Colleen Le Prell, Ph.D., of the University of Michigan’s Kresge Hearing Research Institute, has found that high doses of certain antioxidants reduces noise-induced hearing loss in animals when taken both before and after loud noise.
Dr. Le Prell’s new research, conducted in collaboration with Joseph Miller, Ph.D., revealed that a combination of high doses of vitamins A, C, and E and magnesium, taken one hour before noise exposure and continued as a once-daily treatment for five days, was very effective at preventing permanent noise-induced hearing loss in guinea pigs. The animals had prolonged exposure to sounds as loud as a jet engine at take-off at close range. Her study was recently published online in the journal Free Radical Biology and Medicine.
Recent studies indicate that noise exposure damages sensory cells through the formation of free radicals, damaging molecules known to cause cell death. Le Prell’s research shows that damage to the sensory cells can be prevented by antioxidants that prevent free radical damage by binding to free radical molecules and rendering them harmless.
“Vitamins A, C and E and magnesium worked in synergy to prevent cell damage,” explains Dr. Le Prell.
According to the researchers, pre-treatment presumably reduced free radicals that form during and after noise exposure and also reduced noise-induced constriction of blood flow to the inner ear; and also reduced damage to auditory neurons that can occur due to over-stimulation. The post-noise nutrient doses apparently “scavenged” free radicals that continue to form long-after after this noise exposure ends.
Human trials are expected to begin within two to three months with soldiers in urban combat training exercises, and doses of the micronutrients will be within the ranges considered safe according to the Institute of Medicine and federal nutrition guidelines.