Associations between dietary carotenoid intakes and the risk of depressive symptoms

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 dietary carotenoid intakes and abdominal aortic calcification in adults: National Health and Nutrition Examination Survey 2013-2014

OBJECTIVE

Abdominal aortic calcification (AAC) is an important marker of subclinical atherosclerosis and a predictor of cardiovascular disease. This study aims to explore the association between carotenoid intakes and AAC.

METHODS

We included 2889 participants from the National Health and Nutrition Examination Survey (NHANES). Dietary carotenoid intakes were obtained through 24-h dietary recall interviews. Severe AAC was defined as a Kauppila score > 5. The main analysis utilizes logistic and restricted cubic spline models.

RESULT

Severe AAC was detected in 378 (13.08%) participants. In fully adjusted models, the odds ratios (OR) with 95% confidence intervals (CI) of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoid intakes for individuals with severe AAC were 0.53 (0.23-0.77), 0.39 (0.19-0.80), 0.18 (0.05-0.62), 0.40 (0.20-0.78), 0.53 (0.32-0.88) and 0.38 (0.18-0.77) in the highest versus lowest quartile intake, respectively. Dose-response analyses revealed that all of the carotenoids were associated with decreased risk of severe AAC in a nonlinear trend. Total carotenoid intakes of at least 100ug/kg/day were associated with decreased odds for severe AAC.

CONCLUSION

α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoids were inversely associated with the risk of severe AAC in adults.

Plasma carotenoids and risk of depressive symptomatology in a population-based cohort of older adults

BACKGROUND

As part of a healthy diet, higher carotenoid intakes have been associated with a reduced risk of depression, mainly in adults, while prospective studies on plasma carotenoids in older adults are lacking. The aim of this study was to assess the prospective association between plasma carotenoids and the risk of Depressive Symptomatology (DS) in older adults.

METHODS

The study sample was based on the Three-City cohort of adults aged 65y+ free from DS at enrollment in 1999. Plasma carotenoids were measured at baseline. DS was assessed every 2-3 years over 17 years and defined by a Center for Epidemiologic Studies-Depression Scale score ≥ 16 and/or by antidepressant use. The association between plasma carotenoids or carotenoid/lipids (cholesterol and triglycerides) ratio and the risk for DS was assessed through multiple random-effect logistic regression.

RESULTS

The study sample was composed of 1010 participants (mean age 74 y (±4.9), 58 % of women) followed-up during a median time of 13.4 years. Plasma zeaxanthin and ratios of zeaxanthin/lipids, lutein+zeaxanthin/lipids and β-carotene/lipids were independently associated with a significant reduced risk of DS over time (Odds ratio (OR) = 0.81, 95 % Confidence Interval (CI) [0.67;0.99], OR = 0.79 [0.67;0.98], OR = 0.79 [0.64;0.94] and OR = 0.80 [0.66;0.97] for +1 standard deviation of each exposure respectively).

LIMITATIONS

Plasma carotenoids were only available at study baseline.

CONCLUSION

Focusing on circulating carotenoids and considering lipids levels, the present results suggested an association between higher levels of plasma zeaxanthin, combined lutein+zeaxanthin and β-carotene and a decreased risk of DS over time in older adults.

Dietary Carotene Intake and Suicidal Ideation in Korean Females: Analysis of Data From the Korea National Health and Nutrition Examination Survey (2012, 2013, and 2015)

OBJECTIVE

The suicide rate in Korea was the highest among countries in the Organisation for Economic Co-operation and Development in 2019. In a previous study, higher intake of vegetables and fruits was associated with a lower risk of suicidal ideation, and carotene-rich fruits and vegetables lowered the risk of depression. This study aimed to examine the direct relationship between carotene intake and suicidal ideation, adjusting for the effect on depression.

METHODS

This study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted in 2012, 2013, and 2015. Carotene intake was assessed through a food intake frequency survey with a 24-hour recall. Suicidal ideation and depression were assessed using the mental health section of the KNHANES. We applied logistic regression to assess the relationship between carotene intake and suicidal ideation, adjusting for potential confounders.

RESULTS

A total of 5,480 females aged 19-64 years were included in this study. Carotene intake was significantly lower in the suicidal ideation group (3,034.5±1,756.4 μg/day) than in the nonsuicidal ideation group (3,225.4±1,795.1 μg/day) (p=0.015). We found a significant inverse association between carotene intake and the risk of suicidal ideation after adjusting for potential confounders (odds ratio=0.934, 95% confidence interval=0.873-0.999).

CONCLUSION

These results suggest that carotene intake may be inversely associated with the risk of suicidal ideation. Our findings may inform the development of new nutritional interventions to prevent increases in the risk of suicide worldwide.

Association between serum globulin and cognitive impairment in older American adults

Background and aims

Cognitive impairment is on the rise around the world, with profound economic and social consequences. Serum globulin, a marker of liver function, may also play a role in cognitive function. Unfortunately, no consistent conclusion exists regarding the association between serum globulin and cognitive function.

Methods

Data from the 2011 to 2014 National Health and Nutrition Examination Survey were used to assess the association between serum globulin and cognitive impairment. Cognitive function was assessed by three tests: Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency (AF), and Digit Symbol Substitution Test (DSST). Furthermore, the breakthrough point of cognitive impairment correlated with CERAD < 5, AF < 14, and DSST < 34. A weighted multiple logistics regression model was used to verify the association between serum globulin and cognitive impairment. Generalized additive models (GAMs) and a smooth curve fit (penalty spline method) were used to determine a non-linear relationship between serum globulin and cognitive impairment. Finally, subgroup analysis and interaction tests were conducted to further verify the association between serum globulin and cognitive impairment.

Results

Data from 2,768 participants aged ≥60 (in accordance with the study design) were collected for the final analysis. Data suggested that serum globulin levels were associated with an elevated cognitive impairment based on the AF [full adjustment, OR = 1.05, 95% CI: 1.01-1.08] and DSST [full adjustment, OR = 1.06, 95% CI: 1.02-1.10] tests. Eventually, the GAM and smooth curve fit model was conducted to confirm that the association between serum globulin and cognitive impairment was non-linear. Moreover, the inflection point was 27 g/L serum globulin based on the CERAD test and 35 g/L serum globulin based on the AF test. Finally, the interaction term between serum globulin and cognitive impairment based on the AF test indicated no significant interactions among all variables (all p for interaction >0.05).

Conclusion

The association between serum globulin levels and cognitive impairment is non-linear. A threshold effect exists between serum globulin and cognitive impairment. Large-scale prospective clinical trials are needed to validate our findings.

Safety, Tolerability, and Pharmacokinetics of β-Cryptoxanthin Supplementation in Healthy Women: A Double-Blind, Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

β-cryptoxanthin is a dietary carotenoid for which there have been few studies on the safety and pharmacokinetics following daily oral supplementation.

METHODS

90 healthy Asian women between 21 and 35 years were randomized into three groups: 3 and 6 mg/day oral β-cryptoxanthin, and placebo. At 2, 4, and 8 weeks of supplementation, plasma carotenoid levels were measured. The effects of β-cryptoxanthin on blood retinoid-dependent gene expression, mood, physical activity and sleep, metabolic parameters, and fecal microbial composition were investigated.

RESULTS

β-cryptoxanthin supplementation for 8 weeks (3 and 6 mg/day) was found to be safe and well tolerated. Plasma β-cryptoxanthin concentration was significantly higher in the 6 mg/day group (9.0 ± 4.1 µmol/L) compared to 3 mg/day group (6.0 ± 2.6 µmol/L) (p < 0.03), and placebo (0.4 ± 0.1 µmol/L) (p < 0.001) after 8 weeks. Plasma all-trans retinol, α-cryptoxanthin, α-carotene, β-carotene, lycopene, lutein, and zeaxanthin levels were not significantly changed. No effects were found on blood retinol-dependent gene expression, mood, physical activity and sleep, metabolic parameters, and fecal microbial composition.

CONCLUSIONS

Oral β-cryptoxanthin supplementation over 8 weeks lead to high plasma concentrations of β-cryptoxanthin, with no impact on other carotenoids, and was well tolerated in healthy women.

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.

Association between grip strength and cognitive impairment in older American adults

BACKGROUND AND AIMS

Exponential population aging has led to an increased prevalence of cognitive impairment worldwide. Hand grip strength, which may be associated with physical activity, could be a useful predictor of cognitive impairment. However, few studies have reported the association, if any, between hand grip strength and cognitive function.

METHODS

We used data obtained from the National Health and Nutrition Examination Survey between 2011-2012 and 2013-2014 to investigate the association between hand grip strength and cognitive impairment. Cognitive impairment was assessed using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), animal fluency (AF), and digit symbol substitution test (DSST) scores. Cutoff values of CERAD < 5, AF < 14, and DSST < 34 were used to define cognitive impairment. In this cross-sectional study, we used odds ratios to determine the potential usefulness of hand grip strength for the prediction of cognitive impairment.

RESULTS

This study included 2,623 participants aged ≥60 years. The DSST results showed that hand grip strength was associated with a low risk of cognitive impairment and that subgroup analysis showed that male sex, 60-69 years of age, and the Non-Hispanic (NH)-White, NH Black, and Asian were associated with a significantly low risk of cognitive impairment. The CERAD test results showed that 70-79 years of age and the NH White were significantly associated with a low risk of cognitive impairment. By following full adjustment, we did not observe statistically significant differences between hand grip strength and cognitive impairment based on the CERAD test. The AF test results showed that >80 years of age, female sex, and the NH White were associated with a significantly low risk of cognitive impairment. The most important finding is that a linear association lies between grip strength and cognitive impairment, as well as a sex-based linear association. Machine learning of the XGBoost model suggests that grip strength is one of the top two most important negative predictor variables.

CONCLUSION

We observed an inverse relationship between hand grip strength and cognitive impairment, which might suggest a shared underlying mechanism that needs to be further investigated using a large-scale prospective clinical trial to validate our findings.

Dietary Intake of Carotenoids and Risk of Depressive Symptoms: A Systematic Review and Meta-Analysis

Given the important role of oxidative stress in the pathogenesis of depression, the potential role of dietary antioxidant supplementation in the prevention of depression has attracted considerable attention. Most studies suggest that dietary carotenoids may play a role in maintaining depressive symptoms due to their antioxidant activity, but some studies concluded the contrary. This study conducted a meta-analysis of observational studies to test the relationship between carotenoid supplements and depressive symptoms. After a comprehensive search of the Cochrane Library, PubMed, Embase Scopus, and Web of Science databases from their inception to 28 July 2022, 12 publications met the inclusion and exclusion criteria, of which 8 were cross-sectional studies, 3 were case−control studies, and 1 was a cohort study, involving a total of 33,466 participants. Pooled meta-analysis found that intake of total carotenoids (OR = 0.61, 95% CI [0.53, 0.71], p < 0.01), beta-carotene (OR = 0.61, 95% CI [0.52, 0.70], p < 0.01), alpha-carotene (OR = 0.71, 95% CI [0.60, 0.83], p < 0.01), lycopene (OR = 0.71, 95% CI [0.55, 0.90], p < 0.01), lutein, and/or corn xanthin (OR = 0.53, 95% CI [0.43, 0.66], p < 0.01) was significantly inversely associated with depressive symptoms, while beta-cryptoxanthin (OR = 1.07, 95% CI [0.52, 2.21], p = 0.86) had no significance. At the same time, this meta-analysis was free of publication bias and heterogeneity. Although further studies are needed to elucidate the causal relationship between carotenoids and depressive symptoms, and to further reveal the mechanism of their association, the results of our meta-analysis suggest that carotenoids are protective factors for depressive symptoms, and dietary intake may help in reducing the risk of depressive symptoms.

Potential Psychoactive Effects of Microalgal Bioactive Compounds for the Case of Sleep and Mood Regulation: Opportunities and Challenges

Sleep deficiency is now considered an emerging global epidemic associated with many serious health problems, and a major cause of financial and social burdens. Sleep and mental health are closely connected, further exacerbating the negative impact of sleep deficiency on overall health and well-being. A major drawback of conventional treatments is the wide range of undesirable side-effects typically associated with benzodiazepines and antidepressants, which can be more debilitating than the initial disorder. It is therefore valuable to explore the efficiency of other remedies for complementarity and synergism with existing conventional treatments, leading to possible reduction in undesirable side-effects. This review explores the relevance of microalgae bioactives as a sustainable source of valuable phytochemicals that can contribute positively to mood and sleep disorders. Microalgae species producing these compounds are also catalogued, thus creating a useful reference of the state of the art for further exploration of this proposed approach. While we highlight possibilities awaiting investigation, we also identify the associated issues, including minimum dose for therapeutic effect, bioavailability, possible interactions with conventional treatments and the ability to cross the blood brain barrier. We conclude that physical and biological functionalization of microalgae bioactives can have potential in overcoming some of these challenges.

The Protective Effects of Zeaxanthin on Amyloid-β Peptide 1–42-Induced Impairment of Learning and Memory Ability in Rats

Background and Objectives

Zeaxanthin (ZEA) as one of the biologically active phytochemicals presents a neuroprotective effect. Since ZEA may play its anti-oxidative role in neurodegenerative diseases including Alzheimer’s disease (AD), we hypothesized cognitive defects could be prevented or deferred by ZEA pre-treatment.

Methods and Study Design

All the rats were randomly divided into four groups (control, Aβ1–42, ZEA, and ZEA + Aβ groups). Learning and memory ability of rats, cerebrovascular ultrastructure changes, the redox state, endothelin-1 (ET-1) level, and amyloid-β peptide (Aβ) level in plasma and the Aβ transport receptors which are advanced glycation end products (RAGEs) and LDL receptor-related protein-1 (LRP-1) and interleukin-1β (IL-1β) expressions in the cerebrovascular tissue were measured in the present study.

Results

The escape latency and frequency of spanning the position of platform showed significant differences between the Aβ group and ZEA treatment groups. ZEA could prevent the ultrastructure changes of cerebrovascular tissue. In addition, ZEA also showed the protective effects on regulating redox state, restraining ET-1 levels, and maintaining Aβ homeostasis in plasma and cerebrovascular. Moreover, the disordered expressions of RAGE and LRP-1 and IL-1β induced by Aβ1–42 could be prevented by the pre-treatment of ZEA.

Conclusion

ZEA pre-treatment could prevent learning and memory impairment of rats induced by Aβ1–42. This neuroprotective effect might be attributable to the anti-oxidative and anti-inflammatory effects of ZEA on maintaining the redox state and reducing the Aβ level through regulating the Aβ transport receptors and inflammatory cytokine of the cerebrovascular tissue.

Association between dietary carotenoid intakes and the risk of asthma in adults: a cross-sectional study of NHANES, 2007-2012

OBJECTIVE

To investigate the association between dietary carotenoid intake and asthma using data from a nationally representative sample of US adults.

DESIGN

Cross-section study.

SETTING

The National Health and Nutrition Examination Survey 2007-2012.

PARTICIPANTS

A total of 13 039 participants aged 20-80 years (current asthma n=1784, non-current asthma n=11 255) were included in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Asthma was defined by self-report questionnaires. Weighted logistic regression analyses and the smooth curve fittings were performed to explore the association between total carotenoid intake, dietary carotenoid subgenera, including (α-carotene, β-carotene, β-cryptoxanthin, lutein with zeaxanthin and lycopene) and the risk of asthma.

RESULTS

The ORs with 95% CIs of dietary α-carotene, dietary β-carotene, dietary β-cryptoxanthin, total lutein with zeaxanthin, total lycopene, dietary carotenoid and total carotenoid intake for individuals with current asthma after adjusting the confounders in model 3 were 0.80 (0.67 to 0.95), 0.67 (0.57 to 0.79), 0.68 (0.55 to 0.85), 0.77 (0.61 to 0.98), 0.71 (0.57 to 0.87), 0.75 (0.59 to 0.96) and 0.61 (0.48 to 0.76) in the highest versus lowest quartile, respectively. The smooth curve fittings suggested a non-linear relationship between total carotenoid intake and the risk of current asthma.

CONCLUSIONS

Higher intake of a-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoid were associated with lower odds of having current asthma in the US adults. This is a cross-sectional study and no causal relationship can be drawn, so caution is needed to interpret the results.

Associations of Dietary Vitamin A and Beta-Carotene Intake With Depression. A Meta-Analysis of Observational Studies

Objective

To clarify the associations of dietary vitamin A and beta-carotene intake with depression based on a meta-analysis of observational studies.

Methods

An extensive literature search on February 2022 (PubMed, Web of Science and Embase) was employed to identify observational studies on the associations of dietary vitamin A and beta-carotene intake with depression. The pooled relative risk (RR) of depression for the highest vs. lowest dietary vitamin A and beta-carotene intake category, and the standard mean difference (SMD) of dietary vitamin A and beta-carotene intake for depression vs. control subjects, were calculated.

Results

A total of 25 observational studies (100,955 participants), which included 24 cross-sectional/case-control and 1 prospective cohort study, were included in this study. The overall multi-variable adjusted RR demonstrated that dietary vitamin A intake was inversely associated with depression (RR = 0.83, 95%CI: 0.70–1.00; P = 0.05). In addition, the combined SMD showed that the dietary vitamin A intake in depression was also lower than that in control subjects (SMD = −0.13, 95%CI: −0.18 to −0.07; P < 0.001). On the other hand, the overall multi-variable adjusted RR indicated that dietary beta-carotene intake was negatively associated with depression (RR = 0.63, 95%CI: 0.55–0.72; P < 0.001). The combined SMD showed that the dietary beta-carotene intake in depression was also lower than that in control subjects (SMD = −0.34, 95%CI: −0.48 to −0.20; P < 0.001).

Conclusion

Our results suggest that both dietary vitamin A and beta-carotene intake is inversely associated with depression. However, due to the limited evidence, further prospective cohort studies are still needed.

Dietary choline is inversely associated with depressive symptoms: A cross-sectional study of the National Health and Nutrition Examination Survey (NHANES) 2011 to 2018

BACKGROUND

Dietary choline has neuroprotective actions. However, the relationship between dietary choline and depression has been little studied.

METHODS

We conducted a cross-sectional study to explore the association between dietary choline and depressive symptoms in US adults, using data from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES). 12,906 individuals age ≥20 who had valid information on dietary choline and depressive symptoms were chosen. Depressive symptoms were defined as the score ≥10 of the Patient Health Questionnaire-9 (PHQ-9). Multivariable logistic regression and the restricted cubic splines were used in analyses.

RESULTS

In three models, compared with the bottom quintile, each quintile of dietary choline was significantly associated with a lower risk of depressive symptoms. After adjusted all selected confounding factors and covariates, the odds ratio with the 95% confidence interval of depressive symptoms was 0.57 (95% CI:0.38-0.85) for the highest quintile versus the lowest quintile of dietary choline intake. Statistical significance was also maintained in gender and age stratification studies. In the study of the dose-response relationship, an L-shaped relationship between dietary choline and depressive symptoms was found.

LIMITATIONS

Causality cannot be inferred in a cross-sectional study.

CONCLUSION

In this analysis of US adults, dietary choline intake is inversely associated with the risk of depressive symptoms. An L-shape dose-response relationship between those two was found. Further studies are needed to confirm our results.

Relationships between urinary antimony concentrations and depressive symptoms in adults

BACKGROUND

Antimony is widely used in industrial production. The general population may be exposed to long-term low-dose antimony, and there are no studies on antimony and depression symptoms. This study aims to explore the relationships between urinary antimony concentrations and depressive symptoms in adults.

METHODS

We conducted a cross-sectional study using data from U.S. National Health and Nutrition Examination Survey (NHANES) 2007-2016 for urinary antimony (N = 8538). Depressive symptoms were assessed through Patient's Health Questionnaire (PHQ-9). In order to determine the relationships between urinary antimony concentrations and depressive symptoms, binary logistic regression model and restricted cubic spline were used. Dominance analysis was used to explore the relative importance between variables associated with depressive symptoms.

RESULTS

There was a significant positive relationship between urinary antimony concentrations and depressive symptoms in the general population, and OR with 95% CI was 1.72 (1.15, 2.60). This relationship also occurred in participants without disease status, and OR with 95% CI was 2.05 (1.10, 3.82). After stratified gender, the urinary antimony concentrations were positively correlated with depressive symptoms in the highest tertiles of female participants, and OR with 95% CI was 1.74 (1.06, 2.86). After adjusted urinary lead, arsenic, cadmium, and mercury as covariates, the result was still statistically significant, and OR with 95% CI was 1.83 (1.23, 2.72). Restricted cubic spline showed a nonlinear positive relationship between urinary antimony and depressive symptoms. Based on the result of dominance analysis, the relative importance of urinary antimony concentration accounted for 3.58%.

CONCLUSION

This study indicated that urinary antimony was positively related to depressive symptoms, especially in female.

Nutraceuticals and Physical Activity as Antidepressants: The Central Role of the Gut Microbiota

Major depressive disorder (MDD) is a common mental illness. Evidence suggests that the gut microbiota play an essential role in regulating brain functions and the pathogenesis of neuropsychiatric diseases, including MDD. There are numerous mechanisms through which the gut microbiota and brain can exchange information in a continuous, bidirectional communication. Current research emphasizes the interexchange of signals influenced by the gut microbiota that are detected and transduced in information from the gut to the nervous system involving neural, endocrine, and inflammatory mechanisms, suggesting a relationship between oxidative stress and the pathophysiology of MDD via the hyperactivation of inflammatory responses. Potential sources of inflammation in the plasma and hippocampus of depressed individuals could stem from increases in intestinal permeability. Some nutraceuticals, such as specific probiotics, namely psychobiotics, polyphenols, carotenoids, butyrate, and prebiotics, have been demonstrated to exert an antidepressant activity, but most of them need to be metabolized and activated by gut microorganisms. By inducing changes in the gut microbiota composition, physical exercise might also exert a role in alleviating depression-like symptoms. The mutual relationships among nutraceuticals, exercise, and depression will be discussed, and the potential role of the gut microbiota as a therapeutic target to treat depression will be explored.

A strategy for exploring subgroup-specific effects in nutrition science

Nutrients are an essential part of building and maintaining optimal health. Certain nutrient exposure has been shown to be associated with many important health outcomes, although there is variability among studies. Despite the scientific efforts of many, it is unclear why some well-hypothesised nutrients lack sufficient evidence for clear association with health outcomes. One potential reason for conflicting results is that certain subgroups of patients benefit or are harmed more by adequate or inadequate exposure to certain nutrients. These subgroup-specific effects have historically not been studied, or if they are, it is often in a one-off type of approach where the investigator believes that a subgroup effect could exist based on limited previous data. In the era of big data, improvements can be made in efforts to generate new hypotheses for subgroups of patients and recommendations for precision nutrition can be made. In the present paper, we present a strategy for exploring subgroup-specific effects in nutrient-related studies. This data-driven method can be useful in secondarily exploring which subgroups are harmed/helped most by inadequate/adequate nutrient exposure and could suggest target groups for future clinical trials to test the identified hypotheses. We then present an example study utilizing the National Health and Nutrition Examination Survey (NHANES) data from the years 2001–2006. In this example, a limited selection of nutrients is protective in subgroups of participants with diabetes on their self-reported number of poor mental health days.

Dietary Intake of Flavonoids and Carotenoids Is Associated with Anti-Depressive Symptoms: Epidemiological Study and In Silico-Mechanism Analysis

Flavonoids and carotenoids are bioactive compounds that have protective effects against depressive symptoms. Flavonoids and carotenoids are the two main types of antioxidant phytochemicals. This study investigated the association between flavonoid and carotenoid intake and depressive symptoms in middle-aged Korean females. We analyzed the mechanism of these associations using an in silico method. Depressive symptoms were screened using the Beck Depression Inventory-II (BDI-II), and flavonoid and carotenoid intake were assessed using a semi-quantitative food frequency questionnaire. Using a multivariate logistic regression model, we found that flavones, anthocyanins, individual phenolic compounds, lycopene, and zeaxanthin were negatively associated with depressive symptoms. In silico analysis showed that most flavonoids have high docking scores for monoamine oxidase A (MAOA) and monoamine oxidase B (MAOB), which are two important drug targets in depression. The results of the docking of brain-derived neurotrophic factor (BDNF) and carotenoids suggested the possibility of allosteric activation of BDNF by carotenoids. These results suggest that dietary flavonoids and carotenoids can be utilized in the treatment of depressive symptoms.

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

Vitamin C is a water-soluble antioxidant. Reducing the level of oxidative stress can alleviate depression. Therefore, we investigated the correlation between dietary vitamin C intake and the risk of depressive symptoms in the general population. Data from the 2007–2018 National Health and Nutrition Examination Survey were used in our study. The dietary intake of vitamin C was assessed by two 24-h dietary recalls. Depressive symptoms were assessed with the Patient Health Questionnaire-9. Logistic regression and restricted cubic spline models were applied to assess the relationship between dietary vitamin C intake and the risk of depressive symptoms. The multivariate adjusted odds ratio (95% confidence interval) of depressive symptoms for the highest vs. lowest category of dietary vitamin C intake and vitamin C intake derived from vegetables were 0.73 (0.58–0.91) and 0.73 (0.56–0.95). In subgroup analyses, dietary vitamin C intake was negatively correlated with the risk of depressive symptoms in females 18–39 years old and 40–59 year-old groups. A dose-response analysis showed that there was a nonlinear relationship between dietary vitamin C intake and the risk of depressive symptoms. Dietary vitamin C intake and vitamin C intake derived from vegetables were inversely associated with the risk of depressive symptoms among the general population. We recommend increasing the intake of vegetables in daily diet.

Associations of dietary B vitamins intakes with depression in adults

Background: The impact of the dietary B vitamins intakes on the development of depression has been scarcely investigated. Thus, this study aimed to examine the associations of dietary B vitamins intakes with the risk of depression in American adults. Methods: The data we used in this study were from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. We used the Logistic regression models to analyze the associations of the dietary intakes of B vitamins with the risk of depression. Results: 17,732 individuals (8,623 males and 9,109 females) were enrolled in the study and they were all 18 or older. Compared to the lowest quartile of dietary intake, the ORs (95%CIs) of the highest quartile were 0.64 (0.50-0.82), 0.78 (0.62-0.97), 0.60 (0.47-0.78), 0.65 (0.50-0.84), and 0.71 (0.54-0.95) for vitamin B1, vitamin B2, niacin, vitamin B6, and vitamin B12, respectively. Compared to the people whose dietary intakes below the RDA in the model 2, those with intake meeting the RDA of vitamin B1 (OR: 0.68; 95%CI: 0.56-0.84), niacin (OR: 0.65; 95%CI: 0.51-0.81), B6 (OR: 0.65; 95%CI: 0.52-0.81), or B12 (OR: 0.65; 95%CI: 0.48-0.88) had a lower risk of depression, severally. We also found a nonlinear negative association between dietary vitamin B1, vitamin B2, niacin, vitamin B6, and vitamin B12 intakes and the risk of depression in the dose-response analyses, severally. Conclusions: Our results suggested that dietary vitamin B1, vitamin B2, niacin, vitamin B6, and vitamin B12 intakes may be inversely associated with the risk of depression.

The association between carotenoid intake, mental health, and sleep quality among university students

BACKGROUND

The impact of carotenoid intake on the risk of mental disorders and poor sleep quality is unclear. Thus, we sought to examine the association between carotenoid intake, mental health, and sleep quality among university students.

METHODS

A total of 368 healthy university students (181 men, 49%), aged 18 to 43 years, volunteered for this study. Dietary intake, physical activity, sleep quality, mental health, and body mass index (BMI) were evaluated. A multivariable logistic regression analysis test was used to estimate the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

The mean age of the participants was 22.9 ± 3.9 years and mean BMI was 23.1 ± 3.8 kg/m². The students in the highest quartile of carotenoid intake had a significantly lower risk of poor sleep quality (OR = 0.19, 95% CI: 0.09 to 0.40; P  < 0.001) and depression (OR = 0.27, 95% CI: 0.12 to 0.59; P = 0.001). In the sex-stratified subgroup analysis, the depression risk was significant for men (OR = 0.28, 95% CI: 0.07 to 0.59; P = 0.007), but not for women. Furthermore, we did not observe any specific relationship between carotenoid intake and the risk of anxiety or stress.

CONCLUSION

It appears that the students with higher carotenoid intake may have a better quality of sleep and lower risk of depression. More longitudinal and in-depth qualitative and quantitative research, with a longer-term follow-up, is needed to support the veracity of our findings.