In 1989, a landmark study published in JAMA, showed hearing loss in older adults was independently associated with all forms of dementia including Alzheimer’s disease. Subsequently numerous studies have shown this impact is huge. Hearing loss is not just an associated factor with dementia but appears to be a cause of dementia . Initially, this information did not get the publicity or the study that it should have; as there was bias that hearing loss is an inevitable part of aging and that hearing loss was just associated with the dementia that comes with aging, (not a cause). But we now know so much more.
Here is a summary of the data:
Many additional studies have been finally performed; most notably research done by Dr Frank Lin MD in 2011 at Johns Hopkins University as part of the famous Baltimore Longitudinal Study of Aging. We now know that hearing loss accelerated memory loss by two fold in people with mild hearing loss when followed for 8 years, and 5 fold in people with moderate and severe hearing loss! Again hearing loss is an independent risk factor. Dr Lin in 2014 went on to do research to show hearing loss’s affect on our brains. He showed hearing loss is an independent associated factor with decline in whole brain volume and concentrated regional volume declines in the right temporal lobe. In fact it appears that hearing loss has three distinct mechanisms by which it impairs cognitive function. First: direct negative changes on brain structure as stated above.
Second: Degradation of auditory signal that requires greater cognitive resources for central auditory processing and that reorganization of processing has been shown to impair memory. Third : hearing loss leads to social isolation and interaction which leads to decrease cognitive function.
Is there a solution? Yes.
In 2015, Dawes et al showed that people with hearing loss and who used hearing aids show significantly less decline in memory loss than than matched controls who did not use hearing aids. Furthermore, they showed people who obtain hearing aids at a younger age are more likely to successfully use their hearing aids and use them for a longer period of time. This finding was again found by Deal et. al. In 2015. In 2018 Maharani et al published a study with 2,040 adults age 40 and over; and again they showed people with hearing loss who used hearing aids had significantly less decline in memory scores than matched controls who did not use hearing aids. Finally a study in Germany published in 2016 by Fritze et al., showed that individuals with hearing loss had less depression and less memory loss, if the person with hearing loss showed on the national health claim record he or she had visited an Ear Nose and Throat specialist at any time. The assumption (correctly) was that proper evaluation of the hearing loss occurred with high level intervention and correction with medical/surgical treatment or the fitting of a high quality hearing aid.
In conclusion hearing aids and surgical procedures to restore hearing help you keep your memory and healthy brain function.
If you want a sharp functioning mind in your 60s through 100s, get your hearing tested in your 40’s and see a board certified Ear Nose and Throat doctor. If you are found to have hearing loss (even a mild hearing loss) get a hearing aid; get the best quality hearing aid available.
Remember by the time we are 70 years old three quarters of Americans will have hearing loss. As of today the majority of 70 year olds in the U.S. with hearing loss are not using hearing aids.
Phillip B Flexon MD, FACS
Robin Andrews Au D