After the combination of nutrients, called AuraQuell, was found to be successful in laboratory tests, researchers at the University of Michigan Kresge Hearing Research Institute are now testing if it would benefit humans as well.
"The prevention of noise induced hearing loss is key," said Glenn E. Green, M.D., assistant professor of otolaryngology at the U-M Health System and director of the U-M Children's Hearing Laboratory.
He added: "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."
Developed at the U-M Kresge Hearing Research Institute, AuraQuell is the combination of vitamins A, C and E, plus magnesium, and is given in pill form to patients who are participating in the research.
AuraQuell has been designed so that it could be taken before a person is exposed to loud noises.
In their research on guinea pigs, the scientists reported that the combination of the four micronutrients blocked about 80 percent of the noise-induced hearing impairment.
Now, AuraQuell is being tested in a set of fourmultinational human clinical trials: military trials in Sweden and Spain, an industrial trial in Spain, and a trial involving students at the University of Florida who listen to music at high volumes on their iPods and other PDAs.
"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. That would be a remarkable dream," said co-lead researcher Josef M. Miller, Ph.D.
In his opinion, the military tests in the new study may hold special importance because of the high number of soldiers who develop hearing loss in the line of duty, due to improvised explosive devices (IEDs) and other noises.
Green said that hearing loss commonly occurs, when loud noises trigger the formation of molecules inside the ear and these molecules cause damage to the hair cells of the inner ear. The cells then shut down and scar, and they cannot grow back.
It was found in the study that the new combination of vitamins, when mixed with magnesium, can prevent noise-induced damage to the ears by blocking some of these complex cellular reactions.