Serum levels of retinol and other antioxidants for hearing impairment among Japanese older adults.

BACKGROUND: The objective of this study was to assess the relation between serum levels of retinol and other antioxidants and hearing impairment in Japanese older adults. METHODS: This is a community-based cross-sectional study comprising 762 residents aged 65 years or older in Kurabuchi, Gumma, Japan. We measured serum retinol and other antioxidants (alpha- and gamma-tocopherols, and carotenoids including beta-cryptoxanthin, alpha- and beta-carotenes, lycopene, and lutein plus zeaxanthin) by high-performance liquid chromatography and divided each measurement into quartiles. Hearing impairment was defined as a failure to hear a 30-dB hearing level (HL) signal at 1 kHz and a 40-dB HL signal at 4 kHz in the better ear in pure-tone audiometric tests. The odds ratios (OR) for hearing impairment were calculated for each of the upper three quartiles of retinol and other antioxidant levels relative to the lowest quartile. RESULTS: Crude analysis showed that serum levels of retinol and provitamin A carotenoids (beta-cryptoxanthin, and alpha- and beta-carotenes) were inversely related to the prevalence of hearing impairment. The multiadjusted ORs (95% confidence intervals) for the highest quartile of retinol and the provitamin A family (combinations of provitamin A carotenoids) compared with the lowest were 0.51 (0.26-1.00) and 0.53 (0.27-1.02), respectively. A dose-response relationship was observed for retinol (p = .03) and provitamin A (p = .09). CONCLUSION: Increased serum levels of retinol and provitamin A carotenoids were clearly associated with a decreased prevalence of hearing impairment

Serum antioxidants and age-related macular degeneration among older Japanese.

From the perspective of human nutrition, the prevention of age-related macular degeneration (AMD) through diet control is feasible and desirable. We investigated the relationship between serum antioxidants and AMD in the community-dwelling older Japanese eating a typical Japanese diet. In this study, 722 subjects aged 65 years or older (297 males and 425 females) who had gradable fundus photographs were included. The subjects were divided into three groups of early or late AMD or non-maculopathy. Serum antioxidants (alpha-, gamma-tocopherols, retinol, beta-cryptoxanthin, alpha-, beta-carotenes, lycopene, and lutein and zeaxanthin) were measured with high-performance liquid chromatography. To clarify the combined effect as the group of the antioxidants, we defined the carotene family (alpha-, beta-carotenes and lycopene) and carotenoid family (beta-cryptoxanthin, alpha-, beta-carotenes, lycopene, lutein and zeaxanthin). Tertiles of each serum antioxidant were obtained and the prevalence of early or late AMD was compared with univariate or multivariate analysis. The overall prevalence of early AMD was 4.4% (95% confidence interval: 3.1-6.2) and late AMD was 1.1% (0.5-2.2). Only alpha-tocopherol and beta-cryptoxanthin were related to late AMD as single antioxidants. On the other hand, the carotene and carotenoid families as a combination of antioxidants were protectively associated with late AMD. No relationship was found between serum antioxidants and early AMD. Our findings support the hypothesis that a combination of serum antioxidants obtained from the traditional Japanese diet is protective for late AMD, but not for early AMD