Prevention: Hearing Loss
Evidence strongly suggests hearing loss is associated with higher rates of dementia and mild cognitive impairment (MCI). There is also evidence the severity of the hearing loss may correspond with the severity of dementia. A 2018 study of men in Australia followed a group of men for more that 11 years and tracked their rates of hearing loss, dementia, and MCI. It found the men with significant hearing loss had a 69 percent higher rate of being diagnosed with dementia or MCI. Other studies have also found a link between the two disorders, although not always with such a high percentage.
A 2008 study by researchers at John Hopkins University examined 639 people over 14 years. The study participants who experienced levels of hearing loss had a higher incidence rate of developing dementia; and the risk of developing dementia increased with the severity of hearing loss.
It is not known if hearing loss is a risk factor for dementia, if dementia could be a contributing factor to hearing loss, or if there is a different relationship between hearing and dementia. One possibility is that living with hearing loss requires the brain to use cognitive reserve to help the person hear and process conversations. Using this brain power for communication may mean the brain does not have sufficient reserves for other tasks. Another possibility is that living with hearing loss can cause social isolation and a decrease in social or leisure activities, two risk factors for dementia. Further research is being done to examine the full relationship between hearing loss, dementia, and MCI.