Age-related hearing loss and dementia risk across the lifespan: mechanisms, equity, and prevention.

Abstract

Age-related hearing loss (ARHL) has emerged as a significant and potentially modifiable risk factor for neurodegenerative disorders, including Alzheimer's disease. A growing body of evidence links ARHL to structural and functional changes in the brain, with implications for cognitive decline and dementia onset. However, both ARHL and dementia are multifactorial conditions shaped not only by biological mechanisms but also by broader social determinants of health. Inequities in access to hearing care, underrepresentation of marginalised populations in research, and variability in intervention outcomes emphasise the need for a more inclusive and integrated approach to prevention. This review synthesises current evidence on the neurocognitive consequences of ARHL, the potential mechanistic pathways linking hearing loss to dementia, and the role of inequity. It includes a novel perspective by highlighting the need for cross-cultural, population neuroscience approaches incorporating exposome and equity frameworks that capture phenotypic variability across diverse populations. This review outlines key priorities for advancing neurocognitive and translational research on hearing loss, neurodegeneration, and global health equity. Addressing these gaps is essential to developing equitable strategies for dementia prevention and optimising cognitive health across the lifespan.