Why 'Hearing Loss', Often Overlooked, Holds the Key
Yesterday, I participated in a Dementia Supporter Leader training course and encountered the latest findings regarding dementia.
I learned a great deal from the course as a whole, but among those lessons, I felt strongly that the relationship between hearing loss and dementia, which is deeply related to my own field of expertise, is still not very widely known in Japan.
Although it may be repetitive, I would like to share this important information with you all once again.
Is dementia becoming a 'preventable disease'?
Did you know that approximately 45% of dementia cases may be preventable? Did you know that?
In a standing commission report published in the international medical journal 'The Lancet' in 2024, modifiable factors that increase the risk of developing dementia were identified, indicating that by managing these, approximately 45% of dementia cases worldwide could be prevented or delayed.
12 major lifelong risk factors and their respective contribution rates
This report identifies the main risk factors affecting dementia at each stage of life. The contribution rates for each are also shown, providing hints as to where we should intervene.
-
Early life (0-18 years old)
Less education: 5%
-
Midlife (18-65 years old)
Hearing loss: 7%
High LDL cholesterol: 7%
Depression: 3%
Traumatic brain injury: 3%
Physical inactivity: 2%
Diabetes: 2%
Smoking: 2%
Hypertension: 2%
Obesity: 1%
Excessive alcohol consumption: 1%
-
Late Life (65+ years old)
Social isolation: 5%
Air pollution: 3%
Vision loss: 2%
The "Often-Overlooked Importance" and "Complex Impact" of Hearing Loss (7%)
Now, among these, what I have focused on in particular, as it is my area of expertise, is "hearing loss".
Looking at the list, the contribution rate of hearing loss is "7%", which might seem low at first glance. However, this 7% hides a very significant meaning.
In fact, among mid-life risk factors, if you add up all the so-called lifestyle-related disease risk factors such as "physical inactivity (2%)," "diabetes (2%)," "hypertension (2%)," and "obesity (1%)," it comes to exactly 7%.
In other words, hearing loss alone is as deeply involved in the onset of dementia as the combined risk of these multiple lifestyle-related diseases.
What is even more important is that hearing loss is not limited to the problem of "difficulty hearing."
Hearing loss is deeply associated with other major dementia risk factors such as depression (3%) and social isolation (5%).
When your hearing worsens, conversation becomes a burden, and you tend to go out and interact with others less.
This can easily lead to social isolation and potentially result in mental decline (depressive state).
It is believed that as these multiple factors act in combination, the risk of developing dementia increases even further.
This strongly suggests how complex and important a position hearing loss occupies, not just as the inconvenience of "difficulty hearing," but in brain health and, by extension, dementia prevention.
Why does hearing loss increase the risk of dementia?
The mechanisms by which hearing loss increases the risk of dementia are thought to include the following points:
Brain overload: Because it is difficult to hear, the brain consumes excessive energy to process sound, leaving insufficient resources for cognitive functions.
Social isolation: As conversation becomes a burden and interaction with others decreases, stimulation to the brain is reduced, and social isolation deepens. This is also a risk factor for dementia.
Changes in brain structure: Research is also progressing on how long-term hearing loss is associated with the atrophy of specific regions of the brain.
Addressing hearing loss is an 'investment in the future'
Hearing loss is a modifiable risk factor that can be appropriately managed through means such as the use of hearing aids.
Taking care of your hearing early on is not only about improving communication, but from the perspective of dementia prevention, it can be called a highly effective 'investment in the future'.
Unfortunately, in Japan, there are many people who think, 'It's still too early for hearing aids' or 'It's fine to wait until it gets worse.'
This is thought to be influenced by the social image of hearing aids and differences in welfare systems.
However, in Western countries, it is common for people to actively wear hearing aids from a relatively young age (for example, in their 60s) once they become aware of a decline in their hearing, supplementing their hearing from an early stage.
This is because the impact of hearing loss on the brain and its connection to dementia risk are widely recognized within their welfare systems.
I, too, intend to apply this knowledge and continue to provide information and support as a hearing specialist so that I can contribute to extending everyone's healthy life expectancy.
If you have any concerns about your hearing, please do not hesitate to consult with us.
#DementiaPrevention #HearingLossAndDementia #HearingCare #RoleOfHearingAids #ExtendingHealthyLifeExpectancy #TheLancet #LightHearing #Kumamoto