The Link Between Hearing Loss and Alzheimer’s Disease

Hearing loss and Alzheimer's disease are two of the most prevalent conditions in our society, but what is the link between these two? Recent research has shown that hearing loss could be an early sign of dementia. Loss of hearing can lead to a lack of communication with loved ones, which can cause feelings of isolation. This isolation could potentially lead to depression which is another risk factor for Alzheimer's disease. It is important to seek help from your doctor if you think you're experiencing hearing loss so that it can be addressed as soon as possible and before it leads to something more serious like dementia or depression.

Research About Hearing Loss and Alzheimer’s Disease

In recent years, there have been many studies that show a link between hearing loss and Alzheimer’s disease. One of these studies was done by the Georgetown University Medical Center in Washington D.C., where researchers found that people with mild to moderate hearing loss were twice as likely to develop dementia or Alzheimer’s disease as those who had normal hearing. Other research has shown similar results: older adults with severe cognitive impairment are more likely to have underlying sensor neural hearing loss and additional medical conditions which can put them at risk for both cognitive decline and auditory problems (i.e., tinnitus).

An example of this is a study that found that people with moderate hearing loss are at increased risk for mild cognitive impairment and Alzheimer's disease. This research was based on the Framingham Heart Study, where 595 volunteers between 58 to 68 years old participated in auditory tests and also received brain imaging. They were followed over 10 years to see who got cognitive impairment and/or Alzheimer's. They found that people with mild hearing loss were twice as likely to develop cognitive decline over the next 10 years, and almost five times as likely to develop Alzheimer's disease when compared to people in the normal hearing range.

High-frequency hearing loss is a known risk factor for dementia, according to the study led by researchers at Johns Hopkins Medicine. Researchers found that people experiencing hearing loss in the higher frequencies had a 90 percent greater risk of developing cognitive impairment and a three times increased risk of Alzheimer's disease when compared to those with normal hearing levels.

"We know that high-frequency hearing loss is related to changes in the white matter of the brain, which can be detected by MRI scans," says Susan M. Resnick, Ph.D., a member of the Division of Neuroscience at the Washington University School of Medicine in St. Louis and an expert on hearing loss and cognitive function in older adults. "It's possible that this type of hearing loss may also lead to changes in how well different parts of the brain communicate with each other."

Hearing aids and other technological advances have significantly improved hearing for older adults, but many older adults are not using them due to such factors as financial barriers or stigma. Other studies have suggested that common medication used by older adults may contribute to an increased risk of cognitive decline though this study suggests that hearing loss may be an even bigger factor.

Several studies have linked hearing loss to a higher risk for developing dementia and cognitive decline, but it was not known if this association was simply due to age or other factors. Karim adds that the finding is consistent with his previous research showing that older adults who are exposed to greater amounts of background noise are at a higher risk of developing dementia.

“It would be hard for us to conduct a randomized, controlled trial where we take people with early-stage Alzheimer’s disease and selectively expose them to loud noises to see if they develop symptoms of memory loss or other cognitive problems as they progress,” says Rachel G. Klein, Ph.D., the study’s senior author and professor of otolaryngology and epidemiology at Johns Hopkins University School of Medicine in Baltimore, Md.

Previous studies have found an association between hearing loss and dementia, but it was not known if this link is due simply to age or other factors. Karla V. Ballman, Ph.D., a former Johns Hopkins postdoctoral fellow now at the University Of Pittsburgh School Of Medicine in Pennsylvania, and her colleagues studied 1,766 people without dementia over age 55 who was participants in an ongoing study on aging. The researchers repeated hearing tests they had performed six years earlier to see if there was a link between hearing loss and dementia.

They found that those who had a hearing loss in both ears were three times more likely to develop dementia than people with normal hearing after other factors like age and medical history were taken into account. The risk of developing dementia was even higher for those with worse hearing loss. Men were 50 percent more likely to develop dementia than women overall.

How Does Dementia Affect Hearing?

The loss of hearing is a common result of dementia. The most common cause is damage to the nerve in the inner ear or cochlear nerve. This causes irreversible deafness, no matter how effective your hearing aid is. Other factors that can affect your hearing include:

-Damage to brain cells from lack of oxygen or a build-up of toxins. <.p>

The brain cells are responsible for transmitting sound information to the nerve in your ear and sending it to your brain for interpretation into meaningful sounds. When these cells die, you lose the ability to interpret sound signals from the cochlear nerve, limiting your hearing ability.

-Trouble with certain medications that can cause tinnitus, or ringing in the ears.

A certain kind of hearing loss can be caused by taking no steroidal anti-inflammatory drugs (NSAIDs), which include over-the-counter pain relievers such as ibuprofen and aspirin, and prescription medications such as celecoxib (Celebrex). These drugs block the production of prostaglandins, which are responsible for keeping inflammation levels down in the body. Prostaglandins also increase blood flow to the brain, and without them, it can suffer from oxygen deprivation.

Last Word

The link between hearing loss and Alzheimer’s disease is a topic that deserves more attention. With over 30 million people in America who have some form of hearing impairment, it should be a major focus for health professionals to develop treatments or preventive measures to help this population avoid the risks associated with dementia. If you or someone you know suffers from either hearing loss or Alzheimer's disease, please talk with your doctor about treatment options for both conditions.