The Impact of Heavy Metal Exposure on Auditory Nerve Function: What You Must Know to Protect Your Hearing

In the last decades, the scientific community has given always more attention to a problem that touches the health of the hearing in a way silent and progressive: the exposition to heavy metals. Many persons think that the damages to the auditory capacity depend only from the loud noises or from the ageing. In reality, also the chemical substances that we breathe, that we eat, that we absorb through the skin can arrive to the interior of the auditory system and create lesions that, if not recognised in time, become irreversible.

In this article we will see together how this phenomenon works, which metals are the most dangerous, and what is possible to do in concrete terms for protecting the function of the auditory nerve.

How Heavy Metals Arrive to the Auditory System

The heavy metals, as lead, mercury, cadmium, and arsenic, enter in the organism through various routes: the contaminated air, the water, certain foods (in particular the large fish as tuna and swordfish), the occupational environments, but also some old dental amalgams.

Once in the blood circulation, these substances do not remain in one single point. They travel and distribute themselves in the tissues of the whole body. The auditory system, which is extremely vascularised and metabolically very active, results particularly vulnerable. The cochlea and the auditory nerve receive a constant flow of blood rich in oxygen, and this means that also the toxins arrive there with facility.

In fact, the small hair cells of the cochlea and the fibres of the auditory nerve do not possess a strong capacity of cellular regeneration. When the metal accumulates in these structures, the damage tends to become permanent.

Which Metals Are Most Dangerous for the Hearing

Not all heavy metals act in the same manner. It is useful to understand the differences:

Also the combination between these metals is dangerous. The studies have demonstrated that the simultaneous exposition to two or more substances amplifies the toxic effect in a way that is not simply additive, but multiplicative.

The Mechanism of Damage: What Happens to the Auditory Nerve

For understanding the problem without using complicated terminology, let us imagine the auditory nerve as a cable that transports the electric signal from the ear to the brain. This cable is covered by a protective material (the myelin) and is formed by fibres that must maintain a precise chemical balance for working well.

The heavy metals act at various levels:

• Oxidative stress. The metals provoke the production of free radicals, which attack the membranes of the hair cells and of the nerve fibres. The cells, in this way, lose their capacity to transmit the signal.
• Interference with the ionic channels. The transmission of the nervous impulse depends from the passage of ions as potassium and calcium. Lead and mercury block these channels, and the signal becomes weak or distorted.
• Damage to the myelin. In particular the arsenic and the lead can deteriorate the protective sheath of the nerve, slowing down the conduction of the impulse.
• Reduction of the blood supply. The cadmium causes a constriction of the small vessels that nourish the cochlea, creating a situation of local «suffocation» of the tissues.

These processes do not manifest themselves from one day to the other. They progress slowly, and this is exactly the reason for which many persons do not notice the problem until the loss of hearing becomes significant.

The Signs That Your Hearing Is Suffering

It is important to know the initial signals, because the early recognition permits to intervene before that the damage consolidates itself. The signs to observe include:

• A difficulty to follow the conversation in environments with background noise
• The sensation of hearing «muffled» sounds, in particular the high frequencies
• Tinnitus (buzzing or ringing in the ears) that appears without an evident cause
• A sense of fatigue after having listened for a prolonged time, as if the brain must make more effort for decoding the sounds
• A progressive difficulty in the comprehension of the spoken words, above all in the telephone conversations

If you recognise two or more of these signals and you work in an environment with possible exposition to metals, or you consume regularly large quantities of predatory fish, it is advisable to request a control of the auditory function and, if necessary, an analysis of the heavy metals in the blood.

Strategies of Protection and Nutritional Support

The first level of protection is always the reduction of the exposition. But in parallel, it is possible to sustain the auditory system also from the interior, with an adequate nutritional approach.

The auditory nerve and the cochlear cells have need of specific nutrients for maintaining their function and for contrasting the oxidative stress:

• Antioxidants (vitamin C, vitamin E, glutathione) that contrast the free radicals
• Minerals as zinc and magnesium , which protect the hair cells
• B vitamins , fundamental for the health of the nervous fibres and for the integrity of the myelin
• Omega-3 fatty acids , that sustain the fluidity of the cellular membranes

In this context, some integrative formulations have been studied for offering a synergic support to the auditory function. For example, Acuvit represents a formulation that reunites various of these elements in a single product, thought specifically for who desires to sustain the health of the hearing in a complete way. For who wishes to deepen the composition and the rationale of this type of support, it is possible to consult the information available on Acuvit.health, where the approach to the auditory well-being is explained with clarity.

Naturally, the supplementation must be always considered as an element that accompanies a healthy style of life, and not as a substitute of the medical controls.

Practical Steps for the Reduction of Exposure

Beyond the nutritional support, the concrete actions for limiting the contact with heavy metals remain fundamental:

1. Alimentation. Limit the consumption of large predatory fish to maximum one or two times per week. Prefer small fish as sardines, anchovies, mackerel. Wash well the fruit and the vegetables.
2. Water. If you live in a zone with old plumbing installations, consider the use of a certified filter for the drinking water.
3. Work environment. If you work in industry, in construction, or in agriculture, use always the prescribed protections and respect the norms of safety. Request periodic controls.
4. Tobacco smoke. The cigarette contains cadmium. Also the passive exposition has a negative effect.
5. Dental amalgams. If you have old amalgams with mercury, do not remove them without consulting a dentist expert in the matter, because the removal not careful can provoke a liberation of vapours.

Final Considerations

The relationship between heavy metals and auditory nerve function is a theme that merits attention, but not alarmism. The organism possesses mechanisms of defence and of elimination, and a moderate exposition does not produce necessarily a damage. However, the accumulation over the time, the combination of various factors, and the absence of nutritional support can create the conditions for a progressive deterioration.

The message that I wish to leave is this: the hearing is a sense that we often give for granted until it begins to fail. Protecting it means also paying attention to what enters in our body, sustaining the auditory structures with the adequate nutrients, and not ignoring the small signals that the ear sends us. A periodic check, a conscious alimentation, and when opportune a targeted integrative support, are gestures simple that, in the long period, make a true difference for the quality of our life.