Antioxidant micronutrient impact on hearing disorders: concept, rationale, and evidence☆☆☆
Received 22 June 2009 published online 09 November 2009. Corrected Proof
Abstract
Purpose
Although auditory disorders are complex conditions, device-related modalities dominate current treatment. However, dysfunction from the central cortex to the inner ear apparatus is increasingly thought to be related to biochemical pathway abnormalities and to free radical–induced oxidative damage and chronic inflammation. Therefore, considering appropriate biologic therapy as an adjunct to standard care against these damaging factors may provide rational expansion of treatment options for otolaryngologists and audiologists.
Methods
This review outlines the biologic concepts related to some auditory and vestibular conditions and details the current rationale for utilizing antioxidants for a spectrum of hearing disorders. The strategy is based on the authors' collective experience in antioxidant science and supported with published research, pilot animal data and preliminary clinical observations.
Results
A comprehensive micronutrient approach was developed to exploit these pathways, and demonstrated safety and efficacy against oxidative damage and inflammation and clinically relevant neuroprotection. Cooperative research with Department of Defense institutions used prospective, randomized designs to show (1) reduction in oxidative damage measured in plasma and urine over six months, (2) protection against oxidative damage during 12 weeks of intense military training, (3) protection against inflammation after total body blast exposure (rodents), (4) strong neuroprotection against chemically-induced Parkinson's disease (rodents), (5) nerve VIII function improvement after concussive head injury in military personnel, and (6) tinnitus improvement in majority of patients after 90-day evaluation.
Conclusion
This systematic review of biologic strategies against hearing disorders combined with new animal and human observations may provide a rational basis for expanding current practice paradigms.
aUniversity of Colorado, School of Medicine, Premier Micronutrient Corporation, Clinical Programs Center, Denver, Colorado, USA
bPremier Micronutrient Corporation, Antioxidant Research Institute, Novato, California, USA
cAudiology & Hearing Health, PC., Nashville, Tennessee, USA
Corresponding author. 5655 South Grape Court, Greenwood Village, CO 80121, USA. Tel.: +1 720 201 5057; fax: +1 303 770 2790.
☆ This paper was presented, in part, at the Annual Meeting of the Academy of Doctors of Audiology meeting, November, 2008, Las Vegas, NV.
☆☆ The pilot studies detailed in the last section of the manuscript were partially supported by Department of Defense appropriations through Navy RDT&E:
Line 24, PE 0603729N, Warfighter Protection Advanced Technology
Line 183, PE 0603635M, Marine Corps Ground Combat/Supporting Arms Systems
Line 130, PE 0604771N, Medical Development
1 The first three authors are shareholders in Premier Micronutrient Corporation.
ABSTRACT