Cross-Sectional Study on the Association between Dietary Non-Enzymatic Antioxidant Capacity and Serum Liver Enzymes: The Furukawa Nutrition and Health Study

Dietary antioxidants and liver enzymes in Rafsanjan, a Region in Southeast Iran

Oxidative stress has been considered the main contributor to liver injury. Dietary antioxidants would be expected to improve liver function. The hepatoprotective effects of antioxidants are controversial. In the present study, the associations of some dietary antioxidants and the levels of serum liver enzymes were examined. This cross-sectional study was conducted using the Rafsanjan Cohort Study (RCS) data as a population-based prospective cohort which is a part of the Prospective Epidemiological Research Studies in IrAN (PERSIAN). A total of 9942 participants aged 35-70 years old were included in this study. Among this population, 4631 (46.59%) were male, and 5311 (53.42%) were female. Dietary intakes were collected by a validated food frequency questionnaire (FFQ) with 128 items. Aspartate transaminase (AST), Alanine transaminase (ALT), γ-glutamyl transferase (GGT), and Alkaline phosphatase (ALP) were measured by a biotecnica analyzer. Dichotomous logistics regression models were used to investigate the association between the elevated liver enzymes and intake of dietary antioxidants using crude and adjusted models. In the adjusted model, in subjects with higher consumption of Se, Vit A, Vit E, β-carotene, α-carotene, and β-cryptoxanthin, the odds ratios of elevated ALP were decreased compared to the reference group (ORs 0.79 (0.64-0.96), 0.80 (0.66-0.98), 0.73 (0.60-0.89), 0.79 (0.64-0.96), 0.78 (0.64-0.95), 0.80 (0.66-0.98), and 0.79 (0.64-0.98), respectively). Subjects with higher consumption of Se, Vit A, Vit E, and provitamin A carotenoids (β-carotene, α-carotene, β-cryptoxanthin) showed decreased odds of elevated ALP. These findings support the hypothesis that Se, Vit A, Vit E, and provitamin A carotenoids may be associated with improvements in ALP and act as suppressors against the development of liver injury.

The Association between Habitual Green Tea Consumption and Comprehensive Frailty as Assessed by Kihon Checklist Indexes among an Older Japanese Population

Background: It is unclear whether habitual green tea consumption is related to comprehensive frailty. Objectives: We conducted this study to investigate this relationship among an elderly Japanese population. Methods: This was a cross-sectional study of baseline data from 2012. The study included 5668 Japanese participants (2766 men and 2902 women aged 65 years or older). The subjects completed a validated self-administered food frequency questionnaire that included questions on their green tea consumption. We evaluated comprehensive frailty using a 25-item Kihon Checklist (KCL), which comprised seven domains (instrumental activities of daily living (IADL), physical function, malnutrition, oral or eating function, socialization and housebound, cognitive function, and depression). Frailty was defined as a KCL score greater than or equal to seven. Results: We found that a higher consumption of green tea was associated with a lower prevalence of comprehensive frailty in both sexes. Further age-stratified analysis showed that a higher consumption of green tea among women was associated with a lower prevalence of comprehensive frailty, regardless of age. In men, however, this association was found only in the older age groups. An analysis of the association between green tea consumption and the frailty subdomains showed that green tea consumption was associated with a lower prevalence of oral dysfunction and cognitive problems in both sexes. In addition, only in women was higher green tea consumption found to be associated with a lower prevalence of IADL and mobility-related disability problems. Conclusions: Green tea consumption is inversely associated with the prevalence of comprehensive frailty in Japanese men and women. Longitudinal studies are required to confirm this association.