New research finds that treating hearing loss may be critical for helping to prevent dementia in those at risk for cognitive decline. The study, with nearly 1,000 older adults, adds to growing evidence that getting tested for hearing loss and getting hearing aids for those who need them can slow decline in memory and thinking skills. The study was published in The Lancet and presented at the Alzheimer’s Association International Conference.
The study involved 977 adults ages 70 to 84 with untreated hearing loss. Participants came from two study groups: one group of adults who were already participating in a heart health study and a group of healthy volunteers who were recruited from the community. The participants who came from the heart health study were, on average, older and had more risk factors for cognitive decline than the new healthy volunteers.
Half the group received counseling from an audiologist and hearing aids if they needed them. The other half, the control, got advice on healthy aging from a health educator. Researchers followed the study participants for three years and tested their memory and thinking skills.
The researchers found that hearing aids did not reduce cognitive decline in the total group. But when the researchers analyzed results for the older group who were at higher risk for dementia, those who got the hearing interventions had a 48 percent greater reduction in cognitive decline than the control.
“These results provide compelling evidence that treating hearing loss is a powerful tool to protect cognitive function in later life, and possibly, over the long term, delay a dementia diagnosis,” says professor Frank Lin, M.D., of the Johns Hopkins University School of Medicine and Bloomberg School of Public Health.
The research is the first randomized controlled trial to study whether hearing intervention makes a difference in preventing cognitive decline. Cognitive decline is a decline in abilities severe enough to interfere with daily life and can range from mild cognitive impairment to dementia, according to the Centers for Disease Control and Prevention (CDC). Alzheimer’s is the most common form of dementia.
This study builds on evidence of the link between dementia and hearing loss. In 2020 the Lancet Commission on Dementia said that hearing loss contributed to about 8 percent of dementia cases worldwide, which is equivalent to 800,000 of the nearly 10 million new cases of dementia diagnosed every year. “We’re much more confident that there is a good association between hearing aid use and reversing chance of cognitive decline,” says Justin Golub, M.D., an associate professor of otolaryngology, neurotology and skull base surgery at the New York-Presbyterian/Columbia University Irving Medical Center in New York City.