Dietary Zinc Intake and Its Association with Metabolic Syndrome Indicators among Chinese Adults: An Analysis of the China Nutritional Transition Cohort Survey 2015

Zinc Supplementation in Individuals with Prediabetes and type 2 Diabetes: a GRADE-Assessed Systematic Review and Dose-Response Meta-analysis

Zinc supplementation has therapeutic effects on cardiovascular disease (CVD) risk factors, including dyslipidemia, hyperglycemia, and inflammation as the main contributors to CVD pathogenesis. Since CVD is a major cause of mortality among people with type 2 diabetes mellitus (T2DM), this study aimed to overview the potential effects of zinc supplementation on CVD risk factors in T2DM patients. To determine appropriate randomized clinical trials (RCTs) investigating the effects of zinc supplementation on CVD risk factors, electronic sources including PubMed, Web of Science, and Scopus were systematically searched until January 2023. The heterogeneity of trials was checked using the I2 statistic. According to the heterogeneity tests, random-effects models were estimated, and pooled data were defined as the weighted mean difference (WMD) with a 95% confidence interval (CI). Of the 4004 initial records, 23 studies that met inclusion criteria were analyzed in this meta-analysis. The pooled findings indicated the significant lowering effects of zinc supplementation on triglycerides (TG), total cholesterol (TC), fasting blood glucose (FBG), hemoglobin A1C (HbA1C), and C-reactive protein (CRP), while high-density cholesterol (HDL) concentrations showed an elevation after zinc supplementation. In addition to statistical significance, the effect of zinc supplementation on most of the variables was clinically significant; however, the quality of evidence in the included studies is regarded as low or very low for most variables. Our study demonstrated that zinc supplementation has beneficial effects on glycemic control markers, lipid profile, and CRP levels as a classic marker of inflammation in T2DM. Due to the high degree of heterogeneity between studies and the low rate of quality in them, further well-designed studies are necessitated to strengthen our findings.

Composite dietary antioxidant index is associated with reduced prevalence of metabolic syndrome but not mortality in metabolic syndrome: Results from NHANES 2001-2018

The relationship between the composite dietary antioxidant index (CDAI), a comprehensive measure of individual dietary antioxidants, and the prevalence and mortality of metabolic syndrome (MetS) remains unknown. We aimed to explore these relationships in the National Health and Nutrition Examination Survey (NHANES). We explored these relationships using two independent cohorts. First, we addressed CDAI and the prevalence of MetS in the general population; second, we explored the association between CDAI and mortality in patients with MetS by following NHANES 2001-2018 participants through December 31, 2019. In addition, restricted cubic spline (RCS), stratified analysis, and sensitivity analysis were used for further interpretation. We included 24,514 participants aged 20-85 years, in which the prevalence of MetS was 27.61 %. CDAI was negatively and dose-responsively associated with the prevalence of MetS, however it was not associated with mortality in patients with MetS. In addition, CDAI was associated with a reduced prevalence of certain components of MetS, including dyslipidemia and central obesity. RCS showed a linear correlation between CDAI and MetS and the above components. Stratified analyses indicated that alcohol consumption was a significant influence of CDAI-MetS and that socioeconomic status and lifestyle specificity existed. Sensitivity analysis confirmed the stability of the results. CDAI was protective against the development of MetS in the general population, but not against mortality in patients with MetS. Clinicians need to develop individualized prevention strategies to reduce the development of MetS by modifying CDAI.

Association between soya food consumption and muscle strength in Chinese adolescents: evidence from a cross-sectional study

There is a strong association between soya food consumption and health, but there are few studies on the association with muscular strength, especially in adolescent groups. This study was conducted to understand the status of soya food consumption and its association with muscular strength among secondary school students in southern China. A stratified whole-group sampling method was used to investigate and test the status of soya food consumption and muscular strength of 13 220 secondary school students in southern China. Linear regression analysis and logistic regression analysis were used to analyse the correlations between soya food consumption and muscular strength. Logistic regression analysis showed that compared with secondary school students with soya food consumption ≥ 3 times/week, male students with soya food consumption ≤ 1 time/week (OR = 1·896, 95 % CI: 1·597,2·251) and female students with soya food consumption ≤ 1 time/week (OR = 2·877, 95 % CI: 2·399, 3·449) students had a higher risk of developing lower grip strength (P < 0·001). The frequency of soya food consumption among secondary school students in southern China was 49·00 %, 28·77 % and 22·23 % for ≥ 3 times/week, 2-3 times/week and ≤ 1 time/week, respectively. There is a positive association between soya food consumption and muscle strength among secondary school students in southern China. In the future, increasing the consumption of soybean products can be considered for the improvement of muscle strength.

Association of Plasma Zinc and Copper with Body Composition, Lipids and Inflammation in a Cross-Sectional General Population Sample from Germany

We aimed to relate circulating plasma zinc and copper to a broad spectrum of adiposity-related traits in a cross-sectional Northern German study (n = 841, 42% female, age: 61 ± 12 years). Zinc and copper were measured by inductively coupled plasma-mass spectrometry. Subcutaneous (SAT) and visceral (VAT) adipose tissue and liver fat were derived from 534 and 538 participants, respectively, via magnet resonance imaging. Associations were assessed using multivariable-adjusted linear regression analysis. An increase per one standard deviation (SD) in zinc was associated with direct linear increases in body mass index (BMI) (1.17%; 95% confidence interval (95%CI) 0.15-2.20%), waist circumference (0.85%; 95%CI 0.04-1.67%) and waist-to-hip ratio (0.64%; 95%CI 0.18-1.09%). A 1-SD increment in copper was directly associated with BMI (1.64%; 0.41-2.88%) and waist circumference (1.22%; 95%CI 0.25-2.20%) but not waist-to-hip ratio. Independent of fat intake, zinc displayed associations with VAT (5.73%; 95%CI 2.04-9.56%) and with liver fat (3.84%; 95%CI 1.49-6.25%), the latter association being also independent of BMI. Copper was directly associated with SAT (4.64%; 95%CI 0.31-9.15%) before accounting for BMI, but showed no association with VAT or liver fat. Observed associations suggest a possible relevance of zinc and copper to adiposity. Particularly zinc displayed associations with traits of abdominal adiposity and liver fat.

Study on the correlation and interaction between metals and dyslipidemia: a case-control study in Chinese community-dwelling elderly

Previous studies on the association between metals and dyslipidemia are not completely consistent. There are few studies investigating the relationship between mixed metal exposure and dyslipidemia as well as the effects of metals on dyslipidemia in community-dwelling elderly. To evaluate the correlations and interaction effect between the urinary concentrations of metals and the risk of dyslipidemia in community-dwelling elderly. We designed a case-control study to assess the correlation between urine metals and dyslipidemia in elderly people in the Yinchuan. The urinary levels of 13 metals, including calcium, vanadium, iron, cobalt, zinc, copper, arsenic, selenium, molybdenum, cadmium, tellurium, and thallium, were measured by inductively coupled plasma-mass spectrometry (ICP-MS), and the blood biochemical analyzer was used to measure the blood lipid levels of 3384 senior individuals from four different areas of Yinchuan city. Logistic regression and restricted cubic splines (RCS) were used to explore the correlation and dose-response relationship between urinary metals and the risk of dyslipidemia. Least absolute shrinkage and selection operator (LASSO) regression was used to select metals, and then weighted quantile sum (WQS) regression was used to explore the weight of each metal in mixed metals. Bayesian kernel machine regression (BKMR) was used to explore the interactions between metals on dyslipidemia risk. (1) After selection by LASSO regression, in the multi-metal model, compared with the lowest quartile, the adjusted ORs (95%CI) of the highest quartiles were 0.47 (0.37-0.60) for Fe, 1.43 (1.13-1.83) for Zn, 1.46 (1.11-1.92) for As, 0.59 (0.44-0.80) for Se, 1.53 (1.18-2.00) for Mo, and 1.36 (1.07-1.73) for Te. (2) In the WQS regression model, Fe and Mo accounted for the largest weight in the negative and positive effects of dyslipidemia, respectively. (3) In the BKMR model, there may be a positive interaction between Te and Se on dyslipidemia. Among the mixed metals, Fe, As, Se, Mo, and Te were associated with the prevalence of dyslipidemia, with Fe and Mo contributing the most. There may be certain interactions between Te and Se.

Effect of zinc supplementation on blood glucose level in different age groups of diabetes type 2

Background: Studies on humans have revealed the beneficial effects of zinc (Zn) supplementation in patients with type-2 diabetes. Aim: The present study was designed to investigate the effects of zinc supplementation on blood glucose level in type-2 diabetic patients and determine the interaction between age and zinc supplementation on type-2 diabetic patients. Methods: A randomized placebo-control trial conducted in Bashir Hospital of Sialkot, Allama Iqbal Memorial Hospital Sialkot and Civil Hospital of Daska, Sialkot. 144 diabetic patients were selected including an expected drop-out rate of 20%. All the participants were randomly divided into Group 1 (Treatment group with intervention given Zn tablets 20 mg/day) and Group 2 (control group with placebo effect). Each group was further divided into 2 age categories Category 1 (30-50 years of age) and Category 2 (51-70 Years of age). Demographic data, Anthropometric measurements, 24-h dietary recall, serum blood glucose analysis, HbA1C, and serum zinc levels were recorded at the beginning (0 day) and end of the study (60 days). Results: Final fasting serum glucose levels were significantly lowered in group 1 with (p < 0.05) as compared to group 2, but interestingly, results were significant (p < 0.05) in the older age group (51-70 years) as compared to their younger age counterparts (30-50 years) of group2. A similar trend was also found in the HbA1c, serum Zn levels and BMI of the participants. Conclusion: Results implied the possible phenomenon of better response to Zn supplementation among aged patients as compared to younger counterparts, which may suggest higher Zn demands with advanced age.

Association of Dietary Intake of Zinc and Selenium with Breast Cancer Risk: A Case-Control Study in Chinese Women

As major nonenzymatic antioxidant components in the body, dietary Zinc (Zn) and Selenium (Se) may have an impact on breast cancer development. This study aimed to investigate the relationship between dietary Zn, Se intake and breast cancer risk in Chinese women. The case-control study included 1591 cases and 1622 age-frequency matched controls. Dietary intake was collected using a validated food frequency questionnaire. Dietary Zn and Se were divided into four categories: Zn/Se from plants, Zn/Se from meat, Zn/Se from red meat, and Zn/Se from white meat. Unconditional logistic regression models and restricted cubic spline analyses were performed to identify potential associations. Zn from white meat intake was linearly and inversely associated with breast cancer risk, and Se from red meat intake was linearly and positively associated with breast cancer risk, with adjusted odds ratio and 95% confidence interval of 0.76 (0.61-0.95) and 1.36 (1.04-1.77), respectively. Non-linear relationships were found between total dietary Zn, Zn from meat, Zn from red meat intake and breast cancer risk (p_{non-linearity} < 0.05). In conclusion, dietary Zn and Se intake were associated with breast cancer risk in Chinese women, and the optimal intake of Zn may be beneficial for breast cancer prevention.

Dose-response relationship of elements with blood lipids and the potential interaction: A cross-sectional study from four areas with different pollution levels in China

BACKGROUND

A growing number of researches indicated the association between plasma trace elements and blood lipids. However, the potential interaction and dose-response relationship were less frequently reported.

METHODS

In this study, a total of 3548 participants were recruited from four counties in Hunan Province, South China. Demographic characteristics were collected by face-to-face interviews and inductively coupled plasma mass spectrometry (ICPMS) was used to determine the levels of 23 trace elements in plasma. We applied a fully adjusted generalized linear regression model (GLM) and a multivariate restricted cubic spline (RCS) to estimate the correlation, dose-response relationship and possible interaction between 23 trace elements and four blood lipid markers.

RESULTS

The results indicated positive dose-response relationships of plasma ⁶⁶zinc with triglycerides (TG) and low density lipoprotein cholesterol (LDL-C), plasma ⁷⁸selenium with LDL-C and total cholesterol (TCH), and plasma ⁵⁹cobalt with high-density lipoprotein cholesterol (HDL-C). There was a negative dose-response relationship between ⁵⁹cobalt and LDL-C. Further analysis found that ⁶⁶zinc and ⁵⁹cobalt had an antagonistic effect on the risk of increased LDL-C level.

CONCLUSIONS

This study added new evidence for the potential adverse effects of ⁶⁶Zn and ⁷⁸Se on blood lipids, and provided new insight into the threshold value setting for metals as well as the intervention strategy for dyslipidemia.

A Systematic Study on Zinc-Related Metabolism in Breast Cancer

Breast cancer has become the most common cancer worldwide. Despite the major advances made in the past few decades in the treatment of breast cancer using a combination of chemotherapy, endocrine therapy, and immunotherapy, the genesis, treatment, recurrence, and metastasis of this disease continue to pose significant difficulties. New treatment approaches are therefore urgently required. Zinc is an important trace element that is involved in regulating various enzymatic, metabolic, and cellular processes in the human body. Several studies have shown that abnormal zinc homeostasis can lead to the onset and progression of various diseases, including breast cancer. This review highlights the role played by zinc transporters in pathogenesis, apoptosis, signal transduction, and potential clinical applications in breast cancer. Additionally, the translation of the clinical applications of zinc and associated molecules in breast cancer, as well as the recent developments in the zinc-related drug targets for breast cancer treatment, is discussed. These developments offer novel insights into understanding the concepts and approaches that could be used for the diagnosis and management of breast cancer.

High Dietary Zinc Intake Is Associated with Shorter Leukocyte Telomere Length, Mediated by Tumor Necrosis Factor-α: A Study of China Adults

OBJECTIVES

Diet can influence peripheral leukocyte telomere length (LTL), and various micronutrients have been reported to correlate with it. Zinc is known for its antioxidant properties and immunomodulatory effects. However, there are few epidemiological investigations on the relationship between dietary zinc intake and LTL. This study analyzed the association between dietary zinc and LTL and the potential role of inflammation and oxidative stress among them.

DESIGN

Cross-sectional and community-based study.

SETTING AND PARTICIPANTS

599 participants from rural communities in the Changping suburb of Beijing, China, were recruited.

MEASUREMENTS

Serum lipid profile, glycosylated hemoglobin (HbA1c), oxidative stress marker, and inflammatory cytokines levels were measured. Detailed dietary data were obtained using a 24 h food recall. LTL was assessed using a real-time PCR assay. Spearman analysis, restricted cubic splines (RCS), and general linear regression models were used to determine the association between dietary zinc intake and LTL. Simple regulatory models were also applied to analyze the role of inflammation and oxidative stress among them.

RESULTS

A total of 482 subjects were ultimately included in this analysis. Spearman analysis showed that dietary zinc intake and zinc intake under energy density were negatively correlated with LTL (r=-0.142 and -0.126, all P <0.05) and positively correlated with tumor necrosis factor-α (TNF-α) (r=0.138 and 0.202, all P <0.05) while only dietary zinc without energy adjustment had a positive correlation with superoxide dismutase (SOD). RCS (P for non-linearity=0.933) and multiple linear regression (B=-0.084, P=0.009) indicated a negative linear association between dietary zinc and LTL. The adjustment of TNF-α rather than SOD could abolish the relationship. The mediation model suggested that the unfavorable effect of dietary zinc on LTL was mediated by TNF-α.

CONCLUSIONS

High dietary zinc may correlate with telomere attrition, and TNF-α can act as a mediator in this relationship. In the future, more extensive cohort studies are needed to further explore the relationship between dietary zinc and cellular aging and the specific mechanisms.

J-shaped association between dietary zinc intake and new-onset hypertension: a nationwide cohort study in China

We aimed to investigate the relationship of dietary zinc intake with new-onset hypertension among Chinese adults. A total of 12,177 participants who were free of hypertension at baseline from the China Health and Nutrition Survey were included. Dietary intake was assessed by three consecutive 24-h dietary recalls combined with a household food inventory. Participants with systolic blood pressure ≽ 140 mmHg or diastolic blood pressure ≽ 90 mmHg or diagnosed by a physician or under antihypertensive treatment during the follow-up were defined as having new-onset hypertension. During a median follow-up duration of 6.1 years, 4269 participants developed new-onset hypertension. Overall, the association between dietary zinc intake and new-onset hypertension followed a J-shape (P for non-linearity < 0.001). The risk of new-onset hypertension significantly decreased with the increment of dietary zinc intake (per mg/day: hazard ratio (HR) 0.93; 95% confidence interval (CI) 0.88-0.98) in participants with zinc intake < 10.9 mg/day, and increased with the increment of zinc intake (per mg/day: HR 1.14; 95% CI 1.11-1.16) in participants with zinc intake ≽ 10.9 mg/day. In conclusion, there was a J-shaped association between dietary zinc intake and new-onset hypertension in general Chinese adults, with an inflection point at about 10.9 mg/day.

Nutrition Strategies Promoting Healthy Aging: From Improvement of Cardiovascular and Brain Health to Prevention of Age-Associated Diseases

BACKGROUND

An increasing number of studies suggest that diet plays an important role in regulating aging processes and modulates the development of the most important age-related diseases.

OBJECTIVE

The aim of this review is to provide an overview of the relationship between nutrition and critical age-associated diseases.

METHODS

A literature review was conducted to survey recent pre-clinical and clinical findings related to the role of nutritional factors in modulation of fundamental cellular and molecular mechanisms of aging and their role in prevention of the genesis of the diseases of aging.

RESULTS

Studies show that the development of cardiovascular and cerebrovascular diseases, neurodegenerative diseases, cognitive impairment and dementia can be slowed down or prevented by certain diets with anti-aging action. The protective effects of diets, at least in part, may be mediated by their beneficial macro- (protein, fat, carbohydrate) and micronutrient (vitamins, minerals) composition.

CONCLUSIONS

Certain diets, such as the Mediterranean diet, may play a significant role in healthy aging by preventing the onset of certain diseases and by improving the aging process itself. This latter can be strengthened by incorporating fasting elements into the diet. As dietary recommendations change with age, this should be taken into consideration as well, when developing a diet tailored to the needs of elderly individuals. Future and ongoing clinical studies on complex anti-aging dietary interventions translating the results of preclinical investigations are expected to lead to novel nutritional guidelines for older adults in the near future.

Association of Urinary Zinc Concentrations with Dyslipidemia and Its Subtypes: Baseline Data from the Chinese Multi-Ethnic Cohort (CMEC) Study

This study elucidates the association between urinary zinc concentration and the risk of developing dyslipidemia and its subtypes in China's ethnic minority residents. Based on the baseline survey data of the Chinese Multi-Ethnic Cohort (CMEC) study, 10,620 subjects were included in the study. Logistic regression analysis evaluated the relationship between urinary zinc concentration and dyslipidemia and its subtypes. After adjustment, compared with urinary zinc concentration quartile 1 (Q1), the odds ratios (ORs) and 95% confidence intervals (95% CIs) of dyslipidemia participants in the quartile 2 (Q2), quartile 3 (Q3), and quartile 4 (Q4) groups were 1.091 (0.963, 1.237), 1.151 (1.051, 1.304), and 1.393 (1.230, 1.579), respectively (P for trend < 0.001). While that of hypertriglyceridemia participants in the Q2, Q3, and Q4 groups were 1.130 (0.979, 1.306), 1.283 (1.113, 1.480), and 1.483 (1.287, 1.709), respectively (P for trend < 0.001). Lastly, the ORs and 95% CIs of hyperbetalipoproteinemia participants in the Q2, Q3, and Q4 groups were 1.166 (0.945, 1.439), 1.238 (1.007, 1.522), and 1.381 (1.126, 1.695), respectively (P for trend < 0.002). This study found that urinary zinc concentrations were not associated with hypercholesterolemia and hypoalphalipoproteinemia. The dose-response relationship was non-linear between urinary zinc concentration and dyslipidemia, hypertriglyceridemia and hyperbetalipoproteinemia (P for trend < 0.001). In the stratified analysis, urinary zinc levels were positively associated with the risk of dyslipidemia, hypertriglyceridemia, and hyperbetalipoproteinemia in male, ≥ 60 years old, Miao nationality, hypertension, diabetes, and BMI ≥ 24.0 kg/m² subgroups. Our study provides some possible evidence that elevated urinary zinc concentrations are associated with an increased risk of dyslipidemia, hypertriglyceridemia, hyperbetalipoproteinemia.

Clinical Value of Vitamin D, Trace Elements, Glucose, and Lipid Metabolism in Diagnosis and Severity Evaluation of Psoriasis

Objective

The levels of vitamin D, trace elements, and glucose and lipid metabolism in psoriasis were evaluated, and their value in disease diagnosis and severity evaluation was explored.

Methods

In this study, the serum trace elements, blood glucose, and blood lipid indexes of 360 patients with psoriasis and 500 healthy subjects were compared and analyzed.

Results

The results of 25-(OH) D3, Cu/Zn, and HDL-C in patients with psoriasis were significantly different from those in the control group. With the aggravation of the disease, Psoriasis Area and Severity Index (PASI) was positively correlated with 25-(OH) D3 and HDL-C and negatively correlated with Cu/Zn. The AUC of the three indexes for the diagnosis of psoriasis was 0.899, 0.675, and 0.848, respectively.

Conclusion

There are metabolic abnormalities of 25-(OH) D3, Cu/Zn, and HDL-C in patients with psoriasis, and paying attention to these indicators is conducive to the diagnosis of disease.

Metals and risk of incident metabolic syndrome in a prospective cohort of midlife women in the United States

Exposure to metals may contribute to the development of metabolic syndrome (MetS); however, evidence from midlife women who are at greater risk of cardiometabolic disease is limited. We assessed the associations of 15 urinary metal concentrations with incident MetS in a prospective cohort of midlife women in the United States. The study population included 947 White, Black, Chinese and Japanese women, aged 45-56 years, free of MetS at baseline (1999-2000), who participated in the Study of Women's Health Across the Nation Multi-Pollutant Study. Fifteen metals were detected in almost all participants urine samples using inductively coupled plasma mass spectrometry at the baseline. Incident MetS was identified annually through 2017 as having at least three of the following five components: high blood pressure, impaired fasting glucose, abdominal obesity, high triglycerides, and poor high-density lipoprotein cholesterol. We used the Cox proportional hazards models to investigate the associations between individual metals and MetS incidence. The adjusted hazard ratios (HR) (95% CI) for MetS in associations with each doubling of urinary metal concentration were 1.14 (1.08, 1.23) for arsenic, 1.14 (1.01, 1.29) for cobalt, and 1.20 (1.06, 1.37) for zinc. We further evaluated the associations between metal mixtures and MetS using the elastic net penalized Cox model and summarized the results into the environmental risk score (ERS). Arsenic, barium, cobalt, copper, nickel, antimony, thallium, and zinc had positive weights, and cadmium, cesium, mercury, molybdenum, lead, and tin had negative weights in the construction of the ERS. The adjusted HR of MetS comparing 75th vs. 25th percentiles of the ERS was 1.45 (1.13, 1.87). These findings support the view that arsenic, cobalt, zinc, as well as metal mixtures, might influence the risks of incident MetS in midlife women.

Capsaicin and Zinc Promote Glucose Uptake in C2C12 Skeletal Muscle Cells through a Common Calcium Signalling Pathway

Capsaicin and zinc have recently been highlighted as potential treatments for glucose metabolism disorders; however, the effect of these two natural compounds on signalling pathways involved in glucose metabolism is still uncertain. In this study, we assessed the capsaicin- or zinc- induced activation of signalling molecules including calcium/calmodulin-dependent protein kinase 2 (CAMKK2), cAMP-response element-binding protein (CREB), and target of rapamycin kinase complex 1 (TORC1). Moreover, the expression status of genes associated with the control of glucose metabolism was measured in treated cells. The activation of cell signalling proteins was then evaluated in capsaicin- or zinc treated cells in the presence or absence of cell-permeant calcium chelator (BAPTA-AM) and the CAMKK inhibitor (STO-609). Finally, capsaicin- and zinc-induced glucose uptake was measured in the cells pre-treated with or without BAPTA-AM. Our results indicate that calcium flux induced by capsaicin or zinc led to activation of calcium signalling molecules and promoting glucose uptake in skeletal muscle cells. Pharmacological inhibition of CAMKK diminished activation of signalling molecules. Moreover, we observed an increase in intracellular cAMP levels in the cells after treatment with capsaicin and zinc. Our data show that capsaicin and zinc mediate glucose uptake in C2C12 skeletal muscle cells through the activation of calcium signalling.

The Effect and Potential Mechanism of Maternal Micronutrient Intake on Offspring Glucose Metabolism: An Emerging Field

Diabetes has become the most common metabolic disease around the world. In addition to genetic and environmental factors in adulthood, the early life environment is critical to the progression of diabetes in adults, especially the environment during the fetal period; this concept is called “fetal programming.” Substantial evidence has illustrated the key role of early life macronutrient in programming metabolic diseases. Recently, the effect of maternal micronutrient intake on offspring glucose metabolism during later life has become an emerging field. This review focuses on updated human and animal evidence about the effect of maternal micronutrient status on offspring glucose metabolism and the underlying mechanism.

Identifying the Food Sources of Selected Minerals for the Adult European Population among Rice and Rice Products

The problem of dietary deficiency of several essential elements among different stages of life is still observed. The consumption of whole grains (among others unprocessed rice) is recommended as a part of a healthy diet. This research aimed to determine the content of selected macro- and microelements in rice and rice products to verify whether the tested products could be regarded as a source of selected minerals in the diet of the adult European population.

METHODS

A total of 99 samples from 12 groups of rice products (basmati, black, brown, parboiled, red, wild, white rice and expanded rice, rice flakes, flour, pasta, and waffles) were obtained. The atomic absorption spectrometry method (AAS) was used to determine the content of Ca, Cu, Fe, Mg, Mn, Se and Zn in the study material.

RESULTS

The average measured contents of Ca, Cu, Fe, Mg, Mn, Se and Zn were as follows: 226.3 ± 160.6 mg/kg, 3.6 ± 2.8 mg/kg, 9.4 ± 7.0 mg/kg, 618.0 ± 498.4 mg/kg, 16.7 ± 10.0 mg/kg, 242.9 ± 140.4 µg/kg and 19.5 ± 15.0 mg/kg, respectively. Statistical analyses confirmed the differences in the levels of the studied elements between the subgroups of processed and unprocessed products. Considering the tolerable upper intake level of studied elements, the tested products could be regarded as safe to consume.

CONCLUSION

All tested products can be recommended as a source of Cu, Mn, and Se, while a majority of studied products can be considered a source of Mg and Zn in the diet of the adult European population.

Zinc

Since the discovery of manifest Zn deficiency in 1961, the increasing number of studies demonstrated the association between altered Zn status and multiple diseases. In this chapter, we provide a review of the most recent advances on the role of Zn in health and disease (2010-20), with a special focus on the role of Zn in neurodegenerative and neurodevelopmental disorders, diabetes and obesity, male and female reproduction, as well as COVID-19. In parallel with the revealed tight association between ASD risk and severity and Zn status, the particular mechanisms linking Zn2+ and ASD pathogenesis like modulation of synaptic plasticity through ProSAP/Shank scaffold, neurotransmitter metabolism, and gut microbiota, have been elucidated. The increasing body of data indicate the potential involvement of Zn2+ metabolism in neurodegeneration. Systemic Zn levels in Alzheimer's and Parkinson's disease were found to be reduced, whereas its sequestration in brain may result in modulation of amyloid β and α-synuclein processing with subsequent toxic effects. Zn2+ was shown to possess adipotropic effects through the role of zinc transporters, zinc finger proteins, and Zn-α2-glycoprotein in adipose tissue physiology, underlying its particular role in pathogenesis of obesity and diabetes mellitus type 2. Recent findings also contribute to further understanding of the role of Zn2+ in spermatogenesis and sperm functioning, as well as oocyte development and fertilization. Finally, Zn2+ was shown to be the potential adjuvant therapy in management of novel coronavirus infection (COVID-19), underlining the perspectives of zinc in management of old and new threats.

Association of multiple metals with lipid markers against different exposure profiles: A population-based cross-sectional study in China

We sought to evaluate whether essential and toxic metals are cross-sectionally related to blood lipid levels using data among adults from Shimen (n = 564) and Huayuan (n = 637), two counties with different exposure profiles in Hunan province of China. Traditional and grouped weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were performed to assess association between exposure to a mixture of 22 metals measured in urine or plasma, and lipid markers. Most of the exposure levels of metals were significantly higher in Shimen area than those in Huayuan area (all P-values < 0.001). Traditional WQS regression analyses revealed that the WQS index were both significantly associated with lipid markers in two areas, except for the HDL-C. Grouped WQS revealed that essential metals group showed significantly positive associations with lipid markers except for HDL-C in Huayuan area, while toxic metals group showed significantly negative associations except for HDL-C and LDL-C in Huayuan area. There were no significant joint effects, but potential non-linear relationships between metals mixture and TC or LDL-C levels were observed in BKMR analyses. Although consistent significantly associations of zinc and titanium with TG levels were found in both areas, the metals closely related to other lipid markers were varied by sites. Additionally, the BKMR analyses revealed an inverse U shaped association of iron with LDL-C levels and interaction effects of zinc and cadmium on LDL-C in Huayuan area. The relationship between metal exposure and blood lipid were not identical against different exposure profiles.

Dietary zinc intake and incident chronic kidney disease

BACKGROUND & AIMS

Previous studies have shown that dietary zinc intake is closely related to cardiovascular complications and metabolic derangements. However, the effect of dietary zinc intake on renal function is not fully elucidated.

METHODS

Data from the Korean Genome and Epidemiology Study were used. Dietary zinc intake was assessed by a Food Frequency Questionnaire and dietary zinc density was calculated as absolute zinc intake amount per daily energy intake (mg/1000 kcal day). The participants were categorized into quartiles according to dietary zinc density. The primary end point was incident chronic kidney disease (CKD), defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m².

RESULTS

A total of 7735 participants with normal renal function was included in the final analysis. The mean age was 52.0 ± 8.8 years, 47.5% were male, and mean eGFR was 92.1 ± 16.1 ml/min/1.73 m². The mean daily zinc intake and zinc intake density were 8.6 ± 3.4 mg and 4.4 ± 0.9 mg/1000 kcal, respectively. During a median follow up of 11.5 (1.7-12.5) years and 70,617 person-years of observation, CKD developed in 1409 (18.2%) participants. Multivariable cox hazard analysis revealed that risk for CKD development was significantly higher in the quartile with a mean zinc intake density of 3.6 ± 0.2 mg/1000 kcal compared with the quartile with a mean zinc intake density of 5.6 ± 1.0 mg/1000 kcal (Hazard ratio; 1.36; 95% Confidence Interval 1.18-1.58; P < 0.001). This relationship remained significant even after adjustments for confounding factors.

CONCLUSION

Low dietary zinc intake may increase the risk of CKD development in individuals with normal renal function.

Micronutrient-rich dietary intake is associated with a reduction in the effects of particulate matter on blood pressure among electronic waste recyclers at Agbogbloshie, Ghana

BACKGROUND

Informal recycling of electronic waste (e-waste) releases particulate matter (PM) into the ambient air. Human exposure to PM has been reported to induce adverse effects on cardiovascular health. However, the impact of PM on the cardiovascular health of e-waste recyclers in Ghana has not been studied. Although intake of micronutrient-rich diet is known to modify these PM-induced adverse health effects, no data are available on the relationship between micronutrient status of e-waste recyclers and the reported high-level exposure to PM. We therefore investigated whether the intake of micronutrient-rich diets ameliorates the adverse effects of ambient exposure to PM2.5 on blood pressure (BP).

METHODS

This study was conducted among e-waste and non-e-waste recyclers from March 2017 to October 2018. Dietary micronutrient (Fe, Ca, Mg, Se, Zn, and Cu) intake was assessed using a 2-day 24-h recall. Breathing zone PM2.5 was measured with a real-time monitor. Cardiovascular indices such as systolic BP (SBP), diastolic BP (DBP), and pulse pressure (PP) were measured using a sphygmomanometer. Ordinary least-squares regression models were used to estimate the joint effects of ambient exposure to PM2.5 and dietary micronutrient intake on cardiovascular health outcomes.

RESULTS

Fe was consumed in adequate quantities, while Ca, Se, Zn, Mg, and Cu were inadequately consumed among e-waste and non-e-waste recyclers. Dietary Ca, and Fe intake was associated with reduced SBP and PP of e-waste recyclers. Although PM2.5 levels were higher in e-waste recyclers, exposures in the control group also exceeded the WHO 24-h guideline value (25 μg/m3). Exposure to 1 μg/m3 of PM2.5 was associated with an increased heart rate (HR) among e-waste recyclers. Dietary Fe intake was associated with a reduction in systolic blood pressure levels of e-waste recyclers after PM exposure.

CONCLUSIONS

Consistent adequate dietary Fe intake was associated with reduced effects of PM2.5 on SBP of e-waste recyclers overtime. Nonetheless, given that all other micronutrients are necessary in ameliorating the adverse effects of PM on cardiovascular health, nutrition-related policy dialogues are required. Such initiatives would help educate informal e-waste recyclers and the general population on specific nutrients of concern and their impact on the exposure to ambient air pollutants.

Dairy Intake Would Reduce Nutrient Gaps in Chinese Young Children Aged 3-8 Years: A Modelling Study

Dairy foods are under-consumed among Chinese children. We modeled the impact of increased dairy consumption on nutrient inadequacy and assessed whether the consumption of formulated milk powder for children ≥3 years (FMP3+) is useful for reducing nutrient gaps. Data from 3–8-year-old children, with completed socio-demographic and dietary measurements from the China Health and Nutrition Survey 2015, were used (n = 1122). Dietary intakes were modeled in two scenarios: Scenario 1 added FMP3+ or cow’s milk to reported diet to reach recommended dairy intakes; Scenario 2 replaced the currently consumed milk with an equal volume of FMP3+. Reported nutrient intakes were compared with each model. Only 32.5% of children consumed dairy products; the average intake amount in total was 48.6 g/day. Most children (97.6%) did not meet dairy intake recommendation. Inadequate nutrient intakes were observed for calcium, potassium, thiamin, riboflavin, vitamin C and selenium. In Scenario 1, both FMP3+ and cow’s milk improved the intake of all analyzed nutrients. In Scenario 2, FMP3+ substitution increased the intake of most nutrients, and reduced the proportion of children with an inadequate intake of vitamin C, thiamin, vitamin A, iron, zinc and potassium. Thus, increasing dairy consumption would reduce nutrient gaps, and FMP3+ is a good food source to help children meet nutrient requirements.

Environmental and Health Implications of the Correlation Between Arsenic and Zinc Levels in Rice from an Arsenic-Rich Zone in Cambodia

BACKGROUND

In parts of Cambodia, irrigation of rice with groundwater results in arsenic accumulation in soils and rice, leading to health concerns associated with rice consumption. In Bangladesh and China, low zinc levels in rice have been found in regions where arsenic levels in rice are high. Furthermore, there have been claims that zinc deficiency is responsible for stunting of children in Cambodia. There are limited data on zinc in Cambodian rice, but in rural Asia, rice is the major source of zinc.

OBJECTIVES

To provide a preliminary evaluation of the zinc content in rice grain in Preak Russey, an area with elevated levels of arsenic. The importance of zinc in rice for infants was also assessed.

METHODS

Rice cultivation was evaluated in sixty farms along the Mekong River in Cambodia. Analyses for metals, total arsenic, and arsenic species in the water and rice were conducted at the University of Ottawa, Canada by inductively coupled plasma - mass spectrometry. Analysis of total zinc and arsenic in soils were analyzed in Phnom Penh using X-ray fluorescence spectrometry (XRF). Total zinc in rice was also measured by XRF analysis.

RESULTS

Rice in the Preak Russey area contained zinc with ½ to ¼ of the 1987 Codex standard for rice in Infant Formula. Moreover, our average zinc concentration in rice samples was less than a third that recommended for zinc fortification in rice by the United Nations World Food Programme. There was a significant (α=0.05) negative correlation between the arsenic and zinc content of rice with the lowest zinc levels occurring near the irrigation wells, the source of arsenic. There was a significantly higher content of zinc in rice from farms that fertilized with cow manure.

CONCLUSIONS

Handheld XRF spectrometers are useful tools for detection of zinc levels in rice. The potential for zinc deficiency in farmers in areas of Cambodia with arsenic toxicity is high.

COMPETING INTERESTS

The authors declare no competing financial interests.