New Studies on Hearing Loss and Dementia

Hearing loss can have surprising effects which ripple out much further than just issues following everyday conversations. It’s well known that communication barriers associated with hearing loss can cause rifts in even a person’s closest relationships as well as cause feelings of chronic anxiety, depression, and isolation. However, many studies have documented an increase in cognitive decline leading to higher instances of dementia in patients with hearing loss.

Understanding Dementia

Dementia is a neurodegenerative disease affecting two or more cognitive functions such as memory, or the ability to complete daily tasks. The Centers for Disease Control and Prevention estimates that about 5.8 million people in the United States have dementia, including 5.6 million aged 65 and older and about 200,000 under age 65 with younger-onset Alzheimer's. Alzheimer’s is by far the most common type of dementia making up nearly 60-80% of cases. There is currently no cure for this devastating brain disease which affects not only the patient but the families who are left to care for loved ones who gradually lose touch with who they are.

Untreated Hearing Loss and Higher Instances of Dementia

Multiple studies have identified hearing loss as a significant factor for an increased risk of cognitive issues and dementia. Hearing loss is just one factor among many identified risk factors, some modifiable and some not. Age and family history are significant factors increasing the risk of neurodegenerative issues, but modifiable issues include isolation, depression, sedentary lifestyle, poor diet, and environmental air pollutants in your living environment.  Research identifying the high prevalence of hearing loss as a major factor for dementia leaves many unanswered questions.

Searching for Proof of a Connection

We know that hearing loss and dementia are connected but many are still in disagreement as to if hearing loss causes dementia or vice versa. Similarly, researchers have not been able to fully confirm if hearing aids are helpful in the prevention of dementia, despite concrete numbers showing lower instances in patients who treat their hearing loss with hearing aids. Part of these issues can be attributed to a complete lack of understanding about dementia and its causes in general. Currently, there are medications to prevent the development of dementia, adding valuable cognizant years to people’s lives, but no long-term cure or way to reverse cognitive decline.

New Research Unfolding Around a Connection

Currently, scientists based out of Newcastle University in the UK have developed a new theory as to how and why hearing loss may cause dementia. It’s exciting to report that it is suspected that treatment of hearing loss may help prevent this devastating disease. Now, published in the journal Neuron, Newcastle experts considered key aspects which may contribute to dementia with hearing loss: A lack of sound-related input causing brain atrophy and cognitive impairment causing an increased use of cognitive resources to compensate for the auditory loss.

Hearing and Memory

The team led by Professor Tim Griffiths of Newcastle University’s Faculty of Medical Sciences, explored the regions of the brain centering on long and short-term memory in the temporal lobe. Recent findings signal that the area of the brain responsible for storing long-term memory such as places and events may also function as a place involved in short-term storage and manipulation of auditory information. When people struggle to hear parts of words or words in sentences the brain must compensate to fill in these blanks. This can cause changes in the brain which the researchers believe may directly promote the presence of abnormal proteins, a major precursor to dementia and Alzheimer’s disease.

“The challenge has been to explain how a disorder of the ear can lead to a degenerative problem in the brain.” Explains Griffiths. “We suggest a new theory based on how we use what is generally considered to be the memory system in the brain when we have difficulty listening in real-world environments.

Dr. Will Sedley, from Newcastle University’s Faculty of Medical Sciences, adds: “This memory system engaged in difficult listening is the most common site for the onset of Alzheimer’s disease. We propose that altered activity in the memory system caused by hearing loss and the Alzheimer’s disease process trigger each other.” However, Sedley notes that further research is required.

Treating Hearing Loss

One of the most effective ways to reduce overexertion of cognitive resources which may cause dementia is to treat your hearing loss with hearing aids. The sooner you address the issue, the better. Join the fight against dementia and schedule a hearing exam today.