Ultra-processed food is one of the main contributors to energy supply and consumption in food systems worldwide, and evidence of their detrimental health outcomes in humans is emerging. This study aimed to assess ultra-processed food intake and its association with urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in 139 healthy adolescents in Karaj city in Iran. Usual dietary intake was measured using a 168-item validated food frequency questionnaire. The daily intake of ultra-processed food consumption was determined through the classification of NOVA and general linear models were used to compare the urinary levels of 8-OHdG/creatinine (ng/mg crn) within tertiles of ultra-processed food intake. Adolescents in the higher tertile of ultra-processed food consumption had a significantly higher mean level of urinary 8-OHdG/ creatinine in comparison to the lower tertiles in the crude model (P for trend: 0.003) and after adjustment for confounding variables, including total energy intake, sex, age, body mass index (BMI) for age Z-score, obesity, and physical activity (P for trend:0.004). This association was still significant after adjusting for dietary intake of whole grains, nuts, legumes, the ratio of monosaturated fatty acids (MUFAs) to saturated fatty acids (SFAs) (g/day), and Mediterranean dietary score (P for trend: 0.002). More studies are needed to explore the determinants of ultra-processed food supply, demand, consumption, and health effects; such studies should be applied to develop evidence-informed policies and regulatory mechanisms to improve children’s and adolescents’ food environment policy-making and legislation with special attention to ultra-processed food.

Abstract:Reactive oxygen species (ROS) and oxidative stress (OS) have important role in prevention, initiation and progression of chronic diseases from early childhood, but OS status in healthy young subjects and appropriate methods for its measurement have been remained unclear. Evaluation of urinary biomarker set for OS has not been well documented in Iran. In this study, evaluation of OS from urinary biomarker in healthy adolescents and its relevance to anthropometric index were investigated. Forty-hundred students aged 13 and 19 years old participated in this study. 8-hydroxy-2ʹ-deoxyguanosine (8-OHdG) as marker of oxidative DNA damage was measured in adolescents and also its relation with age, sex and body mass index was studied. Subjects were sampled by multistage cluster sampling. The average ratio of 8-OHdG to creatinine was 4.7±4.1.No significant difference of 8-OHdG was observed between boys and girls in this study.