The severity of depressive symptoms vs. serum Mg and Zn levels in postmenopausal women

Prevalence and associated factors of depression in postmenopausal women: a systematic review and meta-analysis

BACKGROUND

Depression is a prevalent mental health problem in postmenopausal women. Given its significant impact on the quality of life and overall well-being of postmenopausal women, there is need for a comprehensive review and meta-analysis of the existing research globally. This systematic review and meta-analysis evaluated the global prevalence of depression and potential associated factors in postmenopausal women.

METHODS

The Cochrane Library, PubMed, EMBASE, Web of Science, MEDLINE, and PsycINFO databases were systematically searched from inception to March 22, 2023. The meta-analysis used the random-effects model to calculate the prevalence of depression rates and associated factors. In addition, subgroup analysis and sensitivity analysis were performed. Publication bias was assessed using funnel plots, Egger's test, and nonparametric trim-and-fill tests.

RESULTS

The meta-analysis included 50 studies that involved 385,092 postmenopausal women. The prevalence of depression in postmenopausal women was 28.00% (95% CI, 25.80-30.10). Among the factors relevant to depression among postmenopausal women, marital status (OR: 2.03, 95%CI: 1.33-3.11), history of mental illness (OR: 2.31, 95%CI: 1.50-3.57), chronic disease (OR: 3.13, 95%CI: 2.20-4.44), menstrual cycle (OR: 1.42, 95%CI: 1.17-1.72), abortion numbers (OR: 1.59, 95%CI: 1.40-1.80), menopausal symptoms (OR: 2.10, 95%CI: 1.52-2.90), and hormone replacement therapy (OR: 1.76, 95%CI: 1.31-2.35) were risk factors, while physical activity (OR: 0.56, 95%CI: 0.53-0.59), number of breastfed infants (OR: 0.43, 95%CI: 0.19-0.97), menopause age (OR: 0.44, 95%CI: 0.37-0.51) were preventive factors.

CONCLUSIONS

This study demonstrated that the prevalence of postmenopausal depression is high, and some risk factors and protective factors associated with it have been identified. It is necessary to improve screening and management and optimize prevention and intervention strategies to reduce the harmful effects of postmenopausal depression.

Relationships between trace elements and cognitive and depressive behaviors in sprague dawley and wistar albino rats

Introduction: This study investigates the effects of social isolation on mental health and cognitive functions in Sprague Dawley (SD) and Wistar Albino (WIS) rat strains, prompted by the heightened awareness of such impacts amid the COVID-19 pandemic. This study aims to explore the impact of social isolation on memory, learning, and behavioral changes in middle-aged SD and WIS rat strains and to investigate cortical trace element levels, seeking potential correlations between these levels and the observed behavioral responses to social isolation. Methods: Four groups of 14-month-old male rats were established: control and isolated SDs and WIS rats (CONT-SD, ISO-SD, CONT-WIS, ISO-WIS). Morris Water Maze and Porsolt Forced Swimming tests were conducted for behavioral assessment. Following behavioral tests, rats were sacrificed under general anesthesia, and cortices were isolated for analysis of macro and trace element levels (ICP/MS). Results: In behavioral tests, CONT-SD rats exhibited superior performance in the Morris Water Maze test compared to CONT-WIS rats, but displayed increased depressive behaviors following social isolation, as evident in the Porsolt Forced Swimming test (p < 0.05). ISO-SD rats showed elevated levels of Co and Cu, along with reduced levels of Cs and As, compared to ISO-WIS rats. Moreover, isolation resulted in decreased Cu and Mo levels but increased Rb levels in WIS rats. Comparison of trace element levels in naïve groups from different strains revealed lower Zn levels in the WIS group compared to SD rats. Discussion: The findings suggest that the SD strain learns faster, but is more susceptible to depression after isolation compared to the WIS strain. Increased Co and Cu levels in ISO-SD align with previous findings, indicating potential trace element involvement in stress responses. Understanding these mechanisms could pave the way for preventive treatment strategies or therapeutic targets against the consequences of stressors, contributing to research and measures promoting a balanced diet to mitigate neurobehavioral abnormalities associated with social isolation in the future.

Nutritional considerations in major depressive disorder: current evidence and functional testing for clinical practice

Depression is a multifaceted condition with diverse underlying causes. Several contributing and inter-related factors such as genetic, nutritional, neurological, physiological, gut-brain-axis, metabolic and psychological stress factors play a role in the pathophysiology of depression. This review aims to highlight the role that nutritional factors play in the aetiology of depression. Secondly, we discuss the biomedical and functional pathology tests which measure these factors, and the current evidence supporting their use. Lastly, we make recommendations on how practitioners can incorporate the latest evidence-based research findings into clinical practice. This review highlights that diet and nutrition greatly affect the pathophysiology of depression. Nutrients influence gene expression, with folate and vitamin B12 playing vital roles in methylation reactions and homocysteine regulation. Nutrients are also involved in the tryptophan/kynurenine pathway and the expression of brain-derived neurotrophic factor (BDNF). Additionally, diet influences the hypothalamic-pituitary-adrenal (HPA) response and the composition and diversity of the gut microbiome, both of which have been implicated in depression. A comprehensive dietary assessment, combined with appropriate evaluation of biochemistry and blood pathology, may help uncover contributing factors to depressive symptoms. By employing such an approach, a more targeted and personalised treatment strategy can be devised, ultimately leading to improved patient outcomes.

The Important Role of Zinc in Neurological Diseases

Zinc is one of the most abundant metal ions in the central nervous system (CNS), where it plays a crucial role in both physiological and pathological brain functions. Zinc promotes antioxidant effects, neurogenesis, and immune system responses. From neonatal brain development to the preservation and control of adult brain function, zinc is a vital homeostatic component of the CNS. Molecularly, zinc regulates gene expression with transcription factors and activates dozens of enzymes involved in neuronal metabolism. During development and in adulthood, zinc acts as a regulator of synaptic activity and neuronal plasticity at the cellular level. There are several neurological diseases that may be affected by changes in zinc status, and these include stroke, neurodegenerative diseases, traumatic brain injuries, and depression. Accordingly, zinc deficiency may result in declines in cognition and learning and an increase in oxidative stress, while zinc accumulation may lead to neurotoxicity and neuronal cell death. In this review, we explore the mechanisms of brain zinc balance, the role of zinc in neurological diseases, and strategies affecting zinc for the prevention and treatment of these diseases.

Promising leads and pitfalls: a review of dietary supplements and hormone treatments to prevent postpartum blues and postpartum depression

Prevention of postpartum depression (PPD) is important because it typically has a 13% prevalence rate, impactful immediate symptoms with greater risk of suicide, and higher long-term risk of psychiatric symptoms in both the mother and family. There are no universal approaches across all childbearing women that have proven to be preventative for PPD, so it is hoped that dietary and/or hormonal interventions will be developed. There are some effective preventative approaches for PPD, such as psychotherapy and medical management, for the highest risk cases, like when there is a past history of a major depressive episode. The purpose is to review studies that assess dietary and hormonal interventions for prevention of PPD and/or postpartum blues, a high-risk state for PPD. Studies that assess dietary and hormonal interventions for prevention of PPD which included a comparison group were reviewed, including omega-3 fatty acids, mineral and vitamin supplements, amino acid combinations, allopregnanolone, progesterone, and thyroxine. Presently, development of dietary supplements and hormonal products for prevention of PPD is at an early stage with most trials showing results that are either preliminary, not definitive, trend level or variable across studies. Even so, a few directions are not recommended for further investigation such as progesterone and thyroxine. On the other hand, studies of allopregnanolone for prophylaxis of PPD are needed. Also, given the number of trend level findings and the multifactorial etiology of PPD, it may be prudent to investigate combined interventions rather than monotherapies. There is still a major need to develop a dietary supplement that creates resiliency against the biological changes in early postpartum associated with risk for mood disorders and/or PPD.

Serum Levels of Vitamin D, Calcium, Magnesium, and Copper, and their Relations with Mental Health and Sexual Function in Pregnant Iranian Adolescents

Pregnant adolescents are at risk for micronutrient deficiency, psychological problems, and sexual dysfunction. We aimed to determine serum levels of vitamin D, calcium, magnesium, and copper, and also their relations with stress, anxiety, depression, and sexual function in pregnant adolescents. This cross-sectional study was conducted on two hundred 11-19-year-old healthy singleton pregnant women at gestational age of 26-32 weeks, who were covered by public health centers in Tabriz, Iran. Depression was assessed using the Edinburgh Postnatal Depression Scale (EPDS), anxiety and stress using the Depression, Anxiety and Stress Scale-21 (DASS-21), and sexual function using the Female Sexual Function Index (FSFI). The independent t test was employed to determine the relations. Serum levels of vitamin D were found to be deficient (< 20 ng/ml) in 59% of the participants and insufficient (20-29 ng/ml) in 33%. Normal serum levels of calcium were observed in 67% of the participants, those of magnesium in 89.5%, and those of copper in 86%. Moreover, moderate-to-severe anxiety was observed in 38.5%, moderate-to-severe stress in 22.5%, depression in 30%, and sexual dysfunction in 68%. Mean serum level of copper was higher in women with depression compared with those with no depression (100.6 vs 93.0, P = 0.048). No other statistically significant associations were found between serum levels of any of the micronutrients and anxiety, stress, depression, and sexual dysfunction (P > 0.05). The present study indicates high prevalence of micronutrient (especially vitamin D) deficiency, psychological problems, and sexual dysfunction among the pregnant adolescents. It also indicates an association between high serum copper level and depression.

Adaptogenic effects of curcumin on depression induced by moderate and unpredictable chronic stress in mice

Curcumin has been investigated for the prevention and treatment of diseases due to its anti-oxidant, anti-inflammatory, immunomodulatory, and neuroprotective actions. This current study evaluated the adaptogenic effects of a subchronic oral administration of curcumin to Swiss mice that were submitted to a chronic unpredictable mild stress (CUMS) model of depression. Four groups of mice (vehicle control, CO; curcumin control, COC; CUMS + vehicle, CUMS; CUMS + curcumin, CUMSC) were evaluated for the biochemical parameters. The CUMS model caused depressive-like and anxiety-like behavior in the animals when they were viewed in the Forced Swimming Test and in the Elevated Plus Maze Test. The treatments with curcumin prevented the depressive-like behavior in the Forced Swimming Test and they had anxiolytic effects on the non-stressed animals. This was confirmed by the Elevated Plus Maze Test. Curcumin showed antioxidant effects (IC₅₀ of 38.86 ± 1.78 μg/mL) in the in vitro DPPH (2,2-diphenyl-1-picryl-hydrozole) test. The compound also showed antioxidant effects in vivo, increasing the catalase (CAT) levels in the brains of the stressed animals. The biochemical analyses did not reveal potential renal and hepatic damage. Together, these results have demonstrated the antidepressant and antioxidant effects of curcumin, highlighting in this mice model, the compound's novel adaptogenic potential.

Trace elements differences in the depression sensitive and resilient rat models

The etiology and pathophysiology of depressive disorders remain unclear. Increasing evidences have demonstrated that trace elements such as zinc, magnesium, iron, calcium, selenium, manganese and chromium play vital roles in depressive symptoms. We used a Chronic Unpredictable Mild Stress (CUMS) model to simulate social pressure in rat model and compared the levels of trace elements in the plasma and brain. The concentrations trace elements were evaluated using inductively coupled plasma mass spectrometry or inductively coupled plasma-atomic emission spectrometry. In the CUMS model, 57% (12/21) of rats showed no significant decrease in sucrose preference and were grouped as CUMS-resilient; otherwise, CUMS-sensitive. The resilient group had higher levels of iron, sodium, sulfur, manganese and cobalt than the sensitive group in the brain samples (P < 0.05). The sensitive group had lower levels of calcium, potassium, sulfur, selenium and cobalt than the resilient groups, in the plasma samples. The higher levels of iron, calcium, selenium, manganese and cobalt in the resilient group indicated these trace elements might be protective against the development of depressive symptoms in response to stress.

Relationships between depression and food intake in climacteric women

Objective: This study evaluated the associations between food intake - especially omega-3 (n-3) - and depressive symptoms in climacteric women.Methods: Four hundred climacteric women were included in this research. The Kupperman Index, the Center for Epidemiologic Studies Depression Scale, and a 3-day food diary were used to investigate climacteric symptoms, depressive symptoms, and food intake, respectively. Sociodemographic, clinical, and anthropometric variables were also explored.Results: Statistically significant associations were observed between depression and climacteric symptoms, climacteric phase, previous history of depression, antidepressant drug use, family income, sleep pattern, and consumption of carbohydrates, fiber, polyunsaturated fatty acids, magnesium, zinc, and vitamins C, D, and B12. No association was observed between n-3 consumption and depression.Conclusion: Climacteric symptoms and food intake are important factors linked to depression during the climacteric period. Further studies are needed to clarify the changes in this phase of women's lives, as well as to investigate the role of the diet in the depression treatment or prevention.

Vitamin D deficiency mediates the relationship between dietary patterns and depression: a case-control study

BACKGROUND

Depression is a major contributor to disability-adjusted life years (DALY) lost in the world. Dietary patterns are widely used to investigate diet-disease relations. In the current study, the relationship between dietary patterns and depression was investigated. Besides, the role of serum vitamin D, zinc, magnesium, and total antioxidant capacity as potential mediatory variables was studied.

METHODS

It was an individually matched case-control study in which 330 depressed and healthy subjects were recruited for the extraction of dietary patterns; psychiatrists diagnosed major depressive disorder, using the criteria of the Diagnostic and Statistical Manual of Mental Disorders. Serum vitamin D and aforementioned biomarkers were measured for a number of randomly selected depressed and healthy individuals. We conducted mediatory analysis by regression models.

RESULTS

Healthy and unhealthy dietary patterns were associated with the lower and higher odds of depression (OR 0.39, CI 0.17-0.92 and OR 2.6, CI 1.04-6.08), respectively. A significant relationship between serum vitamin D with depression after adjusting for potential confounders was observed as well (OR 0.93, CI 0.87-0.99). According to the mediatory analysis the unhealthy dietary patterns were related to depression via altering the serum vitamin D concentration.

CONCLUSION

This study showed that vitamin D deficiency mediates the relationship between unhealthy dietary patterns and depression. However, to get a clearer result further prospective studies are required.

An Advanced Formulation of a Magnesium Dietary Supplement Adapted for a Long-Term Use Supplementation Improves Magnesium Bioavailability: In Vitro and Clinical Comparative Studies

While general recommendations are for 300-mg magnesium intake a day, an advanced low-dose formulation of magnesium chloride, ChronoMag®, was designed to provide 100 mg of magnesium element, thus decreasing the risk of gastrointestinal side effects and allowing long-term supplementation in health conditions related to low magnesium levels. The present study aimed to compare magnesium release profile and bioavailability between this patented low-dose continuous-release magnesium chloride tablet (100 mg magnesium element) and a reference tablet at the usually prescribed dose (300 mg magnesium element). Magnesium release profile was determined by dissolving the tablets in solutions simulating the gastrointestinal tract environment. A randomized double-blind crossover controlled trial of ChronoMag® versus reference tablet (3 × 100 mg magnesium element tablets) in 12 normo-magnesemic healthy volunteers was conducted to evaluate the bioavailability of the patented magnesium chloride tablets (two 50 mg magnesium tablets, once-a-day intake). While the reference tablet released 100% of its magnesium within 1 h of dissolution, release from the magnesium chloride formulation was continuous for 6 h. Cumulative urinary magnesium levels compared to those with the reference tablet were 76% (0-5 h), 89% (0-10 h), and 87% (0-24 h). Elimination after 24 h was fairly similar with both supplements. Our results suggest that the new magnesium chloride formulation, providing continuous low-dose magnesium release throughout the gastrointestinal tract, improves absorption and bioavailability. This formulation conforms to the physiological mechanism of magnesium absorption throughout the digestive tract, allowing high absorption, and may improve gastrointestinal tolerance in long-term use.

Micronutrient intake adequacy and depression risk in the SUN cohort study

PURPOSE

The aim of the study was to prospectively assess the association between micronutrient intake adequacy and risk of depression.

METHODS

This dynamic cohort study involves Spanish university graduates (SUN Project). Dietary intake was assessed at baseline and after 10 years of follow-up with a semi-quantitative food frequency questionnaire. Micronutrient intake adequacy for vitamins B1, B2, B3, B6, B12, C, A, D, E, folic acid, zinc, iodine, selenium, iron, calcium, potassium, phosphorus, magnesium and chrome was estimated. Inadequate intake for each nutrient was defined when the intake of the nutrient was below the estimated average requirements (EAR) if available or the adequate intake levels, if EARs were not available. We compared participants with inadequate intake for ≥4 nutrients vs. those with one nutrient. Participants were classified as having incident depression if they had no previous history of depression or antidepressants use at baseline, but they reported during follow-up a new clinical diagnosis of depression by a physician, use of antidepressant drugs, or both. Time-dependent multivariable Cox regression models were fitted.

RESULTS

After a median follow-up of 8.5 years, 953 new cases of depression were observed among 13,983 participants. Participants with inadequate intake for ≥4 nutrients showed a significantly higher risk of depression [multivariable hazard ratio (HR) = 1.37; 95% confidence interval (CI) 1.01-1.85]. When the analyses were updated with repeated assessments of intakes, the association was attenuated and it was no longer statistically significant (Multivariable HR = 1.11; 95% CI 0.82-1.51).

CONCLUSIONS

Micronutrient inadequacy in four or more micronutrients could exert a moderate role in the development of depression.

Zinc, Magnesium, Selenium and Depression: A Review of the Evidence, Potential Mechanisms and Implications

Micronutrient deficiency and depression are major global health problems. Here, we first review recent empirical evidence of the association between several micronutrients—zinc, magnesium, selenium—and depression. We then present potential mechanisms of action and discuss the clinical implications for each micronutrient. Collectively, empirical evidence most strongly supports a positive association between zinc deficiency and the risk of depression and an inverse association between zinc supplementation and depressive symptoms. Less evidence is available regarding the relationship between magnesium and selenium deficiency and depression, and studies have been inconclusive. Potential mechanisms of action involve the HPA axis, glutamate homeostasis and inflammatory pathways. Findings support the importance of adequate consumption of micronutrients in the promotion of mental health, and the most common dietary sources for zinc and other micronutrients are provided. Future research is needed to prospectively investigate the association between micronutrient levels and depression as well as the safety and efficacy of micronutrient supplementation as an adjunct treatment for depression.

Analysis of Relations Between the Level of Mg, Zn, Ca, Cu, and Fe and Depressiveness in Postmenopausal Women

Numerous observations suggest a possible connection between the levels of Mg, Zn, Fe, and Zn and the incidence of depressive symptoms. Depression is two to three times more common in women than in men. The menopausal period is extremely conducive to depressive disorders. The aim of this study was to assess the severity of depressive symptoms in postmenopausal women depending on the levels of Mg, Zn, Ca, Cu, and Fe. The study included 198 healthy postmenopausal women at the average age of 56.26 ± 5.55 years. In the first part of the study, standardized research tools were used, namely the Primary Care Evaluation of Mental Disorders (PRIME-MD) and the Beck Depression Inventory (BDI). The second part involved biochemical analysis of Mg, Zn, Ca, Cu, and Fe levels in blood serum. The lowest Cu levels were observed in women without depressive symptoms (1.07 ± 0.22 mg/l) and the highest in those with severe depressive symptoms (1.19 ± 0.17 mg/l), (p ≤ 0.05). The lowest Mg levels were observed in women with depressive symptoms (14.28 ± 2.13 mg/l), and the highest in women without depressive symptoms (16.30 ± 3.51 mg/l), (p ≤ 0.05). The average serum Mg levels (15.75 ± 3.23 mg/l) decreased compared to the reference values (18.77-24 mg/l). What is striking is a potential relation between the levels of Mg and Cu and depressiveness. Our results indicate to a higher vulnerability to depression in a group of women with lower levels of Mg and higher levels of Cu.

Effects of zinc and magnesium supplements on postpartum depression and anxiety: A randomized controlled clinical trial

Postpartum anxiety and depression are prevalent disorders. The authors of this study aimed to determine the effects of zinc and magnesium supplements on depressive symptoms and anxiety in postpartum women referred to three governmental, educational hospitals in Tabriz, Iran during 2014-2015. In this triple-blind, randomized, controlled clinical trial, the participants were randomly assigned to the zinc sulfate, magnesium sulfate, and placebo groups (n = 33 per group). The intervention groups received a 27-mg zinc sulfate tablet or 320-mg magnesium sulfate tablet per day for 8 weeks, whereas the control group received a placebo tablet each day during the same period. The Edinburgh Postnatal Depression Scale and the Spielberger State-Trait Anxiety Inventory were completed before and 8 weeks after the intervention. Blood samples were drawn from each participant to determine serum levels of zinc and magnesium before intervention at 48 hours after delivery. Also, a 24-hour dietary questionnaire was used during the first and last 3 days of the intervention. Adjusting for baseline scores as well as zinc and magnesium serum levels, no significant difference was observed between groups 8 weeks after delivery in mean scores of depressive symptoms (p = .553), state anxiety (p = .995), and trait anxiety (p = .234). This study concluded magnesium and zinc did not reduce postpartum anxiety and depressive symptoms.

Effects of Physical Activity on Trace Elements and Depression Related Biomarkers in Children and Adolescents

Not much is known about the role of physical activity (PA), obesity related variables, and trace elements as potential risk factors affecting neurotransmitters in schoolchildren with depression. Our objective was to investigate the effect of physical activity (PA) on depressive symptoms in children and adolescents. Also, we aimed to study the association of demographic variables, serum levels of Copper (Cu), Zinc (Zn), serotonin, and salivary cortisol with depression in this population. One hundred and fifty school children (90 boys and 60 girls) aged 7-18 years were recruited for this study. All participants were evaluated for depression using CDI-score analysis. Their physical activity levels were checked using pre-validated questionnaires. The serum levels of Copper (Cu), Zinc (Zn), cortisol, and serotonin were estimated using atomic absorption, and immunoassay techniques. About 48.7 % of the study population had depressive symptoms (CDI-score; ≥13), and were classified into mild, moderate, and severe categories. Older children, especially girls, had higher levels of depression. Participants with moderate and severe depression had significantly lower physical activity, serotonin, and zinc levels, Zn/Cu ratios, and significantly higher copper and cortisol levels. Physically active boys showed significantly lower depressive CDI-scores and improvement in cortisol, serotonin, Cu, and Zn concentrations compared to girls of sedentary life style. CDI- scores correlated positively with BMI, cortisol and Cu, and negatively with PA, serotonin and Zn concentrations. BMI, cortisol, serotonin, Cu and Zn, could explain about 59.3-79 % of the depressive symptoms among schoolchildren, according to stepwise regression analysis. This was especially true in especially older girls. PA and an adequate balance in Zn and Cu levels, plays a positive role in improving CDI-depressive score, BMI, serotonin and cortisol levels among schoolchildren.

The Importance of Magnesium in the Human Body: A Systematic Literature Review

Magnesium, the second and fourth most abundant cation in the intracellular compartment and whole body, respectively, is of great physiologic importance. Magnesium exists as bound and free ionized forms depending on temperature, pH, ionic strength, and competing ions. Free magnesium participates in many biochemical processes and is most commonly measured by ion-selective electrode. This analytical approach is problematic because complete selectivity is not possible due to competition with other ions, i.e., calcium, and pH interference. Unfortunately, many studies have focused on measurement of total magnesium rather than its free bioactive form making it difficult to correlate to disease states. This systematic literature review presents current analytical challenges in obtaining accurate and reproducible test results for magnesium.

A longitudinal analysis of diet quality scores and the risk of incident depression in the SUN Project

BACKGROUND

Some studies have pointed out that several dietary patterns could be associated with a reduced risk of depression among adults. This association seems to be consistent across countries, cultures and populations. The objective of the study was to compare and to establish the type of relationship between three diet quality scores and depression in the SUN (Seguimiento Universidad de Navarra) Cohort study.

METHODS

We performed a dynamic cohort study based on Spanish university graduates free of depression at baseline. Dietary intake was repeatedly assessed at baseline and after 10 years of follow-up with a validated semi-quantitative food-frequency questionnaire. Three previously described diet quality scores: Mediterranean Diet Score (MDS), Pro-vegetarian Dietary Pattern (PDP) and Alternative Healthy Eating Index-2010 (AHEI-2010) were built. Participants were classified as having depression if they reported a new clinical diagnosis of depression by a physician or initiated the use of an antidepressant drug during follow-up. Time-dependent Cox regression models with cumulative averages of diet and restricted cubic splines were used to estimate hazard ratios of depression according to quintiles of adherence to the MDS, PDP and AHEI-2010.

RESULTS

One thousand and fifty one incident cases of depression were observed among 15,093 participants from the SUN Cohort after a median follow-up of 8.5 years. Inverse and significant associations were observed between the three diet quality scores and depression risk. The hazard ratios and 95 % confidence intervals for extreme quintiles (fifth versus first) of updated adherence to MDS, PDP and AHEI-2010 were 0.84 (0.69-1.02), 0.74 (0.61-0.89) and 0.60 (0.49-0.72), respectively. The dose-response analyses showed non-linear associations, suggesting that suboptimal adherence to these dietary patterns may partially be responsible for increased depression risk.

CONCLUSIONS

Better adherence to the MDS, PDP and AHEI-2010 was associated with a reduced risk of depression among Spanish adults. However, our data suggested a threshold effect so that although the risk of depression was reduced when comparing moderate versus lower adherence, there was not much extra benefit for the comparison between moderate and high or very high adherence.

Biomarkers of Nutrition for Development (BOND)-Zinc Review

Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. Cellular, tissue, and whole-body zinc homeostasis is tightly controlled to sustain metabolic functions over a wide range of zinc intakes, making it difficult to assess zinc insufficiency or excess. The BOND (Biomarkers of Nutrition for Development) Zinc Expert Panel recommends 3 measurements for estimating zinc status: dietary zinc intake, plasma zinc concentration (PZC), and height-for-age of growing infants and children. The amount of dietary zinc potentially available for absorption, which requires an estimate of dietary zinc and phytate, can be used to identify individuals and populations at risk of zinc deficiency. PZCs respond to severe dietary zinc restriction and to zinc supplementation; they also change with shifts in whole-body zinc balance and clinical signs of zinc deficiency. PZC cutoffs are available to identify individuals and populations at risk of zinc deficiency. However, there are limitations in using the PZC to assess zinc status. PZCs respond less to additional zinc provided in food than to a supplement administered between meals, there is considerable interindividual variability in PZCs with changes in dietary zinc, and PZCs are influenced by recent meal consumption, the time of day, inflammation, and certain drugs and hormones. Insufficient data are available on hair, urinary, nail, and blood cell zinc responses to changes in dietary zinc to recommend these biomarkers for assessing zinc status. Of the potential functional indicators of zinc, growth is the only one that is recommended. Because pharmacologic zinc doses are unlikely to enhance growth, a growth response to supplemental zinc is interpreted as indicating pre-existing zinc deficiency. Other functional indicators reviewed but not recommended for assessing zinc nutrition in clinical or field settings because of insufficient information are the activity or amounts of zinc-dependent enzymes and proteins and biomarkers of oxidative stress, inflammation, or DNA damage.