SAN DIEGO, CALIFORNIA — According to new research published in the Journal of Alzheimer’s Disease this past week, researchers from the University of California San Diego and Kaiser Permanente Washington Health Research Institute delved into the relationship between hearing loss and its potential impact on the brain.
The study, led by principal investigator Linda K. McEvoy, Ph.D., from UC San Diego’s Herbert Wertheim School of Public Health and Human Longevity Science and senior investigator at the Kaiser Permanente Washington Health Research Institute, aimed to explore how hearing loss might be linked to changes in specific brain regions.
Brain Changes in Patients with Hearing Loss
By conducting hearing tests and magnetic resonance imaging (MRI) scans, the researchers observed microstructural differences in certain areas of the brain among participants with hearing loss.
Their findings indicated that individuals with hearing issues displayed distinct variations in brain regions linked to auditory processing, speech and language comprehension, and executive function.
“These results suggest that hearing impairment may lead to changes in brain areas related to processing of sounds, as well as in areas of the brain that are related to attention. The extra effort involved with trying to understand sounds may produce changes in the brain that lead to increased risk of dementia. If so, interventions that help reduce the cognitive effort required to understand speech — such as the use of subtitles on television and movies, live captioning or speech-to-text apps, hearing aids, and visiting with people in quiet environments instead of noisy spaces — could be important for protecting the brain and reduce the risk of dementia.”
–Linda K. McEvoy, Ph.D., Principal Investigator
The study, a collaborative effort between UC San Diego and UC San Diego School of Medicine investigators, utilized data from the Rancho Bernardo Study of Health Aging, involving 130 participants who underwent hearing tests in research clinic visits between 2003 and 2005, followed by MRI scans from 2014 to 2016.
According to Dr. Emilie T. Reas, Ph.D., an assistant professor at UC San Diego School of Medicine and co-author of the study, “The results underscore the importance of safeguarding one’s hearing by limiting exposure to loud noises, using protective gear in noisy environments, and minimizing the use of ototoxic medications.”
Dr. McEvoy highlighted the potential significance of interventions that reduce the cognitive strain associated with understanding speech, such as using subtitles, hearing aids, and opting for quiet environments for conversations. These measures could play a crucial role in safeguarding brain health and lowering the risk of dementia, suggesting a potential pathway to mitigate the impact of hearing impairment on cognitive function.
- McEvoy, Linda K. et al. ‘Elevated Pure Tone Thresholds Are Associated with Altered Microstructure in Cortical Areas Related to Auditory Processing and Attentional Allocation’. Journal of Alzheimer’s Disease, vol. 96, no. 3, pp. 1163-1172, 2023.
Source: UCSD, JAD