Association of Vegetable and Fruit Consumption with Urinary Oxidative Biomarkers in Teenaged Girls: A School-Based Pilot Study in Japan

Hexanoyl-lysine (HEL), 8-hydroxy-2'deoxyguanosine (8-OHdG), and dityrosine (DT) have served as potential biomarkers for detecting oxidative modified lipids, DNA, and proteins in biological samples, respectively. Whether regular higher levels of consumption of vegetables/fruit (V/F) would decrease oxidative modification of these biomolecules in the body remain unelucidated. To examine the association of regular V/F consumption with the generation of these reactive oxygen species-induced biomarkers, this study evaluated V/F consumption in a school-based sample of teenaged girls (mean age 15.6 ± 1.7 years, n = 103), and quantified the formation of oxidative stress biomarkers in their urine. Only 19.4% and 23.3% of participants reported that they consumed the recommended daily amount of vegetables and fruits, respectively. Individuals who consumed lower levels of fruit (<100g/day) or vegetables (<250g/day) had significantly higher HEL excretion in their urine than those who consumed higher levels of fruit (≥100g/day) (p < 0.05) or vegetables (≥250g/day) (p = 0.057). The results of a multiple regression analysis showed that vegetable consumption was an important inhibiting factor of early lipid peroxidation measured as HEL in urine, independent of various confounders (β = - 0.332, p < 0.05). The findings suggest that relatively higher consumption of vegetables would help in the prevention of early lipid peroxidation in adolescents.

A Dietary Intervention High in Green Leafy Vegetables Reduces Oxidative DNA Damage in Adults at Increased Risk of Colorectal Cancer: Biological Outcomes of the Randomized Controlled Meat and Three Greens (M3G) Feasibility Trial

Green leafy vegetables (GLV) may reduce the risk of red meat (RM)-induced colonic DNA damage and colorectal cancer (CRC). We previously reported the primary outcomes (feasibility) of a 12-week randomized controlled crossover trial in adults with habitual high RM and low GLV intake with body mass index (BMI) > 30 kg/m² (NCT03582306). Herein, our objective was to report a priori secondary outcomes. Participants were recruited and enrolled in 2018, stratified by gender, and randomized to two arms: immediate intervention group (IG, n = 26) or delayed intervention group (DG, n = 24). During the 4 week intervention period, participants were provided with frozen GLV and counseled to consume 1 cooked cup equivalent daily. Participants consumed their normal diet for the remaining 8 weeks. At each of four study visits, anthropometrics, stool, and blood were taken. Overall, plasma Vitamin K1 (0.50 ± 1.18 ng/mL, p < 0.001) increased, while circulating 8OHdG (−8.52 ± 19.05 ng/mL, p < 0.001), fecal 8OHdG (−6.78 ± 34.86 ng/mL, p < 0.001), and TNFα (−16.95 ± 60.82 pg/mL, p < 0.001) decreased during the GLV intervention compared to control periods. Alpha diversity of fecal microbiota and relative abundance of major taxa did not differ systematically across study periods. Further investigation of the effects of increased GLV intake on CRC risk is warranted.

Protective Effect of Turmeric against Bisphenol-A Induced Genotoxicity in Rats

In this study, the protective role of turmeric on genotoxic effects of Bisphenol-A exposure in Wistar rats by in vivo experiment were investigated. Bisphenol-A is a known endocrine disruptor and suspected carcinogen, that comes diet through plastics for food packaging and food processing. In this study, rats were divided into three groups of twelve animals each and were administered with Bisphenol-A by oral gavage with levels of 0, 50 and, 100 μg. Half of the animals in each group were fed with feed which contained 3% turmeric (wt/wt), for a period of 4 wk, while the rest of the rats received the same diet treatment without the addition of turmeric. At the end of the experiment, all rats were terminated and the internal organs such as liver, kidney, femurs were collected and analyzed. Mean and SD values were compared by one-way ANOVA and Kruskal-Wallis-Wilcoxon test, the formation of micronuclei was compared using Mann-Whitney U-test. Significant decrease in serum malondialdehyde and urinary 8-hydroxy-2'-deoxyguanosine levels were observed in Bisphenol-A+turmeric groups as compared to Bisphenol-A groups. Bisphenol-A groups exhibited significantly higher mean levels of DNA damage in liver and kidney as compared to the untreated control group. Bisphenol-A group showed significant increase in the formation of micronuclei which was approximately threefold higher as compared to the control group. A significant decrease in DNA migration was observed in Bisphenol-A+turmeric fed groups in liver and kidney. Turmeric feeding significantly inhibited the micronuclei formation induced by Bisphenol-A. The study results indicate that turmeric can protect against Bisphenol-A induced genotoxicity in rats.