Effectiveness in Preventing Hearing Loss: Meta-Analysis of Dietary Consumption Studies

Abstract

Objective: The systematic review with meta-analysis aimed to verify the occurrence of a protective effect on hearing loss due to a higher intake of carotenoids, vitamins A, C, E, and folate present in diets. Methods: The search for scientific articles was carried out by 2 independent researchers in electronic databases. Meta-analysis was performed by constructing summary risk measures for each vitamin or antioxidant, combining the risk ratios or adjusted odds ratios (OR) for the various variables observed in the highest categories of vitamin or antioxidant consumption. Results: Five studies involving an estimated 100 549 participants were included in the quantitative synthesis. The summary measures calculated for the highest quartiles/quintiles of the studies were Hazard ratios (HR) .990 for vitamin C; HR 1.07 and OR .925 for vitamin E; HR .921 for folate and OR .906 for vitamin A. Conclusion: Dietary intake of vitamins and antioxidants was inversely associated with the risk of developing hearing loss. Individuals with a higher intake of antioxidants may have better hearing thresholds, especially with the intake of β-carotene.