For people reading this who’ve suffered some type 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 work well you have to have them tuned and adjusted properly, and then become accustomed to using them.
As if that wasn’t bad enough, it might not be just your ability to hear that is affected, but also cognitive functions. In the latest studies, researchers have found that hearing loss drastically increases your chances of contracting dementia and Alzheimer’s.
One of these research studies, conducted at Johns Hopkins School of Medicine, studied 639 people between the ages of 36 and 90, for a period of sixteen years. The investigators found that at the conclusion of the study, 58 of the volunteers (9%) had developed dementia, and 37 (5.8%) had been diagnosed with Alzheimer’s disease. The degree of hearing loss was positively correlated with the probability of developing either disorder. For every 10 decibel further hearing loss, the risk of developing dementia went up by 20 percent.
Another 16-year study with 1,984 participants found a similar relationship between hearing loss and dementia, but also identified noticeable decline in cognitive abilities in the hearing-impaired. Compared to individuals with normal hearing, those with hearing impairment developed memory loss 40 percent faster. An even more surprising finding in each of the two research studies was that the connection between dementia and hearing loss held true even if the individuals used hearing aids.
Researchers have suggested several theories to explain the connection between loss of hearing and loss of cognitive capabilities. One of these explanations is related to the question that started this article, about needing to work harder to hear; this has been called cognitive overload. Some researchers think that if you are hearing-impaired, your brain exhausts itself just trying to hear that it has a diminished capacity to understand what is being said. The resulting lack of comprehension may cause social isolation, a factor that has been demonstrated in other studies to lead to dementia. 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 environmental, vascular or genetic.
While the person with hearing loss probably finds these study results dismaying, there is a good side with useful lessons to be derived from them.For those people who use hearing aids, these results serve as a reminder to see our hearing specialists on a regular basis to keep the aids perfectly fitted and programmed, so that we’re not constantly straining 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 too. Also, if hearing loss is related to dementia, knowing this might bring about interventional methods that can prevent its development.