Imagine a world where everyday conversations, the laughter of loved ones, and the melodies of your favourite songs slowly fade away. For many people, hearing loss is not just a communication issue but an emotional rollercoaster that leads to exhaustion, headaches, listening fatigue and social isolation. However, recent research has shed light on the crucial link between hearing loss and dementia, giving us more reason than ever to address this issue. 

 

 

September is dementia awareness month and there is much fear-mongering about how hearing loss and dementia are linked. This blog will use the facts to inform you how hearing loss and dementia are linked, and how remaining socially engaged can protect your cognitive well-being.

 

The Hidden Link: Hearing Loss and Dementia

Hearing loss and dementia might seem separate, but science suggests they are more closely connected than we once thought. There are 12 potentially modifiable risk factors that could prevent or delay dementia in up to 40% of cases. The number one modifiable risk factor is hearing loss in midlife, which almost doubles the risk of developing dementia. A recent study found that for every 10 dB of hearing loss, the rate of cognitive decline increased. Those living with untreated hearing loss experienced an accelerated rate by as much as 30-40% compared to their peers with normal hearing. However, treating hearing loss reduces the risk by 8%.

 

Here are the theories of how hearing loss is linked to dementia. 

 

Social Isolation:

Hearing loss is known to cause social isolation and social isolation has a definitive link to dementia. That is well researched and well known, no ifs or buts about it. Social isolation has been shown to increase the risk of dementia by as much as 60%. When you have hearing loss, communication becomes challenging, making you feel isolated and you may withdraw from social interactions. This isolation is a known risk factor for dementia, as it reduces mental stimulation and increases cognitive decline.

 

Social isolation can also increase the risk of coronary heart disease, sedentary lifestyle and depression. These conditions are also linked to dementia. However research has also shown that staying socially active may also help slow down the progression of dementia if you are unlucky enough to get it.

 

Cognitive Load:

When you’re straining to hear constantly due to untreated hearing loss, your brain has to work overtime to process and understand sounds. This increased cognitive load can lead to mental fatigue and reduce cognitive resources available for other tasks, such as memory and problem-solving. Over time, this strain on cognitive resources may contribute to cognitive decline.

 

Recent research has found that individuals who treat hearing loss do not work as hard to listen because they have a reduced cognitive load. This can lead to up to a 20% increase in memory recall when following a conversation.

 

 Auditory Deprivation Hypothesis:

Your brain relies on auditory input for various cognitive functions, including memory and decision-making. Hearing loss deprives the brain of this input, potentially contributing to cognitive decline over time. The Auditory pathways are close to the memory pathways in the brain. When the auditory pathways are not being stimulated enough due to hearing loss, this part of the brain atrophies and so do the neighbouring regions – including the memory pathways.

Source: Queensland Brain Institute – University of Queensland (2018), Lobes of the Brain. 

 

 Brain Atrophy:

Some studies indicate that untreated hearing loss might be linked to faster brain atrophy, a common feature of dementia. Some studies suggest it is the dementia shrinking the brain that causes hearing loss. The exact cause and connection are still under investigation, but this evidence is compelling.

 

Empowerment Through Early Intervention

So yes, there is a link, but it is not all doom and gloom. There is still research being done and there are a lot of hypotheses still being researched. Having hearing loss does not mean you will get dementia, but it is an undeniable risk factor. 

 

Now that you understand the connection between hearing loss and dementia, it’s essential to know that early detection and intervention can make a world of difference:

 

Regular Check-ups:

Routine hearing check-ups are essential. If you’re over 50, make it a habit to get your hearing tested, even if you think everything is fine. Early detection of hearing loss allows for timely intervention.

 

Social Engagement:

Stay socially active! Engage in conversations and enjoy those moments of connection with family and friends. Social engagement can stimulate your brain and potentially reduce the risk of cognitive decline.

 

Hearing Aids and Cochlear Implants:

These are not just about improving your hearing but about preserving your cognitive health. Enhancing your auditory input and reducing the cognitive load associated with untreated hearing loss can protect your cognitive function.

 

  

What about the other modifiable risk factors?

Risk factors are aspects of your lifestyle, environment and genetic background that increase the likelihood of getting a disease. It does not mean you will get the disease. Similarly, having little or no exposure to risk factors does not necessarily protect a person from developing dementia. 

 

There are some modifiable risk factors to prevent you from getting dementia. You can do these things NOW to prevent your chances of getting dementia later on. 

 

I’ve also included the relative risk associated with the modifiable risk factor. This is the likelihood of developing dementia compared to someone without the risk factor. i.e. A Risk factor of 1.0 = same risk as without the modifiable risk factor, 2.0 = double the chance of developing the disease compared to someone without the risk factor. I’ve also listed at what stages of life they have the most impact on your future health.

 

Mid Life Risk Factors (age 45-65)

  1. Hearing Loss = 1.9 (RR) 
  2. Obesity = 1.6 (RR)
  3. High Blood Pressure = 1.6 (RR)

 

Obesity

Obesity in mid-life not only increases the risk of developing dementia but many many many other illnesses that are also associated with dementia. 

 

High Blood Pressure

People who have consistently high blood pressure in their mid-life are more likely to develop dementia compared to those with normal blood pressure.

 

Over 65 risk factors

  1. Depression = 1.9
  2. Smoking = 1.6
  3. Social isolation = 1.6
  4. Diabetes = 1.5
  5. Physical inactivity = 1.4

 

Depression

People who experience depression in mid- or later life have a higher risk of developing dementia. However, the relationship between depression and dementia is still unclear. Like hearing loss, many researchers believe that depression is a risk factor for dementia, whereas others believe it may be an early disease symptom, or both.

 

Smoking

The evidence is solid and consistent that smokers are at a higher risk of developing dementia vs. non-smokers or ex-smokers.

 

Diabetes

People with type 2 diabetes in mid-life are at an increased risk of dementia, particularly Alzheimer’s and vascular dementia. 

 

Sedentary Lifestyle

Physical inactivity in later life increases the risk of developing dementia.

 

Please note: other risk factors that are also well known are high alcohol consumption, not being mentally engaged and a history of brain injury. This study did not include these, so the relative risk is not listed. 

 

 

Conclusion

Hearing loss is more than just communication difficulties; it’s a significant factor in the complex puzzle of cognitive health. It’s important to note that while there is a clear association between hearing loss and dementia, the exact cause and relationship are not fully understood. Research in this area is ongoing, and more studies are needed to understand the mechanisms involved. 

 

If you or someone you know is experiencing hearing loss or cognitive changes, it’s important to seek medical evaluation and appropriate interventions. Early detection and management of both conditions can significantly impact overall quality of life and cognitive health. Likewise, if you have any of the risk factors mentioned above, now is the time to take action. 

 

A hearing device is a medically prescribed communication aid. Your hearing health professional should educate you about your options so you can make an informed decision. But, if you feel like you are being ‘sold’ to, you probably are. Seek another opinion.

 

Hearing loss is not just about hearing better; it’s about remaining socially active and protecting your cognitive well-being and your quality of life. There are tools, interventions and people to assist you to help you stay connected, both to the world of sound and to the world of memories. 

 

Author: Laura Drexler

Creator of Ambient Menu

Masters of Audiology, Bachelor of Health Science

Presenter: Audiology Australia SA Chapter Conference 2023, Flinders University 2023, SA Gerontology Conference SA 2022, Audiology Unchained (Independent Audiology Australia) 2023

Awards: Audiology Australia Internship Award, Flinders University Early Career Alumni Award, Help Awards AMP Healthcare Hero.

Written for: SA Life, 50 So What, Grandparents Magazine

 

 

 

 

REFERENCES

 

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  2. Eckert, M.A. et al. (2012) ‘Auditory cortex signs of age-related hearing loss’, Journal of the Association for Research in Otolaryngology, 13(5), pp. 703–713. doi:10.1007/s10162-012-0332-5.
  3. Lin, F.R. et al. (2011) ‘Hearing loss and cognition in the Baltimore Longitudinal Study of aging.’, Neuropsychology, 25(6), pp. 763–770. doi:10.1037/a0024238.
  4. Lister, J. et al. (2015) ‘Mechanisms of the hearing–cognition relationship’, Seminars in Hearing, 36(03), pp. 140–149. doi:10.1055/s-0035-1555117.
  5. Livingston, G. et al. (2017) ‘Dementia prevention, intervention, and care’, The Lancet, 390(10113), pp. 2673–2734. doi:10.1016/s0140-6736(17)31363-6.
  6. Lobes of the brain (2018) Queensland Brain Institute – University of Queensland. Available at: https://qbi.uq.edu.au/brain/brain-anatomy/lobes-brain.
  7. Montero-Odasso, M., Ismail, Z. and Livingston, G. (2020) ‘One third of dementia cases can be prevented within the next 25 years by tackling risk factors. the case “for” and “against”’, Alzheimer’s Research & Therapy, 12(1). doi:10.1186/s13195-020-00646-x.
  8. Peelle, J.E. and Wingfield, A. (2016) ‘The neural consequences of age-related hearing loss’, Trends in Neurosciences, 39(7), pp. 486–497. doi:10.1016/j.tins.2016.05.001.
  9. Powell, D.S. et al. (2022) ‘Hearing loss and cognition: What we know and where we need to go’, Frontiers in Aging Neuroscience, 13. doi:10.3389/fnagi.2021.769405.
  10. Risk factors for dementia (no date) Alzheimer Society of Canada. Available at: https://alzheimer.ca/en/about-dementia/how-can-i-reduce-risk-dementia/risk-factors-dementia.
  11. Yang, Z. et al. (2022) ‘Effect of hearing aids on cognitive functions in middle-aged and older adults with hearing loss: A systematic review and meta-analysis’, Frontiers in Aging Neuroscience, 14. doi:10.3389/fnagi.2022.1017882.

 

 


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