Dietary intake of nickel and zinc by young children – Results from food duplicate portion measurements in comparison to data calculated from dietary records and available data on levels in food groups

The daily dietary intake of nickel (Ni) and zinc (Zn) by 42 young children, 21 boys and 21 girls, from 4 to 7 years of age, living in urban and rural areas of Germany and having different food consumption behaviour, was determined by the duplicate method with a 7-day sampling period. Dietary records were also kept by the children's parents for the 7-day sampling period. Individual reported food items were identified, assigned to food groups and, together with known Ni and Zn concentrations of foodstuffs, daily intake rates were calculated. The same method was used for calculations of the energy, fat, protein and carbohydrate intake rates.The levels in the food duplicates, determined by atomic absorption spectrometry, were in the range of 69–2000 μg Ni/kg_{dry weight} (geometric mean (GM): 348) and 7.1–43 mg Zn/kg_{dry weight} (GM: 17.5). Daily intake rates based on the 294 individual food duplicate analyses were 12–560 μg Ni/d (GM: 92.3) and 1.5–11 mg Zn/d (GM: 4.63). The results from the dietary records were 35–1050 μg Ni/d (GM: 123) and 1.7–15 mg Zn/d (GM: 5.35).The results of the daily intake rates from both methods showed a correlation with regard to Zn (r=0.56), but no correlation was found between either the Ni intake rates determined with both methods or between the Ni intake rates measured by the duplicate method and calculated intake rates from the dietary records of energy, fat, protein, carbohydrates or drinking water. In the case of nickel, the discrepancies between the methods lead one to suppose that the main factors influencing Ni intake by food are not directly caused by easily assessable food ingredients themselves. It is possible that other factors, such as contaminated drinking water or the transition of Ni from kettles or other household utensils made from stainless steel into the food, may be more relevant. In addition there are some foodstuffs with great variations in concentrations, often influenced by the growing area and environmental factors. Further, some food groups naturally high in Nickel like nuts, cocoa or teas might not have been kept sufficient within the records. In summary, the dietary record method gave sufficient results for Zn, but is insufficient for Ni.Based on the food duplicate analysis, children living in urban areas with consumption of food products from a family-owned garden or the surrounding area and/or products from domestic animals of the surrounding area had about one-third higher Ni levels in their food than children either living in an urban area or children consuming products exclusively from the supermarket. Only slight differences were found with regard to Zn.Compared to the recommendations of the German Society of Nutrition (DGE) (25–30 μg Ni/d and 5.0 mg Zn/d), the participants of the study had a clearly increased Ni and, in view of the geometric mean value, a nearly adequate Zn intake. Health risks are especially given with regard to the influence of nickel intake by food on dermatitis for nickel-sensitive individuals.     

Dietary phytate,zinc and hidden zinc deficiency

Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration ≤ 20 μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be “hidden”. The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency.     

Dietary copper and human health: Current evidence and unresolved issues

Although copper (Cu) is recognized as an essential trace element, uncertainties remain regarding Cu reference values for humans, as illustrated by discrepancies between recommendations issued by different national authorities. This review examines human studies published since 1990 on relationships between Cu intake, Cu balance, biomarkers of Cu status, and health. It points out several gaps and unresolved issues which make it difficult to assess Cu requirements. Results from balance studies suggest that daily intakes below 0.8 mg/day lead to net Cu losses, while net gains are consistently observed above 2.4 mg/day. However, because of an incomplete collection of losses in all studies, a precise estimation of Cu requirements cannot be derived from available data. Data regarding the relationship between Cu intake and potential biomarkers are either too preliminary or inconclusive because of low specificity or low sensitivity to change in dietary Cu over a wide range of intakes. Results from observation and intervention studies do not support a link between Cu and a risk of cardiovascular disease, cognitive decline, arthritis or cancer for intakes ranging from 0.6 to 3 mg/day, and limited evidence exists for impaired immune function in healthy subjects with a very low (0.38 mg/day) Cu intake. However, data from observation studies should be regarded with caution because of uncertainties regarding Cu concentration in various foods and water. Further studies that accurately evaluate Cu exposure based on reliable biomarkers of Cu status are needed.     

Enrichment of fertilizers with zinc: An excellent investment for humanity and crop production in India

Micronutrient malnutrition is a growing concern in the developing world, resulting in diverse health and social problems, such as mental retardations, impairments of the immune system and overall poor health. In recent years, the zinc (Zn) deficiency problem has received increasing attention and appears to be the most serious micronutrient deficiency together with vitamin A deficiency. Zinc deficiency is particularly widespread among children and represents a major cause of child death in the world. In countries where Zn deficiency is well documented as an important public health problem, cereal-based foods are the predominant source of daily calorie and protein intake. Because the concentration of Zn in cereal crops is inherently very low, growing cereals on potentially Zn-deficient soils further decreases grain Zn concentrations. It is, therefore, not surprising that high Zn deficiency incidence in humans occurs predominantly on areas where soils are deficient in plant-available Zn, as shown in many Southeast Asian countries. India has some of the most Zn-deficient soils in the world. Nearly 50% of cultivated soils in India are low in plant-available Zn; these soils are under intensive cultivation of wheat and rice with no or little application of Zn fertilizers. Consequently, cereal crops grown on such Zn-deficient soils contribute only marginally to daily Zn intake. In the rural areas of India, rice and wheat contributes nearly 75% of the daily calorie intake. These facts clearly point to an urgent need for improved Zn concentration of cereal grains in India. Recent calculations indicate that biofortification (enrichment) of rice and wheat grain with Zn, for example by breeding, may save lives of up to 48,000 children in India annually. Breeding new cereal genotypes for high grain Zn concentration is the most realistic and cost-effective strategy to address the problem. However, this strategy is a long-term one, and the size of plant-available Zn pools in soils may greatly affect the capacity of Zn-efficient (biofortified) cultivars to take up Zn and accumulate it in grains. Therefore, application of Zn-containing fertilizers represents a quick and effective approach to biofortifying cereal grains with Zn, thus being an excellent complementary tool to the breeding strategy for successful biofortification of cereals with Zn. Increasing evidence is available from field trials showing that soil and/or foliar application of Zn fertilizers improves grain Zn concentration up to 2- or 3-fold. In the countries where Zn deficiency is both a public health issue and an important soil constraint to crop production, like in India, enrichment of widely applied fertilizers with Zn would be an excellent investment for improving grain Zn while contributing to increased crop production. Recent work by the scientists of the Indian Agricultural Research Institute indicates that the use of Zn-enriched urea in rice and wheat significantly improves both grain Zn concentration and grain yield. It is obvious that enrichment of widely applied fertilizers with Zn and/or foliar application of Zn fertilizers appear to be a high priority with the strongest potential to alleviate Zn deficiency-related problems in India. A Government action and policy plan for enrichment of selected major fertilizers with Zn is required urgently.     

妊娠期糖尿病患者孕前BMI与血糖及膳食营养摄入的相关性分析

目的:分析妊娠期糖尿病患者孕前身体质量指数(Body Mass Index,BMI)与血糖水平及膳食营养摄入的相关性。方法:选择2017年1月-2018年1月于我院治疗的妊娠期糖尿病患者86例作为观察组,另选择血糖水平正常的孕妇60例作为对照组,并依据BMI不同将观察组分为A组(BMI18.5 kg/m~2)、B组(18.5 kg/m~2≤BMI24.0 kg/m~2)、C组(24.0 kg/m~2≤BMI≤28.0 kg/m~2)、D组(BMI28.0 kg/m~2)。比较各组孕前BMI、血糖水平及膳食营养摄入情况。结果:观察组孕前体重、BMI、脂肪供能比均显著高于对照组,碳水化合物摄入量及碳水化合物供能比低于对照组,差异均有统计学意义(P0.05);各组空腹时、餐后2 h血糖水平以及每日能量、脂肪摄入比较结果显示:D组C组B组A组,且组间差异均有统计学意义(P0.05)。结论:孕前BMI与血糖水平及膳食营养摄入存在一定相关性,控制合理体重、保持营养均衡对于降低妊娠期糖尿病发生率具有重要意义。     

Biogeochemistry of selenium and its impact on food chain quality and human health

In areas where soils are low in bioavailable selenium (Se), potential Se deficiencies cause health risks for humans. Though higher plants have been considered not to require this element, the experience with low-Se soils in Finland has provided evidence that the supplementation of commercial fertilizers with sodium selenate affects positively not only the nutritive value of the whole food chain from soil to plants, animals and humans but also the quantity of plant yields. The level of Se addition has been optimal, and no abnormally high concentrations in plants or in foods of animal origin have been observed. Se levels in serum and human milk indicate that the average daily intake has been within limits considered to be safe and adequate. In fact, plants act as effective buffers, because their growth is reduced at high Se levels. They also tend to synthesize volatile compounds in order to reduce excess Se. On the other hand, when added at low concentrations, Se exerts a beneficial effect on plant growth via several mechanisms. As in humans and animals, Se strengthens the capacity of plants to counteract oxidative stress caused by oxygen radicals produced by internal metabolic or external factors. At proper levels it also delays some of the effects of senescence and may improve the utilization of short-wavelength light by plants. High additions are toxic and may trigger pro-oxidative reactions. Thus, the present supplementation of fertilizers with Se can be considered a very effective and readily controlled way to increase the average daily Se intake nationwide.     

Differences in hemoglobin adduct levels of acrylamide in the general population with respect to dietary intake, smoking habits and gender

The variation in dietary exposure to acrylamide (AA) has been studied through measurement of hemoglobin adduct levels from AA, as a measurement of internal dose, in a sample from the blood bank of the Malmö Diet and Cancer Cohort (n = 28,098). The blood donors are well characterised with regard to their food habits, and 142 individuals were selected to obtain highest possible variation in the adduct levels from AA (none, random or high intake of coffee, fried potato, crisp bread and snacks, food items estimated to have high levels of AA).Among 70 non-smokers the AA-adduct levels varied by a factor of 5, and ranged between 0.02 and 0.1 nmol/g, with considerable overlap in AA-adduct levels between the different dietary groups. There was a significant difference between men with high dietary exposure to AA compared to men with low dietary exposure (P = 0.04). No such difference was found for women. As expected a higher level (range: 0.03–0.43 nmol/g) of the AA-adduct, due to AA in tobacco smoke, was found in smokers. Smoking women with high dietary exposure to AA had significantly higher AA-adduct levels compared to smoking women with low dietary exposure (P = 0.01). No such significant difference was found in smoking men. The median hemoglobin (Hb) adduct level in the randomly selected group of non-smokers was compatible with earlier studies (0.031 nmol/g).The variation in the average internal dose, measured as Hb adducts, was somewhat smaller than estimated for daily intake by food consumption questionnaires in other studies. Thus, the observed relatively narrow inter-individual variation in AA-adduct levels means that estimates of individual dietary AA intake have to be very precise if they should be useful in future cancer epidemiology.     

The Effect of Peripheral Administration of Zinc on Food Intake in Rats Fed Zn-adequate or Zn-deficient Diets

Zinc deficiency induces a striking reduction of food intake in animals. To elucidate the mechanisms for this effect, two studies were connectedly conducted to determine the effects of peripheral administration of zinc on food intake in rats fed the zinc-adequate or zinc-deficient diets for a 3-week period. In study 1, two groups of male Sprague-Dawley rats were provided diets made either adequate (ZA; 38.89 mg/kg) or deficient (ZD; 3.30 mg/kg) in zinc. In study 2, after feeding for 3 weeks, both ZA and ZD groups received intraperitoneal (IP) injection of zinc solution with three levels (0.5, 1.0, and 2.0 mug zinc/g body weight, respectively) and cumulative food intake at 0.5, 1, 2, 4, and 24 h, and plasma hormones concentrations were measured. The results in study 1 showed rats fed the ZD diets revealed symptoms of zinc deficiency, such as sparse and coarse hair, poor appetite, susceptibility to surroundings, lethargy, and small movements. Zinc concentrations in serum, femur, and skeletal muscle of rats fed the ZD diets declined by 26.58% (P < 0.01), 27.32% (P < 0.01), and 24.22% (P < 0.05), respectively, as compared with ZA control group. These findings demonstrated that rat models with zinc deficiency and zinc adequacy had been fully established. The results in study 2 showed that IP administration of zinc in both ZA and ZD rats did not influence food intake at each time points (P > 0.05), although zinc deficiency suppressed food intake. Plasma neuropeptide Y (NPY) was higher, but insulin and glucagon were lower in response to zinc deficiency or zinc administration by contrast with their respective controls (P < 0.05). Leptin, T3, and T4 concentrations were uniformly decreased (P < 0.05) in rats fed the ZD diets in contrast to ZA diets; however, no differences (P > 0.05) were observed during zinc injection. Calcitonin gene-related peptide was unaffected (P > 0.05) by either zinc deficiency or zinc administration. The present studies suggested that zinc administration did not affect short-term food intake in rats even in the zinc-deficient ones; the reduced food intake induced by zinc deficiency was fprobably associated with the depression in thyroid hormones. The results also indicated that NPY and insulin varied conversely during the control of food intake.     

碘的安全摄入量范围研究进展

动物实验表明,短期或长期高碘摄入会对机体产生一定的毒性,包括发育毒性、遗传毒性和致畸性等。目前世界各国家及组织对于碘的推荐摄入量（reference nutrition intake,RNI）和可耐受最高摄入量（tolerable upper intake level,UL）的制定一般是基于一些的人体实验研究和人群调查,但由于地理环境及人种差异等原因,所得数据并不统一。由于参照的研究数据不同,各国对不同人群设定的碘安全摄入量参照标准也不尽相同。鉴于此,分析了国际上主要的国家及国际组织制订标准的过程与依据,概述了我国相关标准的制订过程与依据以及El前的研究进展,明确了进一步探讨和研究更适合我国人群的碘的安全摄入量是当前和今后的工作重点之一,也是食盐加碘计划（universal salt iodization,USI）科学实施的重要保障。     

Assessment of dietary intake: NuGO symposium report

Advances in genomics science and associated bioinformatics and technology mean that excellent tools are available for characterising human genotypes. At the same time, approaches for characterising individual phenotypes are developing rapidly. In contrast, there has been much less investment in novel methodology for measuring dietary exposures so that there is now a significant gap in the toolkit for those investigating how diet interacts with genotype to determine phenotype. This symposium reviewed the strengths and limitations of current tools used in assessment of dietary intake and the potential to improve these tools through, for example, the use of statistical techniques that combine information from different sources (such as modelling and calibration methods) to ameliorate measurement error and to provide validity checks. Speakers examined the use of approaches based on technologies such as mobile 'phones, digital cameras and Web-based systems which offer the potential for more acceptable (for study participants) and less laborious (for researchers and participants) routes to more robust data collection. In addition, the application of omics, especially metabolomics, tools to biofluids to identify new biomarkers of intake offers great potential to provide objective measures of food consumption with the advantage that data may be collected in forms that can be integrated readily with other high throughput (nutrigenomic) technologies.     

Effects of chronic caloric restriction on kidney and heart redox status and antioxidant enzyme activities in Wistar rats

Caloric restriction (CR) has been associated with health benefits and these effects have been attributed, in part, to modulation of oxidative status by CR; however, data are still controversial. Here, we investigate the effects of seventeen weeks of chronic CR on parameters of oxidative damage/modification of proteins and on antioxidant enzyme activities in cardiac and kidney tissues. Our results demonstrate that CR induced an increase in protein carbonylation in the heart without changing the content of sulfhydryl groups or the activities of superoxide dismutase and catalase (CAT). Moreover, CR caused an increase in CAT activity in kidney, without changing other parameters. Protein carbonylation has been associated with oxidative damage and functional impairment; however, we cannot exclude the possibility that, under our conditions, this alteration indicates a different functional meaning in the heart tissue. In addition, we reinforce the idea that CR can increase CAT activity in the kidney. [BMB Reports 2012; 45(11): 671-676]     

Effects of Zinc Supplementation on Physical Growth in 2–5-Year-Old Children

Physical growth disorders in under 5-year-old children are a common health problem in many countries including Iran. The aim of this study was to determine effects of supplemental zinc on physical growth in preschool children with retarded linear growth. This study was a community-based randomized controlled trial on 2–5-year-old children with height-for-age below 25th percentile of National Center for Health Statistics growth chart. Ninety children were randomly assigned in zinc group (ZG) or placebo group (PG). After 6 months of zinc or placebo supplementation, we followed up the children for another 6 months. Anthropometric indicators were measured before the intervention and then monthly for 11 months. Forty children in ZG and 45 in PG concluded the study. Zinc supplementation increased weight gain in boys (P = 0.04) and girls (P = 0.05) compared to placebo but had no significant effect on mid-upper arm circumference increment in either sexes. The most significant (P = 0.001) effect of Zinc supplementation was seen in boys’ height increment at the end of follow-up period. Stunted growth rate in ZG changed significantly (P = 0.01) from 26.7% to 2.5% throughout the study. This study showed that daily supplementation of 5 mg elemental zinc for 6 months improves physical growth in terms of height increment and weight gain in children with undesirable linear growth, especially in boys.     

Insights on zinc regulation of food intake and macronutrient selection

Zinc (Zn) is an essential trace element required for human beings and animals. This divalent cation is involved in many physiological functions, including immune and antioxidant function, growth, and reproduction. Deficiency of Zn produces several pathological disorders and abnormalities in its metabolism, such as anorexia, weight loss, poor efficiency, and growth retardation. Although it has been known for more than 50 yr that Zn deficiency regularly and consistently causes anorexia in many animal species, the mechanism that causes this phenomenon still remains an enigma. The present review describes recent research investigating the relationship between Zn deficiency and the regulation of food intake, as well as macronutrient selection.     

Long chain omega-3 fatty acids: Micronutrients in disguise

Considerable information has accumulated to show that DHA and EPA have unique roles that differ from other n-3 fatty acids and the n-6 fatty acids, with increasing understanding of the mechanisms through which these fatty acids reduce risk of disease. DHA and EPA regulate hepatic lipid and glucose metabolism, but are present in foods of animal origin, which are generally high in protein with variable triglycerides and low carbohydrate. Biological activity at intakes too low to provide significant amounts of energy is consistent with the definition of a vitamin for which needs are modified by life-stage, diet and genetic variables, and disease. Recent studies reveal that DHA may play a central role in co-coordinating complex networks that integrate hepatic glucose, fatty acid and amino acid metabolism for the purpose of efficient utilization of dietary protein, particularly during early development when the milk diet provides large amounts of energy from fat.     

Hypothalamic galanin and plasma leptin and ghrelin in the maintenance of energy intake in the Brattleboro rat

Galanin, ghrelin, and leptin are three peptides involved in feeding regulation and more particularly in fat intake. The Brattleboro (di/di) rat is a genetic model of diabetes insipidus characterized by a preference for fat when it is in a food choice situation. Here, we measured hypothalamic galanin concentrations, plasma ghrelin and leptin and dietary preferences of adult di/di Brattleboro rats, di/+ and Long-Evans controls. The Brattleboro rats weighed significantly less than the di/+ rats (−18%; P < 0.001). The fat-to-carbohydrate intake ratio was significantly greater in Brattleboro rats than in di/+ (P < 0.02) when the rats could choose between a high-fat diet and a high-carbohydrate diet. Galanin concentrations were significantly lower in di/di rats than in di/+ rats in the paraventricular nucleus (−56%; P < 0.001), but not in the arcuate nucleus. Plasma leptin was significantly lower in the di/di rats than in the di/+ rats (3.49 ± 0.20 vs. 6.94 ± 0.49 ng/ml; P < 0.001). Plasma ghrelin concentrations were significantly lower in Long-Evans rats than in the di/di rats (−21%; P < 0.01). Given that galanin mRNA is overexpressed in the paraventricular nucleus of Brattleboro rats, these data are consistent with increased release of the peptide. In the Brattleboro rat, this overactive galanin system and the variations of ghrelin and leptin maintain an orexigenic drive favoring a preferential intake of fat which provides the animal with enough energy for its metabolism.     

Zinc nutritional status in obese children and adolescents

Studies in animals and humans have corroborated that zinc (Zn) metabolism is altered in obesity. The present work intends to evaluate the Zn nutritional status in obese children and adolescents by the determination of some biochemical parameters and analyses of the diets. The investigation was carried out in a group of obese children and adolescents (n=23) and compared to a control group (n=21), both between 7 and 14 yr of age. A software analyzed diet information from 3-d food records. Body composition was evaluated by body mass index, bioelectrical impedance, and skinfold measurements. Zinc nutritional status was evaluated by Zn determination in plasma, erythrocyte, and 24-h urine, by atomic absorption spectrophotometry (γ=213.9 nm). Diets consumed by both groups had marginal concentrations of zinc. Zinc concentrations in plasma and erythrocytes were significantly lower in the obese group. Urinary zinc excretion was significantly higher in the same group. The results allowed one to conclude that zinc nutritional status in obese individuals is altered.