Daily consumption of Lactobacillus gasseri CP2305 improves quality of sleep in adults - A systematic literature review and meta-analysis.

BACKGROUND & AIM: The gut-brain axis is one of the proposed interactions between the brain and peripheral intestinal functions; of particular interest is the influence of food components on the gut-brain axis mediated via the gut microbiome. Probiotics and paraprobiotics have been proposed to interact with the intestinal environment and provide health benefits such as improving sleep quality. The aim of this research was to undertake a systematic literature review and meta-analysis to evaluate the current evidence regarding the effects of Lactobacillus gasseri CP2305 on sleep quality for the general population. METHODS: A systematic literature search was conducted of peer-reviewed articles published up to 04 November 2022. Randomised controlled trials were identified that investigated the effects of Lactobacillus gasseri CP2305 on sleep parameters in adults. Meta-analysis of the change in the Pittsburgh Sleep Quality Index (PSQI) global score was conducted. Quality assessments of individual studies were conducted using the Cochrane Risk of Bias and Health Canada tools. RESULTS: Seven studies were included in the systematic literature review; six studies included data for meta-analysis to quantify the effect of L. gasseri CP2305 on sleep quality. The ingestion of L. gasseri CP2305 resulted in significant improvement in the PSQI global score compared to control (-0.77, 95% CI: -1.37 to -0.16, P = 0.01). In the two studies that included electroencephalogram (EEG) data, output was significantly improved for at least half of the measured EEG outcomes after consumption of L. gasseri CP2305. No serious concerns were found in the potential biases of included studies, indirectness of the included evidence, and other methodological issues. CONCLUSION: The present systematic review and meta-analysis indicates significant improvement in sleep quality of adults with mild to moderate stress as an effect of daily consumption of L. gasseri CP2305. Based on existing evidence, the relationship between L. gasseri CP2305 and enhanced sleep quality is plausible, however further investigations are required to confirm the mechanisms of actions for this effect.

The effect of zinc supplementation on glucose homeostasis: a randomised double-blind placebo-controlled trial.

AIMS: The burden and health costs of Type 2 Diabetes Mellitus continue to increase globally and prevention strategies in at-risk people need to be explored. Previous work, in both animal models and humans, supports the role of zinc in improving glucose homeostasis. We, therefore, aimed to test the effectiveness of zinc supplementation on glycaemic control in pre-diabetic adults. METHODS: We conducted a randomized, double-blind, placebo-controlled trial across 10 General Practitioner (GP) practices in NSW, Australia. The trial is known as Zinc in Preventing the Progression of pre-Diabetes (ZIPPeD)Study. Pre-diabetic (haemoglobin A1c [HbA1c] 5.7-6.4%, 39-46 mmol/mol) men and women (N = 98) were all assigned to a free state government telephone health coaching service (New South Wales Get Healthy Information and Coaching Service) and then randomised to either daily 30 mg zinc gluconate or placebo. Blood tests were collected at baseline, 1, 6 and 12 months for the primary outcomes (HbA1c, fasting blood glucose (FBG)); secondary outcomes included Homeostasis Model Assessment 2 (HOMA 2) parameters, lipids, body weight, height, waist circumference, blood pressure and pulse. RESULTS: The baseline-adjusted mean group difference at 6 months, expressed as treatment-placebo, (95% CI) was -0.02 (-0.14, 0.11, p = 0.78) for HbA1c and 0.17 (-0.07, 0.42; p = 0.17) for FBG, neither of which were statistically significant. There were also no significant differences between groups in any of the secondary outcomes. Zinc was well tolerated, and compliance was high (88%). CONCLUSION: We believe our results are consistent with other Western clinical trial studies and do not support the use of supplemental zinc in populations with a Western diet. There may still be a role for supplemental zinc in the developing world where diets may be zinc deficient. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12618001120268. Registered on 6 July 2018.

Using the AUSDRISK score to screen for pre-diabetes and diabetes in GP practices: a case-finding approach.

OBJECTIVE: To identify the optimal AUSDRISK threshold score to screen for pre-diabetes and diabetes. METHODS: A total of 406 adult patients not diagnosed with diabetes were screened in General Practices (GP) between May and October 2019. All patients received a point of care (POC) HbA1c test. HbA1c test results were categorised into diabetes (≥6.5% or ≥48 mmol/mol), pre-diabetes (5.7-6.4% or 39-47 mmol/mol), or normal (<5.7% or 39 mmol/mol). RESULTS: Of these patients, 9 (2%) had undiagnosed diabetes and 60 (15%) had pre-diabetes. A Receiver Operator Characteristic (ROC) curve was constructed to predict the presence of pre-diabetes and diabetes; the area under the ROC curve was 0.72 (95%CI 0.65-0.78) indicating modest predictive ability. The optimal threshold cut point for AUSDRISK score was 17 (sensitivity 76%, specificity 61%, + likelihood ratio (LR) 1.96, - likelihood ratio of 0.39) while the accepted cut point of 12 performed less well (sensitivity 94%, specificity 23%, +LR=1.22 -LR+0.26). CONCLUSIONS: The AUSDRISK tool has the potential to be used as a screening tool for pre-diabetes/diabetes in GP practices. A cut point of ≥17 would potentially identify 75% of all people at risk and three in 10 sent for further testing would be positive for prediabetes or diabetes. IMPLICATIONS FOR PUBLIC HEALTH: Routine case-finding in high-risk patients will enable GPs to intervene early and prevent further public health burden from the sequelae of diabetes.

Zinc in Preventing the Progression of pre-Diabetes (ZIPPeD Study) - study protocol for a randomised placebo-controlled trial in Australia.

BACKGROUND: Diabetes is increasing in incidence, morbidity and treatment costs globally, hence prevention strategies need to be explored. Animal studies and some human data have shown that zinc can improve glycaemic control, but the impact of this effect in a pre-diabetic population remains uncertain. This study is designed to investigate whether zinc gluconate and lifestyle coaching can improve glucose handling and ultimately reduce diabetes incidence in an at-risk pre-diabetic population in Australia. METHODS/DESIGN: The study will be a randomised, placebo-controlled, double-blind clinical trial. The study will be conducted at the Hunter New England Local Health District New South Wales (NSW), Australia. Pre-diabetic (haemoglobin A1c [HbA1c] 5.7-6.4) male and female participants (n = 410) aged 40-70 years will be recruited through the Diabetes Alliance Network, a collaboration of diabetes specialists and general practitioner practices. All participants will be given routine care to encourage healthy lifestyle changes using a telephone coaching service (Get Healthy Information and Coaching Service, NSW Health) and then randomised to receive a supplement, either zinc gluconate (equivalent to 30 mg of elemental zinc) or placebo of identical appearance for 12 months. The identity of the supplements will be blinded to both research personnel and the participants. Participants will be asked to complete medical, lifestyle and dietary surveys and will have baseline and final visits at their general practitioner practice. Primary outcomes will be HbA1c and insulin sensitivity collected at baseline and at 1, 6 and 12 months; secondary outcomes will include fasting blood glucose, fasting cholesterol, blood pressure and body mass index. The primary efficacy endpoint will be judged at 6 months. DISCUSSION: This study will generate new evidence about the potential for health coaching, with or without zinc supplementation, to improve glucose handling and ultimately to reduce progression from pre-diabetes to diabetes. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, ACTRN12618001120268 . Registered on 6 July 2018.

Zinc status at baseline is not related to acute changes in serum zinc concentration following bouts of running or cycling.

Zinc status is implicated in physiological functions related to exercise performance and physical activity. We have previously demonstrated significant changes in serum zinc concentrations following a bout of aerobic exercise, suggestive of a relationship between zinc metabolism and exercise-related functions. In the present study, we aim to determine the association between pre-exercise serum zinc concentration and immediate changes in serum zinc concentration following an aerobic exercise bout. We have previously conducted a systematic literature search of PubMed, Web of Science, Scopus and SPORTDiscus, for studies that investigated the acute effects of aerobic exercise on zinc biomarkers. In the current study, we undertook a secondary analysis using mixed effects meta-regression modelling to determine the relationship between baseline serum zinc concentration and the change in serum zinc concentration immediately after exercise. Meta-regression models revealed no significant relationship between baseline serum zinc concentration and the change in serum zinc concentration following a bout of exercise when all comparisons were included (slope -0.11 ±â€¯0.07 [standard error]; P > 0.05). When comparisons were stratified by exercise modality, no significant relationships were observed for exercise bouts involving cycling or running. The current analyses were limited by the available literature and low statistical power of the meta-regression models. Based on the current available data, the present analysis revealed limited evidence for a relationship between pre-exercise serum zinc concentration and immediate changes in serum zinc levels following a bout of aerobic exercise. Subgroup meta-regression analyses stratified by the mode of exercise bouts did not differ from the overall results. This suggests that zinc status at baseline is not related to acute changes in serum zinc concentration following bouts of aerobic exercise.

Modified Version of Baby-Led Weaning Does Not Result in Lower Zinc Intake or Status in Infants: A Randomized Controlled Trial.

BACKGROUND: Little is known about zinc intakes and status during complementary feeding. This is particularly true for baby-led approaches, which encourage infants to feed themselves from the start of complementary feeding, although self-feeding may restrict the intake of zinc-rich foods. OBJECTIVE: To determine the zinc intakes, sources, and biochemical zinc status of infants following Baby-Led Introduction to SolidS (BLISS), a modified version of Baby-Led Weaning (BLW), compared with traditional spoon-feeding. DESIGN: Secondary analysis of the BLISS randomized controlled trial. PARTICIPANTS/SETTING: Between 2012 and 2014, 206 community-based participants from Dunedin, New Zealand were randomized to a Control or BLISS group. INTERVENTION: BLISS participants received eight study visits (antenatal to 9 months) providing education and support regarding BLISS (ie, infant self-feeding from 6 months with modifications to address concerns about iron, choking, and growth). MAIN OUTCOME MEASURES: Dietary zinc intakes at 7 and 12 months (weighed 3-day diet records) and zinc status at 12 months (plasma zinc concentration). STATISTICAL ANALYSES PERFORMED: Regression analyses were used to investigate differences in dietary intakes and zinc status by group, adjusted for maternal education and parity and infant age and sex. RESULTS: There were no significant differences in zinc intakes between BLISS and Control infants at 7 (median: 3.5 vs 3.5 mg/day; P=0.42) or 12 (4.4 vs 4.4 mg/day; P=0.86) months. Complementary food groups contributing the most zinc at 7 months were "vegetables" for Control infants, and "breads and cereals" for BLISS infants, then "dairy" for both groups at 12 months. There was no significant difference in mean±standard deviation plasma zinc concentration between the Control (62.8±9.8 µg/dL [9.6±1.5 µmol/L]) and BLISS (62.8±10.5 µg/dL [9.6±1.6 µmol/L]) groups (P=0.75). CONCLUSIONS: BLISS infants achieved similar zinc intake and status to Control infants. However, the BLISS intervention was modified to increase iron intake, which may have improved zinc intake, so these results should not be generalized to infants following unmodified BLW.

Modifiable "Predictors" of Zinc Status in Toddlers.

Suboptimal zinc status is common in very young children and likely associated with increased risk of infection and detrimental effects on growth. No studies have determined potentially modifiable "predictors" of zinc status in toddlers from high-income countries. This cross-sectional analysis of 115 toddlers from the Baby-Led Introduction to SolidS (BLISS) study used weighed diet records (three non-consecutive days) to assess dietary intake, and a venous blood sample (trace-element free techniques) to assess plasma zinc, at 12 months of age. "Predictors" of plasma zinc were determined by univariate analysis and multiple regression. Mean (SD) plasma zinc was 9.7 (1.5) µmol/L, 60% were below the IZiNCG reference limit of <9.9 µmol/L. Median (25th, 75th percentiles) intake of zinc was 4.4 (3.7, 5.4) mg/day. Red meat intake (p = 0.004), consumption of zinc-fortified infant formula (3-6 mg zinc/100 g) (p = 0.026), and food fussiness (p = 0.028) were statistically significant "predictors" of plasma zinc at 12 months. Although higher intakes of red meat, and consumption of infant formula, are potentially achievable, it is important to consider possible barriers, particularly impact on breastfeeding, cost, and the challenges of behavior modification. Of interest is the association with food fussiness-further research should investigate the direction of this association.

Lower Serum Zinc Concentration Despite Higher Dietary Zinc Intake in Athletes: A Systematic Review and Meta-analysis.

BACKGROUND: Zinc is an essential trace element that has been implicated in numerous biological functions, including immunity, energy metabolism and antioxidative processes. Recent evaluations of the literature have provided evidence of significant acute changes in zinc metabolism following a bout of aerobic exercise. OBJECTIVE: The aim of this study was to determine the zinc status of trained athletes compared with control populations, as described in cross-sectional studies. DESIGN: We conducted a systematic literature search of the PubMed, Scopus, SPORTDiscus and Cochrane Library electronic databases from inception to 28 January 2016 to identify cross-sectional studies that determined the zinc status of athletes compared with a control population. Meta-analysis of the differences in serum zinc concentration and dietary zinc intake between groups were conducted. RESULTS: Twelve studies were included in the systematic review. Of the included studies, nine and eight studies provided sufficient data for the meta-analysis of serum zinc concentration and dietary zinc intake, respectively. Serum zinc concentration was significantly lower in athletes [- 0.93 µmol/L, 95% confidence interval (CI) - 1.62 to - 0.23] despite significantly higher dietary zinc intake compared with the control population (2.57 mg/day, 95% CI 0.97-4.16). Data on erythrocyte and urinary zinc from the included studies were insufficient for meta-analysis. CONCLUSIONS: Despite higher total dietary zinc intake, athletes generally have lower serum zinc concentration, which suggests that athletes have higher requirement of zinc than those who are physically inactive. Further investigations of zinc metabolism during exercise and dietary zinc requirement in active populations are needed to establish evidence-based recommendations.

Association between dietary zinc intake and mortality among Chinese adults: findings from 10-year follow-up in the Jiangsu Nutrition Study.

PURPOSE: Population studies of the association between zinc intake and mortality yield inconsistent findings. Using data from Jiangsu Nutrition Study, we aimed to assess the association between zinc intake and mortality among Chinese adults. METHODS: We prospectively studied 2832 adults aged 20 years and older with a mean follow-up of 9.8 years. At baseline, food intake was measured by 3-day weighed food record (WFR) between September and December in 2002. Death occurrence was assessed in 2012 during a household visit as well as by data linkage with the regional death registry. Hazard ratios (HRs) and 95% CI were calculated using competing risks regression (CVD and cancer mortality) and Cox proportional hazards analysis (all-cause mortality). RESULTS: During 27,742 person-years of follow-up, there were 184 deaths [63 cancer deaths and 70 cardiovascular disease (CVD) deaths]. Dietary zinc to energy ratio was positively associated with cancer and all-cause mortality. Across quartiles of the zinc to energy ratio from low to high, the HR (95% CI) for all-cause mortality was 1.00, 1.80 (95% CI 1.10-2.95), 1.55 (95% CI 0.96-2.50), and 1.85 (95% CI 1.11-3.07), respectively. Comparing the extreme quartiles of the zinc to energy ratio, the HR for cancer mortality was 2.28 (95% CI 1.03-5.04). CONCLUSION: Zinc intake was positively related to all-cause mortality and cancer mortality.

Quantifiable effects of regular exercise on zinc status in a healthy population-A systematic review.

Zinc is an essential mineral of which its functions have potential implications on exercise performance and beneficial adaptations of physical activity. While the effects of aerobic exercise on zinc metabolism acutely have been well described, the effect of long-term exercise training on zinc status remains unclear. The present review aims to determine the effects of exercise training on markers of zinc status in an apparently healthy adult population. We conducted a systematic literature search on PubMed, Scopus, SPORTDiscus and Cochrane Library from inception to 28 January 2016 to identify interventional or cohort studies that investigated the effects of exercise training on indices of zinc status. Pairwise comparisons of mean differences in within-group change were calculated and summarised visually in forest plots. Six studies satisfied the inclusion criteria for the systematic review, of which 5 studies included data on changes in serum zinc concentrations and 3 studies provided changes in dietary zinc intake. Two comparisons showed significantly higher increase of serum zinc concentrations in the exercise group compared to control, while one comparison reported significantly lower change in serum zinc for the exercising group. The exercise groups consumed significantly higher dietary zinc compared to controls in two comparisons. The present review revealed an incomplete evidence base in evaluating the effect of long-term exercise training on markers of zinc status. Further well-designed investigations are required to elucidate the relationship for establishment of dietary recommendation in populations who are continuing exercise interventions.

Plasma/Serum Zinc Status During Aerobic Exercise Recovery: A Systematic Review and Meta-Analysis.

BACKGROUND: Exercise and the subsequent recovery processes have been proposed to induce disturbances in zinc homeostasis. We previously reported acute increase in serum zinc concentration immediately after aerobic exercise; the change in the indices of zinc status during exercise recovery was not explored. OBJECTIVE: The aim of the current analysis is to determine the changes in zinc biomarkers during recovery from an aerobic exercise bout. METHODS: We conducted a systematic literature search on PubMed, Web of Science, Scopus and SPORTDiscus electronic databases from inception to 20 December 2014 to identify studies that investigated the acute effects of exercise on selected indices of zinc status. Meta-analyses were conducted to determine the change in serum zinc concentration during exercise recovery, defined as up to 4 h following exercise cessation, compared to pre-exercise levels. RESULTS: Forty-five studies were included in the systematic literature review, of which 12 studies (providing 18 comparisons) reported serum zinc levels after the cessation of exercise. During exercise recovery, serum zinc concentration was significantly lower than pre-exercise values (-1.31 ± 0.22 µmol/L, P < 0.001; mean ± SE). Secondary analyses showed a significant decrease of serum zinc levels in all categories of participants' training status, mode of exercise and time of blood collection. Insufficient data were available for meta-analysis of other zinc biomarkers. CONCLUSIONS: The present analysis showed that serum zinc levels decrease significantly during exercise recovery, compared to pre-exercise levels. This extends our previous report of an increase in serum zinc immediately after exercise. We postulate that the exercise-induced fluctuations in zinc homeostasis are linked to the muscle repair mechanisms following exercise; the potential for zinc to enhance the exercise recovery process remains to be determined.

Interrelationships among mediators of cellular zinc homeostasis in healthy and type 2 diabetes mellitus populations.

SCOPE: The involvement of zinc in multiple physiological systems requires tight control of cellular zinc concentration. This study aims to explore the relationships among selected mediators of cellular zinc homeostasis in an apparently healthy (AH) population and a cohort with type 2 diabetes mellitus (T2DM). METHODS AND RESULTS: Baseline data of three trials forming two cohorts, AH (n = 70) and T2DM (n = 42), were used for multivariate analyses to identify groupings within ten zinc transporter and metallothionein (MT) gene expressions, stratified by health status. Multiple regression models were used to explore relationships among zinc transporter/MT groupings and plasma zinc. Gene expression of zinc transporters and MTs, with the exception of ZnT6, were significantly lower in the T2DM cohort (p < 0.01). Cluster analysis showed that the groupings of zinc transporters and MTs were largely similar between the two cohorts, with the exception for ZnT1 and ZIP7. Zinc transporters and MTs were significant determinants of plasma zinc (r2 = 0.48, p = 0.001) in the AH cohort, but not in the T2DM cohort. CONCLUSION: The current study suggests altered cellular zinc homeostasis in T2DM and supports the use of multiple zinc transporters and MTs groupings to further understand zinc homeostasis in health and T2DM.

Zinc Status and Risk of Cardiovascular Diseases and Type 2 Diabetes Mellitus-A Systematic Review of Prospective Cohort Studies.

Zinc is an essential trace element with proposed therapeutic effects in Type 2 diabetes mellitus (DM), however, the associations between zinc status and the prospective risks of cardiovascular diseases (CVD) and Type 2 DM have not been evaluated. The current systematic review aims to determine the relationships between zinc intake or plasma/serum zinc levels and prospective incidence of CVD and Type 2 DM. Fourteen papers describing prospective cohort studies were included, reporting either CVD (n = 91,708) and/or Type 2 DM (n = 334,387) outcomes. Primary analyses from four out of five studies reported no association between zinc intake and CVD events, when adjusted for multiple variables. Higher serum zinc level was associated with lower risk of CVD in three out of five studies; pronounced effects were observed in vulnerable populations, specifically those with Type 2 DM and patients referred to coronary angiography. The limited evidence available suggests no association between zinc status and Type 2 DM risk. Further investigations into the mechanisms of zinc's action on the pathogenesis of chronic diseases and additional evidence from observational studies are required to establish a recommendation for dietary zinc in relation to the prevention of CVD and Type 2 DM.

Zinc Intake, Zinc Bioavailability and Plasma Zinc in Obese Adolescents with Clinical Insulin Resistance Following Low Energy Diets.

BACKGROUND: Zinc has a critical role in metabolism and growth. This study aims to determine the effects of low-energy diets differing in macronutrient composition on zinc intake, estimated zinc bioavailability (phytate:zinc molar ratio) and plasma zinc concentration and associations between zinc status and cardiometabolic markers in obese adolescents with clinical insulin resistance (IR). METHODS: Eighty-seven obese adolescents (10-17 years, body mass index z-score 2.3 ± 0.37) with clinical IR were randomized to a low-energy diet (6.0-8.0 MJ), which was either high carbohydrate or moderate carbohydrate with increased protein. Twenty-four-hour dietary recalls were collected at 6, 9 and 12 weeks. Plasma zinc concentration and cardiometabolic markers were assessed at baseline and 12 weeks. RESULTS: Zinc intake did not differ between the 2 diet groups (p = 0.612). The high-carbohydrate group had a higher phytate intake (894 vs. 671 mg, p = 0.018) and phytate:zinc molar ratio (9.4 vs. 7.4, p = 0.009) than the increased-protein group. Plasma zinc concentration did not change from baseline in either of the diet groups, but correlated positively with zinc intake (r = 0.235, p = 0.042) and % energy from protein (r = 0.383, p = 0.001), and inversely with % energy from carbohydrate (r = -0.296, p = 0.010). CONCLUSIONS: Low energy diets for obese adolescents at risk of diabetes may need increased protein content to optimize zinc bioavailability.

Comparison of Very Low Energy Diet Products Available in Australia and How to Tailor Them to Optimise Protein Content for Younger and Older Adult Men and Women.

Very low energy diets (VLED) are efficacious in inducing rapid weight loss but may not contain adequate macronutrients or micronutrients for individuals with varying nutritional requirements. Adequate protein intake during weight loss appears particularly important to help preserve fat free mass and control appetite, and low energy and carbohydrate content also contributes to appetite control. Therefore, the purpose of this study was to compare the nutritional content (with a focus on protein), nutritional adequacy and cost of all commercially-available VLED brands in Australia. Nutritional content and cost were extracted and compared between brands and to the Recommended Dietary Intake (RDI) or adequate intake (AI) of macronutrients and micronutrients for men and women aged 19-70 years or >70 years. There was wide variability in the nutritional content, nutritional adequacy and cost of VLED brands. Most notably, even brands with the highest daily protein content, based on consuming three products/day (KicStart™ and Optislim(®), ~60 g/day), only met estimated protein requirements of the smallest and youngest women for whom a VLED would be indicated. Considering multiple options to optimise protein content, we propose that adding pure powdered protein is the most suitable option because it minimizes additional energy, carbohydrate and cost of VLEDs.

Immediate Effects of Aerobic Exercise on Plasma/Serum Zinc Levels: A Meta-analysis.

BACKGROUND: Zinc is involved in numerous metabolic roles, including energy metabolism, immunity, and antioxidative effects. Zinc losses during exercise, in particular through sweat, are well documented. However, conflicting results have been reported for changes in circulating and tissue zinc concentration as a result of exercise. The purpose of this article is to quantify the immediate effect of aerobic exercise on plasma or serum zinc levels, in healthy participants. METHODS: We conducted a systematic review of peer-reviewed articles published up to December 20, 2014, to identify studies that investigated the acute effects of exercise on selected indices of zinc status. Meta-analyses were conducted to determine the change in serum zinc concentration immediately after a bout of aerobic exercise. RESULTS: Forty-five studies were included in the systematic literature review. Of the included studies, sufficient data were available from 34 studies (providing 46 comparisons) to quantify the change in serum zinc concentration after exercise. Serum zinc concentration was significantly higher immediately after exercise (0.45 ± 0.12 µmol·L(-1), P < 0.001; mean ± SE). Secondary analyses showed greater increase in serum zinc for untrained individuals and exercise sessions that involved running or maximal intensity. Insufficient data were available to determine the effects of exercise on urinary, sweat, and erythrocyte zinc. CONCLUSIONS: The present systematic review and meta-analysis indicated significant increase in serum zinc concentration immediately after an aerobic exercise session, suggesting acute perturbations in zinc homeostasis. Further research is required to ascertain the long-term effects of exercise on zinc metabolism and potential consequences for dietary zinc requirement for physically active populations.

Zinc-induced upregulation of metallothionein (MT)-2A is predicted by gene expression of zinc transporters in healthy adults.

The usefulness of zinc transporter and metallothionein (MT) gene expressions to detect changes in zinc intake remains unclear. This pilot study aimed to determine the effects of zinc supplementation on zinc transporter and MT gene expressions in humans. Healthy adults (n = 39) were randomised to zinc treatment (ZT), receiving 22 mg Zn/day (n = 19), or no treatment (NT) (n = 20). Blood samples were collected on Days 0, 2, 7, 14, and 21. Plasma zinc and serum C-reactive protein concentrations were analysed. Gene expression of zinc transporters and MT in peripheral blood mononuclear cells was analysed using real-time PCR. Using repeated-measures ANOVA, MT-2A gene expression and fold change were found to be higher in the ZT group (P = 0.025 and P = 0.016, respectively) compared to the NT group, specifically at Day 2 (40 ± 18 % increase from baseline, P = 0.011), despite no significant increase in plasma zinc concentration. In a multiple regression model exploring the changes in gene expressions between Days 0 and 21, the change in MT-2A gene expression was correlated with changes in all zinc transporter expressions (r (2) = 0.54, P = 0.029); the change in ZIP1 expression emerged as a univariate predictor (P = 0.003). Dietary zinc intake was predictive of zinc transporter and MT expressions (P = 0.030). Physical activity level was positively correlated with baseline ZIP7 expression (r = 0.36, P = 0.029). The present study shows that MT-2A expression is related to changing expression of zinc transporter genes, specifically ZIP1, in response to zinc supplementation. The current report adds to our understanding of MT in the coordinated nature of cellular zinc homeostasis.

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

Pregnant women are vulnerable to a low zinc status due to the additional zinc demands associated with pregnancy and foetal development. The present systematic review explores the relationship between habitual vegetarian diets and dietary zinc intake/status during pregnancy. The association between vegetarian diets and functional pregnancy outcome also is considered. A literature search was conducted of MEDLINE; PubMed; Embase; the Cochrane Library; Web of Science; and Scopus electronic databases up to September 2014. Six English-language observational studies qualified for inclusion in the systematic review. A meta-analysis was conducted that compared the dietary zinc intake of pregnant vegetarian and non-vegetarian (NV) groups; the zinc intake of vegetarians was found to be lower than that of NV (-1.38 ± 0.35 mg/day; p < 0.001); and the exclusion of low meat eaters from the analysis revealed a greater difference (-1.53 ± 0.44 mg/day; p = 0.001). Neither vegetarian nor NV groups met the recommended dietary allowance (RDA) for zinc. In a qualitative synthesis; no differences were found between groups in serum/plasma zinc or in functional outcomes associated with pregnancy. In conclusion; pregnant vegetarian women have lower zinc intakes than NV control populations and both groups consume lower than recommended amounts. Further information is needed to determine whether physiologic adaptations in zinc metabolism are sufficient to meet maternal and foetal requirements during pregnancy on a low zinc diet.

Vegetarian diets across the lifecycle: impact on zinc intake and status.

Optimal zinc status is an important consideration when evaluating the nutritional adequacy of vegetarian diets. In the absence of animal tissue sources of zinc and with increased intake of inhibitors of zinc absorption, phytic acid in particular, the bioavailability of zinc is thought to be lower from vegetarian as compared to omnivorous diets. The aim of this chapter is to review the research that examines the effects of vegetarian compared to omnivorous diets on zinc intake and zinc status in the elderly, adults, children, pregnancy, and lactation. A narrative review of the published literature was undertaken, focusing on observational studies in humans that reported zinc intake and biomarkers of zinc status at various stages of the life cycle. Compared to their respective nonvegetarian control groups, adult male and female vegetarians have lower dietary zinc intakes and serum zinc concentrations. However in the elderly, children, and in women during pregnancy and lactation, there is insufficient evidence to determine whether zinc intake and status are lower in vegetarians compared to omnivores. Inconsistencies in study findings reflect variations inherent in the definition of vegetarian diets, and in many instances compromised statistical power due to a small sample size. Improved methods for the assessment of zinc status are required to determine whether homeostatic responses are sufficient to maintain an adequate zinc status in vegetarians, particularly during times of increased requirement. Appropriate dietary advice to increase the zinc content and bioavailability of vegetarian diets throughout the life cycle is prudent.

Challenges and Opportunities in Scaling-Up Nutrition in Healthcare.

Healthcare continues to be in a state of flux; conventionally, this provides opportunities and challenges. The opportunities include technological breakthroughs, improved economies and increasing availability of healthcare. On the other hand, economic disparities are increasing and leading to differing accessibility to healthcare, including within affluent countries. Nutrition has received an increase in attention and resources in recent decades, a lot of it stimulated by the rise in obesity, type 2 diabetes mellitus and hypertension. An increase in ageing populations also has meant increased interest in nutrition-related chronic diseases. In many middle-income countries, there has been an increase in the double burden of malnutrition with undernourished children and overweight/obese parents and adolescents. In low-income countries, an increased evidence base has allowed scaling-up of interventions to address under-nutrition, both nutrition-specific and nutrition-sensitive interventions. Immediate barriers (institutional, structural and biological) and longer-term barriers (staffing shortages where most needed and environmental impacts on health) are discussed. Significant barriers remain for the near universal access to healthcare, especially for those who are socio-economically disadvantaged, geographically isolated, living in war zones or where environmental damage has taken place. However, these barriers are increasingly being recognized, and efforts are being made to address them. The paper aims to take a broad view that identifies and then comments on the many social, political and scientific factors affecting the achievement of improved nutrition through healthcare.