Latest Hearing News
WebMD Health News
Reviewed By Louise Chang, MD
So say scientists including Colleen Le Prell, PhD, of the University of Michigan's Kresge Hearing Research Institute.
So far, Le Prell's team has only tested the nutrient mixture against noise-induced hearing loss in guinea pigs.
But the results of those guinea pig tests provide a "compelling rationale for human trials," the researchers write.
Their report appears in Free Radical Biology & Medicine.
The researchers studied four groups of male guinea pigs. Each group got one of the following treatments once daily for six days:
- Magnesium and vitamins A, C, and E
- Vitamins A, C, and E without magnesium
- Magnesium only
- Salt water (placebo)
One hour after the first treatment, the guinea pigs were exposed to 120 decibels of noise for five consecutive hours.
To put that in perspective, 120 decibels is as loud as an ambulance siren, according to the National Institute on Deafness and Other Communication Disorders (NIDCD).
Prolonged exposure to any noise above 85 decibels can cause gradual hearing loss, notes the NIDCD. Wearing earplugs or other special ear muffs may help protect hearing in noisy settings.
The guinea pigs were only exposed to the noise once. They got daily doses of their assigned treatment for the five days following noise exposure.
Five days after noise exposure, the guinea pigs took hearing tests and had their ears examined.
The guinea pigs that got the combination treatment of magnesium and vitamins A, C, and E had the least amount of noise-induced hearing loss and ear damage.
The guinea pigs in the three other groups had no hearing benefits. Magnesium and vitamins A, C, and E may work best together to prevent noise-induced hearing loss, the researchers write.
The study doesn't show whether the treatment given before noise exposure was more important than the treatments given after noise exposure.
The researchers speculate that the nutrient combination might reduce hearing loss even when it's only given after exposure to noise, but this study didn't test that theory.
The University of Michigan has applied for patents for the nutrient combination's use in preventing noise-induced hearing loss.
One of the researchers -- Josef Miller, PhD of the University of Michigan and the Center for hearing and Communication at Sweden's Karolinska Institute -- is the founder and chairman of a company called OtoMedicine, Inc., which is developing the vitamin and magnesium treatment.
SOURCES: Le Prell, C. Free Radical Biology & Medicine, online edition; Feb. 20, 2007. National Institute on Deafness and Other Communication Disorders: "How Loud Is Too Loud? Bookmark." National Institute on Deafness and Other Communication Disorders: "Noise-Induced Hearing Loss." News release, University of Michigan.
© 2007 WebMD Inc. All rights reserved.