Randomised controlled trial suggests hearing aids can slow cognitive decline in people with dementia

A recent study has looked at whether using hearing aids could reduce cognitive decline in cognitively healthy older adults with hearing loss as well as people with dementia.

There is a strong link between hearing loss and dementia. A report published in The Lancet in 2020 identified hearing loss as one of 12 key risk factors for dementia that are possibly modifiable, meaning that they can be changed to reduce dementia risk. The review suggested that one in three cases of dementia could be prevented if more people took care of their health throughout their lives.

Now, a new study, entitled ‘Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial’ and published in The Lancet, has compared the rate of cognitive decline over a three-year period between people who did and did not receive hearing aids.

The ACHIEVE study was a randomised controlled trial of adults aged 70–84 years with untreated hearing loss and without substantial cognitive impairment. It took place at four community study sites across the USA.

Participants were recruited from two study populations at each site. The first group was older adults participating in a long-standing observational study of cardiovascular health, and the other group comprised of healthy de novo volunteers.

These participants were randomly and equally assigned to one of two hearing interventions. The first intervention was audiological counselling and provision of hearing aids. The second intervention was individual sessions with a health educator covering topics on chronic disease prevention. Each intervention was followed up every six months.

Between 9 November 2017 and 25 October 2019, 490 participants were assigned to the hearing aid intervention group and 487 participants were assigned to the health education group.

The study found that among the cognitively healthy adults, the three-year cognitive change was not significantly different between the hearing intervention and health education control groups.

However, the findings showed that among people in the hearing aid group, there was a “significant difference” in three-year cognitive change between the participants.

Hearing aid intervention reduced cognitive decline among participants at increased risk of cognitive decline. Those with a higher risk of cognitive decline who received hearing aids had an almost 50 percent reduction in the rate of cognitive decline compared with people in the health education group at a lower risk of cognitive decline.

This suggests that using hearing aids for people with increased risk of cognitive decline, including people with dementia, may significantly slow down cognitive decline.

The study received funding from the US National Institutes of Health. Read the full study on The Lancet.