Researchers at the University of Michigan Kresge Hearing Research Institute are hopeful that a specific combination of nutrients could help protect the ear against hearing loss induced by loud noises. While the condition is of major concern among military personnel, preventing the return to duty of a large number of troops deployed in Afghanistan and Iraq, it has also been identified as a potential threat to iPod users and others who listen to music through headphones at high volume.
It had been believed until recently that noise causes hearing loss by mechanical vibrations which destroyed inner ear structures. The discovery that intense noise generates free radicals that damage the inner ear cells has led researchers to develop a protective formula that can be ingested prior to exposure to noisy environments. University of Michigan Healthy System assistant professor of otolaryngology Glenn E. Green, MD, and colleagues formulated the combination of vitamins A, C and E, and magnesium as a nutritional supplement. Pre-treatment with these nutrients reduces free radicals that form during and after noise exposure, and may also reduce damage to auditory neurons that can occur due to overstimulation. The supplement is being tested in military trials conducted in Sweden and Spain, a Spanish industrial trial, and a National Institute of Health-funded trial of University of Florida student iPod users. Laboratory studies have demonstrated a reduction in hearing impairment subsequent to noise exposure of approximately 80 percent in animals that received the nutrients.
"The prevention of noise induced hearing loss is key," noted Dr Green, who is the director of the University of Michigan Children's Hearing Laboratory. "When we can't prevent noise-induced hearing loss through screening programs and use of hearing protection, then we really need to come up with some way of protecting people who are still going to have noise exposure. My hope is that this medication will give people a richer, fuller life."
"If we can even see 50 percent of the effectiveness in humans that we saw in our animal trials, we will have an effective treatment that will very significantly reduce noise-induced hearing impairment in humans," added co-lead researcher says co-lead researcher Josef M. Miller, PhD, who is the director of the Center for Hearing Disorders at the Kresge Hearing Research Institute. "That would be a remarkable dream."
Related Health Concern: Tinnitus
Tinnitus is a subjective disorder characterized as chronic ringing, roaring, buzzing, humming, chirping, or hissing in the ears in the absence of environmental noise (ATA 2002). Symptoms of tinnitus are frequently found in elderly persons and are often associated with hearing loss related to the aging process (presbycusis). Although the cause is usually unknown, tinnitus can be a symptom of almost any ear disorder, including infection (otitis media), a blocked ear canal (ear wax) or eustachian tube, otosclerosis (overgrowth of bone in the middle ear), labyrinthitis, and Meniere's disease. Even blast injury from explosions has been known to cause symptoms of tinnitus. Additionally, adverse side effects from some drugs (e.g., aspirin and antibiotics) cause tinnitus symptoms.
If tinnitus is caused by age-related hearing loss or damage to your ears from exposure to excessive noise, there is no treatment to reduce the noise (MFMER 2001; NIH 2001). Instead, treatment consists largely of managing the condition. Not every suggested treatment works for everyone, so you may need to try several to find one that will help. It is important to avoid anything that could make your tinnitus worsen, including smoking, alcohol, and loud noises. If you are a construction worker, an airport worker, a hunter, or are often exposed to loud noise at home or at work, you should wear ear plugs or special ear protection (muffs) to protect your hearing (NIH 2001).
People in large cities are exposed to potentially damaging loud noises on a daily basis. Studies have shown that noise exposure causes magnesium to be excreted from the body (Mocci et al. 2001). It is possible that supplementing with magnesium could reduce noise-induced ear damage and thus reduce the likelihood of new-onset tinnitus. Few studies document that magnesium relieves tinnitus symptoms, but many patients have experienced relief by using magnesium (Attias et al. 1994).