In 2011 hearing loss was identified as a risk factor for dementia, with a higher risk of getting dementia with increasing severity of hearing loss [1][2]. There are several reasons as to why this could be the case [3][4][5]:
- There could be a common cause for some forms of hearing loss and dementia.
- The effort of listening with a hearing loss could create a “cognitive load” that means that there are fewer resources within the brain available for other cognitive functions.
- Hearing loss might lead to social isolation, which is known to contribute to an increased risk of dementia [6][7].
- The loss of auditory input into the brain could cause changes that lead to cognitive decline and dementia.
- Hearing loss could cause people to perform more poorly on certain cognitive tests. However, the connection between hearing loss and dementia still persists after the tests are presented visually instead of verbally.
It is possible that more than one of these could be true at the same time.
Hearing loss is one of several potentially modifiable risk factors that may reduce the risk of getting dementia [8][9], along with others such as smoking, obesity and lack of physical exercise.
Age-related hearing loss is associated with smaller brain volumes, and hearing impairment can accelerate the rate at which the brain shrinks [10][11][12]. Research has also shown that parts of the brain normally used to process sound can be diverted to other purposes when hearing loss is present. This can be reversed when hearing aids are used [13].
Research into whether using hearing aids can lower the risk of dementia is still in its early stages. There have been small-scale research studies which have examined whether using a hearing aid or aids can slow cognitive decline [14]. Most have shown at least some improvement in cognitive function with the use of hearing aids [14][15][16][17]. However, some did not [14].
A large study is examining whether, over the longer term, using hearing aids can actually reduce the risk dementia [18]. We await the results with interest!
References
- Lin FR, Metter J, O’brien RJ, Resnick SM, Zonderman AB, Ferrucci L. Hearing loss and incident dementia. Arch Neurol [Internet]. 2011 Feb [cited 2023 Feb 13]; 2(4): 215-20. Available at: https://jamanetwork.com/journals/jamaneurology/fullarticle/802291
- Thomson RS, Auduong P, Miller AT, Gurgel RK. Hearing loss as a risk factor for dementia: a systematic review. Laryngoscope Investig Otolaryngol [Internet]. 2017 Mar [cited 2023 Feb 3];2(2):69-79. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527366/
- Beck DL, Band S, Clarke NA. Hearing loss and cognition: a discussion for audiologists and hearing healthcare professionals. JOENTR. 2020;12(3): 72-8.
- Stahl SM. Does treating hearing loss prevent or slow the progress of dementia? Hearing is not all in the ears, but who’s listening? CNS Spectr [Internet]. 2017 Jun [cited 2023 Jan 5];22930:247-50. Available at: https://www.cambridge.org/core/journals/cns-spectrums/article/does-treating-hearing-loss-prevent-or-slow-the-progress-of-dementia-hearing-is-not-all-in-the-ears-but-whos-listening/2CDD0B1106D81D559C4D74E4CE162E7C
- Uchida Y, Sugiura S, Nishita Y, Saji N, Sone M, Ueda H. Age-related hearing loss and cognitive decline – the potential mechanisms linking the two. Auris Nasus Larynx [Internet]. 2019 Feb [cited 2022 Dec 30];46(1):1-9. Available at: https://www.sciencedirect.com/science/article/pii/S0385814618304589?via%3Dihub
- Sharma RK, Chern A, Golub JS. Age-related hearing loss and the development of cognitive impairment and late-life depression: a scoping overview. Semin Hear [Internet]. 2021 Feb [cited 2022 Nov 28]; 42(1):10-25. Available at: https://pubmed.ncbi.nlm.nih.gov/33883788/
- Pronk M, Deeg DJH, Smits C, van Tilburg TG, Kuik DJ, Festen JM, et al. Prospective effects of hearing status on loneliness and depression in older persons: identification of subgroups. Int J Audiol [Internet]. 2011 Dec [cited 2021 Apr 20];50(12):887-96. Available at: https://pubmed.ncbi.nlm.nih.gov/21929374/
- Livingston G, Sommerlad A, Orgeta V, Costafreda SG, Huntley J, Ames D, et. al. Dementia prevention, intervention, and care. Lancet [Internet]. 2017 Jun [cited 2023 Apr 20];390(10113):2673-2734. Available at: https://pubmed.ncbi.nlm.nih.gov/28735855/
- Weinstein BE. Dementia and age-related hearing loss – part II. Hear J [Internet]. 2017 Nov [cited 2023 Apr 20]; 70(11):26-30. Available at: https://journals.lww.com/thehearingjournal/Fulltext/2017/11000/Dementia_and_Age_Related_Hearing_Loss___Part_II.4.aspx
- Golub JS. Brain changes associated with age-related hearing loss. Otol Neurotol. 2017;25(5):347-52.
- Lin FR, Ferruci L, An Y, Goh JO, Doshi J, Metter EJ, et al. Association of hearing impairment with brain volume changes in older adults. NeuroImage [Internet]. 2014 [cited 2023 Mar 6];90:84-92. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3951583/
- Rigters SC, Bos D, Metselaar M, Roshchupkin GV, Baatenburg de Jong RJ, Arfan Ikram M, et. al. Hearing impairment is associated with smaller brain volume in aging. Front Aging Neurosci [Internet]. 2017 [cited 2023 Mar 20];9. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5247429/
- Glick HA, Sharma A. Cortical neuroplasticity and cognitive function in early-stage, mild-moderate hearing loss: evidence of neurocognitive benefit from hearing aid use. Front Neurosci [Internet]. 2020 [cited 2023 Jan 12];14. Available at: https://www.frontiersin.org/articles/10.3389/fnins.2020.00093/full
- Amieva H, Ouvrad C. Does treating hearing loss in older adults improve cognitive outcomes? A review. J Clin Med [Internet]. 2020 [cited 2023 Feb 3];9(805). Available at: https://www.mdpi.com/2077-0383/9/3/805
- Dawes P, Emsley R., Cruickshanks KJ. Hearing loss and cognition: the role of hearing aids, social isolation and depression. PLoS One [Internet]. 2015 [cited 2023 Feb 27]; 11. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4356542/
- Deal JA, Albert MS, Arnold M, Bangdiwala SI, Chisolm T, Davis S, et. al. A randomized feasibility pilot trial of hearing treatment for reducing cognitive decline: results from the aging and cognitive health evaluation in elders pilot study. Alzheimer’s Dement.: Transl Res Clin [Internet]. 2017 [cited 2021 Feb 13]; 3:410-15. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5651440/
- Maharani A, Dawes P, Nazroo JY, Rampubolon G, Pendelton N, Leroi I. Longitudinal relationships between hearing aid use and cognitive function in older Americans. JAGS [Internet]. 2018 [cited 2023 Feb 6];66(6):1130-36. Available at: https://agsjournals.onlinelibrary.wiley.com/doi/10.1111/jgs.15363
- Jayakody DMP, Almeida OP, Ford AH, Atlas, MD, Lautenschlager NT, Friedland PL et. al. Hearing aids to support cognitive functions of older adults at risk of dementia: the HearCog trial – clinical protocols. BMC Geriat [Internet]. 2020 [cited 2023 Apr 24];20(508). Available at: https://bmcgeriatr.biomedcentral.com/articles/10.1186/s12877-020-01912-1