Epidemiologic research since 2010 led by Center faculty has established the contribution of hearing loss to the risk of cognitive decline and dementia in older adults.
The Lancet Commission report on dementia, released in 2017 and updated in 2020, drew primarily from work by Center researchers and concluded that among all known risk factors for dementia, hearing loss is the single modifiable risk factor carrying the greatest population attributable risk, exceeding the risk conferred individually by hypertension and other factors. See the Lancet Commission report.
Research by Center faculty, including Jennifer Deal and Frank Lin, is actively focused on the mechanism underlying the relationship between hearing, cognition, and brain aging in population-based studies. Ongoing work includes investigating the relationship of hearing to Alzheimer’s disease biomarkers and how hearing may affect brain structure and networks, as measured through structural and functional brain magnetic resonance imaging.
Cochlear Center epidemiologic research led to the Aging and Cognitive Health Evaluation in Elders study. Sponsored by the National Institute on Aging, ACHIEVE is a first-in-kind, ongoing, large-scale randomized trial led by Cochlear Center faculty designed to definitively determine if treating hearing loss in older adults could reduce the loss of thinking and memory abilities (cognitive decline) that can precede dementia. The ACHIEVE study also looks at other health outcomes, including mental health and well-being, physical function, and health care use.
Participants in the ACHIEVE study came from two distinct study populations: a group of adults who were already participating in a heart health study and a group of healthy volunteers who were newly recruited from the community. The 238 participants who came from the heart health study were, on average, older and had more risk factors for cognitive decline than the 739 new healthy community volunteers. Participants were randomly assigned to hearing intervention or a health education control and then followed for 3 years with tests of thinking and memory.
ACHIEVE study main findings, published in the Lancet, showed that in older adults at increased risk for cognitive decline, hearing intervention slowed down loss of thinking and memory abilities by 48% over 3 years.