photo of a hand behind an ear
A precursor of the vitamin B3 (niacin) can help protect the ears from nerve damage that can cause hearing loss

Vitamin B3 compound could help prevent hearing loss

2 December, 2014

Natural Health News — Researchers have found a way to prevent noise-induced hearing loss using a simple chemical compound that is a precursor to vitamin B3 (niacin).

This discovery by scientists at from Weill Cornell Medical College and the Gladstone Institutes has important implications for preventing hearing loss.

In a study published in the journal Cell Metabolism, the researchers used the chemical nicotinamide riboside (NR) to protect the nerves in the cochlea. The cochlea, or inner ear, transmits sound information through these nerves along a pathway to the brain. Exposure to loud noises can damage the synapses connecting the nerves and the hair cells in the cochlea, resulting in noise-induced hearing loss.

The researchers involving laboratory animals set out to prevent this nerve damage by giving mice NR before or after exposing them to loud noises. NR was successful at preventing damage to the synaptic connections, avoiding both short-term and long-term hearing loss. What’s more, NR was equally effective regardless of whether it was given before or after the noise exposure.

“One of the major limitations in managing disorders of the inner ear, including hearing loss, is there are a very limited number of treatments options. This discovery identifies a unique pathway and a potential drug therapy to treat noise-induced hearing loss,” says Kevin Brown, MD, PhD, an associate professor of otolaryngology-head and neck surgery at the University of North Carolina School of Medicine and one of the authors of the paper.

The researchers chose NR because it is a precursor to the chemical compound nicotinamide adenine dinucleotide (NAD+), which had previously been shown to protect cochlea nerve cells from injury.

Beyond just preventing hearing loss, the researchers think the results may have broader applications because of the underlying way NR protects nerve cells. The scientists showed that NR and NAD+ prevent hearing loss by increasing the activity of the protein sirtuin 3 (SIRT3), which is critically involved in the function of mitochondria, the powerhouses of the cell.

SIRT3 decreases naturally as we age, which could partially explain aging-related hearing loss. Additionally, some individuals carry different variations of the SIRT3 genes that result in reduced enzyme activity, which may make them more susceptible to noise-induced hearing loss.