Impact of consuming green and yellow vegetables on the depressive symptoms of junior and senior high school students in Japan

Association between commuting and mental health among Japanese adolescents

AIM

Mental health issues in adolescence contribute to various disease burdens later in life and are associated with violence, crime, and suicide. Activities such as sleep, diet, exercise, and time spent using electronic devices are related to declining mental health. However, few studies have examined the association between commuting times to school and mental health. This study tested the hypothesis that high school students' long commuting times are associated with poor mental health.

METHOD

A cross-sectional study was conducted between October and December 2022 among 2067 students at two private high schools. Survey items included participant information (sex, grade, school), commuting time, mental health status (Patient Health Questionnaire 9 [PHQ-9]: depressive symptoms, and Generalized Anxiety Disorder 7 [GAD-7]: anxiety symptoms), lifestyle factors, and sleep-related factors.

RESULTS

Data from 1899 high school students were analyzed. The prevalence of depressive and anxiety symptoms was 17.3% and 19.0%, respectively. A commuting time of ≥1 h was significantly associated with depressive symptoms (adjusted odds ratio: 1.60 [95% confidence interval]: 1.14-2.24) and anxiety symptoms (adjusted odds ratio: 1.51 [95% confidence interval]: 1.09-2.10). Sex, grade, use of ≥8 h/day of electronic devices, and chronotype were significantly associated with depressive symptoms, while sex, grade, use of ≥8 h/day of electronic devices, and insomnia were significantly associated with anxiety symptoms.

CONCLUSION

It is suggested that long commuting times are associated with poor mental health in high school students. Parents and schools should consider commuting time when advising students on school selection to maintain their mental health.

Associations of vegetable and fruit intake, physical activity, and school bullying with depressive symptoms in secondary school students: the mediating role of internet addiction

BACKGROUND

Few studies have simultaneously focused on the associations of vegetable and fruit intake, physical activity, school bullying, and Internet addiction (IA) with depressive symptoms. This study aimed to explore the direct and indirect effects of the above factors on depressive symptoms in adolescents by constructing a structural equation model (SEM).

METHODS

This study was conducted in Qingdao from September to November 2021. A total of 6195 secondary school students aged 10-19 years were included in the analysis. Information on all variables was assessed using a self-administered questionnaire. An SEM was constructed with depressive symptoms as the endogenous latent variable, IA as the mediating variable, and vegetable and fruit intake, physical activity, and school bullying as the exogenous latent variables. The standardized path coefficients (β) were the direct effects between the latent variables, and the indirect effects were obtained by the product of direct effects between relevant latent variables.

RESULTS

The median value with the interquartile range of depressive symptom scores was 7 (3,12). Vegetable and fruit intake (β=-0.100, P<0.001) and physical activity (β=-0.140, P<0.001) were directly negatively related to depressive symptoms. While school bullying (β=0.138, P<0.001) and IA (β=0.452, P<0.001) were directly positively related to depressive symptoms. IA had the greatest impact on depressive symptoms. Vegetable and fruit intake, physical activity, and school bullying could not only directly affect depressive symptoms, but also indirectly affect depressive symptoms through the mediating effect of IA, the indirect effects and 95% confidence intervals (CIs) were -0.028 (-0.051, -0.007), -0.114 (-0.148, -0.089) and 0.095 (0.060, 0.157), respectively. The results of the multi-group analysis showed that the SEM we constructed still fit in boy and girl groups.

CONCLUSIONS

The results indicated that vegetable and fruit intake, physical activity, school bullying, and IA had a significant direct impact on depressive symptoms, among which IA had the greatest impact. In addition, both vegetable and fruit intake, school bullying, and physical activity indirectly affected depressive symptoms through the mediating effect of IA. The impact of IA on depressive symptoms should be given extra attention by schools and parents. This study provides a scientific and effective basis for the prevention and control of adolescent depressive symptoms.

Association between drinking water quality and mental health and the modifying role of diet: a prospective cohort study

BACKGROUND

Environmental factors play an important role in developing mental disorders. This study aimed to investigate the associations of metal and nonmetal elements in drinking water with the risk of depression and anxiety and to assess whether diets modulate these associations.

METHODS

We conducted a prospective cohort study including 24,285 participants free from depression and anxiety from the Yinzhou Cohort study in the 2016-2021 period. The exposures were measured by multiplying metal and nonmetal element concentrations in local pipeline terminal tap water samples and total daily drinking water intakes. Cox regression models adjusted for multi-level covariates were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (95%CIs).

RESULTS

During an average follow-up period of 4.72 and 4.68 years, 773 and 1334 cases of depression and anxiety were identified, respectively. A 1 standard deviation (SD) increase in manganese exposure reduced the incidence of depression by 8% (HR 0.92, 95%CI 0.88 to 0.97). In contrast, with a 1 SD increase in copper and cadmium exposure, the incidence of depression increased by 6% (HR 1.06, 95%CI 1.01 to 1.11) and 8% (HR 1.08, 95%CI 1.00 to 1.17), respectively. The incidence of anxiety increased by 39% (HR 1.39, 95%CI 1.20 to 1.62), 33% (HR 1.33, 95%CI 1.03 to 1.71), and 14% (HR 1.14, 95%CI 1.03 to 1.25) respectively for a 1 SD increase in manganese, iron, and selenium exposure. Diets have a moderating effect on the associations of metal and nonmetal elements with the risk of anxiety. Stronger associations were observed in older, low-income groups and low-education groups.

CONCLUSIONS

We found significant associations between exposure to metal and nonmetal elements and depression and anxiety. Diets regulated the associations to some extent.

Macronutrient intake as a prospective predictor of depressive symptom severity: An exploratory study with adolescent elite athletes

BACKGROUND

Appropriate availability of macro- and micronutrients has an important impact on cognitive performance, mood and mental health. Although the critical role of nutrition for elite athletes' performance was recognized early on, little is known about whether consumption of specific macronutrients (carbohydrates, proteins, fat) predict the development of future depressive symptoms in adolescent elite athletes.

METHODS

Participants were recruited from three Swiss Olympic Partner Schools (SOPS) in the Northwestern German speaking part of Switzerland. A total of 97 adolescent elite athletes (38% girls, Mage = 16.35 ± 1.19) participated in the study. Depressive symptoms (PHQ9) were assessed at baseline and after 10 months follow-up. A 3-day food recall was completed three months after the baseline assessment. Linear regression analyses were used to examine whether macronutrients predict depression symptom severity after controlling for covariates and baseline depressive symptoms.

RESULTS

Higher protein consumption in athletes was a prospective predictor of lower depressive symptom severity at follow-up (β = -35, p < .05). Several deviations from recommended nutritional standards were observed in elite athletes.

CONCLUSIONS

The findings of this exploratory study support the notion that dietary behaviour may be prospectively associated with athletes' mental health. However, more research is required with larger samples and more in-depth assessment techniques. Future research should also examine whether nutrition education and dietary modification can be used to prevent depressive symptoms among adolescent elite athletes.

Associations between dietary intake, diet quality and depressive symptoms in youth: A systematic review of observational studies

Background: Depression is the third leading cause of worldwide disease burden among youth, and nutrition- and diet-related behaviors have been considered as an effective strategy for reducing the risk of depressive symptoms. This systematic review aims to examine associations between dietary intake and diet quality with depressive symptoms among youth. Methods: In this systematic review, a search of scientific articles published between 2000 and 2021 was performed in four databases (CINAHL, Embase, PsycInfo, and PubMed) according to the PRISMA checklist. After applying inclusion and exclusion criteria, observational studies that focused on associations between micronutrient, macronutrient, food group intake, and diet quality and depressive symptoms among youth, ages 3 to 18, were selected for review. Results: Thirty-two articles met the review criteria. Dietary intake of magnesium, vitamin B12, fiber, fruits, vegetables, and fish were consistently inversely related to depressive symptoms. However, the evidence of associations between intake of vitamins B6, C, D, and E, iron, copper, zinc, omega-3 fatty acids, carbohydrate, and dietary fat and depressive symptoms was mixed. Dietary effects on decreased depressive symptoms were more pronounced in children than adolescents. Additionally, most studies failed to adjust for potential confounding variables. Conclusion: This review provides preliminary and comprehensive evidence for a relationship between dietary intake, diet quality, and depressive symptoms in youth. Although the results are heterogeneous and more research is needed, our findings indicate the importance of nutrition interventions for youth for decreasing depressive symptoms or for preventing further symptom exacerbation.

Dietary patterns and internalizing symptoms in children and adolescents: A meta-analysis

CONTEXT

Studies of child and adolescent internalizing symptoms and dietary pattern have produced mixed results.

OBJECTIVES

To quantify the association between dietary patterns and internalizing symptoms, including depression, in children and adolescents.

DATA SOURCES

Embase, PsycINFO, MEDLINE, Web of Science and Cochrane up to March 2021.

STUDY SELECTION

Observational studies and randomized controlled trials with mean age ⩽ 18 years, reporting associations between diet patterns and internalizing symptoms.

DATA EXTRACTION

Mean effect sizes and 95% confidence intervals were determined under a random-effects model.

RESULTS

Twenty-six studies were cross-sectional, 12 were prospective, and 1 used a case-control design. The total number of participants enrolled ranged from 73,726 to 116,546. Healthy dietary patterns were negatively associated with internalizing (r = -0.07, p < 0.001, 95% confidence interval [-0.12, 0.06]) and depressive symptoms (r = -0.10, p < 0.001, 95% confidence interval [-0.18, -0.08]). Effect sizes were larger for studies of healthy dietary patterns and internalizing and depressive symptoms using self-report versus parent-report measures, as well as in cross-sectional studies of healthy dietary patterns and depression compared to prospective studies. Unhealthy dietary patterns were positively associated with internalizing (r = 0.09, p < 0.001, 95% confidence interval [0.06, 0.14]) and depressive symptoms (r = 0.10, p < 0.01, 95% CI [0.05, 0.17]). Larger effect sizes were observed for studies of unhealthy dietary patterns and internalizing and depressive symptoms using self-report versus parent-report measures.

LIMITATIONS

A lack of studies including clinical samples and/or physician diagnosis, and a paucity of studies in which anxiety symptoms were the primary mental health outcome.

CONCLUSION

Greater depression and internalizing symptoms are associated with greater unhealthy dietary patterns and with lower healthy dietary intake among children and adolescents.

Associations Between Consumption of Different Vegetable Types and Depressive Symptoms in Japanese Workers: A Cross-Sectional Study

Purpose

Vegetable intake is an important part of our everyday diet and is associated with many positive health outcomes. Although previous studies have investigated the association between vegetable consumption and depressive symptoms among various populations, no study has examined this association in the adult working population. The present study investigated whether the frequency of consumption of a specific type of vegetable is associated with the prevalence of depressive symptoms in Japanese adult workers.

Participants and Methods

The final participants consisted of 1724 Japanese adults, and a cross-sectional study was conducted to analyze the results. The frequency of vegetable consumption and depressive symptoms was evaluated using a brief-type self-administered diet history questionnaire and the Zung Self-Rating Depression Scale (SDS), respectively. The association between the variables was examined using Poisson regression analysis. Age-stratified analysis was performed, and SDS cut-off values of 45 and 50 were used to perform a sensitivity analysis.

Results

After adjustment for covariates, including age, body mass index, sociodemographic and lifestyle-related variables, health condition, C-reactive protein, and other dietary variables, an inverse association was found between tomato product consumption and the prevalence of depressive symptoms among men (P for trend <0.01); however, no significant association was found for other vegetable types. For women, there was no association between the frequency of consumption of any of the vegetable types and the prevalence of depressive symptoms. The results were confirmed by the age-stratified analysis for both genders.

Conclusion

Consumption of tomato products may help alleviate depressive symptoms, regardless of differences in dietary culture among men.

Does diet play a role in the prevention and management of depression among adolescents? A narrative review

BACKGROUND

Depression is one of the major causes of illness and disability, while suicide is the second leading cause of death amongst adolescents. Although many factors determine the mental health of an individual, diet has been gaining popularity as a key modifiable factor in the prevention and management of depression. Nutritional Psychiatry is an emerging field where researchers suggest that the food we consume influences our mental well-being.

AIM

This review aims to explore the significance of diet, nutrient deficiencies, imbalances, and unhealthy dietary patterns in the prevention and management of unipolar depression or major depressive disorder among adolescents.

METHODS

Electronic databases such as PubMed, Scopus, Google Scholar, Science Direct, and MEDLINE were searched using keywords such as "mental health," "depression," "adolescents," "diet," "dietary pattern," and pertinent articles (N = 68) were retrieved and reviewed.

RESULTS

The Mediterranean and traditional diets rich in complex carbohydrates, omega-3 fatty acids, B-group vitamins and several amino acids have shown negative correlation with the incidence of depression. On the other hand, Western dietary patterns (sweetened beverages, processed/ junk food, and foods rich in saturated fatty acids), along with low consumption of fruits and vegetables have been linked to an increased risk of depression among adolescents.

CONCLUSION

Dietary modification can prove to be a cost-effective strategy for the prevention and treatment of depression among adolescents. Diet and nutrition need to be recognized as key modifiable targets for the prevention of mental disorders and nutritional medicine should be considered as an integral part of psychiatric treatment.

Exploring the association between mental wellbeing, health-related quality of life, family affluence and food choice in adolescents

Young people choose energy-dense, nutrient-poor diets, yet understanding of potential determinants is limited. Associations between food choices, mental wellbeing, health-related quality of life (HRQoL) and family affluence were explored to identify targets for intervention to promote dietary health and wellbeing in young people. Adolescents were recruited via post-primary schools in the UK and surveyed at two time-points when aged 13-14 years and 15-16 years. The questionnaire enquired about mental wellbeing using the Short Warwick-Edinburgh Mental Wellbeing Scale, HRQoL using the KIDSCREEN-10, socio-economic status using the Family Affluence Scale and food choice by Food Frequency Questionnaire (FFQ). With missing and anomalous cases excluded, the sample comprised 1208 cases. Factor analysis on the FFQ indicated five food choice factors: 'Junk Food'; 'Meat'; 'Healthy Protein'; 'Fruit/Vegetables'; 'Bread/Dairy'. Multivariate regression analysis indicated that frequent consumption of Junk Food was associated with being male and lower mental wellbeing. Frequent Meat intake was associated with being male and with lower HRQoL. Frequent choice of Bread/Dairy foods was more common among males and associated with higher wellbeing and greater affluence. Those who consumed Fruit/Vegetables frequently were more likely to be female, have higher HRQoL, higher mental wellbeing, and greater family affluence. These direct associations endured between time points. The dietary factors were not mutually exclusive. Those who frequently chose Junk Food were less likely to choose Fruit/Vegetables. Frequent choice of Meat was associated with more frequent choice of Junk Food and Healthy Protein. Intervention to improve dietary and psychological health in young people should target males, those in less affluent households, seek to reduce consumption of 'junk' food, and increase fruit and vegetable intake.