Zinc Status of Vegetarians during Pregnancy: A Systematic Review of Observational Studies and Meta-Analysis of Zinc Intake

Protective effects of polysaccharide extracted from green alga Chaetomorpha linum against zinc and copper-induced testicular toxicity in male mice

This study aimed to investigate the effects of copper (CuSO4) and zinc (ZnSO4) overload on male reproductive toxicity and the potential of a polysaccharide extracted from green alga Chaetomorpha linum (PS) in mitigating their toxicities. Adult male mice strain of 25 ± 2 g of weight was subdivided into eight groups. Group 1 served as control; group 2 received PS (200 mg/kg), and groups 3 and 4 received intraperitoneally zinc (60 mg/kg b.w) and copper (33 mg/kg b.w), respectively. Group 5 received both zinc (60 mg/kg b.w) and copper (33 mg/kg b.w), group 6 received zinc (60 mg/kg b.w) associated with PS (200 mg/kg), group 7 received copper (33 mg/kg b.w) associated with PS (200 mg/kg), and group 8 received zinc (60 mg/kg b.w) and copper (33 mg/kg b.w) associated with PS (200 mg/kg). Results suggested that ZnSO4 and CuSO4 significantly decreased the functional sperm parameters. Furthermore, extended exposure to these elements increased oxidative stress biomarkers, including malondialdehyde (MDA) as a measure of lipid peroxidation and advanced oxidation protein products (AOPP) indicating protein oxidative damage. This process also reduces the activity of antioxidant enzymes such as glutathione (GSH) and glutathione peroxidase (GPx), which neutralize and catalyze free radicals. Histopathological changes in mice testis were also studied. However, the co-treatments with PS significantly reduced these effects and promoted the reproductive parameters in male mice. In conclusion, PS exhibited protective effects against zinc and copper-induced reproductive toxicity, making it a potential adjuvant treatment for testicular toxicity.

Knowledge, attitude and practices of health professionals with regard to plant-based diets in pregnancy: a scoping review

OBJECTIVE

This scoping review aimed to systematically map and describe the existing evidence regarding the knowledge, attitudes and practices of health professionals with regard to plant-based diets during pregnancy and to highlight areas for further research.

DESIGN

Following a pre-registered protocol, online databases were searched using a comprehensive search string, in addition to selected grey literature sources, and reference lists of included studies. The studies were independently screened for eligibility by two authors, SM and JM. Data from all eligible studies were charted by the first author, and a narrative summary was performed.

SETTING

Maternal health care services.

RESULTS

Ten studies were included for review, from New Zealand (n 2), Australia (n 2), Germany, Netherlands, United Kingdom, France, Italy and Peru. Most of these studies were observational, employed various validated and non-validated survey instruments, interviews and one education intervention. Knowledge was the most frequently assessed outcome in the reviewed studies. Health professionals' knowledge of plant-based nutrition in pregnancy was reported to be limited and frequently attributed to a lack of nutrition training. Participants' personal dietary patterns and work specialisation appear to be closely associated with their knowledge, attitudes and practices regarding plant-based diets.

CONCLUSION

This review identified a significant research gap regarding health professionals' practices in relation to plant-based diets during pregnancy. Additionally, this review has demonstrated the need for further research, awareness and practice protocols to promote high-quality care and education or professional development to address the prevalent lack of knowledge among this group.

Cardiovascular health and cancer risk associated with plant based diets: An umbrella review

CONTEXT

Cardiovascular diseases (CVDs) and cancer are the two main leading causes of death and disability worldwide. Suboptimal diet, poor in vegetables, fruits, legumes and whole grain, and rich in processed and red meat, refined grains, and added sugars, is a primary modifiable risk factor. Based on health, economic and ethical concerns, plant-based diets have progressively widespread worldwide.

OBJECTIVE

This umbrella review aims at assessing the impact of animal-free and animal-products-free diets (A/APFDs) on the risk factors associated with the development of cardiometabolic diseases, cancer and their related mortalities.

DATA SOURCES

PubMed and Scopus were searched for reviews, systematic reviews, and meta-analyses published from 1st January 2000 to 31st June 2023, written in English and involving human subjects of all ages. Primary studies and reviews/meta-analyses based on interventional trials which used A/APFDs as a therapy for people with metabolic diseases were excluded.

DATA EXTRACTION

The umbrella review approach was applied for data extraction and analysis. The revised AMSTAR-R 11-item tool was applied to assess the quality of reviews/meta-analyses.

RESULTS

Overall, vegetarian and vegan diets are significantly associated with better lipid profile, glycemic control, body weight/BMI, inflammation, and lower risk of ischemic heart disease and cancer. Vegetarian diet is also associated with lower mortality from CVDs. On the other hand, no difference in the risk of developing gestational diabetes and hypertension were reported in pregnant women following vegetarian diets. Study quality was average. A key limitation is represented by the high heterogeneity of the study population in terms of sample size, demography, geographical origin, dietary patterns, and other lifestyle confounders.

CONCLUSIONS

Plant-based diets appear beneficial in reducing cardiometabolic risk factors, as well as CVDs, cancer risk and mortality. However, caution should be paid before broadly suggesting the adoption of A/AFPDs since the strength-of-evidence of study results is significantly limited by the large study heterogeneity alongside the potential risks associated with potentially restrictive regimens.

Neurodevelopmental Consequences of Dietary Zinc Deficiency: A Status Report

Zinc is a tightly regulated trace mineral element playing critical roles in growth, immunity, neurodevelopment, and synaptic and hormonal signaling. Although severe dietary zinc deficiency is relatively uncommon in the United States, dietary zinc deficiency is a substantial public health concern in low- and middle-income countries. Zinc status may be a key determinant of neurodevelopmental processes. Indeed, limited cohort studies have shown that serum zinc is lower in people diagnosed with autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and depression. These observations have sparked multiple studies investigating the mechanisms underlying zinc status and neurodevelopmental outcomes. Animal models of perinatal and adult dietary zinc restriction yield distinct behavioral phenotypes reminiscent of features of ASD, ADHD, and depression, including increased anxiety and immobility, repetitive behaviors, and altered social behaviors. At the cellular and molecular level, zinc has demonstrated roles in neurogenesis, regulation of cellular redox status, transcription factor trafficking, synaptogenesis, and the regulation of synaptic architecture via the Shank family of scaffolding proteins. Although mechanistic questions remain, the current evidence suggests that zinc status is important for adequate neuronal development and may be a yet overlooked factor in the pathogenesis of several psychiatric conditions. This review aims to summarize current knowledge of the role of zinc in the neurophysiology of the perinatal period, the many cellular targets of zinc in the developing brain, and the potential consequences of alterations in zinc homeostasis in early life.

Major and trace mineral composition of milk from lactating women following vegan, vegetarian and omnivore diets

Approximately one-in-ten reproductive age adults in the USA follow a plant-based diet, yet there is limited information on the influence of vegan and vegetarian diets on the mineral composition of breast milk. This study explored the major and trace mineral composition in breast milk and associations with maternal diet patterns. We used a cross-sectional design to collect a single sample of breast milk from individuals following vegan (n 23), vegetarian (n 19) and omnivore (n 21) diet patterns. Plant-based diet (n 42) was defined as following either vegan or vegetarian diets. Sixteen minerals were assessed using inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Data were evaluated using traditional statistical techniques and five different machine learning approaches. The distribution of Se (median; quartile 1 and 3) was significantly different between groups (vegetarians 21, 18-26 µg/l; vegans 19, 18-25 µg/l and omnivores 17, 14-20 µg/l; P = 0·007) using a Kruskal-Wallis test. Machine learning techniques also identified Se as a potential biomarker for differentiating breast milk by maternal diet pattern. Individuals following a plant-based diet generally had a lower BMI, higher breast milk Se and lower breast milk I and Fe concentrations compared with those following omnivore diets. This suggests that maternal dietary pattern (plant-based v. omnivore) may be helpful clinical information to consider when caring for the breast-feeding dyad, with the strongest evidence related to differences in Se concentration.

Association of COVID-19 mortality with serum selenium, zinc and copper: Six observational studies across Europe

Introduction

Certain trace elements are essential for life and affect immune system function, and their intake varies by region and population. Alterations in serum Se, Zn and Cu have been associated with COVID-19 mortality risk. We tested the hypothesis that a disease-specific decline occurs and correlates with mortality risk in different countries in Europe.

Methods

Serum samples from 551 COVID-19 patients (including 87 non-survivors) who had participated in observational studies in Europe (Belgium, France, Germany, Ireland, Italy, and Poland) were analyzed for trace elements by total reflection X-ray fluorescence. A subset (n=2069) of the European EPIC study served as reference. Analyses were performed blinded to clinical data in one analytical laboratory.

Results

Median levels of Se and Zn were lower than in EPIC, except for Zn in Italy. Non-survivors consistently had lower Se and Zn concentrations than survivors and displayed an elevated Cu/Zn ratio. Restricted cubic spline regression models revealed an inverse nonlinear association between Se or Zn and death, and a positive association between Cu/Zn ratio and death. With respect to patient age and sex, Se showed the highest predictive value for death (AUC=0.816), compared with Zn (0.782) or Cu (0.769).

Discussion

The data support the potential relevance of a decrease in serum Se and Zn for survival in COVID-19 across Europe. The observational study design cannot account for residual confounding and reverse causation, but supports the need for intervention trials in COVID-19 patients with severe Se and Zn deficiency to test the potential benefit of correcting their deficits for survival and convalescence.

Prenatal Zinc Deficient Mice as a Model for Autism Spectrum Disorders

Epidemiological studies have shown a clear association between early life zinc deficiency and Autism Spectrum Disorders (ASD). In line with this, mouse models have revealed prenatal zinc deficiency as a profound risk factor for neurobiological and behavioral abnormalities in the offspring reminiscent of ASD behavior. From these studies, a complex pathology emerges, with alterations in the gastrointestinal and immune system and synaptic signaling in the brain, as a major consequence of prenatal zinc deficiency. The features represent a critical link in a causal chain that leads to various neuronal dysfunctions and behavioral phenotypes observed in prenatal zinc deficient (PZD) mice and probably other mouse models for ASD. Given that the complete phenotype of PZD mice may be key to understanding how non-genetic factors can modify the clinical features and severity of autistic patients and explain the observed heterogeneity, here, we summarize published data on PZD mice. We critically review the emerging evidence that prenatal zinc deficiency is at the core of several environmental risk factors associated with ASD, being mechanistically linked to ASD-associated genetic factors. In addition, we highlight future directions and outstanding questions, including potential symptomatic, disease-modifying, and preventive treatment strategies.

Nutrient Composition of a Selection of Plant-Based Ground Beef Alternative Products Available in the United States

BACKGROUND

Sales of plant-based foods intended as direct replacements for animal products have been growing in the United States. Little is known about the nutritional quality of these products.

OBJECTIVE

Our aim was to evaluate the nutritional quality of a selection of plant-based ground beef alternative products available in the US marketplace and compare it with the nutrient content of ground beef.

DESIGN

We conducted an analysis of the food and nutrient composition information available for plant-based ground beef alternative products in the 2020 version of the University of Minnesota Nutrition Coordinating Center Food and Nutrient Database.

PARTICIPANT/SETTING

We analyzed a selection of 37 plant-based ground beef alternative products available in the United States in 2019.

MAIN OUTCOMES MEASURES

Food product content of energy, macronutrients, fatty acids, vitamins, minerals and selected additional food components was measured.

STATISTICAL ANALYSIS

The percent Daily Value (DV) per 3-ounce cooked portion of each product was determined for nutrients with a DV. The median, interquartile range (IQR), minimum, and maximum nutrient values were calculated for all products by classification as vegan and nonvegan.

RESULTS

The median saturated fat content of the plant-based ground beef alternatives products as a %DV was 4% (IQR 2%). Vitamin and minerals for which median %DV values for plant-based ground beef alternative products were 10% or higher included folate (10%, IQR 10%), niacin (21%, IQR 7%), iron (10%, IQR 5%), phosphorous (10%, IQR 4%), sodium (18%, IQR 7%), manganese (20%, IQR 20%), and copper (24%, IQR 10%). The median dietary fiber content of the plant-based ground beef alternative products was 15% of the DV (IQR 6%). Most of the products contained less protein, zinc, and vitamin B12 than ground beef.

CONCLUSIONS

The major brands of plant-based ground beef alternative products examined in this study have nutritional strengths as well as some shortcomings. Additional research to examine a broader set of plant-based meat alternative products, such as those designed as substitutes for chicken and pork, is warranted.

Vegetarian diets during pregnancy, and maternal and neonatal outcomes

BACKGROUND

Vegetarian diets are becoming increasingly popular in the USA. Limited research has examined the health consequences of vegetarian diets during pregnancy. We comprehensively examined associations of vegetarianism during pregnancy with maternal and neonatal outcomes.

METHODS

We used data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development's Fetal Growth Studies-Singletons, a prospective multi-site cohort of 1948 low-risk pregnant women of four races/ethnicities (White, Black, Hispanic, Asian/Pacific Islander) in the USA (2009-2013). Vegetarianism was self-reported and also defined based on dietary patterns measured using a self-administered first-trimester food-frequency questionnaire (full [lacto-ovo and vegan], pesco-, semi- and non-vegetarians). Neonatal outcomes included birthweight and neonatal anthropometric measures, small for gestational age, small for gestational age with neonatal morbidity and preterm delivery. Maternal outcomes included gestational weight gain, gestational diabetes, hypertensive disorders of pregnancy and gestational anaemia.

RESULTS

Ninety-nine (6.2%) women self-reported being vegetarian. The diet-based definition identified 32 (2.0%) full vegetarians, 7 (0.6%) pesco-vegetarians and 301 (17.6%) semi-vegetarians. Neonates of diet-based full vegetarians had higher odds of being small for gestational age [adjusted odds ratio (ORadj) = 2.51, 95% confidence interval: 1.01, 6.21], but not of being small for gestational age with a postnatal morbidity. Full vegetarians had marginally increased the odds of inadequate second-trimester gestational weight gain (ORadj = 2.24, 95% confidence interval: 0.95, 5.27).

CONCLUSION

Vegetarian diets during pregnancy were associated with constitutionally smaller neonatal size, potentially via the mothers' reduced gestational weight gain. Notably, vegetarianism was not associated with small-for-gestational-age-related morbidities or other adverse maternal outcomes.

Associations between Maternal Dietary Patterns and Perinatal Outcomes: A Systematic Review and Meta-Analysis of Cohort Studies

The aim was to systematically review and meta-analyze prospective cohort studies investigating the relation between maternal dietary patterns during pregnancy with pregnancy and birth outcomes. PubMed, Scopus, and ISI Web of Science were searched from inception until October 2019 for eligible studies. Studies reporting relative risk, ORs, or incidences (for binary data) or means ± SDs or B-coefficients (for continuous outcomes) comparing the highest and lowest adherence with maternal dietary patterns were included. Dietary patterns were categorized as "healthy," "unhealthy," or "mixed." No language restrictions were applied. Study-specific effect sizes with SEs for outcomes of interest were pooled using a random-effects model. Quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Sixty-six relevant publications were included. A higher maternal adherence to a healthy diet was associated with a reduced risk of gestational hypertension (14%, P < 0.001), maternal depression (40%, P = 0.004), low birth weight (28%, P = 0.001), preterm birth (56%, P < 0.001), higher gestational weight gain (Hedges' g: 0.15; P = 0.01), and birth weight (Hedges' g: 0.19; P = 0.007). Higher maternal adherence to an unhealthy or a mixed diet was associated with higher odds of gestational hypertension (23%, P < 0.001 for unhealthy, and 8%, P = 0.01 for mixed diet). In stratified analyses, a higher healthy eating index was associated with reduced odds of being large based on gestational age (31%, P = 0.02) and a higher head circumference at birth (0.23 cm, P = 0.02). The Mediterranean and "prudent" dietary patterns were related to lower odds of being small based on gestational age (46%, P = 0.04) and preterm birth (52%, P = 0.03), respectively. The overall GRADE quality of the evidence for most associations was low or very low, indicating that future high-quality research is warranted. This study was registered at http://www.crd.york.ac.uk/PROSPERO as CRD42018089756.

Vegetarian diets during pregnancy: effects on the mother's health. A systematic review

While interest in vegetarian nutrition has been steadily increasing, some aspects have not yet been consistently investigated. One topic requiring evidence-based confirmation is the adoption of a vegetarian diet during pregnancy and lactation. Maternal diet is not only correlated with the fetus's and infant's health, but appears relevant for that of the mother as well. Not only is an adequate delivery of nutrients to the fetus and infant mandatory, but the increased physiological needs of the maternal body require an adequate supply of nutrients and can represent harmful stress events that may lead to well-defined pathological conditions. In this review, we aim to systematically investigate state-of-the-art of vegetarian diets during pregnancy and lactation, focusing on maternal nutritional status and pregnancy outcomes. Data are scarce, often inconsistent and not homogeneous for many of the topics we considered, mainly because only a few studies have been performed in developed countries, whereas other studies have derived from developing countries, where vegetarianism can be a proxy indicator of malnutrition. For this reason, we did not find sufficient data to provide evidence-based information and recommendations. To date, the available literature does not clearly support a negative impact on the mother's health and pregnancy outcomes, but, analogously with the findings in the vegetarian adult population, an improvement in the quality of studies might facilitate finding more information on the possible positive impact of well-planned vegetarian diets during pregnancy and lactation. More epidemiological and interventional studies are warranted, in order to address the question as to whether vegetarian nutrition represents an advantage for the mother or poses nutritional issues that need further attention.

Health outcomes associated with vegetarian diets: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

Several meta-analyses evaluated the association between vegetarian diets and health outcomes. To integrate the large amount of the available evidence, we performed an umbrella review of published meta-analyses that investigated the association between vegetarian diets and health outcomes.

METHODS

We performed an umbrella review of the evidence across meta-analyses of observational and interventional studies. PubMed, Embase, Cochrane Database of Systematic Reviews, and ISI Web of Knowledge. Additional articles were retrieved from primary search references. Meta-analyses of observational or interventional studies that assessed at least one health outcome in association with vegetarian diets. We estimated pooled effect sizes (ESs) using four different random-effect models: DerSimonian and Laird, maximum likelihood, empirical Bayes, and restricted maximum likelihood. We assessed heterogeneity using I2 statistics and publication bias using funnel plots, radial plots, normal Q-Q plots, and the Rosenthal's fail-safe N test.

RESULTS

The umbrella review identified 20 meta-analyses of observational and interventional research with 34 health outcomes. The majority of the meta-analyses (80%) were classified as moderate or high-quality reviews, based on the AMSTAR2 criteria. By comparison with omnivorous diets, vegetarian diets were associated with a significantly lower concentration of blood total cholesterol (pooled ES = -0.549 mmol/L; 95% CI: -0.773 to -0.325; P < 0.001), LDL-cholesterol (pooled ES = -0.467 mmol/L; 95% CI: -0.600 to -0.335); P < 0.001), and HDL-cholesterol (pooled ES = -0.082 mmol/L; 95% CI: -0.095 to -0.069; P < 0.001). In comparison to omnivorous diets, vegetarian diets were associated with a reduced risk of negative health outcomes with a pooled ES of 0.886 (95% CI: 0.848 to 0.926; P < 0.001). In comparison to omnivores, Seventh-day Adventists (SDA) vegetarians had a significantly reduced risk of negative health outcomes with a pooled ES of 0.721 (95% CI: 0.625 to 0.832; P < 0.001). Non-SDA vegetarians had no significant reduction of negative health outcomes when compared to omnivores (pooled ES = 0.973; 95% CI: 0.873 to 1.083; P = 0.51). Vegetarian diets were associated with harmful outcomes on one-carbon metabolism markers (lower concentrations of vitamin B12 and higher concentrations of homocysteine), in comparison to omnivorous diets.

CONCLUSIONS

Vegetarian diets are associated with beneficial effects on the blood lipid profile and a reduced risk of negative health outcomes, including diabetes, ischemic heart disease, and cancer risk. Among vegetarians, SDA vegetarians could represent a subgroup with a further reduced risk of negative health outcomes. Vegetarian diets have adverse outcomes on one-carbon metabolism. The effect of vegetarian diets among pregnant and lactating women requires specific attention. Well-designed prospective studies are warranted to evaluate the consequences of the prevalence of vitamin B12 deficiency during pregnancy and infancy on later life and of trace element deficits on cancer risks.

PROSPERO REGISTRATION NUMBER

CRD42018092470.

Biomarkers of Cardiovascular Risk in Obese Women and their Relationship with Zinc Status

Background:

Excessive adipose tissue, in the case of common obesity, has been associated with an endocrine-metabolic alteration that contributes to a manifestation of dyslipidemia. To identify mechanisms which are involved in disorders of lipid metabolism, several nutrients have been studied, especially zinc, which act by regulating transcription factors that are important for synthesis and oxidation of lipids and act as an anti-inflammatory and antioxidant nutrient. Thus, the study makes an assessment of the zinc status and biomarkers of cardiovascular risk in obese women.

Methods:

A case-control study enrolling obese (body mass index (BMI) ≥35 kg/m²) and eutrophic (BMI 18.5-24.9 kg/m²) Brazilian women was conducted. Dietary zinc intake was assessed by the three-day food registry. Plasma, erythrocyte and urinary zinc concentrations were determined by inductively coupled plasma optical emission spectrometry. Cardiovascular risk was assessed by plasma concentrations of lipid fractions, and by anthropometric measures.

Results:

Both groups showed a dietary zinc intake above the recommendations, with no statistical difference between them (p >0.05). Mean plasma and erythrocyte zinc concentrations were significantly reduced in obese women, compared to the control group (p <0.05). Urinary zinc excretion was significantly higher in obese women (p <0.05), who also had a significantly higher cardiovascular risk when compared to the control group (p <0.05). An inverse correlation between dietary zinc intake and waist-hip ratio was found in obese women.

Conclusion:

Obese women presented zinc redistribution characterized by reduced concentrations in plasma and erythrocytes, dietary zinc intake above the recommended, and increased zinc excretion in the urine. This study shows dyshomeostasis of zinc in obesity, a possible role in adiposity control and, consequently, its protective role against cardiovascular risk, due to its influence on risk biomarkers, such as waist-hip ratio.

Of Mice and Men: The Effect of Maternal Protein Restriction on Offspring's Kidney Health. Are Studies on Rodents Applicable to Chronic Kidney Disease Patients? A Narrative Review

In the almost 30 years that have passed since the postulation of the "Developmental Origins of Health and Disease" theory, it has been clearly demonstrated that a mother's dietary habits during pregnancy have potential consequences for her offspring that go far beyond in utero development. Protein malnutrition during pregnancy, for instance, can cause severe alterations ranging from intrauterine growth retardation to organ damage and increased susceptibility to hypertension, diabetes mellitus, cardiovascular diseases and chronic kidney disease (CKD) later in life both in experimental animals and humans. Conversely, a balanced mild protein restriction in patients affected by CKD has been shown to mitigate the biochemical derangements associated with kidney disease and even slow its progression. The first reports on the management of pregnant CKD women with a moderately protein-restricted plant-based diet appeared in the literature a few years ago. Today, this approach is still being debated, as is the optimal source of protein during gestation in CKD. The aim of this report is to critically review the available literature on the topic, focusing on the similarities and differences between animal and clinical studies.

Global diversity of dietary intakes and standards for zinc, iron, and copper

BACKGROUND

The essentiality of trace elements in human diets is well recognized and adequate levels are a critical component of optimal health. To date, public health efforts have focused primarily on macronutrients or trace minerals that are easily analyzed. The goal of this research is to provide assessment of the dietary standards developed for Zn, Fe, and Cu in 100+ developed, marginal, and developing countries. We summarize the current recommendations and changes from the last decade, categorize and provide scientific basis for values established, factors that affect requirements, and current global challenges.

METHODS

The electronic databases of Google Scholar, PubMed, Embase, Web of Science and Cochrane Library were searched using the keywords "trace minerals," "micronutrients, ""zinc," "iron," "copper," "dietary standards" and "recommendations." A total of 123 studies published from 1965 to 2019 were included.

RESULTS

The World Health Organization (WHO) has established dietary standards to address nutrient deficiencies, prevent infections and ensure basic metabolic functions; these are utilized by most developing countries. Developed countries or their alliances have established values similar to or higher than the WHO, primarily for promotion of optimal health and well-being. Transitional countries are more concerned with issues of bioavailability, food security and undernutrition. Globally, Zn and Cu recommendations are lower in women than in men; Fe requirements are higher to compensate for menstrual losses. Important considerations in establishing guidelines for these minerals include bioaccessibility, dietary practices and restrictions, food processing, interactions, and chemical forms. The global challenges of the triple burden of malnutrition, hidden hunger, increased consumption of ultra-processed foods and obesity have been associated with Zn, Fe, and Cu deficiencies.

CONCLUSION

This research provides public policy and health professionals evidenced-based information useful for the establishment of dietary standards world-wide.

First Trimester Serum Copper or Zinc Levels, and Risk of Pregnancy-Induced Hypertension

Early identification of women at risk of developing pregnancy-induced hypertension (PIH) is very important. The involvement of copper (Cu) and zinc (Zn) in the oxidative balance suggests the possibility of their association with this disease, in which oxidative stress plays a key role. However, it has not been established so far whether the microelement levels in early pregnancy may be risk markers of the disease, as prospective studies are limited in number. In our innovative single-center study, we identified from a prospective cohort of healthy women in the 10–14th week of a single pregnancy: women subsequently developing pregnancy-induced hypertension (n = 121) and matched women remaining normotensive (n = 363). We measured the concentrations of microelements in the serum from 10–14 week, using the inductively coupled plasma mass spectrometry (ICP-MS). The odds ratios of the disease (and 95% confidence intervals) were assessed in logistic regression. In the whole cohort, the odds ratio (OR) of PIH was 1.52 (p = 0.174) for women in the lowest (Q1) quartile of Cu (≤1540.58 µg/L) compared with women in the highest (Q4) quartile (>1937.46 µg/L), but adjusted odds ratio (AOR) was 2.17 (p = 0.019) after adjusted for pre-pregnancy body mass index (BMI) and gestational age at recruitment. The higher levels of Cu in the subgroup of BMI ≥ 25 kg/m² compared to normal BMI were found (1847.64 vs. 1673.36 µg/L; p < 0.0001). In the subgroup of women with the normal pre-pregnancy BMI, the adjusted odds ratio of PIH was AOR = 2.95 (p = 0.040) for Q1 vs. Q4 quartile. Our results suggest that lower Cu levels in early pregnancy may be connected with higher risk of PIH, but BMI affected estimated odds ratios. Zinc levels had no effect on the risk.

Effect of Zinc Supplementation on Lipid Profile in Obese People: A Systematic Review

Background:

Many studies have investigated the influence of minerals on the control of changes in lipid metabolism in obese individuals. The objective of this study was to describe, in a systematic review, the clinical trial outcomes of zinc supplementation and lipid profiles of obese participants.

Methods:

This review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. A survey was conducted for selecting clinical trials related to the effects of zinc supplementation on lipid profiles in obese people, using the following databases: PubMed, SciVerse ScienceDirect and Cochrane.

Results:

After the selection process, five articles were identified as eligible for this review and it was observed that the clinical trials included adults and children of both sexes, in three different countries, and with zinc supplementation doses ranging from 20 to 100 mg/day. None of the studies observed changes in High-Density Lipoprotein (HDL-c) with zinc supplementation. On the other hand, three studies observed a positive effect of zinc supplementation on triglycerides, and two found an effect on Low-Density Lipoprotein (LDL-c) and total cholesterol.

Conclusion:

The results of this systematic review provide evidence on the benefits of zinc supplementation on lipid profiles in obese individuals. However, new intervention studies are needed to elucidate the function of the nutrient in protection against disorders related to lipid metabolism, as well as the standardization of the type, dose, and time of zinc supplementation.

The Effects of Vegetarian and Vegan Diet during Pregnancy on the Health of Mothers and Offspring

Vegetarian and vegan diets have increased worldwide in the last decades, according to the knowledge that they might prevent coronary heart disease, cancer, and type 2 diabetes. Althought plant-based diets are at risk of nutritional deficiencies such as proteins, iron, vitamin D, calcium, iodine, omega-3, and vitamin B12, the available evidence shows that well planned vegetarian and vegan diets may be considered safe during pregnancy and lactation, but they require a strong awareness for a balanced intake of key nutrients. A review of the scientific literature in this field was performed, focusing specifically on observational studies in humans, in order to investigate protective effects elicited by maternal diets enriched in plant-derived foods and possible unfavorable outcomes related to micronutrients deficiencies and their impact on fetal development. A design of pregestational nutrition intervention is required in order to avoid maternal undernutrition and consequent impaired fetal growth.

Is a vegetarian diet safe to follow during pregnancy? A systematic review and meta-analysis of observational studies

Background: Whether a vegetarian diet is appropriate for pregnancy remains unclear. Objective: This study aimed to determine the association between vegetarian diet during pregnancy and various maternal-fetal outcomes. Method: PubMed-Medline, EMBASE, and Cochrane Library databases were searched for relevant articles published by August 30, 2017. Quantitative data were analyzed by a random-effects model with pooled odds ratios or weighted mean difference (WMD) and 95% confidence interval as aggregate estimations. Results: A total of 19 observational studies were identified for each of meta-analysis and narrative review. The overall estimated relation between vegetarian pregnancy and low birth weight (LBW) was marginally significant (1.27 (0.98, 1.65), P = 0.07, I²=0%). Asian (India/Nepal) vegetarian mothers exhibited increased risks to deliver a baby with LBW (1.33 (1.01, 1.76), P = 0.04, I²=0%). However, the WMD of neonatal birth weight in five studies suggested no difference between vegetarians and omnivores. Given the high heterogeneity of the included studies, lack of high-quality evidence, and limited studies included for each category, we failed to reach conclusive results regarding the risks of hypospadias, intrauterine growth retardation, maternal anemia, and gestational diabetes mellitus. Conclusion: Asian vegetarian mothers presented increased risks to deliver babies with LBW than those of omnivores. Large-scale prospective studies focusing on pre- and/or early gestational nutrition will help clarify the correlation between vegetarian diet and various pregnancy outcomes.

Elemental Metabolomics and Pregnancy Outcomes

Trace elements are important for human health and development. The body requires specific micronutrients to function, with aberrant changes associated with a variety of negative health outcomes. Despite this evidence, the status and function of micronutrients during pregnancy are relatively unknown and more information is required to ensure that women receive optimal intakes for foetal development. Changes in trace element status have been associated with pregnancy complications such as gestational diabetes mellitus (GDM), pre-eclampsia (PE), intrauterine growth restriction (IUGR), and preterm birth. Measuring micronutrients with methodologies such as elemental metabolomics, which involves the simultaneous quantification and characterisation of multiple elements, could provide insight into gestational disorders. Identifying unique and subtle micronutrient changes may highlight associated proteins that are affected underpinning the pathophysiology of these complications, leading to new means of disease diagnosis. This review will provide a comprehensive summary of micronutrient status during pregnancy, and their associations with gestational disorders. Furthermore, it will also comment on the potential use of elemental metabolomics as a technique for disease characterisation and prediction.

Pregnancy, Proteinuria, Plant-Based Supplemented Diets and Focal Segmental Glomerulosclerosis: A Report on Three Cases and Critical Appraisal of the Literature

Chronic kidney disease (CKD) is increasingly recognized in pregnant patients. Three characteristics are associated with a risk of preterm delivery or small for gestational age babies; kidney function reduction, hypertension, and proteinuria. In pregnancy, the anti-proteinuric agents (ACE-angiotensin converting enzyme-inhibitors or ARBS -angiotensin receptor blockers) have to be discontinued for their potential teratogenicity, and there is no validated approach to control proteinuria. Furthermore, proteinuria usually increases as an effect of therapeutic changes and pregnancy-induced hyperfiltration. Based on a favourable effect of low-protein diets on proteinuria and advanced CKD, our group developed a moderately protein-restricted vegan-vegetarian diet tsupplemented with ketoacids and aminoacids for pregnant patients. This report describes the results obtained in three pregnant patients with normal renal function, nephrotic or sub-nephrotic proteinuria, and biopsy proven diagnosis of focal segmental glomerulosclerosis, a renal lesion in which hyperfiltration is considered of pivotal importance (case 1: GFR (glomerular filtration rate): 103 mL/min; proteinuria 2.1 g/day; albumin 3.2 g/dL; case 2: GFR 86 mL/min, proteinuria 3.03 g/day, albumin 3.4 g/dL; case 3: GFR 142 mL/min, proteinuria 6.3 g/day, albumin 3.23 g/dL). The moderately restricted diet allowed a stabilisation of proteinuria in two cases and a decrease in one. No significant changes in serum creatinine and serum albumin were observed. The three babies were born at term (38 weeks + 3 days, female, weight 3180 g-62th centile; 38 weeks + 2 days, female, weight 3300 g-75th centile; male, 38 weeks + 1 day; 2770 g-8th centile), thus reassuring us of the safety of the diet. In summary, based on these three cases studies and a review of the literature, we suggest that a moderately protein-restricted, supplemented, plant-based diet might contribute to controlling proteinuria in pregnant CKD women with focal segmental glomerulosclerosis. However further studies are warranted to confirm the potential value of such a treatment strategy.

A best practice position statement on pregnancy in chronic kidney disease: the Italian Study Group on Kidney and Pregnancy

Pregnancy is increasingly undertaken in patients with chronic kidney disease (CKD) and, conversely, CKD is increasingly diagnosed in pregnancy: up to 3 % of pregnancies are estimated to be complicated by CKD. The heterogeneity of CKD (accounting for stage, hypertension and proteinuria) and the rarity of several kidney diseases make risk assessment difficult and therapeutic strategies are often based upon scattered experiences and small series. In this setting, the aim of this position statement of the Kidney and Pregnancy Study Group of the Italian Society of Nephrology is to review the literature, and discuss the experience in the clinical management of CKD in pregnancy. CKD is associated with an increased risk for adverse pregnancy-related outcomes since its early stage, also in the absence of hypertension and proteinuria, thus supporting the need for a multidisciplinary follow-up in all CKD patients. CKD stage, hypertension and proteinuria are interrelated, but they are also independent risk factors for adverse pregnancy-related outcomes. Among the different kidney diseases, patients with glomerulonephritis and immunologic diseases are at higher risk of developing or increasing proteinuria and hypertension, a picture often difficult to differentiate from preeclampsia. The risk is higher in active immunologic diseases, and in those cases that are detected or flare up during pregnancy. Referral to tertiary care centres for multidisciplinary follow-up and tailored approaches are warranted. The risk of maternal death is, almost exclusively, reported in systemic lupus erythematosus and vasculitis, which share with diabetic nephropathy an increased risk for perinatal death of the babies. Conversely, patients with kidney malformation, autosomal-dominant polycystic kidney disease, stone disease, and previous upper urinary tract infections are at higher risk for urinary tract infections, in turn associated with prematurity. No risk for malformations other than those related to familiar urinary tract malformations is reported in CKD patients, with the possible exception of diabetic nephropathy. Risks of worsening of the renal function are differently reported, but are higher in advanced CKD. Strict follow-up is needed, also to identify the best balance between maternal and foetal risks. The need for further multicentre studies is underlined.