Hearing loss linked to increased dementia risk
A Taiwanese study involving 16,270 adults, of whom half had newly diagnosed hearing loss, found that those with hearing loss had a higher risk of dementia, particularly among those aged 45-64. Six comorbidities (cerebrovascular disease, diabetes, anxiety, depression, alcohol-related illnesses, and head injury) were also significantly associated with a higher dementia risk.
Among the study participants, 1,868 developed dementia during the 13-year study period.
Hearing loss linked to limitations, distress, and memory loss in older people
Data from the 2016 Comprehensive Survey of Living Conditions of Japan has found that, of those 137,723 respondents who were aged 65 or older, about 9% reported hearing loss. There were substantial differences between those with hearing loss and those without:
- 28.9% of those with hearing loss reported limitations in outdoor activities such as shopping or travel, vs. 9.5% of those without hearing loss
- 39.7% of those with hearing loss reported psychological distress, vs 19.3%
- 37.7% of those with hearing loss reported memory loss, vs only 5.2% of those without hearing loss.
Wearing hearing aid may help protect brain in later life
Data from the PROTECT online study of 25,000 older adults (50+) has found that those who wear a hearing aid for age-related hearing problems maintain better brain function over time than those who do not.
Participants undertook annual cognitive tests over two years. After that time, the group who wore hearing aids performed better in measures assessing working memory and aspects of attention than those who did not.
The findings were presented at the 2019 annual Alzheimer's Association International Conference, Los Angeles.
Hearing loss linked to greater cognitive decline but education mitigates effect
A large, long-running study, involving 1,164 older adults (mean age 73.5), found that, while hearing impairment was associated with accelerated cognitive decline, the impact might be lessened by higher education.
The study found that almost half of the participants (49.8%) had mild hearing impairment, with 16.8% suffering moderate-to-severe hearing loss. Those with more serious hearing impairment showed worse performance on the MMSE and the Trail-Making Test, Part B. Hearing impairment was also associated with greater decline in performance over time, for both the mildly and more severely impaired.
However, the association of mild hearing impairment with rate of cognitive decline was found only among those without a college education, while moderate-to-severe hearing impairment was associated with steeper MMSE decline regardless of education level.
Somewhat surprisingly, degree of social engagement did not affect the association of hearing impairment with cognitive decline.
Male hearing loss linked to cognitive decline
An eight-year longitudinal study among 10,107 older men (62+) found that hearing loss was associated with higher risk of subjective cognitive decline.
Compared with men with no hearing loss, the relative risk of cognitive decline was 30% higher among men with mild hearing loss, 42% higher among men with moderate hearing loss, and 54% higher among men with severe hearing loss but who did not use hearing aids. While those who did use hearing aids showed a reduced risk of cognitive decline (37%), this wasn’t statistically significant (not enough men in these groups, I assume).
The men were all health professionals. Subjective cognitive function was assessed using a six-item questionnaire, which was administered three times, at four-yearly intervals.
Signs of memory problems could be symptoms of hearing loss instead
A very small study found that 11 out of 20 participants being evaluated for cognitive concerns had some form of mild to severe hearing loss, but only 4 of them used hearing aids. A quarter of the participants didn’t show any signs of memory loss due to a brain disorder. It’s suggested that, for some, cognitive problems may derive directly from hearing impairments, and can be fixed by addressing this issue.
Hearing loss is the third most common chronic health condition in older adults, which is experienced by 50% of individuals over the age of 65 and 90% of people over the age of 80. It takes an average of 10 years before people seek treatment and fewer than 25% of those who need hearing aids will buy them.
Healthy diet may lower risk of hearing loss in women
A large, long-running study (the Nurses' Health Study II ) has found that eating a healthy diet was associated with a lower risk of acquired hearing loss in women. Women whose diets most closely resembled the AMED or DASH dietary patterns had an approximately 30% lower risk of moderate or worse hearing loss, compared with women whose diets resembled these dietary patterns the least.
The Alternate Mediterranean diet (AMED) diet includes extra virgin olive oil, grains, legumes, vegetables, fruits, nuts, fish and moderate intake of alcohol. The Dietary Approaches to Stop Hypertension (DASH) diet is high in fruits and vegetables and low-fat dairy, and low in sodium.
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Alattar, A. A., Bergstrom, J., Laughlin, G. A., Kritz-Silverstein, D., Richard, E. L., Reas, E. T., … McEvoy, L. K. (n.d.). Hearing impairment and cognitive decline in older, community-dwelling adults. The Journals of Gerontology: Series A. https://doi.org/10.1093/gerona/glz035
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Dupuis, K., Yusupov, I., Vandermorris, S., Murphy, K., Rewilak, D., Stokes, K., & Reed, M. (2019). Considering Age-Related Hearing Loss in Neuropsychological Practice: Findings from a Feasibility Study. Canadian Journal on Aging / La Revue Canadienne Du Vieillissement, 38(2), 245-252. doi:10.1017/S0714980818000557
(2018). Adherence to Healthful Dietary Patterns Is Associated with Lower Risk of Hearing Loss in Women.
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