NMN protects your ear health and even prevents hearing loss?

[ Highlights ]

•        Compared to young mice, old mice exhibit hearing loss .

•        NMNis NAD⁺ Improving metabolism may help alleviate age-related hearing loss (ARHL) .

Aging and Hearing Loss

One of the most common inconveniences many people experience as they age is hearing loss . Difficulty hearing can make conversation difficult, lead to social isolation , and is also known to be a risk factor for dementia . In fact , several epidemiological studies have shown that older adults with severe hearing loss experience a faster rate of cognitive decline and an increased risk of developing dementia . Hearing problems are not simply a problem for the ears; they are an important aging phenomenon that is directly related to brain health .

Although it is not a life-threatening problem but a significant problem that greatly affects the quality of life , there is currently no treatment that can fundamentally prevent age-related hearing loss (ARHL) .

Mice, like people, experience hearing loss as they age . Researchers use a test called auditory brainstem response (ABR) , which measures the brain's electrical signals in response to sound to assess hearing .

Young mice respond to soft sounds , but older mice need louder sounds to elicit the same response . This suggests that hearing loss occurs with age .

▲ old age of the mouse hearing ability loss characteristic

young On the mouse ( white ) Compared to old age Mouse ( gray ) is
several At frequency of the brain Electrical Activity ( ABR threshold ) Stimulate for
more high The robber's The sound It is necessary ,
This is old age of the mouse hearing ability loss It suggests

The ingredient to note here is NMN

NMN ( nicotinamide mononucleotide ) is a precursor that is converted in our bodies into a substance called NAD+ . NAD+ is essential for cellular energy metabolism and age-related functions , but its levels in the body decrease with age and are associated with various aging diseases . Conversely , NAD+ Research results are reporting that supplementation can alleviate these problems .

A recent study from Wellness Science Labs in Japan observed significant effects when NMN was administered to a mouse model of hearing loss due to aging .

How does NMN affect hearing ?

 < Research Summary >

1)    Administration of 500 mg/kg of NMN per day for 13 weeks inhibited the progression of hearing loss in mice .

2)    Increased NAD+ levels in the inner ear tissues responsible for hearing

3)    The expression of genes related to ion metabolism is regulated , and a protective effect against oxidative stress is confirmed.

In other words , NMN has shown new possibilities for preventing hearing loss .

< Experimental Methods and Results >

Previous studies have shown that a compound called NR ( nicotinamide riboside ) can help prevent hearing loss . So, wouldn't another NAD+ precursor , NMN ( nicotinamide mononucleotide ) , have the same effect ?

To confirm this, the research team conducted an experiment by administering NMN to C57BL/6J mice, which are prone to hearing loss .

Subjects : Young mice, 12 weeks old ( approximately 21 years old in humans )

Method : NMN 500 mg/kg daily for 13 weeks

Comparison : Control group fed only water vs. group fed NMN

As a result , mice fed only water showed a clear hearing loss over time . In contrast , mice fed NMN responded to quieter sounds even at the same age .

That is , NMN inhibited the progression of hearing loss .

▲ NMN 's hearing ability loss prevention effect

Just water administered old age Mouse ( gray ) and Compared at the time ,
NMN administered old age The mouse ( red ) operates at a frequency of 32Hz
of the brain Electrical Activity ( ABR threshold ) Stimulating place more low sound The robber I need it .
This is NMN hearing ability loss To suppress It suggests .

A healthy balance of ions ( electrically charged metals ) is crucial for the cells in your ear to function properly . Iron and zinc, in particular, play a crucial role in ear health , particularly in the process of converting sound into electrical signals .

But as we age, this balance is disrupted, causing oxidative stress to cause cell damage and ultimately hearing loss .

The researchers found that NMN alters gene activity in the cochlea of ​​the inner ear . In particular , it was found to be involved in regulating the metabolism of metal ions such as iron and zinc, which may help maintain homeostasis in the inner ear * and reduce oxidative stress .

* Inner ear : The innermost part of the ear , the cochlea contained in the inner ear is the organ responsible for hearing.

That is , in mice fed NMN, the genes in the cochlea changed , which led to better iron and zinc balance, less cell damage, and ultimately, hearing protection .

finish

However , this study is in the animal testing ( mice ) stage and has not been proven to have the same effect in humans . Although it is still in the animal testing stage , this study suggests a new treatment that can alleviate age-related hearing loss through NMN supplementation .

If further research is conducted in the future , it is expected that NMN may play an important role in the problem of age-related hearing loss .

[source]

Hattori K, Hamaguchi T, Azuma-Suzuki R, Higashi S, Manji A, Morifuji M. Administration of nicotinamide mononucleotide suppresses the progression of age-related hearing loss in mice. Hear Res. 2025 Mar;457:109182. doi: 10.1016/j.heares.2025.109182. Epub 2025 Jan 5. PMID: 39778468.