Middle-age hearing loss could accelerate cognitive decline

by Daniel Fink, MD, Chair, The Quiet Coalition

Photo credit: Kindel Media

According to SciTechDaily, hearing loss in mid-life could accelerate cognitive decline. The São Paulo Research Foundation reported on research published in the Journal of Alzheimer’s Disease. The article is behind a paywall, but the abstract can be accessed.

The research is based on a longitudinal study of Brazilian civil servants in São Paulo. The subjects were in their 50s when the study began. They were tested on memory, verbal fluency and hearing — which was measured using audiometry. Hearing loss was defined as a greater than 25 decibel decrement in the better ear. Participants were studied for a mean of eight years and the tests were repeated.

Analysis showed that hearing loss was associated with cognitive decline. Putative causal mechanisms include a reduction of information reaching the brain, and the social isolation that often comes with hearing loss.

The UK medical journal The Lancet has brought worldwide attention to the fact that dementia is not an inevitable part of aging, and can be prevented. Among the preventable causes of dementia are better treatment of cardiovascular risk factors like blood pressure and serum cholesterol, but prevention of hearing loss is the single most important factor.

Most doctors and members of the public still think that hearing loss is part of normal aging, as shown by the terms presbycusis and age-related hearing loss. However, a careful analysis of the world’s literature suggests that hearing loss in old age is largely the result of a lifetime of cumulative excessive noise exposure. I spoke about this at the 12th Congress of the International Commission on Biological Effects of Noise in Zurich in 2017. My analysis was supported by a 2020 paper from the Massachusetts Eye and Ear Infirmary.

Avoiding noise-induced hearing loss is simple and inexpensive. If something sounds loud, it’s too loud. Turn down the volume, use hearing protection or leave the noisy environment and one won’t develop noise-induced hearing loss. One might also avoid developing dementia, too.