Study Finds: Hearing Aids May Lower Cognitive Decline In Adults With Dementia Risk

Hearing aids may protect against cognitive decline in older adults at greater risk of dementia, according to a study published on Tuesday in The Lancet journal.

“But any cognitive benefits of treating age-related hearing loss are likely to vary depending on an individual’s risk of cognitive decline,” said Lin.

The global research

Hearing loss is one of the most common age-related conditions in the world, affecting 2 out of every 10 adults at the age of 60. However, only about 1 in 10 people with this condition in low and middle-income countries, and less than 3 out of 10 in high-income countries, are currently using hearing aids.

The researchers said that untreated hearing loss is linked to a higher rate of cognitive decline, and was estimated to contribute about 8 percent to dementia cases worldwide in 2020, which is about 8 lakh out of the almost 10 million new dementia cases diagnosed annually.

According to the researchers, previous studies suggest that treatment of hearing loss may improve cognitive function and reduce the risk of dementia.

However, this may be because people who have the money to treat their hearing loss may be healthier and less likely to experience cognitive decline than people who do not, they said.

So, the effectiveness of using hearing aids to reduce cognitive decline in hearing-impaired older adults remained uncertain.

To get a better understanding of this, the latest study looked at 977 adults with untreated hearing loss aged 70–84 who were free from significant cognitive impairment in 4 communities across the US.

At each site, participants were recruited from two groups: older adults enrolled in a long-term observational cardiovascular health study (the Atherosclerosis Risk in Communities (ARIC) study) and new volunteers recruited from the same communities, generally healthier than participants in the ARIC study.

Patients were randomized to receive either a hearing (audiological counseling, hearing aids) or a control (more generalized counseling, healthy aging) intervention and followed up twice a year for 3 years.

The main analysis of the results combining the ARIC study and the volunteer cohorts showed no evidence of cognitive decline over time, with no significant differences in cognitive change between the hearing and health education control groups over 3 years.

In contrast, the ARIC cohort had a 48 percent lower 3-year change in cognitive change for the hearing intervention group compared to the control group.

The healthy volunteer cohort (which had fewer risk factors and a much lower rate of cognitive decline) showed no difference in 3-year cognitive changes for the hearing intervention and the control groups.

“Although our primary analysis of the combined ARIC and health volunteer cohorts did not find a difference in cognitive decline for those using hearing aids, when we did sensitivity analyses to test its robustness there was clear evidence indicating a significant benefit for older adults in the ARIC cohort who had more risk factors for cognitive decline,” Lin said.