Association between a dietary-based micronutrient adequacy index and hearing loss in community-dwelling older adults

Abstract Background The effect of dietary micronutrient adequacy on hearing loss is unknown. The aim of this study was to examine the cross-sectional association between dietary micronutrient adequacy and hearing loss among community-dwelling older adults. Methods This study included 1608 adults aged 65 y from the Seniors-ENRICA-2 cohort. Habitual diet was assessed with a validated computerized diet history. The intakes of 10 micronutrients (calcium, magnesium, potassium, zinc, iodine, vitamins A, C, D, E, and folate) were expressed as percentages relative to dietary reference intakes, with higher scores indicating greater adequacy. Dietary micronutrient adequacy was computed as the average of all nutrient scores. Hearing loss was defined as pure-tone average >40 dB-aHL in the better ear for standard frequency (0.5, 1, and 2 kHz), speech frequency (0.5, 1, 2, and 4 kHz), and high frequency pure tone average (PTA) (3, 4, and 8 kHz). Logistic regression models were conducted, after adjusting for sociodemographic factors, lifestyle, comorbidities, cognitive impairment and hearing-related variables. Results Of the 1608 participants, 813 were men (50.6%); mean (SD) age was 73.8 (4.3) years. The prevalence of hearing loss was 13.3% at speech frequency. A high dietary micronutrient adequacy index was associated with hearing loss: OR (95% CI) for tertile 3 vs. 1 was 0.57 (0.35-0.94) for standard frequency, 0.58 (0.38-0.89) for speech frequency, and 0.69 (0.51-0.93) for high frequency PTA. No differences were observed for the association among the subgroups of participants defined by sex, body mass index, physical activity and chronic diseases. Conclusion Higher dietary-based micronutrient adequacy was associated with lower prevalence of hearing loss across all frequency ranges.