December 28, 2022
Scientists increasingly recognize the importance of good hearing for brain health. In terms of modifiable risk factors for developing dementia, poor hearing has more of an impact than smoking, high blood pressure and lack of exercise. Preventing or treating hearing loss in middle age has the potential to cut the likelihood of developing dementia years down the road by almost 10 percent, studies suggest.
So what should you do if your hearing is not as sharp as it used to be, but you want to keep your mind just as sharp as it always was? Consider a hearing aid, according to a new report.
The study found that hearing aids and other technologies that restore hearing, such as cochlear implants, reduced the risk for cognitive decline by 19 percent in those with hearing loss, and that the benefits of better hearing accrue over time. In the short term, improved hearing also led to a slight (3 percent) improvement in memory and thinking skills. The findings were published in JAMA Neurology.
For the study, researchers in Singapore pooled data from 31 studies on hearing loss involving 137,484 older men and women. Their average age, in each of the studies, ranged from 64 to 86. The studies followed participants for up to 25 years.
Analysis of the studies suggested that restoring hearing, most commonly through the use of hearing aids, could help to prevent or at least slow down dementia, and possibly delay its onset, over the long term. The earlier you started wearing hearing aids, the better. But it was never too late to start using hearing aids. Even people with mild cognitive impairment, a brain disorder that often progresses to full-blown dementia, saw benefits. Those who wore hearing aids to restore hearing had about a 20 percent lower risk of progressing to dementia compared to their peers whose poor hearing went uncorrected.
Scientists aren’t sure why hearing loss may contribute to brain problems. One theory is that people with hearing problems are less likely to go out and engage socially, forgoing outings with friends and no longer attending concerts and other events. Social isolation and feelings of loneliness are associated with an increased risk of Alzheimer’s and other forms of dementia. Having a wide social network, on the other hand, may reduce dementia risk.
Researchers also speculate that because additional energy is needed to process sound in those who are hearing impaired, it may make it harder for them to process memories.
Experts say that hearing aids should be worn for at least four hours a day, and the longer, the better. Wearing hearing aids can present special challenges to someone with Alzheimer’s disease but, as this analysis found, the benefits can be significant.
Exposure to loud noise over a lifetime is one of the top causes of age-related hearing loss. Impacted earwax, a common problem in people with Alzheimer’s disease and those living in assisted living facilities, can exacerbate hearing loss, impeding communication and worsening aggression and other disruptive behaviors.
Hearing loss affects an estimated two out of three adults over 70, yet only about 14 percent of adults with hearing loss wear hearing aids. The good news is that quality over-the-counter hearing aids are fast becoming more affordable and available, including models that can be worn by people with Alzheimer’s disease. Ask your doctor about what hearing aids might be right for you. A good hearing aid may provide years-long benefits for an aging brain.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Sources: Brian Sheng Yep Yeo, MBBS; Harris Jun Jie Muhammad Danial Song, MBBS; Emma Min Shuen Toh, MBBS; et al: “Association of Hearing Aids and Cochlear Implants With Cognitive Decline and DementiaA Systematic Review and Meta-analysis.” JAMA Neurology, December 5, 2022
Michael W. Denham, MPhil; Rachel E. Weitzman, MD, MPH, MS; Justin S. Golub, MD, MS: “Hearing Aids and Cochlear Implants in the Prevention of Cognitive Decline and Dementia.” Editorial, JAMA Neurology, December 5, 2022