Johns Hopkins Researchers Implicate Hearing Loss In Dementia Development In Seniors
Can you name the most popular electronic gadget in the senior citizen community? Nope, it’s not the iPhone, but rather the hearing aid. Hearing loss has long been heralded as the quintessential sign of aging, right up there with ear hair growth and retirement. However innocuous the latter two events, though, researchers are beginning to grow more interested in hearing loss. A team at Johns Hopkins University in particular has found a frighteningly strong association between hearing loss and the development of dementia. Dementia refers to an overall decline of cognitive ability and manifests in different forms, of which Alzheimer’s disease is the most common.
Using data from the Baltimore Longitudinal Study on Aging, university researchers isolated 639 participants whose hearing and cognitive abilities were tested between 1990 and 1994. At the beginning of the study, none of the participants had dementia. 125 suffered from mild hearing loss, while fifty-three had moderate hearing loss and a final six experienced severe hearing loss. The rest of the participants had no hearing loss.
At the end of the study period, in 2008, fifty-eight participants had been diagnosed with dementia, and thirty-seven of them specifically had Alzheimer’s disease. Dr. Frank Lin, the head of the research team, found that those who had greatest hearing loss at the beginning of the study were most likely to develop dementia. The risk was worst for participants over the age of sixty – for them, thirty-six percent of the dementia risk was found to be associated with hearing loss. In addition, for every ten decibels of hearing lost, the chance of Alzheimer’s shot up twenty percent.
Different theories are being offered to help explain the link, but no one hypothesis yet reins supreme. Some suggest that cognitive overload caused by the constant “brain strain” of decoding sounds may help facilitate the development of dementia. Others say that hearing loss contributes to a particular degree of social isolation, a condition that does have a strong association with dementia. Still others suggest that the two happen concurrently, controlled by similar processes or in similar regions.
The last explanation has created some hope in the medical community. If hearing loss indeed results from the same deterioration that contributes to the development of dementia – breakdown of vascular structure, for example – then the underlying causes of the condition may be forestalled by medication before symptoms ever arise.
Finally, the researchers did not hesitate to point out that an increased risk for a disease does not indicate a 100% chance of contracting it. There are many other factors that contribute to dementia and Alzheimer’s disease, and hearing loss may be one of them Other risk factors include gum disease, type 2 diabetes and cardiovascular disease. In other words, don’t worry too much if you find yourself - like Horton the Elephant from Dr. Seuss’s Horton Hears A Who - frequently uttering, "Speak up, please!"