Oral zinc supplementation may improve cognitive function in schoolchildren

Associations of essential element serum concentrations with autism spectrum disorder

This case-control study explored the associations between autism spectrum disorder (ASD) and the serum concentration of nine chemical elements in children. The study recruited 92 Chinese children with ASD and 103 typically developing individuals. Serum concentrations of nine chemical elements (calcium, iodine, iron, lithium, magnesium, potassium, selenium, strontium, and zinc) were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). An unconditional logistic regression model was used to analyze the associations between the serum concentrations of the elements and the risk of ASD. After adjusting for confounders, the multivariate analysis results showed that zinc ≤ 837.70 ng/mL, potassium > 170.06 μg/mL, and strontium ≤ 52.46 ng/mL were associated with an increased risk of ASD, while selenium > 159.80 ng/mL was associated with a decreased risk of ASD. Furthermore, the degree of lithium and zinc deficiency was associated with ASD severity. The results indicated that metallomic profiles of some specific elements might play important roles in the development of ASD, a finding of scientific significance for understanding the etiology, and providing dietary guidance for certain ASD types.

Effects of marginal zinc deficiency on learning and memory ability after birth

Zinc deficiency during pregnancy and severe zinc deficiency after birth both impaired learning and memory ability, but the effects of marginal zinc deficiency (MZD) after birth on learning and memory are unclear. In the first experiment, 4-week-old male rats were randomly divided into three groups: the marginal zinc-deficient group (MZG, 10 mg kg^-1, 1/3 RNI), normal zinc group (NZG, 30 mg kg^-1, RNI), and paired zinc group (PZG, 30 mg kg^-1). After a 4-week feeding period, the brain weight, brain coefficient, and serum zinc concentration were measured, and hippocampal proteomics analysis was performed. In the second experiment, 4-week-old male rats were fed the same diet for 8 weeks. In addition to the previously mentioned indicators, the Morris water maze results, brain pathology, post-translational modifications (PTMs) of hippocampal proteins, and the concentrations of indicators known to be related to learning and memory were analyzed. In both experiments, compared with those of the NZG, the food intake, body weight and serum zinc of the MZG were significantly decreased, and the brain weight was unchanged, but the brain coefficient was increased. Two hippocampal proteomics analyses and PTM screening showed that MZD did not change the expression and PTM of proteins. The brain pathology, learning, memory and the concentrations of indicators known to be related to learning and memory were not changed by MZD. Our study confirmed that marginal zinc deficiency (10 mg kg^-1, 1/3 RNI) had no effect on the learning and memory abilities of rats after birth.

Most Effective Combination of Nutraceuticals for Improved Memory and Cognitive Performance in the House Cricket, Acheta domesticus

Background: Dietary intake of multivitamins, zinc, polyphenols, omega fatty acids, and probiotics have all shown benefits in learning, spatial memory, and cognitive function. It is important to determine the most effective combination of antioxidants and/or probiotics because regular ingestion of all nutraceuticals may not be practical. This study examined various combinations of nutrients to determine which may best enhance spatial memory and cognitive performance in the house cricket (Acheta domesticus (L.)). Methods: Based on the 31 possible combinations of multivitamins, zinc, polyphenols, omega-3 polyunsaturated fatty acids (PUFAs), and probiotics, 128 house crickets were divided into one control group and 31 experimental groups with four house crickets in each group. Over eight weeks, crickets were fed their respective nutrients, and an Alternation Test and Recognition Memory Test were conducted every week using a Y-maze to test spatial working memory. Results: The highest-scoring diets shared by both tests were the combination of multivitamins, zinc, and omega-3 fatty acids (VitZncPuf; Alternation: slope = 0.07226, Recognition Memory: slope = 0.07001), the combination of probiotics, polyphenols, multivitamins, zinc, and omega-3 PUFAs (ProPolVitZncPuf; Alternation: slope = 0.07182, Recognition Memory: slope = 0.07001), the combination of probiotics, multivitamins, zinc, and omega-3 PUFAs (ProVitZncPuf; Alternation: slope = 0.06999, Recognition Memory: slope = 0.07001), and the combination of polyphenols, multivitamins, zinc, and omega-3 PUFAs (PolVitZncPuf; Alternation: slope = 0.06873, Recognition Memory: slope = 0.06956). Conclusion: All of the nutrient combinations demonstrated a benefit over the control diet, but the most significant improvement compared to the control was found in the VitZncPuf, ProVitZncPuf, PolVitZncPuf, and ProPolVitZncPuf. Since this study found no significant difference between the performance and improvement of subjects within these four groups, the combination of multivitamins, zinc, and omega-3 fatty acids (VitZncPuf) was concluded to be the most effective option for improving memory and cognitive performance.

Effect of zinc supplementation on quality of life and sleep quality in young women with premenstrual syndrome: a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Premenstrual syndrome is a prevalent disorder affecting a large number of women in their reproductive ages. Nutritional importance of zinc has been known for a long time and studies have shown that zinc can positively affect psychological disorders.

PURPOSE

The aim of this study was to evaluate the effects of zinc supplementation on quality of life and sleep quality of young women diagnosed with premenstrual syndrome.

METHODS

This randomized, double-blind, placebo-controlled trial was carried out on 60 young university women that were allocated into two groups of intervention who took 30 mg/day of elemental zinc or placebo for three months. Pre- and post-intervention, participants completed the questionnaires of quality of life and Pittsburgh sleep quality.

RESULTS

After supplementation, quality of life score in the intervention group was increased (+ 9.185 ± 7.29, P < 0.001), however, in comparison with the control group, results were not significant; Physical aspects of quality of life score were significantly enhanced (+ 5.55 ± 3.71 vs. + 0.13 ± 2.87, P < 0.001). Sleep quality was marginally improved just in the zinc group (- 1.48 ± 4.12, P = 0.07).

CONCLUSION

Zinc supplementation for 12 weeks had beneficial effects on physical aspects of quality of life in young women with premenstrual syndrome.

Association between circulating zinc/ferritin levels and parent Conner's scores in children with attention deficit hyperactivity disorder

ADHD is one of the most common neurobehavioral disorders among children and adolescents. In this prospective study, we aimed to measure circulating zinc and ferritin levels in children with ADHD, pick up the deficient ones to give zinc and iron supplements then compare before and after treatment according to their Conner's scores and Wecsler IQ test. Current study included fifty children diagnosed as having ADHD by DSMV criteria, their zinc and ferritin levels were measured by Colorimetric method and enzyme-linked immunosorbent assay (ELISA) respectively. They were divided into: group I (zinc only deficient),group II (zinc and ferritin deficient),group III (non-deficient), cases with mineral deficiency received zinc (55 mg/day) and/or iron (6 mg/kg/day) for 6 months then reassessed by parent Conner's rating scale. In group 1, there was no significant difference between the Wecsler verbal and non-verbal IQ scores and oppositional and cognitive problems in Conner's scores before and after zinc supplements, although there was significant improvement in attention, hyperactivity, emotional liability and impulsivity. In group II, there was significant improvement in verbal and total IQ but not in performance IQ, also there was significant improvement in hyperactivity, emotional liability and impulsivity with no significant difference in oppositional, cognitive problems and inattention before and after zinc/ iron supplements. In Conclusion, Zinc supplements in adjuvant to the main treatment significantly improved symptoms of ADHD children. However, a combined zinc and iron supplements was superior to zinc alone in alleviating ADHD symptoms as well as IQ improvement.

Associations of maternal zinc and magnesium with offspring learning abilities and cognitive development at 4 years in GUSTO

Objectives: Minerals deficiencies during pregnancy have been shown to be associated with poorer cognitive outcomes in offspring. This study aimed to investigate associations of maternal plasma zinc and magnesium concentrations with cognitive development in 4-year old children from the Growing Up in Singapore Towards healthy Outcome cohort.Methods: Maternal plasma zinc and magnesium concentrations were measured at 26-28 weeks' gestation. The Lollipop test of school readiness, tests of working memory, number knowledge, receptive vocabulary, and phonological awareness were performed in children at 4 years. Associations were examined in 715 mother-offspring pairs using linear regressions adjusted for key confounders.Results: Maternal plasma zinc and magnesium concentrations were 812 ± 144 µg/L and 19.9 ± 1.8 mg/L (mean±SD); 19% and 71% of mothers were zinc deficient and magnesium insufficient, respectively. After adjustment for multiple testing, higher maternal zinc concentrations (per SD increment) were associated with 0.35 higher scores in Lollipop subtest 2 of picture description and spatial identification (95% CI: 0.13, 0.58); higher maternal magnesium concentrations (per SD increment) were associated with 0.65 higher scores in Lollipop subtest 4 of letters and writing identification (95% CI: 0.23, 1.07).Discussion: No significant associations were observed for other tests, suggesting little long term influences of maternal zinc and magnesium on child's cognitive development.

Serum Zinc Level and Eating Behaviors in Children Receiving Zinc Supplements without Physician Prescription

Background:

The aim of the study was to compare the serum zinc level and eating behaviors in 2–8-year-old children with and without arbitrarily zinc supplementation.

Materials and Methods:

This case–control study was conducted from December 2015 to December 2017 in Isfahan, Iran. The case group consisted of seventy children, aged 2–8 years, who have received zinc supplement without physician prescription; the controls were an equal number of age-matched children who did not receive any supplement. The serum zinc level was measured, and eating behaviors were identified using Children's Eating Behavior Questionnaire (CEBQ).

Results:

There was no significant difference in serum zinc level between two groups (P = 0.18). Some differences in CEBQ subscales were identified between the groups studied. In the control group, the subscale of enjoyment of food was higher than the case group (P < 0.001). In the case group, the subscales of food fussiness and satiety responsiveness were higher than controls (P < 0.001).

Conclusion:

In this study, serum zinc levels were not significantly different between the two groups, and arbitrarily zinc supplementation does not play an important role in improving anorexia subscales.

The Relationship of Children's Intelligence Quotient and Blood Lead and Zinc Levels: a Meta-analysis and System Review

The purpose of this study was to analyze the existing studies and to investigate the relationship between children's full-scale intelligence quotient (FIQ), verbal IQ (VIQ), and performance IQ (PIQ) and their blood lead (Pb) and zinc (Zn) levels. All documents in Chinese and English were collected from the PubMed, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) databases from inception date to December 30, 2016. RevMan software (version 5.2) was used for the meta-analysis and Stata software (version 12.0) for the meta-regression and sensitivity analyses. A total of 32 eligible literatures was included in the study. Seven prevalence studies showed that the blood Pb level was negatively correlated with children's IQ. The results of the meta-analysis from 22 case-control studies indicate a significant difference between FIQ and PIQ with blood Pb levels, detailed as the FIQ score with a weighted mean difference (WMD) = -6.60 (95% CI: -9.01, -4.20), P < 0.001; PIQ WMD = -8.85 (95% CI: -12.651, -5.05), P < 0.001; but VIQ WMD = -3.32 (95% CI: -6.98, 0.33), P > 0.05. Three studies on the blood Zn concentrations were with a FIQ WMD = 7.88 (95% CI: -0.07, 15.83), VIQ WMD = 7.73 (95% CI: -7.40, 22.86), and PIQ WMD = 6.69 (95% CI: -7.13, 20.51), all P > 0.05. The results indicate that Pb is harmful to children's intelligence development, especially in PIQ. Zn is beneficial to intelligence, although more studies are needed.

The Effect of Zinc Supplementation on Sleep Quality of ICU Nurses: A Double Blinded Randomized Controlled Trial

This study examined the effect of zinc supplementation on the sleep quality (SQ) of intensive care unit (ICU) nurses. In a double-blind, randomized controlled trial, 54 ICU nurses were randomly assigned to the intervention group ( n = 27) that received 220 mg zinc sulfate capsules every 72 hours for 1 month and the control group ( n = 26) that received placebo. Sleep quality of ICU nurses was measured by calculating the total quality sleep score using the Pittsburgh Sleep Quality Index (PSQI). The serum zinc level was a secondary outcome. All measurements were calculated at both baseline and 1 month after intervention. The total PSQI, subjective SQ, and sleep latency scores for the intervention group were significantly lower than the control group, which means that the SQ of ICU nurses in the intervention group improved from baseline. The serum zinc level of the intervention group at the end of the study was significantly higher than the control group, which means that zinc supplementation improved participants’ serum zinc level. Based on these findings, the researcher suggested that zinc supplementation could be associated with better SQ, subjective SQ, and sleep latency in this group of workers.

Importance of zinc for the human body in the aspect of zinc supplementation

Cynk jest jednym z głównych pierwiastków śladowych organizmu, spełniającym rolę katalityczną, strukturalną i regulacyjną. Jest niezbędny do podziałów komórkowych i różnicowania powstających komórek, uczestniczy w homeostazie, reakcjach odpornościowych, w apoptozie i starzeniu się organizmu. Cynk jest również składnikiem wielu enzymów i białek oraz odgrywa ważną rolę w spermatogenezie i syntezie hormonów steroidowych. Niedostateczna podaż cynku dotyczy ok. 30% ludności świata. Oprócz niedostatecznej podaży z pokarmem, przyczyną niedoboru cynku mogą być niektóre schorzenia oraz nieprawidłowe wchłanianie tego pierwiastka. Schorzenia, wynikające z niedoboru tego pierwiastka, mogą występować zarówno u dzieci, jak i dorosłych. Suplementacja diety preparatami cynku w wielu przypadkach jest niezbędna, jednak samodzielne jego stosowanie, bez stwierdzonego niedoboru i bez konsultacji z lekarzem, może doprowadzić do występowania działań niepożądanych w wyniku jego nadużywania, w tym także niebezpiecznych interakcji z innymi stosowanymi preparatami i żywnością.

Differential Effects of Low- and High-dose Zinc Supplementation on Synaptic Plasticity and Neurogenesis in the Hippocampus of Control and High-fat Diet-fed Mice

In the present study, we investigated the concentration-dependent effect of zinc (Zn) supplementation on the adult hippocampus in a high-fat diet (HFD)-fed obese mouse model. Four-weeks after HFD- and control diet (CD)-feeding, mice were provided with low (15 ppm) or high (60 ppm) doses of Zn in their drinking water for additional 4 more weeks along with their respective diets. Compared to the CD-fed mice, HFD-feeding elicited the reduction of neurogenic markers such as nestin, Ki67, doublecortin (DCX), and 5-bromo-2'-deoxyuridine (BrdU) in the dentate gyrus. Additionally, HFD-feeding reduced the levels of synaptic markers (synaptophysin and N-methyl-D-aspartate receptor) and brain-derived neurotrophic factor (BDNF), while lipid peroxidation was significantly increased in the hippocampus of HFD-fed mice. Against detrimental effects of high-dose Zn, low-dose Zn supplementation in CD-fed mice did not yield any remarkable changes in these parameters. Interestingly, administration of low doses of Zn to HFD-induced obese mice prominently ameliorated HFD-induced changes in neurogenic, synaptic plasticity markers and BDNF levels as well as lipid peroxidation in the hippocampus. In contrast, high-dose Zn supplementation in HFD-fed mice exacerbated the reduction of markers for neurogenesis and synaptic plasticity as well as BDNF levels, but not 4-HNE levels, in the hippocampus. These results suggest that low-dose Zn supplementation in obese mice could reverse the HFD-induced reduction in neurogenic and synaptic marker proteins in the hippocampus by reducing lipid peroxidation and improving BDNF expression, while high-dose Zn supplementation exacerbates the reduction of neurogenesis by affecting synaptic markers and BDNF levels in the hippocampus.

Brazilian studies on zinc deficiency and supplementation: emphasis on children

Abstract Objectives: to review the literature of studies developed in Brazil on zinc deficiency and the effects of supplementation. Methods: a literature review based on bibliographic research was carried out in SciELO, LILACS and MEDLINE/PUBMED databases. A total of 133 studies on zinc deficiency and 116 on the effects of supplementation were identified. Thirty-two articles, 16 of which were observational and 16 interventional, were analyzed. Results: the studies focused mainly on children (75.0% of the observational and 81.25% of the experimental studies). Biochemical deficiency of zinc in children presented great variability, from 0.0% to 74.3%, with expressive prevalence in most studies. Dietary inadequacy among children presented variability from 16.6% to 46.0%. Five from seven studies showed a positive effect of zinc supplementation on micronutrient nutritional status. Conclusions: there is evidence of zinc deficiency in children as a public health problem, preventable through micronutrient supplementation.

Metal ions influx is a double edged sword for the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is a common form of dementia in aged people, which is defined by two pathological characteristics: β-amyloid protein (Aβ) deposition and tau hyperphosphorylation. Although the mechanisms of AD development are still being debated, a series of evidence supports the idea that metals, such as copper, iron, zinc, magnesium and aluminium, are involved in the pathogenesis of the disease. In particular, the processes of Aβ deposition in senile plaques (SP) and the inclusion of phosphorylated tau in neurofibrillary tangles (NFTs) are markedly influenced by alterations in the homeostasis of the aforementioned metal ions. Moreover, the mechanisms of oxidative stress, synaptic plasticity, neurotoxicity, autophagy and apoptosis mediate the effects of metal ions-induced the aggregation state of Aβ and phosphorylated tau on AD development. More importantly, imbalance of these mechanisms finally caused cognitive decline in different experiment models. Collectively, reconstructing the signaling network that regulates AD progression by metal ions may provide novel insights for developing chelators specific for metal ions to combat AD.

Nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children

BACKGROUND

Zinc is an essential nutrient that is required for numerous metabolic functions, and zinc deficiency results in growth retardation, cell-mediated immune dysfunction, and cognitive impairment.

OBJECTIVE

This study evaluated nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children.

DESIGN

We performed a randomised, controlled, triple-blind study. The children were divided into a control group (10% sorbitol, n=31) and an experimental group (10 mg Zn/day, n=31) for 3 months. Anthropometric and dietary assessments as well as bioelectrical measurements were performed in all children.

RESULTS

Our study showed (1) an increased body mass index for age and an increased phase angle in the experimental group; (2) a positive correlation between nutritional assessment parameters in both groups; (3) increased soft tissue, and mainly fat-free mass, in the body composition of the experimental group, as determined using bioelectrical impedance vector analysis; (4) increased consumption of all nutrients, including zinc, in the experimental group; and (5) an increased serum zinc concentration in both groups (p<0.0001).

CONCLUSIONS

Given that a reference for body composition analysis does not exist for intervention studies, longitudinal studies are needed to investigate vector migration during zinc supplementation. These results reinforce the importance of employing multiple techniques to assess the nutritional status of populations.

Zinc deficiency impairs the renewal of hippocampal neural stem cells in adult rats: involvement of FoxO3a activation and downstream p27(kip1) expression

Zinc plays an important role in the development and maintenance of central neural system. Zinc deficiency has been known to alter normal brain function, whose molecular mechanism remains largely elusive. In the present study, we established a zinc deficiency-exposed rat model, and, using western blot and immunohistochemical analyses, found that the expression of FoxO3a and p27(kip1) was remarkably up-regulated in the rat brain hippocampus. Immunofluorescence assay showed that FOXO3a and p27(kip1) were significantly co-localized with nestin, the marker of neural stem cells (NSCs). Furthermore, we identified that the proportion of proliferating NSCs was markedly decreased in zinc-deficient rat hippocampaus. Using C17.2 neural stem cells, it was revealed that exposure to zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethy) ethylenediamine induced the expression of FoxO3a and p27(kip1) , which coincided with reduced NSC proliferation. Furthermore, depletion of FoxO3a inhibited p27(kip1) expression and restored the growth of NSCs. On the basis of these data, we concluded that FoxO3a/p27(kip1) signaling might play a significant role in zinc deficiency-induced growth impairment of NSCs and consequent neurological disorders. We describe here that zinc deficiency induces the proliferative impairment of hippocampal neural stem cells partially through the activation of FOXO3a-p27 axis in rats. Neural progenitor cells exhibited significantly up-regulated expression of FOXO3a and p27 after zinc deficiency in vivo and in vitro. Depletion of FOXO3a ameliorates zinc deficiency-induced expression of p27 and growth impairment of neural stem cells. We provide novel insight into the mechanisms underlying zinc deficiency-induced neurological deficits.

Growth and development in Chinese pre-schoolers with picky eating behaviour: a cross-sectional study

Objective

To explore the associations between picky eating behaviour and pre-schoolers’ growth and development. Corresponding potential mechanisms, such as nutrient and food subgroup intake, as well as micronutrients in the blood, will be considered.

Methods

Picky eating behaviour was present if it was reported by parents. From various areas of China, 937 healthy children of 3-7 years old were recruited using a multi-stage stratified cluster sampling method. Children and their mothers’ socio-demographic information and children’s anthropometry, intelligence, blood samples, one 24-hour dietary intake record and food frequency questionnaire were collected. Z-scores and intelligence tests were used to evaluate growth and development (cognitive development). Multilevel models were employed to verify the associations between picky eating behaviour and growth and development.

Results

The prevalence of picky eating as reported by parents was 54% in pre-schoolers. Compared with the non-picky eaters, weight for age in picky eaters was 0.14 z-score (95% CI: -0.25, -0.02; p = 0.017) lower while no significant difference was found in intelligence (p > 0.05). Picky eating behaviour lasting over two years was associated with lower weight for age, as was nit-picking meat (the prevalence from parents’ perception was 23% in picky eaters) (p < 0.05). Picky eaters consumed fewer cereals, vegetables, and fish (p < 0.05), and had a lower dietary intake of protein, dietary fibre, iron, and zinc (p < 0.05). There were no differences in the concentrations of essential minerals in whole blood (p > 0.05).

Conclusions

Picky eating behaviour is reported by parents in half of the Chinese pre-schoolers, which is negatively associated with growth (weight for age). Lower protein and dietary fibre as well as lower iron and zinc intakes were associated with picky eating as were lower intakes of vegetables, fish and cereals.