Tinnitus is the perception of sound in the absence of an external stimuli. This condition affects approximately 10% to 15% of the population; its cause is unknown and the underlying mechanisms are not understood. Oxidative stress is thought to possibly be involved in tinnitus, and some antioxidants have been studied as potential supportive options, as there are currently no effective medications.
According to a new study published last week in Nutrients, researchers investigated the effects of antioxidant supplementation in patients with tinnitus. Oxidative stress can lead to cellular changes in hair cells, apoptosis, cochlear degeneration, and changes in supporting auditory and neurological structures. Previous research has shown that higher plasma levels of oxidative stress markers and lower antioxidant activity have been documented in tinnitus patients compared with healthy individuals.
This was a randomized, double-blind, placebo-controlled clinical trial including seventy patients ranging from 25 to 75 years of age over a 12-week period. The patients were randomly divided into two groups, an antioxidant supplementation group or placebo. The antioxidant group consumed one multivitamin and mineral complex along with alpha-lipoic acid (300 mg twice daily on an empty stomach). Clinical and laboratory assessment included serum total antioxidant capacity (TAC), oxidized LDL, superoxide dismutase (SOD), tinnitus loudness and frequency, and minimum masking level (MML). In addition, scores in Tinnitus Handicap Inventory questionnaire (THI), Tinnitus Functional Index (TFI), and Visual Analogue Scale (VAS) were completed at baseline and at the end of the study.
As a result, tinnitus loudness, MML, THI, and VAS significantly decreased from baseline only in the antioxidant supplementation group. There were significant improvements in hearing thresholds across all frequencies, with the overall changes being significantly different at the frequencies of 250 Hz, 2000 Hz, 4000 Hz, 10,000 Hz, and 12,000 Hz. Improvements in frequencies between 250 Hz and 8000 Hz are clinically significant, as these are the frequencies used for speech recognition and in which tinnitus patients could benefit for better understanding speech and language.
There were also insignificant changes in serum TAC, SOD, and oxLDL levels. This study demonstrates that supplementation with a multivitamin and antioxidants may help reduce the discomfort and intensity of tinnitus. Lipoic acid has been well researched to show neuroprotective properties and B vitamins play an essential role in cell metabolism as well as healthy nerve function.
By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS
Source: Petridou A, Zagora E, et al. The Effect of Antioxidant Supplementation in Patients with Tinnitus and Normal Hearing or Hearing Loss: A Randomized, Double-Blind, Placebo Controlled Trial. 12 December 2019. Nutrients, 11(12), 3007.