September 11, 2020
September is celebrated globally as World Alzheimer’s Month. How does that concern our hearing practice? Alzheimer’s disease is one of the strongest-associated conditions with untreated hearing loss. Recently, The Lancet published a report on the global state of Alzheimer’s, acknowledging that 40% of cases are brought about by a combination of 12 modifiable risk factors. For reference, these are:
Obviously, while some of these risk factors are within the power of an individual to control, others will require concerted group efforts put forward by governmental organizations around the world. And while hearing loss is itself on this list, many of the other factors are also risk factors for hearing loss.
Alzheimer’s disease is a type of dementia. Dementia is a progressive brain disorder characterized by memory troubles, cognitive problems, behavioral issues and abnormal mood shifts. While there are other forms of dementia, somewhere between 60-80% of cases fall under the Alzheimer’s disease umbrella.
Alzheimer’s disease is not a normal part of aging but a disorder that is caused by the buildup of plaque and protein “tangles” in parts of the brain. Usually diagnosed consequent of obvious memory trouble, Alzheimer’s patients generally live about 4-8 years after diagnosis, though sometimes live up to 20 years. Alzheimer’s disease is the 6th most common cause of death in the United States.
While the link between dementia and hearing loss has been statistically established beyond a doubt by multiple studies in different corners of the globe, it’s not yet known exactly why this link exists. One thing that is clear is that hearing aids help slow or prevent the onset of dementia – and Alzheimer’s disease is one of the most common forms of the condition.
There are two main theories as to why hearing loss might lead to Alzheimer’s disease.
The first has to do with social isolation. As hearing loss progresses, it becomes more and more difficult to participate in conversations. It’s fatiguing to try to keep up with what’s being said when we need to piece sentences together from partial understanding and context clues. Social events become a chore, and our time with friends and family becomes exhausting.
The link between hearing loss and social isolation, loneliness and depression is well-established, and this is how it begins. Once we begin to withdraw from social life, the unfortunate trajectory is laid out for us: social isolation is a definite risk factor for Alzheimer’s disease.
A second theory about how hearing loss is connected to dementia and Alzheimer’s disease has to do with the atrophy of the auditory cortex. This phenomenon is seen in many patients whose hearing loss has gone untreated for a long time.
As hearing loss progresses and the brain sees less information coming to it from the ears, the auditory cortex literally begins to shrink. The brain cells do not die, but the grey matter supporting the neural network shrinks in size.
The effects of this process are seen when a person who has been living with hearing loss for a long time finally gets hearing aids: they’ve lost the ability to understand speech! Luckily, with some effort and frequent use of their hearing aids, they can retrain their brains to comprehend speech. Many audiologists offer training courses to help those who are new to hearing aids to get comfortable listening to speech again.
If hearing aids never enter the picture, it’s possible that this atrophy of the auditory cortex proceeds to earlier onset of dementia and Alzheimer’s disease.
While hearing aids are a big part of the picture in terms of staving off Alzheimer’s disease, research strongly indicates that an anti-inflammatory diet such as the Alternate Mediterranean diet (AMED) or Dietary Approaches to Stop Hypertension (DASH) can both help slow the progress of age-related hearing loss as well as Alzheimer’s disease. Of course, a healthy diet is also an important measure toward preventing other problems throughout the body such as cardiovascular disease. Exercise in mid-life is also strongly recommended to help prevent Alzheimer’s disease.
The Better Hearing Institute, a non-profit organization, recommends getting a hearing test once every decade until age 50, and once every three years after that. If you’re due for a hearing test, contact us today and keep up with your hearing health, brain health, and general sense of well-being.