Hearing Loss and Dementia Risk: Understanding the Connection
Dementia is a growing public health crisis. Globally, 47 million people in 2015 were living with dementia, and this number is expected to triple by 2050 because of the aging population. There are currently no proven therapies that can cure, prevent, or reduce the risk of dementia, but the research on the role of hearing interventions in dementia is promising.
People who develop hearing problems during mid-life (aged 40-65) may have an increased risk of developing dementia. However, whether or not someone develops dementia depends on many other factors besides their hearing.
Regardless of any possible link with dementia, it’s important to get your hearing tested to support living well day-to-day. There is some evidence that, if needed, using hearing aids may reduce cognitive symptoms and slow cognitive decline in people at risk of dementia, though it’s not yet clear if using hearing aids can prevent dementia. Remember that hearing loss is only a risk factor.
Age-Related Hearing Loss and Dementia
Age-related hearing loss is a common condition affecting older people. It often starts with problems hearing what other people say, especially in noisy environments. Symptoms can start gradually and be difficult to notice. This makes early detection and treatment difficult.
There are two types of hearing loss: peripheral hearing loss and central hearing loss. Peripheral hearing loss is the reduced abilities of the ears to detect sounds. This does increase a person’s risk of developing dementia. Central hearing loss involves problems with processing sounds in the brain that are not able to be corrected with hearing aids. This may be a very early symptom of Alzheimer’s disease, as sound processing parts of the brain are affected by the disease.
The Link Between Hearing Loss and Dementia Risk
Research shows that a person’s hearing loss is related to an increased risk of developing dementia. The amount of hearing loss and length of time someone has hearing loss also impacts dementia risk.
People with hearing problems may also be more likely to withdraw from social situations and become more isolated over time. Social isolation and depression are both risk factors for dementia.
Hearing loss may also mean that the areas of the brain that help us understand sounds and speech have to work harder to understand what sounds are. There have been many studies looking into the association between peripheral hearing loss and memory and thinking problems, or dementia.
A large piece of work looked at all the things that are related to an increased risk of developing dementia. When assessing a risk factor, researchers look at the number of people who develop dementia who have that risk factor, compared to those who don’t. In this case, researchers analyzed many studies and showed that hearing loss is one of twelve main factors that leads to the highest risk of developing dementia.
One study found that people with a mild, moderate, and severe hearing loss, respectively, had a 2x, 3x, and 5x greater risk of being diagnosed with dementia over time compared to people without hearing loss.
Impact of Hearing Loss on the Brain
Researchers believe that hearing loss increases the risk of developing dementia through its effects on the brain and communication. Hearing loss prevents sounds from clearly reaching the brain, forcing the brain to work harder to understand sound. This stress may lead to faster aging of the brain and limit a person’s optimal thinking and memory abilities. Hearing loss can also limit our ability to optimally communicate and engage with others which contributes to social isolation and dementia risk.
ACHIEVE Study Findings
The Aging & Cognitive Health Evaluation in Elders, or ACHIEVE, study investigates whether treating hearing loss with technologies such as hearing aids could reduce the risk of developing dementia. This definitive study is sponsored by the National Institute on Aging and was completed in 2023.
Treating hearing loss in older adults at increased risk for cognitive decline slows down loss of thinking and memory abilities. The ACHIEVE study, a multicenter randomized trial that involved 977 older adults ages 70-84 years with untreated hearing loss, found that in older adults at increased risk for cognitive decline, treating hearing loss with hearing aids slowed down loss of thinking and memory abilities by 48% over 3 years.
Hearing loss may be a particularly important target in global efforts to reduce the rate of dementia because hearing loss is very common in older adults but often goes untreated. Treatment of hearing loss with hearing aids does not carry any health risks and has now been shown in the ACHIEVE study to slow down loss of thinking and memory abilities within 3 years for older adults at increased risk for cognitive decline. Hearing loss is treatable, but there are significant barriers to accessing care.
ACHIEVE study findings suggest that treatment of hearing loss may be a low-risk intervention for slowing cognitive decline in older adults at increased risk for cognitive decline.
Tracking hearing aid use over a long period showed that it was associated with less decline in memory skills. Hearing aid use was also associated with fewer memory problems and thinking problems independent of dementia.
Often, managing hearing loss works best when you start doing it early on. This means protecting your hearing from a young age. For example, you can avoid listening to loud noises for long periods and wear ear protection when necessary.
Even low levels of hearing loss have been associated with increased dementia risk and a decrease in memory and thinking skills. A new analysis underscores the importance of good hearing for good brain health. A new study found that people in their 50s with even slight impairments to their hearing had brain changes typical of the earliest stages of dementia. They were also at increased risk of developing Alzheimer’s disease or other forms of dementia years down the road. Many of the previous studies of hearing loss and dementia have focused on people age 70 and older, when hearing loss becomes more common and pronounced.
This study, published in JAMA Network Open, looked at a younger population, following them for 15 years. Researchers at Boston University and other institutions analyzed data from 2,178 men and women who were part of the Framingham Heart Study, which has tracked the cardiovascular and neurologic health of thousands of men and women over multiple generations. Participants were free of dementia or other serious memory problems at the study’s start. They got regular hearing exams as well as tests of memory and thinking skills, and many got MRI brain scans and other tests to look for brain abnormalities. The researchers found, through follow-ups over the 15-year period, that participants who had hearing loss of more than a slight degree in midlife had a 70 percent or greater increase in the risk of developing Alzheimer’s disease or other forms of dementia. The risk of Alzheimer’s was especially prominent in those with midlife hearing loss who inherited the APOE-E4 gene variant from one or both parents, with a near tripling of dementia risk.
Hearing loss in midlife was also associated with signs of brain aging. Those who showed mild or greater hearing loss in midlife had significantly smaller brain volumes than their peers with only slight or no hearing loss. Smaller brain volume is a sign of brain aging that increases the chances of developing dementia down the road. Accelerated declines in executive function, which involves skills like organization and planning, were also seen. The results underscore the importance of getting hearing tests even in midlife. Hearing loss may place a cognitive load on the brain, scientists suspect. Straining to hear things in a noisy environment can take a lot of mental effort, pulling attention away from other mental tasks. Poor hearing can also make people feel isolated and less likely to seek out social contact. If even slight hearing impairments are detected, a hearing aid may be a wise investment for long-term brain health. Quality over-the-counter hearing aids are fast becoming more affordable and available, and many are very small and unobtrusive. As ear buds and other on-the-ear devices become increasingly common among young people, wearing a hearing aid carries far less of the social stigma that it did in earlier generations.
Protect Your Hearing to Reduce Dementia Risk
You may be able to book a free hearing test at your local optician or speak to your GP about being referred to an audiologist (a doctor for hearing). This will show up any hearing issues and provide ways of managing them, such as using a hearing aid.
Studies have shown that people who use hearing aids to manage their hearing loss are less likely to develop dementia.
One recommendation to create a category of over-the-counter hearing aids to spur innovation and increase affordability was passed into law in 2017. seniors will still need access to hearing care support services that are not covered by Medicare or nearly any other private insurance plans. Policy changes are needed to increase affordable access and insurance coverage for hearing treatment/intervention. A Medicare hearing benefit to cover these two components of hearing intervention was included in the 2021 Build Back Better Act but was not passed.
| Level of Hearing Loss | Increased Risk of Dementia |
|---|---|
| Mild Hearing Loss | 2x greater risk |
| Moderate Hearing Loss | 3x greater risk |
| Severe Hearing Loss | 5x greater risk |