Effect of phytase on zinc absorption from a millet-based porridge fed to young Burkinabe children

Accelerating the healing of hard-to-heal wounds with food supplements: nutritional analysis in the Côte d'Ivoire

OBJECTIVE

Hard-to-heal wounds are an important, yet often neglected, public health issue in low- and middle-income countries (LMICs). Malnutrition has been identified as a risk factor for prolonged healing times. However, nutritional supplements are not routinely provided for patients with hard-to-heal wounds, and so this study aimed to investigate their benefits.

METHOD

This 9-month study was conducted in the Taabo Health and Demographic Surveillance System in the south-central part of Côte d'Ivoire. Patients with wounds (≥30mm2) were recruited. Treatment was standardised for inpatients (72%) and outpatients (28%). There were three intervention groups: supplemented with soy; orange flesh sweet potato (OFSP); or both. Another group was included without supplement, serving as control. General linear models were employed to assess the effects of log initial wound size, type of wound, food treatment group, haemoglobin, sex, age, place of treatment and body mass index on the rate of wound closure.

RESULTS

The cohort consisted of 56 patients, 41 of whom were placed in intervention groups, and the remainder as controls. Within the cohort, 37 (66%) patients suffered from Buruli ulcer, 15 (27%) from traumatic wounds and four (7%) from erysipelas. We found a significant effect (p=0.004) of diet supplemented with OFSP on the wound healing rate.

CONCLUSION

OFSP is a nutritional rehabilitation supplement, characterised by a high content of beta-carotene and carbohydrates. It is associated with shortened wound healing times, reduced discomfort and reduced cost of wound care. Further research should investigate the effect of a diet rich in beta-carotene, in combination with standard medical care, on hard-to-heal wound healing in LMICs.

Toward revising dietary zinc recommendations for children aged 0 to 3 years: a systematic review and meta-analysis of zinc absorption, excretion, and requirements for growth

CONTEXT

The Food and Agriculture Organization of the United Nations and the World Health Organization are updating their dietary zinc recommendations for children aged 0 to 3 years.

OBJECTIVE

The aim of this review was to retrieve and synthesize evidence regarding zinc needs for growth as well as zinc losses, absorption, and bioavailability from the diet.

DATA SOURCES

MEDLINE, Embase, and Cochrane Library databases were searched electronically from inception to August 2020. Studies assessing the above factors in healthy children aged 0 to 9 years were included, with no limits on study design or language.

DATA EXTRACTION

Ninety-four studies reporting on zinc content in tissue (n = 27); zinc absorption (n = 47); factors affecting zinc bioavailability (n = 30); and endogenous zinc losses via urine, feces, or integument (n = 40) met the inclusion criteria. Four reviewers extracted data and two reviewers checked for accuracy.

DATA ANALYSES

Studies were synthesized narratively, and meta-analyses of zinc losses and gains as well the subgroups of age, type of feeding, country's income, and molar ratio of phytate to zinc were conducted. Meta-analysis revealed an overall mean (95%CI) urinary and endogenous fecal zinc excretion of 17.48 µg/kg/d (11.80-23.15; I2 = 94%) and 0.07 mg/kg/d (0.06-0.08; I2 = 82%), respectively, with a mean fractional zinc absorption of 26.75% (23.69-29.81; I2 = 99%). Subgrouping by age revealed differences in mean values associated with the transition from milk-based diets to solid food during the first 3 years of life.

CONCLUSION

This review synthesizes data that may be used to formulate zinc requirements in young children. Results should be interpreted with caution because of considerable heterogeneity in the evidence.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020215236.

Zinc Fortification: Current Trends and Strategies

Zinc, through its structural and cofactor roles, affects a broad range of critical physiological functions, including growth, metabolism, immune and neurological functions. Zinc deficiency is widespread among populations around the world, and it may, therefore, underlie much of the global burden of malnutrition. Current zinc fortification strategies include biofortification and fortification with zinc salts with a primary focus on staple foods, such as wheat or rice and their products. However, zinc fortification presents unique challenges. Due to the influences of phytate and protein on zinc absorption, successful zinc fortification strategies should consider the impact on zinc bioavailability in the whole diet. When zinc is absorbed with food, shifts in plasma zinc concentrations are minor. However, co-absorbing zinc with food may preferentially direct zinc to cellular compartments where zinc-dependent metabolic processes primarily occur. Although the current lack of sensitive biomarkers of zinc nutritional status reduces the capacity to assess the impact of fortifying foods with zinc, new approaches for assessing zinc utilization are increasing. In this article, we review the tools available for assessing bioavailable zinc, approaches for evaluating the zinc nutritional status of populations consuming zinc fortified foods, and recent trends in fortification strategies to increase zinc absorption.

Protective role of zinc in the pathogenesis of respiratory diseases

Respiratory diseases remain a major cause of morbidity and mortality worldwide. An imbalance of zinc, an essential trace element, is associated with a variety of lung diseases. We reviewed and summarized recent research (human subjects, animal studies, in vitro studies) on zinc in respiratory diseases to explore the protective mechanism of zinc from the perspective of regulation of oxidative stress, inflammation, lipid metabolism, and apoptosis. In the lungs, zinc has anti-inflammatory, antioxidant, and antiviral effects; can inhibit cancer cell migration; can regulate lipid metabolism and immune cells; and exerts other protective effects. Our comprehensive evaluation highlights the clinical and experimental effects of zinc in the pathogenesis of respiratory diseases. Our analysis also provides insight into the clinical application of zinc-targeted therapy for respiratory diseases.

Applying Zinc Nutrient Reference Values as Proposed by Different Authorities Results in Large Differences in the Estimated Prevalence of Inadequate Zinc Intake by Young Children and Women and in Cameroon

Nutrient reference values (NRVs) for zinc set by several expert groups differ widely and may affect the predicted prevalence of inadequate zinc intake. We examined this possibility using NRVs published by four different authorities and nationally representative dietary intake data collected among children aged 12–59 months and women in Cameroon. Usual zinc intake was estimated from 24 h recall data using the National Cancer Institute method. Prevalences of total zinc intake below the dietary requirement and of “absorbable zinc intake” below the physiological requirement were estimated using NRVs published by the World Health Organization (WHO), US Institute of Medicine (IOM), International Zinc Nutrition Consultative Group (IZiNCG), and European Food Safety Authority (EFSA). The prevalence of inadequate zinc intake ranged from 10% (IZiNCG—physiological requirement, 95% CI 7–13%) to 81% (EFSA—physiological requirement, 95% CI 78–84%) among children and 9% (WHO—physiological requirement, 95% CI 8–11.0%) to 94% (IOM—physiological requirement, 95% CI 92–95%) among women These differences in the prevalence of inadequate intake translated into sizeable differences in the predicted benefit and cost-effectiveness of zinc fortification programs. Depending on the NRVs applied, assessments differ regarding the need for and design of zinc fortification programs. Efforts are needed to harmonize NRVs for zinc.

Content and Nutritional Evaluation of Zinc in PDO and Traditional Italian Cheeses

Zinc is an essential mineral which plays a key role in several important biological processes in the human body. The determination of its level in food matrices can contribute to the food quality characterization and to the adequacy of the diet. Animal food products generally have a higher zinc content compared to vegetables. Among them, dairy products consumption can provide a great contribution to the zinc reference intakes. In this study, different Italian cheeses (38 Protected Denomination of Origin and 9 Traditional) were evaluated for their zinc content. Cow cheeses generally showed the highest zinc content (1.83-7.75 mg/100 g cheese), followed by sheep cheeses (1.34-3.69 mg/100 g), and cheeses from mixed milk (0.39-4.54 mg/100 g). The only cheese from buffalo milk (Mozzarella di Bufala Campana PDO) showed a zinc content of 2.14 mg/100 g. The great variability in the zinc content observed among the samples is the result of the influence of several factors, such as the feeding system, the species (cow, sheep, goat, and buffalo), and the cheese-making. Most of the samples resulted in a great contribution (>10%) to the zinc Daily Reference Intake set by EU (10 mg/day), with only two samples contributing to less than 4%.

Improvement of nutrient bioavailability in millets: Emphasis on the application of enzymes

Millets are a traditional staple food of the dryland regions of the world and are rich in essential nutrients like protein, fatty acids, minerals, vitamins, and dietary fiber. Also, millets commonly synthesize a range of secondary metabolites to protect themselves against adverse conditions. These factors are collectively termed anti-nutritional factors and the existence of these factors in millets might reduce the accessibility of the nutrients in humans. Some of these factors include protease inhibitors, tannins, non-starch polysaccharides-glucans, phytates, and oxalates each of which might directly or indirectly affect the digestibility of nutrients. Methods like soaking, germination, autoclaving, debranning, and the addition of exogenous enzymes have been used to reduce the anti-nutritional factors and elevate the bioavailability of the nutrients. This review summarizes various methods that have been used to improve nutrient bioavailability, specifically emphasizing the use of enzymes to improve nutrient bioavailability from millets. © 2021 Society of Chemical Industry.

Effect of exogenous phytase added to small-quantity lipid-based nutrient supplements (SQ-LNS) on the fractional and total absorption of zinc from a millet-based porridge consumed with SQ-LNS in young Gambian children: a randomized controlled trial

BACKGROUND

Dietary phytate inhibits zinc absorption from composite meals in adults.

OBJECTIVE

The objective of this study was to investigate the effect of adding exogenous phytase to a small-quantity lipid-based nutrient supplement (SQ-LNS) on zinc absorption among young children.

METHODS

In a double-blind randomized controlled trial, intraindividual differences in fractional and total absorption of zinc (FAZ and TAZ, respectively) from a millet-based porridge containing SQ-LNS with and without phytase were measured in 30 asymptomatic children 18-23 mo of age in the Kiang West district of The Gambia. Using a crossover design, children received for 1 d each porridge test meals with 20 g SQ-LNS containing 8 mg zinc and either 1) exogenous phytase or 2) no exogenous phytase. The test meals were provided on consecutive days in randomized order. FAZ was measured using a triple stable isotope tracer ratio technique with Zn-67 and Zn-70 as oral tracers and Zn-68 as the intravenous tracer.

RESULTS

Twenty-six participants completed the study. The prevalence of stunting and wasting were 20% and 13%, respectively; no children had low plasma zinc concentrations (<65 μg/dL). Total mean ± SD dietary zinc intake from the test meals was 7.3 ± 2.2 mg (phytate:zinc molar ratio = 3.1 ± 0.3, not accounting for phytase activity). Mean FAZ increased from 8.6% ± 1.3% to 16.0% ± 1.3% when exogenous phytase was added to the SQ-LNS product (P < 0.001). Mean TAZ from test meals containing SQ-LNS with phytase was more than double that from test meals containing SQ-LNS without phytase (1.1 ± 0.1 mg and 0.5 ± 0.1 mg, respectively; P < 0.001).

CONCLUSIONS

The addition of exogenous phytase to SQ-LNS increased both FAZ and TAZ. These results suggest that phytate reduction may be an important strategy to increase zinc absorption among young children. This trial was registered at clinicaltrials.gov as NCT02668133.