Dietary Vitamin C and Vitamin C Derived from Vegetables Are Inversely Associated with the Risk of Depressive Symptoms among the General Population

Association between 29 food groups of diet quality questionnaire and perceived stress in Chinese adults: a prospective study from China health and nutrition survey

PURPOSE

Diet plays a fundamental role in promoting resilience against stress-related disorders. We aimed to examine the overall and sex-specific association between food groups and perceived stress in adults.

METHODS

We analyzed the prospective data of 7,434 adults who completed both the 2011 and 2015 surveys of the China Health and Nutrition Survey (CHNS). The Diet Quality Questionnaire (DQQ) was used to code all the food items of 2011 dietary intake into 29 food groups, and perceived stress in 2015 was measured using a 14-item perceived stress scale (PSS-14). Univariate analysis and logistic regression models were used to examine the relationship between food groups and perceived stress.

RESULTS

People who perceived a higher level of stress (PSS-14 total score > 25) made up 41.5% and 45.1% of the male and female groups, respectively (χ2 = 9.605, p = 0.002). Individuals with increased intake of food groups such as legumes, other vegetables, other fruits, yogurt, poultry, fish & seafood, fluid milk, and fruit juice were less likely to experience a higher level of psychological stress (OR range: 0.544-0.892, p < 0.05). Additionally, we found sex-specific associations between food groups and perceived stress. The difference in the proportion of food groups, such as fluid milk and fish & seafood, between the two stress groups in men was statistically significant (p < 0.025). In the female group, the distribution of eight food groups, like legumes and nuts & seeds, between the two stress groups was statistically significant (p < 0.025).

CONCLUSION

This study indicated that food groups were differentially associated with perceived stress.

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.

Smartphone survey data reveal the timecourse of changes in mood outcomes following vitamin C or kiwifruit intervention in adults with low vitamin C

Vitamin C-rich foods can improve mood; however, the timecourse of these benefits is unknown. This study utilised intensive longitudinal smartphone surveys from a three-armed placebo-controlled trial to determine mood-related changes following supplementation with vitamin C (250 mg tablet/d), kiwifruit (2 SunGold™ kiwifruit/d) or a placebo (1 tablet/d). Secondary data were analysed from the KiwiC for Vitality trial (Trial ID: ACTRN12617001031358). Adults (n 155, 63 % female, aged 18-35 years) with low plasma vitamin C (<40 μmol/l) completed a 14-d lead-in, 28-d intervention and 14-d washout. Participants self-reported vitality (SF-36), mood (POMS total mood disturbance), flourishing (flourishing scale), sleep quality, sleep quantity and physical activity every second day using smartphone surveys. Plasma vitamin C, measured fortnightly, reached saturation after 2 weeks of vitamin C or kiwifruit supplementation. Kiwifruit supplementation improved vitality and mood within 4 days, peaking around 14-16 days, and improved flourishing from day 14. Vitamin C marginally improved mood until day 12. Incremental AUC analyses revealed significant overall effects of kiwifruit consumption on vitality and mood compared with placebo, which were stronger than effects for vitamin C tablets, but attenuated when adjusting for covariates. Sensitivity analyses of participants with low baseline vitamin C status revealed improved mood (vitamin C and kiwifruit) and flourishing (kiwifruit only). This is the first study to use intensive smartphone surveys to model the day-to-day timecourse of mood-related states following vitamin C intervention and highlights the value of using smartphone surveys to reveal the temporal changes in mood-related outcomes following nutrient supplementation.

Process optimisation for enzymatic clarification of indigenous wild watermelon (Citrullus lanatus) juice

A fundamental step in improving the quality and consumer acceptability of wild watermelon (Citrullus lanatus) is the process of juice clarification. The aim of this research was to investigate the physicochemical properties of crude wild watermelon (Citrullus lanatus) juice and to optimise the processing conditions, incubation time, incubation temperature and enzyme concentration for the enzymatic clarification of the crude juice. Crude wild watermelon juice samples were treated with pectinase enzyme in different concentrations (0.05 to 0.15 w/w%), at different incubation temperatures (30-50 oC) and for different incubation durations (60-180 min). The effects of the different treatments on turbidity, clarity, viscosity, lightness, and brix were determined. The response models adequately predicted turbidity, clarity, and viscosity at R2 > 0.5, but not lightness considering that R2 < 0.5. The model was statistically significant in predicting turbidity (R2 = 0.86), clarity (R2 = 0.81), viscosity (R2 = 0.97) and brix (R2 = 0.94) - but not lightness (R2 = 0.24) at p < 0.05. The enzyme concentration did not significantly affect turbidity, clarity, and lightness, but it did significantly affect brix positively (p < 0.05). Response surface methodology software was used to determine optimal clarification conditions. In conclusion, the optimum conditions for crude watermelon juice clarification were 0.15 w/w% enzyme concentration, 60 min incubation time and 60 oC incubation temperature. The optimum output parameters were 14.18 NTU for turbidity, 0.04 Abs for clarity, 52.30 L* value for lightness, 1.96 cps for viscosity and 3.08% for Brix.

Oxidative balance scores and depressive symptoms: Mediating effects of oxidative stress and inflammatory factors

BACKGROUND

Few studies have examined the combined effects of dietary and lifestyle factors on depressive symptoms. This study aimed to evaluate the association between oxidative balance score (OBS) and depressive symptoms and the underlying mechanisms.

METHODS

A total of 21,283 adults from the 2007 to 2018 National Health and Nutrition Examination Survey (NHANES) were included. Depressive symptoms were defined as a total score of ≥10 on the Patient's Health Questionnaire (PHQ-9). Twenty dietary and lifestyle factors were selected to calculate the OBS. Multivariable logistic regression analyses were used to evaluate the association between OBS and depression risk. Mediation analyses were conducted to explore the roles of oxidative stress and inflammatory markers.

RESULTS

In multivariate model, a significant negative association was found between OBS and depression risk. Compared with those in OBS tertile 1, participants in tertile 3 had lower odds of developing depressive symptoms (OR:0.50; 95 % CI:0.40-0.62; P < 0.001). Restricted cubic splines showed a linear relationship between OBS and depression risk (P for nonlinearity = 0.67). Moreover, higher OBS was found to be associated with lower depression scores (β = -0.07; 95 % CI:-0.08, -0.05; P < 0.001). GGT concentrations and WBC counts mediated the association between OBS and depression scores by 5.72 % and 5.42 %, respectively (both P < 0.001), with a joint mediated effect of 10.77 % (P < 0.001).

LIMITATIONS

This study was a cross-sectional design making it difficult to infer a causal association.

CONCLUSIONS

OBS is negatively associated with depression, which may be mediated in part by oxidative stress and inflammation.

Tet Enzyme-Mediated Response in Environmental Stress and Stress-Related Psychiatric Diseases

Mental disorders caused by stress have become a worldwide public health problem. These mental disorders are often the results of a combination of genes and environment, in which epigenetic modifications play a crucial role. At present, the genetic and epigenetic mechanisms of mental disorders such as posttraumatic stress disorder or depression caused by environmental stress are not entirely clear. Although many epigenetic modifications affect gene regulation, the most well-known modification in eukaryotic cells is the DNA methylation of CpG islands. Stress causes changes in DNA methylation in the brain to participate in the neuronal function or mood-modulating behaviors, and these epigenetic modifications can be passed on to offspring. Ten-eleven translocation (Tet) enzymes are the 5-methylcytosine (5mC) hydroxylases of DNA, which recognize 5mC on the DNA sequence and oxidize it to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Tet regulates gene expression at the transcriptional level through the demethylation of DNA. This review will elaborate on the molecular mechanism and the functions of Tet enzymes in environmental stress-related disorders and discuss future research directions.

Association of Urinary Iodine Concentration with Depressive Symptoms among Adults: NHANES 2007-2018

The association between iodine status and depressive symptoms has not been investigated in the general population. Therefore, we drew 8935 participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 to explore their association. In NHANES, Inductively Coupled Plasma Dynamic Reaction Cell Mass Spectroscopy was utilized to measure urinary iodine concentration (UIC), and Patient Health Questionnaire-9 was used to assess depressive symptoms. Meanwhile, we fitted logistic regression and restricted cubic spline models. We found that high UIC was associated with a higher prevalence of depressive symptoms than the normal UIC group (OR: 1.50, 95% CI: 1.04-2.16). This association was particularly pronounced and further strengthened among females (OR: 1.90, 95% CI: 1.19-3.01) and participants aged 40-59 (OR: 1.90, 95% CI: 1.11-3.25). Moreover, we found that low UIC was associated with a high prevalence of depressive symptoms among females (OR: 1.50, 95% CI: 1.02-2.18). Moreover, the dose-response relationship between UIC and depressive symptoms presented a general trend of decreased, steady transiently, and then increased. We found that participants with high UIC had a higher prevalence of depressive symptoms than those with normal UIC. Meanwhile, we also found that females with low UIC had higher odds of reporting depressive symptoms.

Associations of Dietary Vitamin C and E Intake With Depression. A Meta-Analysis of Observational Studies

Objective

The associations of dietary vitamin C and E intake with depression remains conflicting. This meta-analysis of observational study was therefore employed to clarify the issue further.

Methods

An extensive literature review (PubMed, Web of Science and Embase) was performed in January 2022 to identify the observational studies on the associations of dietary vitamin C and E intake with depression. The pooled relative risk (RR) of depression for the highest versus lowest dietary vitamin C and E intake category, and the weighted mean difference (WMD) of dietary vitamin C and E intake for depression versus control subjects, were calculated.

Results

A total of 25 observational studies (91966 participants) were included in this meta-analysis. The overall multi-variable adjusted RR demonstrated that dietary vitamin C intake was inversely associated with depression (RR = 0.72, 95% CI: 0.57 to 0.91; P = 0.005). In addition, the combined WMD showed that the dietary vitamin C intake in depression was lower than that in control subjects (WMD = −11.58, 95% CI: −14.88 to −8.29; P < 0.001). Similarly, the overall multi-variable adjusted RR demonstrated that dietary vitamin E intake was negatively associated with depression (RR = 0.84, 95% CI: 0.72 to 0.98; P = 0.02). Moreover, the combined WMD showed that the dietary vitamin E intake in depression was also lower than that in control subjects (WMD = −0.71, 95% CI: −1.07 to −0.34; P < 0.001).

Conclusion

The results of this meta-analysis suggest that both dietary vitamin C and E intake is inversely associated with depression. However, due to the limited evidence, more well-designed prospective cohort studies are still needed.