Exposure of cadmium from infant formulas and weaning foods

Elemental composition of toxic and essential elements in rice-based baby foods from the United States and other countries: A probabilistic risk analysis

Consumption of rice-based foods provides essential nutrients required for infants and toddlers' growth. However, they could contain toxic and excess essential elements that may affect human health. The study aims to determine the composition of rice-based baby foods in the USA and outside and conduct a multiple-life stages probabilistic exposure and risk assessment of toxic and essential elements in children. Elemental concentrations were measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in thirty-three rice-based baby foods. This includes 2 infant formulas, 11 rice baby cereals, and 20 rice snacks produced primarily in the United States, China, and other countries. A probabilistic risk assessment was conducted to assess risks of adverse health effects. Results showed that infant formula had higher median concentrations of selenium (Se), copper (Cu), zinc (Zn), sodium (Na), magnesium (Mg), calcium (Ca), and potassium (K) compared to rice baby cereal and rice snacks. On the contrary, rice snacks had the highest median concentration of Arsenic (As) (127 μg/kg) while rice baby cereals showed the highest median concentration of Cd (7 μg/kg). A higher lifetime estimated daily intake was observed for samples manufactured in the USA compared to those from China and other countries. Hazard quotient (HQ < 1) values were suggestive of minimal adverse health effects. However, lifetime carcinogenic risk analysis based on total As indicated an unacceptable cancer risk (>1E-04). These findings show a need for ongoing monitoring of rice-based foods consumed by infants and toddlers as supplementary and substitutes for breast milk or weaning food options. This can be useful in risk reduction and mitigation of early life exposure to improve health outcomes.

Probabilistic risk assessment for determining nonessential metals in commercial infant formula products in Taiwan

During the early months of life, infant formula plays a crucial role as a primary source of both food and essential nutrients for infants, serving as a replacement for or supplement to breast milk. However, nonessential metals in infant formulas are a concern because infants are highly vulnerable to chemical exposure. The aim of this study was to investigate infant exposure to nonessential metals in infant formula products in Taiwan and assess the associated health risks. In this study, concentrations of arsenic (As), barium (Ba), cadmium (Cd), manganese (Mn), lead (Pb), and vanadium (V) in 45 formula products for 0-1-year-old infants were determined by inductively coupled plasma mass spectrometry. The mean As, Ba, Cd, Mn, Pb, and V concentrations were 6.42, 280, 3.72, 1425, 20.4, and 21.9 µg/kg, respectively. According to our probabilistic simulation of the estimated daily intake of metals, the proportion of hazard quotients exceeding one was 7.69% for As and 3.29% for Mn, and that of hazard index (HI) values exceeding 1 was >17% for metals. Arsenic had the largest HI contribution (46.9%), followed by Mn (22.3%) and Pb (12.7%). The nonessential metals content in infant formula raises potential noncarcinogenic health concerns for infants in Taiwan. Therefore, regulations for nonessential metals must be imposed on related food products in Taiwan, with a particular focus on As and Mn.

Lead, mercury, and cadmium levels in breast milk and infant hair in the late period of lactation in Ankara, Turkey

Lead (Pb), mercury (Hg), and cadmium (Cd) have known harmful effects on children's well-being. The object of this study was to measure the levels of heavy metals (Pb, Hg, and Cd) in breast milk and infant hair, connected environmental factors, and the impact on infant growth and development at 8 months. Seventy-four breast milk samples and 46 infant hair samples were analyzed. Cd, Pb, and Hg were detected in 99%, 91%, and 87% of breast milk samples, respectively. Cd levels were higher in the hair of infants in extended families, living in older houses and when there was a maternal history of anemia and postpartum anemia. Hg levels in breast milk were higher in Denver II suspicious/abnormal infants than in Denver II normal infants. Further biomonitoring studies and preventive measures should be conducted to minimize exposure to toxic metals in early childhood period.

A Narrative Review of Toxic Heavy Metal Content of Infant and Toddler Foods and Evaluation of United States Policy

Excessive exposure to inorganic contaminants through ingestion of foods, such as those commonly referred to as heavy metals may cause cancer and other non-cancerous adverse effects. Infants and young children are especially vulnerable to these toxic effects due to their immature development and high ’food intake/ body weight' ratio. Concerns have been raised by multiple independent studies that heavy metals have been found to be present in many foods in the infant and child food sector. Most recently, reports from the U.S. House of Representatives Subcommittee on Economic and Consumer Policy suggest subpar testing practices, lenient or absent standards, and limited oversight of food manufacturers perpetuate the presence of these contaminants in infant and toddler foods. The aim of this narrative review is to evaluate the current state of policies in the United States designed to safe-guard against excessive heavy metal exposure and to discuss what is presently known about the presence of the so-called heavy metals; arsenic, lead, mercury and cadmium found in infant and toddler foods. PubMed was used to search for studies published between 1999 and 2022 using a combination of search terms including: “heavy metal,” “contamination,” “infant,” “toddler,” and “complementary food”.

Human Health Risk Assessment of Arsenic, Cadmium, Lead, and Mercury Ingestion from Baby Foods

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As, Cd and Pb detected in baby foods containing fruit, grain, and root vegetables.

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Select product HIs exceeded 1 for As and Pb using conservative assumptions.

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Cancer risks exceeded 10⁻⁶ and were driven by As from grain products.

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Analysis revealed minimal risk under most scenarios using conservative assumptions.

Recently, the U.S. House of Representatives reported on the presence of heavy metals in raw ingredients used in baby foods and in finished baby food products themselves. In light of these concerns, this study aimed to evaluate potential risks associated with the presence of heavy metals in baby food products. We analyzed 36 baby food samples representing four ingredient categories (fruit; leguminous vegetable; root vegetable; or grain) for arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb). We assessed the potential lifetime cancer and non-cancer health risks posed to infants and toddlers following daily consumption of these chemicals in each food type, based on established daily food-specific ingestion rates. Daily doses were compared against selected reference values and oral slope factors to determine non-cancer hazard indices (HIs) and lifetime cancer risks. Hazard indices indicated a potential for non-cancer risk (e.g., HIs > 1.0) under only a few exposure scenarios, including for As and Pb under selected product type and age/concentration assumptions. Increases in lifetime cancer risks for all analytes across the ingredient categories evaluated ranged from 3.75 × 10⁻⁵ to 5.54 × 10⁻⁵; cancer risks were primarily driven by As from grain products. Though a limited set of exposure scenarios indicated a potential for health risk, the exposure assumptions in this assessment were conservative, and the heavy metal concentrations we found in baby foods are similar to those observed in similar whole foods. Based on these findings and the limited scenarios under which risks were identified, this study indicates that an infant’s typical intake of baby food is unlikely to pose health risks from heavy metals above accepted tolerable risk levels under most exposure scenarios.

Metallomics Analysis for Assessment of Toxic Metal Burdens in Infants/Children and Their Mothers: Early Assessment and Intervention Are Essential

Accumulation of toxic metals in infants/children is of serious concern worldwide, from the viewpoint of their harmful effects on the normal growth and development. This metallomics study investigates the extent of toxic metal burdens in infants/children and the relationship to those in their mothers for 77 child/mother pair subjects. For mercury, its geometric mean concentration in infants/children was of similar level to that in their mothers, and a high-significant close correlation was observed between infants/children and their mothers (β = 0.758, r = 0.539, p < 0.0001). A significant but less intimate mother/child relationship was observed for arsenic (β = 0.301, r = 0.433), lead (β = 0.444, r = 0.471) and aluminum (β = 0.379, r = 0.451). Remarkably, the burden levels of lead, cadmium and aluminum in infants/children were approximately three times higher than those in their mothers (p < 0.0001), and the burden levels in some individuals were several tens of times higher than in the mothers. In contrast, some essential metal levels such as zinc, magnesium and calcium in infants/children were significantly lower than those in their mothers, and 29 individuals (37.7%) in the child subjects were estimated to be zinc-deficient. In addition, significant inverse correlations were observed between zinc and lead (r = −0.267, p = 0.019), and magnesium and arsenic (r = −0.514, p < 0.0001). These findings suggest that these toxic metal burdens and essential metal deficiencies in infants/children are of serious concern for their neurodevelopment, indicating that the early assessment and intervention are crucial. It is expected that larger epidemiological and intervention studies will provide a reasonable and essential pathway for intervention of neurodevelopment disorders.

Selenium and cadmium in bioaccessible fraction of organic weaning food: Risk assessment and influence of dietary components

BACKGROUND

The tendency of some sectors of the population to consume organic food has also come to include baby food. Nevertheless, it is necessary to develop studies to support the true nutritional and toxicological value of these products, making special emphasis in several trace elements. To our knowledge, no studies have been conducted on this type of organic food.

METHODS

Weaning foods with different formulations categorized as organic were analyzed to determine Se and Cd contents as well as its bioaccesibility. The analyses were conducted by electro thermal atomic absorption spectroscopy (ET - AAS) after the treatment of the samples with acid mineralization. Besides, macronutrient analyses (protein, fat and dietary fiber) were also developed. Finally, a novelty statistic approach such as @Risk was used to evaluate contributions to DRI or PTWI of Se and Cd derived for consumption of these weaning foods.

RESULTS

Se content ranged between 2.44-15.4 μg Kg ¹. Samples with meat ingredients showed the highest Se contents, while weaning foods consisting of fruits or vegetables presented the lowest concentrations. Se bioccessible concentration ranged between 1.90-4.35 μg Kg^-1 with a greater uniformity amongst analyzed samples. Regarding Cd, concentrations of this heavy metal ranged between 1.23 and 3.64 μg Kg^-1. Furthermore, Cd bioaccessibility of organic weaning foods ranged between 0.17 and 1.38 μg Kg^-1. The solubility of all samples studied was around 20% from the initial Cd concentration. A negative statistical correlation between fat content - Cd bioaccesible (p < 0.05; r = - 0.756) and Cd content - Se bioaccesible (p < 0.05; r = - 0.777) were also found.

CONCLUSIONS

Cd concentrations are considerably lower than those reported in weaning formulas which were not categorized as organic. On the other hand, the analysed organic jars did not represent a significant source of Se. The probabilistic assessment developed, showed that contributions to DRI of Se for infants 1-3 years old by consumption of these weaning foods, are excessively low (15% at best).

Perinatal and Childhood Exposure to Cadmium, Manganese, and Metal Mixtures and Effects on Cognition and Behavior: A Review of Recent Literature

Lead (Pb) and mercury (Hg) neurotoxicity is well established. In recent years, a growing body of evidence suggests that environmental exposure to other metals including arsenic (As), cadmium (Cd), and manganese (Mn) and their mixtures also poses public health threats. In this paper, we summarize the recent literature examining the relationship of prenatal and childhood environmental metal exposures with cognitive and behavioral outcomes in children. We conducted a literature search to identify epidemiologic studies that examined the relationship of Cd, Mn, and metal mixtures with children's neurodevelopmental/cognitive and behavioral outcomes. We restricted the search to peer-reviewed studies published in English between January 2009 and March 2015. We identified a total of 31 articles of which 16, 17, and 16 studies examined the effects of Cd, Mn, or metal mixtures, respectively. Based on our review, there is suggestive evidence that prenatal/childhood Cd exposure may be associated with poorer cognition, but additional research is clearly needed. We found little evidence of behavioral effects of early life Cd exposure, and no studies found a significant relationship with attention deficit hyperactivity disorder. Studies of early life Mn exposure consistently reported negative impacts on both cognition and behavior. There is also growing evidence that co-exposure to multiple metals can result in increased neurotoxicity compared to single-metal exposure, in particular during early life. Few studies have evaluated behavioral effects related to metal co-exposure.

Estimation of autistic children by metallomics analysis

Clarification of the pathogenesis and treatment of autism spectrum disorders is one of the challenges today. In this study, we examine scalp hair concentrations of 26 trace elements for 1,967 children with autistic disorders (1,553 males and 414 females). Five-hundred and eighty-four (29.7%), 347 (17.6%) and 114 (5.8%) subjects was found deficient in zinc, magnesium and calcium, respectively, and 2.0% or less in the other essential metals. The incidence rate of mineral deficiency was highly observed in infants aged 0-3 year-old. In contrast, 339 (17.2%), 168 (8.5%) and 94 (4.8%) individuals was found suffering from high burden of aluminium, cadmium and lead, and 2.8% or less from mercury and arsenic burden. These findings suggest that infantile zinc- and magnesium-deficiency and/or toxic metal burdens may epigenetically play principal roles as environmental factors in autistic disorders and that metallomics approach may lead to early screening and prevention of the neurodevelopment disorders.

Cadmium Transport in a Model of Neonatal Intestinal Cells Correlates to MRP1 and Not DMT1 or FPN1

Newborns have a higher gastrointestinal uptake of cadmium than adults. In adults, the iron transporters DMT1 and FPN1 are involved in the intestinal absorption of cadmium, while in neonates, the mechanisms for cadmium absorption are unknown. We have investigated possible cadmium transporters in the neonatal intestine by applying a model of immature human intestinal epithelial Caco-2 cells. To mimic the continuous cadmium exposure via diet in neonates, cells were allowed to differentiate for 7 days in medium containing 1 μM CdCl₂. A dramatic upregulation of the MT1 gene expression followed cadmium pretreatment, indicating a high sensitivity of the immature cells to cadmium. Cadmium pretreatment increased the basolateral efflux of ¹⁰⁹Cd, without causing any effects on the passive diffusion of mannitol or the transepithelial electrical resistance. The augmented transport of cadmium was correlated to an upregulation of MRP1 gene expression and increased activity of the efflux protein MRP1. No effects were observed on gene expression of the efflux proteins MRP2 and P-gp or the iron transporters DMT1, DMT1-IRE and FPN1. In conclusion, our data indicate that continuous cadmium exposure increases the absorption of the metal in immature intestinal cells and that MRP1 is involved in the intestinal cadmium absorption in newborns.

Infantile zinc deficiency: association with autism spectrum disorders

Elucidation of the pathogenesis and effective treatment of autism spectrum disorders is one of the challenges today. In this study, we examine hair zinc concentrations for 1,967 children with autistic disorders (1,553 males and 414 females), and show considerable association with zinc deficiency. Histogram of hair zinc concentration was non-symmetric with tailing in lower range, and 584 subjects were found to have lower zinc concentrations than −2 standard deviation level of its reference range (86.3–193ppm). The incidence rate of zinc deficiency in infant group aged 0–3 year-old was estimated 43.5 % in male and 52.5 % in female. The lowest zinc concentration of 10.7 ppm was detected in a 2-year-old boy, corresponding to about 1/12 of the control mean level. These findings suggest that infantile zinc deficiency may epigenetically contribute to the pathogenesis of autism and nutritional approach may yield a novel hope for its treatment and prevention.

Lead, cadmium and aluminum in Canadian infant formulae, oral electrolytes and glucose solutions

Lead (Pb), cadmium (Cd) and aluminum (Al) were determined in 437 individual samples of infant formulae, oral electrolytes and 5% glucose solutions available in Canada. In the electrolytes, Cd and Pb concentrations were all below 0.01 and 0.041 ng g⁻¹, respectively. In the 5% glucose solutions, Pb and Cd levels averaged 0.01 and 0.09 ng g⁻¹, respectively. Reported on an as-consumed basis, Pb levels in milk- and soya-based formulae averaged 0.90 and 1.45 ng g⁻¹, respectively, while Cd levels averaged 0.23 and 1.18 ng g⁻¹, respectively Average Al levels on an as-consumed basis were 440 ng g⁻¹ (range 10–3400 ng g⁻¹) in milk-based formulae and 730 ng g⁻¹ (range 230–1100 ng g⁻¹) in soy-based formulae. Al concentrations increased in the following order: plain formula < low-iron formula < iron-supplemented formula < casein hydrolysate formula ≈ premature formula ≤ soy formula. For example, in the powdered formulae, average Al concentrations were 18 ng g⁻¹ for plain milk-based, 37 ng g⁻¹ for low-iron, 128 ng g⁻¹ for iron supplemented, 462 ng g⁻¹ for lactose-free, 518 ng g⁻¹ for hypoallergenic and 619 ng g⁻¹ for soy-based formula. Al concentrations, as-consumed, increased with decreasing levels of concentration: powder < concentrated liquid < ready-to-use. Formulae stored in glass bottles contained between 100 and 300 ng g⁻¹ more Al than the same formulae stored in cans. The source of the increased Al did not appear to be the glass itself, because most electrolytes and glucose solutions, also stored in glass, contained less than 8 ng g⁻¹ Al. Corresponding differences in Pb and Cd levels were not observed. Al concentrations varied substantially among manufacturers; however, all manufacturers were able to produce plain milk-based formulae containing less than 50 ng g⁻¹ Al, i.e. within the range of Al concentrations found in human milk. Next to soya-based and hypoallergenic formulae, premature formulae contained among the highest concentrations of Al, ranging 851–909 ng g⁻¹ from one manufacturer and 365–461 ng g⁻¹ from another.

Effect of selenium pre-treatment on antioxidative enzymes and lipid peroxidation in Cd-exposed suckling rats

Since there are no data about the protective role of selenium (Se) against cadmium (Cd)-induced oxidative damage in early life, we studied the effect of Se supplementation on antioxidative enzyme activity and lipid peroxidation (through thiobarbituric acid reactive substances; TBARS) in suckling Wistar rats exposed to Cd. Treated animals received either Se alone for 9 days (8 μmol, i.e., 0.6 mg Se as Na(2)SeO(3) kg(-1) b.w., daily, orally; Se group), Cd alone for 5 days (8 μmol, i.e., 0.9 mg Cd as CdCl(2) kg(-1) b.w., daily, orally; Cd group), or pre-treatment with Se for 4 days and then co-treatment with Cd for the following 5 days (Se + Cd group). Our results showed that selenium supplementation, with and without Cd, increased SOD activity in the brain and kidney, but not in the liver and GSH-Px activity across all tissues compared to control rats receiving distilled water. Relative to the Cd group, Se + Cd group had higher kidney and brain SOD and GSH-Px activity (but not the liver), while in the liver caused increased and in the brain decreased TBARS level. These results suggest that Se stimulates antioxidative enzymes in immature kidney and brain of Cd-exposed rats and could protect against oxidative damage.

Impact of iron status on cadmium uptake in suckling piglets

Low iron status is known to increase the uptake of dietary cadmium in both adolescents and adults and there are indications that cadmium is absorbed from the intestine by the two major iron transporters divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1). In addition, it has been suggested that duodenal metallothionein (MT) may limit the transport of cadmium across the intestinal epithelium. The present investigation was undertaken to examine whether iron status influences cadmium absorption in newborns by applying a model of suckling piglets and the possible roles of duodenal DMT1, FPN1 and MT. An oral cadmium dose (20 microg/kg body weight) was given daily for 6 consecutive days on postnatal days (PNDs) 10-15 to iron-deficient or iron-supplemented piglets. The cadmium dose was chosen to keep the cadmium level at a realistically low but still detectable level, and without inducing any adverse health effects in the piglets. As indicators of cadmium uptake, cadmium levels in blood and kidneys were measured on PND 16 by inductively coupled plasma-mass spectrometry (ICP-MS). Cadmium levels in blood were statistically significantly correlated with cadmium levels in kidneys. The cadmium uptake was not higher in iron-deficient suckling piglets; rather, we detected a higher cadmium uptake in the iron-supplemented ones. The expression and localisation of DMT1, FPN1 and MT were not affected by iron status and could therefore not explain the findings. Our results suggest that there are developmental differences in the handling of both iron and cadmium in newborns as compared to adults.

Effects of cadmium and zinc on the quality of quail's eggs

We report the effects of cadmium (Cd) and zinc (Zn) on the quality of Japanese quail's eggs. For this study, 60 birds were divided into 3 groups of 20 subjects each. The animals in group 1 received 4 mg Zn/d, whereas those in group 2 were given a combination of 4 mg Zn/d and 0.12 mg Cd/d. The quails in group 3 were not given any supplements, acting as controls. The distribution of Cd and Zn in the eggs, the eggs' mass, and the strength and thickness of the shells were determined after 35 and 58 d of supplementation. Zinc showed a positive effect on the mass of eggs and accumulated mainly in the egg white. The content of Cd was significantly lower in the egg yolk of birds in group 1 (p<0.001), whereas those in group 2 had decreased eggshell thickness and strength in comparison to groups 1 and 3 (p<0.001). These results suggest that the adverse effects of Cd on the quality parameters of eggs from commercially important bird species can be, at least in part, counteracted by Zn supplementation.

A piglet model for studies of gastrointestinal uptake of cadmium in neonates

Newborns are believed to have a higher gastrointestinal uptake of inorganic cadmium (Cd) than adults. However, relevant models for investigations of absorption of dietary Cd in neonates are lacking. In the present study, piglets were exposed to 2 or 20 microg Cd/kg body weight (b wt) per day by repeated oral administrations of CdCl2 dissolved in deionized water or infant follow-up formula from days 0 to 10. Elevated and dose-dependent Cd retention in blood and tissues resulted from this low-dose Cd exposure, as determined at day 11. Follow-up formula reduced Cd uptake in comparison to deionized water. However, Cd distribution to the kidneys was higher when Cd was given in formula than in water. Metallothionein (MT) levels in liver, kidney and duodenum were six, three and two times higher, respectively compared to an un-exposed control. Differences in bioavailability and distribution of low-dose Cd given in various diets to newborns could be detected by the proposed piglet model.

Bioavailability of cadmium from in vitro digested infant food studied in Caco-2 cells

The solubility and bioavailability of cadmium (Cd) in infant foods, three cereal- and milk-based diets and two ready-to-use baby dishes, were studied after in vitro digestion and by using human intestinal Caco-2 cells. The solubility of Cd after in vitro digestion varied between diets; liver casserole had the highest solubility and was lower after infant as compared to adult digestion conditions. Generally, more Cd was soluble in infant intestinal than gastric juice in contrast to the results from the adult digestion. Caco-2 cells were incubated with supernatants of infant digests that had been equilibrated with (109)Cd during the in vitro digestion procedure, and cellular uptake and transport of (109)Cd were measured after 180 min. Statistically significant differences in both uptake and transport of Cd were detected between some of the diets and a control solution containing only digestive enzymes and (109)CdCl(2). Uptake of soluble Cd in the cells varied between diets from 4 to 6%, and the transport over the monolayers was 1-2% of the dose. We conclude that age specific digestion conditions as well as composition of diets affect both solubility and bioavailability of Cd.