Hearing loss and mental decline are two common conditions of aging, and now a new study finds that both of these things may be related. During the study, elderly who have hearing loss are more likely to develop other problems such as memory and thinking power compared to elderly who have normal hearing. On average, study participants with hearing problems have a significant mental disorder three years earlier than those who have normal hearing.
Research shows that hearing loss is associated with the decreased mental function.
About two-thirds of adults over the age of 70 years have some levels of hearing loss. And the number of people with dementia is expected to double over the next two decades as an elderly population.
Researchers are now hoping to learn whether hearing aids can slow the mental decline in the elderly. Otologist and epidemiologist, Frank R. Lin, MD, Ph.D., who led the study, said that only about 15% of people who need hearing aids.
Our findings emphasize how important it is for doctors to discuss hearing problems with their patients and be proactive in addressing the problem of hearing from time to time”, said Lin, an assistant professor at the Johns Hopkins University School of Medicine, Baltimore.
The study involved nearly 2000 men and women aged 70 to 80 years who also took part in the study of aging and health that began in the late 1990s. The hearing was tested in the fifth year of study, where men and women undergo a series of tests over the next six years to assess memory loss and thinking power.
The men and women with hearing loss showed evidence of the decline by 30 to 40 percent faster than those who have normal hearing. Meanwhile, people with severe hearing loss experienced a sharper decline in mental function. The research was published online in the journal JAMA Medicine Internal.
Although this does not explain how the relationship of hearing loss in the elderly with memory problems and thinking power, Lin said there are several theories that can explain this problem.
The first theory is that social isolation among people with untreated hearing loss is one of the causes of their mental decline. Previous research has identified loneliness as risk factors for the decline, he said.
Another theory is that a person’s memory has limits with respect to the number of information received and the operations that can be performed.
“The task of the inner ear is to take voice and encode them with the accurate recording before the signal coming into the brain to decode. But with a hearing loss, the brain takes a long time to do so. If the brain keeps releasing more resources to decode the voice code, it will affect cognitive functioning,” said Lin.
Neurologist and Alzheimer’s researcher, Marc L. Gordon, MD, said that the study is interesting, but he said if further studies are necessary to confirm that the hearing loss has a direct impact on mental decline and to understand the reasons for the linkage.
He added that this study emphasizes the importance of addressing not only on the hearing loss but also on impaired vision in the elderly.