Purpose This study aimed to determine the prevalence of myopia among children and adolescents aged 6–16 years during COVID-19 pandemic in Tianjin, China. Methods This was a cross-sectional study using data from the Tianjin Child and Adolescent Research of Eye between March and June in 2021. A total of 909 835 children and adolescents aged 6–16 years from 1348 primary and secondary schools in Tianjin, China were recruited. Prevalence of myopia with 95% CIs was described in different regions, sexes and ages. The regions-standardised prevalence rate and chain growth rate of myopia in different ages were described the characteristics of myopia. Results A total of 864 828 participants (95.05% participation rate) were included in the analysis. The age range was 6–16 with a mean age of 11.50±2.79 years. The overall prevalence of myopia was 54.71% (95% CI 54.60% to 54.81%). The prevalence of myopia was 57.58% (95% CI 57.43% to 57.73%) for girls and 52.05% (95% CI 51.91% to 52.20%) for boys. Students living in the six central districts had the highest prevalence of moderate myopia (19.09% (95% CI 19.01% to 19.17%)) and high myopia (5.43% (95% CI 5.39% to 5.48%)). The regions-standardised prevalence of myopia was increased by age and the highest chain growth rate of myopia was up to 47.99% at 8 years. Conclusions The prevalence of myopia in Tianjin is high during COVID-19 pandemic. The progression of myopia started to increase dramatically at 8 years, and the increasing slowed down at 14 years. For policy-makers, intervention in the lower age groups may be important to control myopia progression.

Introduction: It is uncertain whether folic acid (FA) combined with docosahexaenoic acid (DHA) could improve cognitive performance. This study evaluated the effects of a 12-month FA and DHA supplementation, in combination or alone, on cognitive function, DNA oxidative damage, and mitochondrial function in participants with mild cognitive impairment (MCI). Methods: This randomized, double-blind, placebo-controlled trial recruited MCI participants aged 60 years and older. Two hundred and eighty participants were randomly divided in equal proportion into four groups: FA + DHA (FA 800 μg/d + DHA 800 mg/d), FA (800 μg/d), DHA (800 mg/d), and placebo groups daily orally for 12 months. The primary outcome was cognitive function evaluated by the Wechsler Adult Intelligence Scale-Revised (WAIS-RC). Cognitive tests and blood mechanism-related biomarkers were determined at baseline and 12 months. Results: During the 12-month follow-up, scores of full intelligence quotient (βDHA: 1.302, 95% CI: 0.615, 1.990, p < 0.001; βFA: 1.992, 95% CI: 1.304, 2.679, p < 0.001; βFA+DHA: 2.777, 95% CI: 2.090, 3.465, p < 0.001), verbal intelligence quotient, and some subtests of the WAIS-RC were significantly improved in FA + DHA and single intervention groups compared to the placebo group. Moreover, the FA and DHA intervention combination was superior to either intervention alone (p < 0.001). Meanwhile, FA, DHA, and their combined use significantly decreased 8-OHdG level and increased mitochondrial DNA copy number compared to the placebo (p < 0.05). Conclusions: Supplementation of FA and DHA, alone or combined, for 12 months can improve cognitive function in MCI participants, possibly through mitigating DNA oxidative damage and enhancing mitochondrial function. Combined supplementation may provide more cognitive benefit than supplementation alone.

Objectives This study aimed to explore the influence of the interaction between parental myopia and lifestyle on myopia among school-age children. Design Cross-sectional study. Setting This study used data from the Tianjin Child and Adolescent Research of Eye between August and October 2022. Participants A total of 49 035 participants between 6 and 18 years of age were eligible for this study. Primary and secondary outcome measures The primary outcome was the interaction between eye-healthy lifestyle and parental myopia on myopia. Parental myopia and eye-healthy lifestyle were ascertained by a Child and Adolescent Behavior Questionnaire. The lifestyle risk score (LRS) of eye health was calculated based on beta-coefficient in the backward regression model. The interaction between LRS and parental myopia was analysed by multivariate logistic regression. The predictive value of different predicted models was estimated using receiver operating characteristic curves. Multiple linear regression was used to evaluate the associations of lifestyle risk factors and parental myopia with spherical equivalent refraction, which were defined as the secondary outcomes. Results A total of 31 839 participants aged 6–18 years were included, and the myopia prevalence was 55.46%. Eye-healthy lifestyle and parental myopia were significantly associated with myopia, as was interaction. The predictive value for LRS & parental myopia was 0.714 (95% CI: 0.709 to 0.720), which was higher than LRS (0.693, 95% CI: 0.687 to 0.699) and parental myopia (0.710, 95% CI: 0.704 to 0.716) separately. Conclusions High-risk lifestyles of myopia and parental myopia were significantly associated with a higher risk of myopia, and the combination had the strongest effect. For children, lifestyle adjustment should be prioritised in preventing myopia, especially for those with parental myopia.

To examine the mental health status and related factors in children and adolescents, and to assess age groups and sexes differences in factors influencing mental health. This cross-sectional study was performed on Chinese children aged 6-18 years from November 2021 to January 2022. Mental health difficulties were accessed by the Strengths and Difficulties Questionnaire. Multivariate logistic regression was used to analyze factors associated with mental health status. Multiple linear regression was used to evaluate factors associated with the scores of the Strengths and Difficulties Questionnaire. The prevalence of mental health difficulties was 12.98% (n =1348). Age (OR, 0.909, [95%CI, 0.830-0.996]), sex (OR, 1.424, [95%CI, 1.033-1.963]) and screen time on weekdays ("≥2" h/d vs "< 1" h/d: OR, 2.001, [95%CI, 1.300-3.080]) were related factors for mental health difficulties. For children (year ≤ 12), the strongest related factor for mental health difficulties was screen time on weekdays ("≥ 2" h/d vs "< 1" h/d: OR, 1.821 [95%CI, 1.203-2.755]). The risk of mental health difficulties in females with ≥ 2 h/d screen time on weekends was 3.420 times higher than those with < 1 h/d (OR, 3.420, [95%CI, 1.923-6.081]). The prevalence of mental health difficulties among children and adolescents was relatively high. The lower age, female sex and excessive screen time were associated with a higher risk of mental health difficulties. The factors influencing mental health varied by different age groups and sexes. Thus, specific measures for different age groups and sexes should be adopted to mitigate the impact.

Objectives: To systematically summarise and evaluate the existing evidence of the associations between diverse folate exposures and the risk of colorectal cancer (CRC), while identifying evidence quality. Design: Umbrella review of meta-analyses. Data sources: PubMed, Web of Science, Cochrane and Embase were searched from the database inception to March 2024, with an update to 12 October 2025. Eligibility criteria: We included meta-analyses of randomised controlled trials or observational studies that investigated the associations between folate exposures and CRC or precancerous lesions (ie, adenoma and polyps). Data extraction and synthesis: For each association, we recalculated the summary effect size with 95% CI using the DerSimonian and Laird random-effects model, heterogeneity ( I ² statistic), 95% prediction interval, small-study effect (Egger’s test) and excess significance bias (χ² test). Results: This umbrella review included five meta-analyses describing 10 associations between folate exposures and CRC risk. In the general population, moderate-quality evidence supported an inverse association between total folate intake (from foods and supplements) and CRC risk (RR 0.84; 95% CI 0.80 to 0.90), while low-quality evidence suggested inverse associations of dietary folate intake (from foods alone) (RR 0.88; 95% CI 0.81 to 0.96) and folic acid supplement intake (RR 0.83; 95% CI 0.77 to 0.90) with CRC risk. Among patients with inflammatory bowel disease, low-quality evidence suggested an inverse association between folic acid supplement intake and CRC incidence (HR 0.71; 95% CI 0.53 to 0.96). Additionally, elevated circulating folate levels were observed to have a provoking effect on advanced-stage tumours (OR 1.95; 95% CI 1.18 to 3.22; Grading of Recommendations Assessment, Development and Evaluation (GRADE): very low). Sensitivity analysis revealed a potential increased risk of adenoma recurrence associated with folic acid supplement use among patients with a history of adenoma (RR 1.05; 95% CI 0.86 to 1.29; GRADE: high). Conclusions: These findings suggest that consuming dietary folate and total folate intake may be beneficial in CRC primary prevention. Specifically, folic acid supplements may inhibit colorectal carcinogenesis in normal tissues while promoting cancer in the established neoplastic foci. PROSPERO registration number: CRD42024537550.