Hearing Loss & Dementia
Recently, there has been many scientific research studies that connect hearing loss to an increased risk for dementia. According to one study published in 2011 by the Johns Hopkins School of Medicine, people with severe or profound hearing loss may be about five times as likely than their peers without hearing loss to develop dementia over the course of many years(1).
however, this number is set to rise significantly. In fact, the World Health Organization estimates that cases of dementia are set to triple by 2050. As a society, it is important for us to educate ourselves about dementia, its signs, and ways to potentially prevent or delay it.
What is Dementia?
Dementia is a broad term that covers many symptoms of cognitive decline. Most often, dementia is defined as “a decrease in memory or overall thinking skills that reduce a person’s ability to complete daily activities”(2). Currently, Alzheimer’s disease is the most commonly diagnosed type of dementia. It is estimated that a person develops Alzheimer’s disease every 65 seconds in the United States alone(3). Dementia is a progressive disorder, meaning it typically starts very mildly and gets more severe over time. Currently, there is no cure for Alzheimer’s disease or dementia, however, various treatment options do exist that can help prolong a person’s quality of life and mental ability when living with Alzheimer’s disease or other forms of dementia.
How are Dementia and Hearing Loss Linked?
Cognitive decline is not scientifically proven to have a direct connection to hearing loss, however, many studies have found that those with hearing loss tend to experience a higher risk for developing dementia than their peers with average hearing.
As mentioned above, one of the most notable studies on the connection between hearing loss and dementia came out of Johns Hopkins School of Medicine in 2011. To complete this study, Frank Lin and his research team used data from the Biltmore Longitudinal Study on Aging (BLSA) on 639 men and women. These men and women were frequently assessed by BLSA in both cognitive abilities as well as hearing over the course of 18 years. Even after controlling for other potentially contributing factors such as age, sex, socioeconomic status, race and smoking habits - people with hearing loss were more likely to have experienced cognitive decline over the course of the study than those with normal hearing. In fact, those with just mild hearing loss were about twice as likely to have developed dementia and those with the most severe or profound hearing losses were about five times as likely to have experienced dementia than their peers with normal hearing(4).
Why Does This Connection Between
Hearing Loss and Dementia Exist?
Researchers are not entirely sure why there seems to be a correlation between hearing loss and dementia.
Two frames of thought have developed on this issue,
and the correct answer probably lies within a combination of both of them
Social Isolation
The first potential cause for the correlation is social isolation. For many years, social isolation has been a known risk factor for developing dementia. Unfortunately, people with hearing loss tend to withdraw from social situations as they become more frustrating and less enjoyable. This unintentional social isolation could potentially be the link between hearing loss and dementia.
Cognitive Limit
The second school of thought is regarding our limited cognitive capability. Each of use have a finite amount of cognitive resources our brain can expend. If our brains are consistently using a greater amount of resources to strain to hear, less resources are available for other tasks such as problem solving or memory(5).
Do Hearing Aids Help?
New research out of the University of Manchester in the United Kingdom has shown some exciting results on the potential for hearing aids to slow cognitive decline. In this study, participants were given a cognitive assessment every two years over an 18 year period.
During each assessment, participants were also asked whether or not they use hearing aids. For all of the 2040 self-reported hearing aid users, rates of cognitive decline began to slow at about the same time they also reported starting hearing aid use. These findings held true after adjusting for other factors such as overall health and socioeconomic status(6).