ABSTRACT
BACKGROUND/OBJECTIVES@#Asthma and allergic rhinitis (AR) are closely related and considered as allergic respiratory diseases (ARD), and their prevalence has recently increased. Data on the association of dietary antioxidant vitamin intake with asthma and AR in adults are limited. The present study aimed to investigate the associations of vitamin A and C intake with asthma, AR, and all cases of both diseases in young adults who participated in a cross-sectional national survey, with the use of high-sensitivity C-reactive protein (hs-CRP) level as an effect modifier. @*SUBJECTS/METHODS@#This study included 6,293 male and female adults aged 20–49 years from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted between 2016 and 2018. The questionnaire-based reports on asthma and AR diagnosis were used to determine outcome variables. Further, 24-h recall data on dietary vitamin A and C, carotene, and retinol intake were acquired. Logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence interval (CI). @*RESULTS@#Dietary vitamin C intake was inversely associated with asthma prevalence among participants with hs-CRP levels (≥ 1 mg/L); the OR of asthma prevalence was 0.27 (95% CI, 0.08–0.84) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Similar association analyses limiting to non-users of dietary supplements were performed to rule out the potential effects of supplement intake on the outcomes; results showed a stronger association. However, the association between vitamin C and asthma was not significant in participants with hs-CRP levels < 1 mg/L; the OR of asthma was 1.44 (95% CI, 0.66–3.16) for participants with vitamin C consumption ≥ 75 mg/day compared with those consuming < 20 mg/day. Vitamin C intake was not associated with AR.Moreover, there was no association between vitamin A intake and neither asthma nor AR. @*CONCLUSIONS@#These findings suggest that higher vitamin C intake may play a potential role in reducing asthma prevalence. Nevertheless, further studies should be conducted to evaluate whether this association is causal.
ABSTRACT
SUBJECTS/METHODS@#A factorial randomized, double-blinded, placebo-controlled crossover study included 47 adults (25 men and 22 women) who were free of chronic disease.Stratified randomized allocation considered age and gender for three interventions, group A (supplementation with γ-PGA 600 mg; n = 16), group B (supplementation with VitB6 100 mg; n = 14), and group C (dual supplementation of both γ-PGA 600 mg and VitB6 100 mg;n = 17). Participants underwent a 1-mon intervention period, followed by a 1-mon washout period, and then a second 1-mon intervention period. Differences (mean ± SD) in nighttime sleep status before and after supplementation were compared between the placebo and intervention groups using nonparametric tests. @*RESULTS@#Significant changes in sleep duration (0.27 ± 0.98 h, P < 0.05) and the Pittsburgh Sleep Quality Index global score (−0.52 ± 1.58, P < 0.05) indicating improved sleep status were observed in the intervention compared with the placebo of group C while no significant changes were observed in groups A and B. No statistical significance was detected between the intervention and the placebo; however, there was a greater increase in the group C intervention (4.59 ± 38.5 ng/mL) in serum serotonin concentrations than the groups A and B interventions. No side effects were observed. @*CONCLUSIONS@#On the basis of these findings, the dual supplementation of γ-PGA and VitB6 may be effective as functional food components to improve nighttime sleep status.Trial Registration: Clinical Research Information Service Identifier: KCT0005083
ABSTRACT
SUBJECTS/METHODS@#A factorial randomized, double-blinded, placebo-controlled crossover study included 47 adults (25 men and 22 women) who were free of chronic disease.Stratified randomized allocation considered age and gender for three interventions, group A (supplementation with γ-PGA 600 mg; n = 16), group B (supplementation with VitB6 100 mg; n = 14), and group C (dual supplementation of both γ-PGA 600 mg and VitB6 100 mg;n = 17). Participants underwent a 1-mon intervention period, followed by a 1-mon washout period, and then a second 1-mon intervention period. Differences (mean ± SD) in nighttime sleep status before and after supplementation were compared between the placebo and intervention groups using nonparametric tests. @*RESULTS@#Significant changes in sleep duration (0.27 ± 0.98 h, P < 0.05) and the Pittsburgh Sleep Quality Index global score (−0.52 ± 1.58, P < 0.05) indicating improved sleep status were observed in the intervention compared with the placebo of group C while no significant changes were observed in groups A and B. No statistical significance was detected between the intervention and the placebo; however, there was a greater increase in the group C intervention (4.59 ± 38.5 ng/mL) in serum serotonin concentrations than the groups A and B interventions. No side effects were observed. @*CONCLUSIONS@#On the basis of these findings, the dual supplementation of γ-PGA and VitB6 may be effective as functional food components to improve nighttime sleep status.Trial Registration: Clinical Research Information Service Identifier: KCT0005083