dementia, diagnosing the hearing loss early may allow for early intervention to avert the onset or advancement.