Dietary antioxidant intake is associated with the prevalence but not incidence of age-related hearing loss
Objectives: Diet is one of the few modifiable risk factors for age-related hearing loss. We aimed toexamine the link between dietary and supplement intakes of antioxidants, and both the prevalence and 5-yearincidence of measured hearing loss. Design: Cross-sectional and 5-year longitudinal analyses. Setting: BlueMountains, Sydney, Australia. Participants: 2,956 Blue Mountains Hearing Study participants aged 50+ atbaseline, examined during 1997-9 to 2002-4. Measurements: Age-related hearing loss was measured and definedas the pure-tone average of frequencies 0.5, 1.0, 2.0 and 4.0 kHz >25 dB HL. Dietary data were collected in asemi-quantitative food frequency questionnaire, and intakes of -carotene; -carotene; -cryptoxanthin; lutein andzeaxanthin; lycopene; vitamins A, C and E; iron and zinc were calculated. Results: After adjusting for age, sex,smoking, education, occupational noise exposure, family history of hearing loss, history of diagnosed diabetesand stroke, each standard deviation (SD) increase in dietary vitamin E intake was associated with a 14% reducedlikelihood of prevalent hearing loss, odds ratio, OR, 0.86 (95% confidence interval, CI, 0.78-0.98). Those in thehighest quintile of dietary vitamin A intake had a 47% reduced risk of having moderate or greater hearing loss(>40 dB HL) compared to those in the lowest quintile of intake, multivariable-adjusted OR 0.53 (CI 0.30-0.92), Pfor trend = 0.04. However, dietary antioxidant intake was not associated with the 5-year incidence of hearingloss. Conclusions: Dietary vitamin A and vitamin E intake were significantly associated with the prevalence ofhearing loss. However, dietary antioxidant intake did not increase the risk of incident hearing loss. Further large,prospective studies are warranted to assess these relationships in older adults.