Hearing Down - Alzheimer's Up
Back in the mid 1980s an American study compared 36 people with impaired hearing to 120 whose hearing was normal. Even though the two groups were similar in almost every other way – age, gender, race, etc. -- after 12 months the decline in cognitive function in those with hearing problems was almost double that of the control group.1 A follow-up study by the same researchers a few years later compared 100 adults suffering from Alzheimer's to 100 cognitively healthy people of the same age, gender and education. Hearing loss was found to be notably higher in the Alzheimer's group. The greater the hearing loss, the greater the chances of developing dementia.2 Fast-forward to 2011. A team at Johns Hopkins found in their study that the risk of dementia among those with hearing loss was between two and five times greater compared to those with good hearing. As the degree of hearing loss increased, so did the risk for dementia.3 The evidence is overwhelming, and growing. Last year, analyzing data from four previous studies, a research group from China found a near five-fold greater risk of developing Alzheimer's for people who were hearing impaired compared to those with normal hearing.4 This is just a small selection of the studies that demonstrate the link between hearing loss and dementia. But you might be wondering if a hearing aid really helps. Glad you asked. . . The most recent study looked to see if using a hearing aid changes the degree to which cognition is impaired.Memory Loss Reduced by Three-Quarters
The study was conducted by a research team from the University of Manchester, England, and published in the Journal of the American Geriatric Society in July. They followed the progress of 2,040 participants in the American Health and Retirement survey conducted from 1996 to 2014. All were 50 or older when the study began, and started using hearing aids some years later. Cognitive measurements based on immediate and delayed recall of ten words were conducted every two years. This is a standard, popular test for memory. Comparing rates of cognitive decline before and after the participants started to wear hearing aids, and taking into account multiple factors that could cast doubt on the results, they found the devices slowed cognitive decline by 75%.5 Dr. Asri Maharani, Honorary Research Fellow and one of the study authors, said, "Age is one of the most important factors implicated in cognitive decline. We find that hearing...interventions may slow it down and perhaps prevent some cases of dementia, which is exciting – though we can’t say yet that this is a causal relationship."Barriers to Overcome
Another study author, audiology specialist Dr. Piers Dawes, added that it's not clear why improving hearing made such a difference, but he thinks isolation from other people and resultant lack of physical activity could be involved. "And there are barriers to overcome: people might not want to wear hearing aids because of stigma attached to wearing them, or they feel the amplification is not good enough or they’re not comfortable." He believes a way forward could be to screen adults to identify problems and "demedicalizing the whole process so treatment is done outside the clinical setting. That could reduce stigma." Hearing aids today are more technically advanced than ever before, and keep getting better. Some are even being developed that have more than one function, as Dr. Dawes explains: "Wearable hearing devices are coming on stream nowadays which...not only assist your hearing, but give you access to the Internet and other services."6 So it's important not to neglect your ears. The National Institutes of Health provide an interactive quiz to see if you need a hearing test. and you can also test your sense of pitch by visiting: https://www.nidcd.nih.gov/health/do-you-need-hearing-test-quiz- https://www.ncbi.nlm.nih.gov/pubmed/3950288
- http://www.ncbi.nlm.nih.gov/pubmed/2926927
- http://www.ncbi.nlm.nih.gov/pubmed/21320988
- https://www.ncbi.nlm.nih.gov/pubmed/27896493
- https://www.ncbi.nlm.nih.gov/pubmed/29637544
- https://www.manchester.ac.uk/discover/news/hearing-and-visual-aids-linked-to-slower-age-related-memory-loss/
