Study finds hearing loss linked to accelerated brain tissue loss
Hearing loss isn’t just an annoying inconvenience – a new study has revealed it could be harmful for your brain.
The results from Johns Hopkins University and the National Institute on Aging joint study found that hearing loss is linked to accelerated brain tissue loss. The findings add to a growing list of health issues associated with hearing loss, including increased risk of dementia, falls and hospitalisations.
Researchers used information from the ongoing Baltimore Longitudinal Study of Aging, an initiative started in 1958 by National Institute of Aging to track various health factors, to compare brain changes over time between adults with normal hearing and those with impaired hearing. They tracked the results of 126 participants who underwent yearly MRI scans for 10 years. Each also had physicals at the time of the first MRI in 1994, including hearing tests. At the starting point, 75 had normal hearing, and 51 had impaired hearing, with at least a 25-decibel loss.
The study found that participants who already had hearing loss suffered from accelerated rates of brain atrophy, around an additional cubic centimetre of brain tissue, compared to those with normal hearing. Those with impaired hearing also had more shrinkage in particular regions, including the superior, middle and inferior temporal gyri which are brain structures responsible for processing sound and speech.
Frank Lin Ph.D., researcher and assistant professor at Johns Hopkins said that they weren’t surprised that the parts responsible for sound and speech are affected in those with hearing loss, as tissue shrinkage in those areas might simply be a consequence from lack of stimulation. However, the professor emphasises that these structure don’t work in isolation, they also play roles in memory and sensory integration. And they have been shown to be linked with the early phases of dementia and Alzheimer's disease.
"Our results suggest that hearing loss could be another 'hit' on the brain in many ways," professor Lin explains.
But the main message that professor Lin and his fellow researchers want everyone to know is you need to treat your hearing loss rather than ignoring it.
"If you want to address hearing loss well," professor Lin says, "you want to do it sooner rather than later. If hearing loss is potentially contributing to these differences we're seeing on MRI, you want to treat it before these brain structural changes take place."