Seniors with hearing loss are significantly more likely to develop dementia over time than those who retain their hearing, according to a study by Johns Hopkins and the National Institute on Aging.
The findings could lead to new ways to combat dementia. Although the link between the two conditions is unknown, the research suggests that a common pathology may underlie both or the strain of decoding sounds over the years may overwhelm the brains of people with hearing loss, leaving them more vulnerable to dementia. Hearing loss could lead to dementia by making individuals more socially isolated, a known risk factor for dementia and other cognitive disorders.
Whatever the cause, their finding may offer a starting point for interventions — even as simple as hearing aids — that could delay or prevent dementia by improving patients’ hearing.
“Researchers have looked at what affects hearing loss, but few have looked at how hearing loss affects cognitive brain function,” says Frank Lin, M.D., Ph.D., assistant professor in the Division of Otology at Johns Hopkins University School of Medicine. The new study, published in Archives of Neurology, focused on 639 people whose hearing and cognitive abilities were tested as part of the BLSA between 1990 and 1994. While about a quarter of the volunteers had some hearing loss at the start of the study, none had dementia.
These volunteers were closely followed with repeat examinations every one to two years; by 2008, 58 of them had developed dementia. The researchers found that study participants with hearing loss at the beginning of the study were significantly more likely to develop dementia by the end. The more hearing loss they had, the higher their likelihood of developing the memory-robbing disease.