Dietary supplement use in elementary school children: a Japanese web-based survey.

BACKGROUND: A variety of dietary supplements are commercially available. However, the efficacy and safety of dietary supplement use in children are not well established. Understanding dietary supplement use is important for developing public health policy regarding dietary supplements. This study aimed to investigate the types of dietary supplements used and characteristics of dietary supplement users among Japanese elementary school children. METHOD: We conducted a cross-sectional web-based questionnaire study. Dietary supplement use, socio-demographics, and health-related behaviors were assessed through mother-reported questionnaire. Types of dietary supplements were identified based on ingredient using product barcodes and brand names. Multivariate logistic regression analysis was conducted to investigate the socio-demographics and health-related behaviors associated with supplement use. RESULTS: Among 4933 children, 333 (6.8%) were identified as dietary supplement users. The most common supplement was amino acids or protein (1.4%), followed by n-3 fatty acids or fish oil (1.0%), probiotics (1.0%), multivitamins (0.9%), multivitamin-minerals (0.8%), and botanicals (0.8%). Overall, any dietary supplement use was significantly associated with the highest frequency of sports participation (odds ratio [OR], 2.58; 95% confidence interval [CI], 1.65-4.02), highest household income (OR, 1.87; 95% CI, 1.13-3.10), highest maternal educational level (OR, 1.82; 95% CI, 1.31-2.52), and male sex (OR, 1.38; 95% CI, 1.09-1.75). The highest frequency of sports participation was significantly associated with higher odds of use of amino acids or protein (OR, 6.06; 95% CI, 1.78-20.6) and multivitamins (OR, 3.56; 95% CI, 1.11-11.5), compared to the lowest frequency of sports participation. CONCLUSION: This study showed that Japanese children primarily use non-vitamin, non-mineral supplements. Non-vitamin, non-mineral supplements should thus be included in future studies aimed at monitoring dietary supplement use. We also found that dietary supplement use in children was associated with sports participation. Guidelines for dietary supplement use for children, in particular sport participants, are needed.

A Genome-Wide Association Study Identifies the Association between the 12q24 Locus and Black Tea Consumption in Japanese Populations.

Several genome-wide association studies (GWASs) have reported the association between genetic variants and the habitual consumption of foods and drinks; however, no association data are available regarding the consumption of black tea. The present study aimed to identify genetic variants associated with black tea consumption in 12,258 Japanese participants. Data on black tea consumption were collected by a self-administered questionnaire, and genotype data were obtained from a single nucleotide polymorphism array. In the discovery GWAS, two loci met suggestive significance (p < 1.0 × 10-6). Three genetic variants (rs2074356, rs144504271, and rs12231737) at 12q24 locus were also significantly associated with black tea consumption in the replication stage (p < 0.05) and during the meta-analysis (p < 5.0 × 10-8). The association of rs2074356 with black tea consumption was slightly attenuated by the additional adjustment for alcohol drinking frequency. In conclusion, genetic variants at the 12q24 locus were associated with black tea consumption in Japanese populations, and the association is at least partly mediated by alcohol drinking frequency.

GWAS of habitual coffee consumption reveals a sex difference in the genetic effect of the 12q24 locus in the Japanese population.

BACKGROUND: Studies on genetic effects of coffee consumption are scarce for Asian populations. We conducted a genome-wide association study (GWAS) of habitual coffee consumption in Japan using a self-reporting online survey. RESULTS: Candidate genetic loci associated with habitual coffee consumption were searched within a discovery cohort (N = 6,264) and confirmed in a replication cohort (N = 5,975). Two loci achieved genome-wide significance (P < 5 × 10- 8) in a meta-analysis of the discovery and replication cohorts: an Asian population-specific 12q24 (rs79105258; P = 9.5 × 10- 15), which harbors CUX2, and 7p21 (rs10252701; P = 1.0 × 10- 14), in the upstream region of the aryl hydrocarbon receptor (AHR) gene, involved in caffeine metabolism. Subgroup analysis revealed a stronger genetic effect of the 12q24 locus in males (P for interaction = 8.2 × 10- 5). Further, rs79105258 at the 12q24 locus exerted pleiotropic effects on body mass index (P = 3.5 × 10- 4) and serum triglyceride levels (P = 8.7 × 10- 3). CONCLUSIONS: Our results consolidate the association of habitual coffee consumption with the 12q24 and 7p21 loci. The different effects of the 12q24 locus between males and females are a novel finding that improves our understanding of genetic influences on habitual coffee consumption.

Carcinogenic risk of copper gluconate evaluated by a rat medium-term liver carcinogenicity bioassay protocol.

Carcinogenic risk and molecular mechanisms underlying the liver tumor-promoting activity of copper gluconate, an additive of functional foods, were investigated using a rat medium-term liver carcinogenicity bioassay protocol (Ito test) and a 2-week short-term administration experiment. In the medium-term liver bioassay, Fischer 344 male rats were given a single i.p. injection of N-nitrosodiethylamine at a dose of 200 mg/kg b.w. as a carcinogenic initiator. Starting 2 weeks thereafter, rats received 0, 10, 300 or 6,000 ppm of copper gluconate in diet for 6 weeks. All rats underwent 2/3 partial hepatectomy at the end of week 3, and all surviving rats were killed at the end of week 8. In the short-term experiment, rats were given 0, 10, 300 or 6,000 ppm of copper gluconate for 2 weeks. Numbers of glutathione S-transferase placental form (GST-P) positive lesions, single GST-P-positive hepatocytes and 8-oxoguanine-positive hepatocytes, and levels of cell proliferation and apoptosis in the liver were significantly increased by 6,000 ppm of copper gluconate in the medium-term liver bioassay. Furthermore, hepatic mRNA expression of genes relating to the metal metabolism, inflammation and apoptosis were elevated by 6,000 ppm of copper gluconate both in the medium-term liver bioassay and the short-term experiments. These results indicate that copper gluconate possesses carcinogenic risk toward the liver at the high dose level, and that oxidative stress and inflammatory and pro-apoptotic signaling statuses may participate in its underlying mechanisms.