The three-year outcomes of the Evaluation of Hearing Aids and Cognitive Effects (ENHANCE) study suggest that using hearing aids may benefit long-term cognitive health. 
 
Recently published in Frontiers in Aging Neuroscience, the study compared cognitive performance over three years, assessing new hearing aid users against non-users at 18-month intervals. 
The hearing aid users were clients from an audiology clinic, while the non-users participated in the Australian Imaging Biomarkers and Lifestyle (AIBL) Flagship Study of Aging. All participants were 60 years or older. 
 
After three years, the group using hearing aids maintained relative cognitive stability, whereas the non-user group experienced significant cognitive decline. The non-user group demonstrated greater annual declines in most cognitive subtests compared to the hearing aid group, except for one subtest where the trend was similar but not statistically significant. This difference persisted despite the hearing aid group experiencing a faster rate of hearing loss over the period. Adjusting for educational differences among participants did not alter the overall results. Therefore, hearing aids may be a crucial public health strategy for delaying cognitive decline and potentially reducing or slowing the onset of dementia. 
 
Cognitive Aging 
Aging affects cognitive function, with the brain aging alongside the rest of the body. This process can begin as early as our twenties and varies significantly among individuals. Differences in cognitive aging rates can be more pronounced among people of the same age than between those of different ages. 
 
While cognitive aging usually does not impede daily activities, many people notice a decline in memory sharpness, increased effort required for task switching, and slower cognitive processing. 
 
Hearing Loss and Cognitive Decline 
Hearing loss is often linked to an accelerated rate of cognitive decline, raising the risk of dementia for those with untreated hearing loss. Research indicates that cognitive decline rates increase with the severity of hearing loss. For individuals with mild hearing loss, the risk of cognitive decline nearly doubles compared to those with normal hearing, and for those with severe hearing loss, the risk is almost five times greater. 
 
It is believed that up to 40% of dementia cases could be preventable. Of the 12 modifiable risk factors identified by the Lancet Commission on Dementia, hearing loss is the largest contributor. 
 
Potential Explanations for the Link Between Hearing Loss and Cognitive Decline 
 
Several theories propose explanations for the association between hearing loss and cognitive decline. One theory suggests that less sound stimulation leads to brain degeneration, altering brain structure and function. Another theory posits that more cognitive effort is required to process speech when hearing is impaired, diverting cognitive resources from other brain functions. A third theory proposes that reduced environmental stimulation and communication difficulties lead to lower social participation, causing loneliness and depression, which in turn affect brain structure and function. 
 
As hearing loss can precede dementia by years or even decades, there may be an opportunity to address these mechanisms before dementia onset. 
 
Promoting Cognitive Health and Healthy Aging with Hearing Aids 
Hearing loss is also linked to a higher risk of falls, more frequent hospitalizations and medical service use, depression, and even increased mortality. Many people are unaware of these associations. 
 
Taking action to maintain good hearing and effective communication can promote cognitive health, support overall healthy aging, maintain function, and improve quality of life. Social connection is vital, as lacking it can be as detrimental as smoking 15 cigarettes a day. 
 
Preventative measures are best taken before hearing loss leads to adverse outcomes, while the brain remains adaptable, allowing it to rewire itself as hearing is restored. 
 
 
References 
Salthouse, T.A. (2010). Major issues in cognitive aging. Vol. 49, New York, U.S.: Oxford University Press. 
 
Lin, F.R., et al. (2013). Hearing loss and cognitive decline in older adults. JAMA Internal Medicine. 
 
Livingston, G., et al. (2017). Dementia prevention, intervention, and care. The Lancet, 390(10113): 2673-2734. 
 
Livingston, G. et al. (2020). Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. The Lancet, 396(10248): 413-446. 
 
Oster, C. (1976). Sensory deprivation in geriatric patients. Journal of the American Geriatrics Society, 24(10): 461-464. 
 
Baltes, P. & Lindenberger, U. (1997). Emergence of a powerful connection between sensory and cognitive functions across the adult life span: a new window to the study of cognitive aging? Psychology and Aging, 12(1): 12. 
 
Fulton, S.E., et al. (2015). Mechanisms of the hearing–cognition relationship. Seminars in Hearing, 36(3): 140-149. 
 
Jiam, N.T.L., Li, C. & Agrawal, Y. (2016). Hearing loss and falls: A systematic review and meta-analysis. The Laryngoscope, 126(11): 2587-2596. 
 
Genther, D.J., et al., (2013). Association of hearing loss with hospitalization and burden of disease in older adults. JAMA, 309(22): 2322-2324. 
 
Cosh, S., et al. (2018). The relationship between hearing loss in older adults and depression over 12 years: findings from the English Longitudinal Study of Ageing (ELSA). Journal of Affective Disorders, 236: 176-182. 
 
Genther, D.J., et al. (2015). Association between hearing loss and hospitalization in older adults. Journal of the American Medical Association. 
 
Holt-Lunstad, J., Smith, T.B., Baker, M., Harris, T., & Stephenson, D. (2015). Loneliness and social isolation as risk factors for mortality: a meta-analytic review. Perspectives on Psychological Science, 10(2), 227-237. 
Share this post:
Our site uses cookies. For more information, see our cookie policy. Accept cookies and close
Reject cookies Manage settings