Dietary acrylamide intake during pregnancy and fetal growth-results from the Norwegian mother and child cohort study (MoBa)

Dietary acrylamide exposure and health risk assessment of pregnant women: A case study from Türkiye

This study aimed to determine the acrylamide exposure of pregnant women resulting from the consumption of bread, coffee, and French fries and to evaluate it in terms of carcinogenic and non-carcinogenic health risks. Retrospective 24-h food consumption data of pregnant women (n = 487) was obtained using the Food Frequency Questionnaire (FFQ). Dietary acrylamide exposure was calculated according to a deterministic model, and the data were assessed by hazard index (HI) and carcinogenic risk (CR). The mean daily acrylamide exposure of pregnant women aged 18-30 and ≥31 years and in the 1st, 2nd, and 3rd trimesters was 31.4, 35.4, 38.7, 31.3, and 32.4 μg/day, respectively. The acrylamide exposure data were not significantly different among different age groups and pregnancy periods (p > .05). Dietary acrylamide exposure in pregnant women of different age groups and trimesters may cause significant and serious health problems in terms of carcinogenic risk. According to their level of contribution to average acrylamide exposure, the foods were ranked as follows: French fries> bread> coffee. There is a significant risk of cancer due to exposure to acrylamide from French fries and bread other than coffee. The findings suggest that pregnant women should avoid consuming French fries, bread, and coffee with high acrylamide levels for both their own health and their newborns' health.

From a toxin to an obesogen: a review of potential obesogenic roles of acrylamide with a mechanistic approach

Obesity and obesity-related disorders such as cancer, type 2 diabetes, and fatty liver have become a global health problem. It is well known that the primary cause of obesity is positive energy balance. In addition, obesity is the consequence of complex gene and environment interactions that result in excess calorie intake being stored as fat. However, it has been revealed that there are other factors contributing to the worsening of obesity. The presence of nontraditional risk factors, such as environmental endocrine-disrupting chemicals, has recently been associated with obesity and comorbidities caused by obesity. The aim of this review was to examine the evidence and potential mechanisms for acrylamide having endocrine-disrupting properties contributing to obesity and obesity-related comorbidities. Recent studies have suggested that exposure to environmental endocrine-disrupting obesogens may be a risk factor contributing to the current obesity epidemic, and that one of these obesogens is acrylamide, an environmental and industrial compound produced by food processing, particularly the processing of foods such as potato chips, and coffee. In addition to the known harmful effects of acrylamide in humans and experimental animals, such as neurotoxicity, genotoxicity, and carcinogenicity, acrylamide also has an obesogenic effect. It has been shown in the literature to a limited extent that acrylamide may disrupt energy metabolism, lipid metabolism, adipogenesis, adipocyte differentiation, and various signaling pathways, and may exacerbate the disturbances in metabolic and biochemical parameters observed as a result of obesity. Acrylamide exerts its main potential obesogenic effects through body weight increase, worsening of the levels of obesity-related blood biomarkers, and induction of adipocyte differentiation and adipogenesis. Additional mechanisms may be discovered. Further experimental studies and prospective cohorts are needed, both to supplement existing knowledge about acrylamide and its effects, and to clarify its established relationship with obesity and its comorbidities.

Two decades of research in dietary acrylamide: What do we know today

After nearly two decades since acrylamide was first raised as a potential safety issue in foods, significant progress has been made in understanding its formation during cooking, how to reduce levels in the most concerned foods, and the possible cancer risk to humans. Despite the huge wealth of knowledge gathered on this topic over the past years, a few new discoveries in occurrence, mitigation, analysis and risk assessment are worthy to note. This short review highlights the salient novelties pertaining to acrylamide, particularly in the areas of formation & analysis, existing and possible future regulations in the European Union, and finally considerations that may lead to possibly revisiting the toxicity of acrylamide and the main metabolite, glycidamide.

Dietary intake of acrylamide in the Norwegian EuroMix biomonitoring study: Comparing probabilistic dietary estimates with haemoglobin adduct measurements

Acrylamide is a probable human carcinogen with widespread exposure via food. The present study compared acrylamide intake measurements obtained from haemoglobin adduct levels and self-registered dietary consumption data in a group of 144 Norwegian healthy adults. Acrylamide adducts to N-terminal valine in haemoglobin were measured and used to estimate the intake via the internal dose approach which showed a median (interquartile range) of 0.24 (0.19-0.30) μg/kg bw/day. Data from weighed food records and food frequency questionnaires from the same individuals were used for probabilistic modelling of the intake of acrylamide. The median acrylamide intake was calculated to be 0.26 (0.16-0.39) and 0.30 (0.23-0.39) μg/kg bw/day, respectively from the two sources of self-registered dietary consumption data. Overall, a relatively good agreement was observed between the methods in pairwise comparison in Bland-Altman plots, with the methods disagreeing with 7% or less of the values. The intake estimates obtained with the two dietary consumption methods and one biomarker method are in line with earlier dietary estimates in the Norwegian population. The Margin of Exposure indicate a possible health risk concern from dietary acrylamide. This is the first study with a comparison in the same individuals of acrylamide intake estimates obtained with these methods.

Investigation of the effects of swimming exercises in rats given acrylamide

BACKGROUND

Acrylamide is a toxic substance used in industrial and laboratory processes. Acrylamide exposure has a toxic effect on many systems. Protective mechanisms should be developed against the effects caused by acrylamide.

OBJECTIVE

In our study, we investigated whether exercise has a protective effect against the changes that acrylamide will cause in pancreas.

METHODS

32 adult Sprague-Dawley male rats were used. Control group was given only saline. Exercise group was applied swimming exercise for 1hour daily for 4 weeks. Acrylamide group was given 50mg/kg acrylamide by gavage for 4 weeks. Acrylamide+exercise group was applied 50mg/kg acrylamide for 4 weeks and swimming exercise for 1hour daily. After the experiment, fasting blood glucose and oral glucose tolerance test measurements were performed. Then, blood and pancreas samples were taken.

RESULTS

Acrylamide exposure caused an increase in fasting blood glucose and oral glucose tolerance, a decrease in insulin levels and oxidative stress in acrylamide group. In exercise group, these values were similar to control group and no significant change was observed in acrylamide+exercise group. While there was an increase in the number of alpha cells in acrylamide group compared to the other groups, here was a decrease in the number of beta cells compared to control group.

CONCLUSION

We can say that acrylamide causes changes in the islets of Langerhans by affecting alpha and beta cell numbers. The protective effect of exercise on beta and alpha cell mass was not statistically significant in the acrylamide+exercise group. When the results were examined, the decrease in oxidative stress and the higher number of beta and alpha cells in the acrylamide+exercise group compared to the acrylamide group suggested that 4 weeks of swimming exercise may have an effect on acrylamide exposure.

Comparison between pollutants found in breast milk and infant formula in the last decade: A review

Since ancient times, breastfeeding has been the fundamental way of nurturing the newborn. The benefits of breast milk are widely known, as it is a source of essential nutrients and provides immunological protection, as well as developmental benefits, among others. However, when breastfeeding is not possible, infant formula is the most appropriate alternative. Its composition meets the nutritional requirements of the infant, and its quality is subject to strict control by the authorities. Nonetheless, the presence of different pollutants has been detected in both matrices. Thus, the aim of the present review is to make a comparison between the findings in both breast milk and infant formula in terms of contaminants in the last decade, in order to choose the most convenient option depending on the environmental conditions. For that, the emerging pollutants including metals, chemical compounds derived from heat treatment, pharmaceutical drugs, mycotoxins, pesticides, packaging materials, and other contaminants were described. While in breast milk the most concerning contaminants found were metals and pesticides, in infant formula pollutants such as metals, mycotoxins, and packaging materials were the most outstanding. In conclusion, the convenience of using a feeding diet based on breast milk or either infant formula depends on the maternal environmental circumstances. However, it is important to take into account the immunological benefits of the breast milk compared to the infant formula, and the possibility of using breast milk in combination with infant formula when the nutritional requirements are not fulfilled only with the intake of breast milk. Therefore, more attention should be paid in terms of analyzing these conditions in each case to be able to make a proper decision, as it will vary depending on the maternal and newborn environment.

Dietary Acrylamide Exposure and Cancer Risk: A Systematic Approach to Human Epidemiological Studies

Acrylamide, identified by the International Cancer Research Center as a possible carcinogenic compound to humans, is a contaminant formed as a result of the thermal process in many foods, such as coffee, French fries, biscuits and bread, which are frequently consumed by individuals in their daily lives. The biggest concern about acrylamide is that the health risks have not yet been fully elucidated. For this reason, many studies have been carried out on acrylamide in the food, nutrition and health equation. This study focused on epidemiological studies examining the associations between dietary acrylamide exposure and cancer risk. For this purpose, articles published in PubMed, Isı Web of Knowledge, Scopus and Science Direct databases between January 2002 and April 2022 were systematically examined using various keywords, and a total of 63 articles were included in the study. Although some studies on reproductive, urinary, gastrointestinal, respiratory and other systems and organs stated that there is a positive relationship between dietary acrylamide exposure and cancer risk, many publications did not disclose a relationship in this direction. Studies examining the relationship between dietary acrylamide exposure and cancer should be planned to include more people and foods in order to obtain more reliable results. Making research plans in this way is very important in terms of guiding health policies to be formed in the future.

Maternal acrylamide exposure during pregnancy and fetal growth: A systematic review and dose-response meta-analysis of epidemiological studies

BACKGROUND

Acrylamide is a food contaminant linked to developmental toxicity in animals and possibly in humans.

OBJECTIVES

We performed a systematic review and dose-response meta-analysis of epidemiological studies evaluating the relationship between maternal acrylamide exposure during pregnancy and the risk of being small for gestational age (SGA) and birth weight, birth head circumference and birth length.

METHODS

We performed the literature search in PubMed, Scopus, and Web of Science, until June 6th, 2022. Studies carried out in mother-newborn pairs, assessing maternal acrylamide exposure during pregnancy, either via dietary assessments or biomarkers i.e., hemoglobin adducts of acrylamide (AA-Hb) and glycidamide (GA-Hb), and evaluating birth outcomes were included. We employed a random-effects model to assess the pooled effect estimates and their 95% confidence intervals (CI) for the association between acrylamide exposure and birth outcomes. Risk of Bias for Nutrition Observational Studies tool was used for bias assessment.

RESULTS

Out of 169 records identified, five original studies were eligible, including 53,870 mother-newborn pairs in total. Means were 21.9 μg/day for estimated dietary acrylamide exposure (3 studies), and 18.4 and 14.9 pmol/g for AA-Hb and GA-Hb, respectively (2 studies). Higher risk of SGA and lower birth weight and head circumference were observed in the highest quartile of AA-Hb [odds ratio (OR): 1.20 (95% CI: 1.08; 1.33); mean difference (MD): -131 g (95% CI: -204; -58) and -0.31 cm (95% CI: -0.58; -0.04), respectively], and GA-Hb [OR: 1.36 (95% CI: 1.13; 1.64), MD: -161 g (95% CI: -271; -52); and MD: -0.38 cm (95% CI: -0.66; -0.10), respectively], whereas a lower birth length was observed only in the highest quartile of GA-Hb (MD: -0.85 cm (95% CI: -1.38; -0.33). Results from the dose-response meta-analysis between increasing maternal acrylamide exposure during pregnancy and birth weight showed no clear evidence of a deviation from linearity.

CONCLUSIONS

Overall, our findings strengthen the evidence of an adverse effect of maternal acrylamide exposure during pregnancy on fetal growth. These results encourage to increase preventive actions towards lowering acrylamide exposure in the population.

Association between acrylamide exposure and the odds of developmental disabilities in children: A cross-sectional study

Background

The association between acrylamide exposure and the odds of developmental disabilities (DDs) is unclear. We conducted this analysis to explore whether acrylamide exposure is related to DDs.

Methods

We analyzed a sample of 1,140 children aged 6-17 years old from the US National Health and Nutrition Examination Survey 2013-2014 to 2015-2016. DDs were determined by reports of parents. Acrylamide exposure was evaluated by the hemoglobin adducts of acrylamide (HbAA) and its major metabolite glycidamide (HbGA). We investigated the association using binomial logistic regression analysis by taking HbAA and HbGA as continuous or quartile variables. Restricted cubic splines (RCS) were used to explore the non-linear relationship between HbAA or HbGA and the odds of DDs. Interaction analysis and propensity score matching (PSM) were used to validate the results.

Results

A total of 134 participants were reported to have DDs. The median level of HbAA and HbGA was 41.6 and 40.5 pmol/g Hb, respectively. HbAA and HbGA were not associated with the odds of DDs when taken as continuous variables. When divided into quartiles, there was no evidence for a linear trend for HbAA and HbGA. RCS showed that there was a J-shaped association between HbGA and the odds of DDs (P for non-linearity, 0.023). The results were consistent in interaction analysis by age, gender, and race, and after PSM.

Conclusion

HbGA level was associated with the odds of DDs in a J-shaped manner among children. Further investigation is warranted to determine the causality and underlying mechanisms.

Prenatal acrylamide exposure results in time-dependent changes in liver function and basal hematological, and oxidative parameters in weaned Wistar rats

Acrylamide (ACR) is a toxic compound commonly found in fried, baked and heat-processed starchy foods. The current study investigated the time-dependent effects of maternal exposure to non-toxic ACR doses on the oxidative stress, liver function, and basal blood morphology of the rat offspring. Pregnant, Wistar rats were randomly divided into the control group or the groups administrated with ACR (3 mg/kg b.w./day): long exposure for 15 days, medium exposure for 10 days and short exposure for 5 days during pregnancy. Body mass, blood morphology and hematology, serum concentrations of growth hormone, IGF-1, TNF-α, IL-1β, IL-6 and insulin, liver histomorphometry, liver activity of beclin1, LC2B and caspase3, markers of oxidative stress and the activity of antioxidative enzymes in blood serum and the liver were measured in offspring at weaning (postnatal day 21). Even short prenatal exposure to ACR led to oxidative stress and resulted in changes in liver histomorphometry and upregulation of autophagy/apoptosis. However, the most significant changes were observed following the long period of ACR exposure. This study has shown for the first time that ACR is responsible for changes in body mass in a time-dependent manner, which could lead to more serious illnesses like overweight and diabetes later in life.

Time Trends of Acrylamide Exposure in Europe: Combined Analysis of Published Reports and Current HBM4EU Studies

More than 20 years ago, acrylamide was added to the list of potential carcinogens found in many common dietary products and tobacco smoke. Consequently, human biomonitoring studies investigating exposure to acrylamide in the form of adducts in blood and metabolites in urine have been performed to obtain data on the actual burden in different populations of the world and in Europe. Recognizing the related health risk, the European Commission responded with measures to curb the acrylamide content in food products. In 2017, a trans-European human biomonitoring project (HBM4EU) was started with the aim to investigate exposure to several chemicals, including acrylamide. Here we set out to provide a combined analysis of previous and current European acrylamide biomonitoring study results by harmonizing and integrating different data sources, including HBM4EU aligned studies, with the aim to resolve overall and current time trends of acrylamide exposure in Europe. Data from 10 European countries were included in the analysis, comprising more than 5500 individual samples (3214 children and teenagers, 2293 adults). We utilized linear models as well as a non-linear fit and breakpoint analysis to investigate trends in temporal acrylamide exposure as well as descriptive statistics and statistical tests to validate findings. Our results indicate an overall increase in acrylamide exposure between the years 2001 and 2017. Studies with samples collected after 2018 focusing on adults do not indicate increasing exposure but show declining values. Regional differences appear to affect absolute values, but not the overall time-trend of exposure. As benchmark levels for acrylamide content in food have been adopted in Europe in 2018, our results may imply the effects of these measures, but only indicated for adults, as corresponding data are still missing for children.

Trends of Exposure to Acrylamide as Measured by Urinary Biomarkers Levels within the HBM4EU Biomonitoring Aligned Studies (2000–2021)

Acrylamide, a substance potentially carcinogenic in humans, represents a very prevalent contaminant in food and is also contained in tobacco smoke. Occupational exposure to higher concentrations of acrylamide was shown to induce neurotoxicity in humans. To minimize related risks for public health, it is vital to obtain data on the actual level of exposure in differently affected segments of the population. To achieve this aim, acrylamide has been added to the list of substances of concern to be investigated in the HBM4EU project, a European initiative to obtain biomonitoring data for a number of pollutants highly relevant for public health. This report summarizes the results obtained for acrylamide, with a focus on time-trends and recent exposure levels, obtained by HBM4EU as well as by associated studies in a total of seven European countries. Mean biomarker levels were compared by sampling year and time-trends were analyzed using linear regression models and an adequate statistical test. An increasing trend of acrylamide biomarker concentrations was found in children for the years 2014–2017, while in adults an overall increase in exposure was found to be not significant for the time period of observation (2000–2021). For smokers, represented by two studies and sampling for, over a total three years, no clear tendency was observed. In conclusion, samples from European countries indicate that average acrylamide exposure still exceeds suggested benchmark levels and may be of specific concern in children. More research is required to confirm trends of declining values observed in most recent years.

Risk assessment of the exposure of Spanish children to acrylamide using human biomonitoring

Acrylamide (AA) is an organic contaminant that naturally forms in starchy foods during high-temperature cooking under low-moisture conditions. It is mainly produced from the sugars and amino acids present in food by the Maillard reaction. When humans are exposed to AA, AA is eliminated in the urine as mercapturic acid conjugates, primarily including N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA), N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA3), and N-acetyl-3-[(3-amino-3-oxopropyl)sulfinyl]-L-alanine (AAMA-Sul), which are used as exposure biomarkers of AA in human biomonitoring studies. Although the carcinogenic effects of AA on humans have not been demonstrated yet, some studies have shown that AA may negatively affect children's health. The main objective of this study was to evaluate the exposure of Spanish children (n = 612) to AA. For this purpose, the levels of AAMA, AAMA-Sul, and GAMA3 in first-morning urine samples were analyzed by "dilute and shoot" and liquid chromatography coupled to tandem mass spectrometry. The three metabolites were detected in all the children involved in this study in the following order (geometric mean (GM)): AAMA (79 ng ml^-1) > AAMA-Sul (28 ng ml^-1) > GAMA3 (18 ng ml^-1). Statistical analysis suggested that the intake of fried potato products and biscuits could be associated with higher levels of AA metabolites in urine. Estimated daily intakes of AA in the children under study were in the range of 1.2-1.5 μg AA·kg-body weight^-1·day^-1 (GM). Risk assessment calculations indicate that the health risk of AA exposure cannot be overlooked and the exposure of Spanish children to AA should be closely monitored.

Developmental neurotoxicity of acrylamide and its metabolite glycidamide in a human mixed culture of neurons and astrocytes undergoing differentiation in concentrations relevant for human exposure

Neural stem cells (NSCs) derived from human induced pluripotent stem cells were used to investigate effects of exposure to the food contaminant acrylamide (AA) and its main metabolite glycidamide (GA) on key neurodevelopmental processes. Diet is an important source of human AA exposure for pregnant women, and AA is known to pass the placenta and the newborn may also be exposed through breast feeding after birth. The NSCs were exposed to AA and GA (1 ×10^-8 - 3 ×10^-3 M) under 7 days of proliferation and up to 28 days of differentiation towards a mixed culture of neurons and astrocytes. Effects on cell viability was measured using Alamar Blue™ cell viability assay, alterations in gene expression were assessed using real time PCR and RNA sequencing, and protein levels were quantified using immunocytochemistry and high content imaging. Effects of AA and GA on neurodevelopmental processes were evaluated using endpoints linked to common key events identified in the existing developmental neurotoxicity adverse outcome pathways (AOPs). Our results suggest that AA and GA at low concentrations (1 ×10^-7 - 1 ×10^-8 M) increased cell viability and markers of proliferation both in proliferating NSCs (7 days) and in maturing neurons after 14-28 days of differentiation. IC₅₀ for cell death of AA and GA was 5.2 × 10^-3 M and 5.8 × 10^-4 M, respectively, showing about ten times higher potency for GA. Increased expression of brain derived neurotrophic factor (BDNF) concomitant with decreased synaptogenesis were observed for GA exposure (10^-7 M) only at later differentiation stages, and an increased number of astrocytes (up to 3-fold) at 14 and 21 days of differentiation. Also, AA exposure gave tendency towards decreased differentiation (increased percent Nestin positive cells). After 28 days, neurite branch points and number of neurites per neuron measured by microtubule-associated protein 2 (Map2) staining decreased, while the same neurite features measured by βIII-Tubulin increased, indicating perturbation of neuronal differentiation and maturation.

Review of the state of the art of acrylamide human biomonitoring

Human biomonitoring (HBM) is a very useful tool for assessing human exposure to acrylamide (AA). In the framework of the Human Biomonitoring Initiative (HBM4EU) AA was included in its second list of priority substances due to the potential threat to human health. HBM data on AA are scarce, but the use of specific and sensitive biomarkers represents a reliable indicator of exposure. In this review an overview of available knowledge on HBM of AA is provided in terms of: i) preferred exposure biomarkers and matrices for the HBM of AA; ii) analytical methods for determining its biomarkers of exposure in the most used specimens; iii) current HBM data available; and iv) tools for interpreting HBM data for AA in relation to risk assessment. Finally, future trends in this field are discussed.

Acrylamide in widely consumed foods - a review

Acrylamide (AA) is considered genotoxic, neurotoxic and a 'probable human carcinogen'. It is included in group 2 A of the International Agency for Research on Cancer (IARC). The formation of AA occurs when starch-based foods are subjected to temperatures higher than 120 °C in an atmosphere with very low water content. The aim of this review is to shed light on the toxicological aspects of AA, showing its regulatory evolution, and describing the most interesting mitigation techniques for each food category involved, with a focus on compliance with EU legislation in the various classes of consumer products of industrial origin in Europe.

Vitamin D mediates the association between acrylamide hemoglobin biomarkers and obesity

Mediation analysis aims to discover the role of intermediate variables from exposure to disease. The current study was performed to evaluate how vitamin D mediates the association between acrylamide hemoglobin biomarkers and obesity. Data were collected on 10,377 adults participating in the National Health and Nutrition Examination Survey (NHANES) 2003-2006 and 2013-2014 aged ≥ 18 years. Obesity was assessed through body mass index and abdominal circumference measurements. Generalized linear and restricted cubic spline (RCS) regression were used to estimate the association between vitamin D and acrylamide hemoglobin biomarkers, and the mediation effect of vitamin D was also discussed. After adjusting for potentially confounding factors, vitamin D had strong negative associations with serum concentrations of acrylamide hemoglobin adducts (HbAA, HbGA, and HbAA + HbGA). The RCS plots demonstrated that vitamin D was inversely and nonlinearly associated with HbAA and HbAA + HbGA while inversely and linearly associated with HbGA, and also a striking difference when vitamin D was lower than 60 nmol/L. Mediation analysis suggested that a negative correlation between acrylamide and obesity was mediated by vitamin D. The current study is expected to offer a fresh perspective on reducing the toxicity of acrylamide.

Hemoglobin adducts of acrylamide in human blood - What has been done and what is next?

Acrylamide forms in many commonly consumed foods. In animals, acrylamide causes tumors, neurotoxicity, developmental and reproductive effects. Acrylamide crosses the placenta and has been associated with restriction of intrauterine growth and certain cancers. The impact on human health is poorly understood and it is impossible to say what level of dietary exposure to acrylamide can be deemed safe as the assessment of exposure is uncertain. The determination of hemoglobin (Hb) adducts from acrylamide is increasingly being used to improve the exposure assessment of acrylamide. We aim to outline the literature on Hb adduct levels from acrylamide in humans and discuss methodological issues and research gaps. A total of 86 studies of 27,966 individuals from 19 countries were reviewed. Adduct levels were highest in occupationally exposed individuals and smokers. Levels ranged widely from 3 to 210 pmol/g Hb in non-smokers and this wide range suggests that dietary exposure to acrylamide varies largely. Non-smokers from the US and Canada had slightly higher levels as compared with non-smokers from elsewhere, but differences within studies were larger than between studies. Large studies with exposure assessment of acrylamide and related adduct forming compounds from diet during early-life are encouraged for the evaluation of health effects.

Exposure assessment of Spanish lactating mothers to acrylamide via human biomonitoring

Acrylamide (AA) is an organic compound classified as "Probably carcinogenic to humans" (Group 2 A) that can be found principally in processed carbohydrate-rich foods and tobacco smoke. In humans, after exposure, AA is rapidly metabolized and excreted in urine, predominantly as N-acetyl-S-(2-carbamoylethyl)-l-cysteine (AAMA), N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-l-cysteine (GAMA3) and N-Acetyl-3-[(3-amino-3-oxopropyl)sulfinyl]-L-alanine (AAMA-Sul), which can be used as short-term biomarkers of exposure to AA. In this study, the presence of AA metabolites in urine samples of lactating mothers living in Spain (n = 114) was analyzed by "dilute and shoot" and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). All urinary metabolites were detected in 100% of the analyzed samples, with geometric means of 70, 33 and 15 ng ml^-1, for AAMA, AAMA-Sul and GAMA3, respectively. The consumption of coffee, bread and precooked food products were found to be significant predictors of internal exposure to AA. An estimated daily intake (EDI) of AA based on its urinary metabolites was calculated, obtaining mean values between 1.2 and 1.9 μg AA·kg bw^-1·day^-1 in the target population. The risk assessment was evaluated using both reverse and forward dosimetry, showing an average margin of exposure (MOE) of 349 and a hazard quotient (HQ) of 5.5. Therefore, AA exposure should be considered a medium priority for risk assessment follow-up in the Spanish population, since a health concern with respect to non-neoplastic toxicity could not be discarded.

Acrylamide Content in Breast Milk: The Evaluation of the Impact of Breastfeeding Women's Diet and the Estimation of the Exposure of Breastfed Infants to Acrylamide in Breast Milk

Acrylamide in food is formed by the Maillard reaction. Numerous studies have shown that acrylamide is a neurotoxic and carcinogenic compound. The aim of this study was to determine the level of acrylamide in breast milk at different lactation stages and to evaluate the impact of breastfeeding women's diet on the content of this compound in breast milk. The acrylamide level in breast milk samples was determined by LC-MS/MS. Breastfeeding women's diet was evaluated based on the 24 h dietary recall. The median acrylamide level in colostrum (n = 47) was significantly (p < 0.0005) lower than in the mature milk (n = 26)-0.05 µg/L and 0.14 µg/L, respectively. The estimated breastfeeding women's acrylamide intake from the hospital diet was significantly (p < 0.0001) lower than that from the home diet. We found positive-although modest and borderline significant-correlation between acrylamide intake by breastfeeding women from the hospital diet µg/day) and acrylamide level in the colostrum (µg/L). Acrylamide has been detected in human milk samples, and a positive correlation between dietary acrylamide intake by breastfeeding women and its content in breast milk was observed, which suggests that the concentration can be reduced. Breastfeeding women should avoid foods that may be a source of acrylamide in their diet.

Gestational acrylamide exposure and biomarkers of fetal growth: Probing the mechanism underlying the association between acrylamide and reduced fetal growth

INTRODUCTION

Four epidemiological studies have shown a negative association between prenatal acrylamide exposure and birth size. In order to shed light on the possible underlying mechanism(s), we analysed associations between acrylamide biomarkers and biomarkers related to fetal growth.

METHODS

In newborns of the ENVIRONAGE birth cohort (n ranges from 215 to 434), we investigated the association between prenatal acrylamide exposure (acrylamide and glycidamide hemoglobin adduct levels in cord blood) and thyroid hormones (TSH, T3, T4 and the ratio of T4 to T3 in cord plasma), insulin-related factors (cord plasma insulin and IGF1, and placental IGF2), neurotrophins (cord plasma BDNF, and placental NGF, NT3 and NT4), and cord plasma homocysteine and progesterone, using multiple linear regression analysis. In addition, we investigated whether the biomarkers mediated the associations between prenatal acrylamide exposure and birth outcomes.

RESULTS

We observed lower cord plasma TSH (-10.2% [95% CI: -15.0, -4.3]) and higher placental NGF levels (10.0% [95% CI 3.7, 17.4]) for a twofold increase of acrylamide adducts, a decrease in the ratio of cord plasma free T4 and free T3 with higher acrylamide and glycidamide adducts of -2.9% (95% CI: -5.7, -0.1) and -3.9% (95% CI: -6.2, -1.6) for a twofold increase in acrylamide and glycidamide adduct levels, respectively, and higher cord plasma free T3 with increases in both acrylamide and glycidamide adducts of 2.8% (95% CI: 0.2, 5.6) and 3.6% (95% CI: 0.8, 6.6) for a twofold increase in acrylamide and glycidamide adduct levels, respectively. Additionally, a twofold increase in glycidamide adducts was associated with lower cord plasma insulin levels, particularly among newborns of non-smoking mothers (-11.2% [95% CI: -19.5, -0.1]). Cord plasma insulin seemed to mediate the association between glycidamide adducts and birth weight.

CONCLUSIONS

A decrease in cord plasma insulin levels may be (a marker of) a mechanism by which gestational acrylamide exposure is associated with decreased fetal growth. The possible health consequences of the associations between gestational acrylamide exposure and thyroid hormones and neurotrophins warrant future study.

Acrylamide exposure and pulmonary function reduction in general population: The mediating effect of systemic inflammation

Acrylamide exposure along with resultant potential adverse health effects have attracted global concern, and the World Health Organization calls for more and urgent studies on the health risks from acrylamide. However, the association and mechanism between acrylamide exposure and pulmonary dysfunction remain unclear. Our goals were to investigate the relationship of internal acrylamide exposure with lung function reduction, and the potential mediating role of systematic inflammation in that relationship. Our study was conducted within the Wuhan-Zhuhai cohort. Urinary biomarkers of acrylamide exposure (N-acetyl-S-(2-carbamoylethyl)-l-cysteine, AAMA; N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-l-cysteine, GAMA) and lung function were determined among 3271 general adults, of whom 2595 had test results of systemic inflammatory marker plasma C-reactive protein (CRP). We employed linear mixed models to assess the relations among urinary acrylamide metabolites, pulmonary function and plasma CRP, and PRODCLIN program to evaluate the mediating role of CRP. We observed that urinary acrylamide metabolites were inversely and dose-dependently related to lung function (P trend<0.05). Each 1-unit increment in log-transformed level of AAMA, GAMA, or AAMA+GAMA (ΣUAAM) was significantly (P < 0.05) related to a 59.9-, 64.2-, or 64.3-mL reduction in FVC, and a 53.9-, 59.7-, or 58.5-mL reduction in FEV₁, respectively. Such relationships were independent of smoking, and were significant in physically inactive rather than physically active participants. AAMA (β = 0.10), GAMA (β = 0.16) and ΣUAAM (β = 0.12) were significantly (P < 0.05) related to increased CRP, which was significantly (P < 0.05) related to reduced FVC (β = -55.3) and FEV₁ (β = -40.6). We further found that increased CRP significantly (P < 0.05) mediated 6.34-11.1% of the urinary acrylamide metabolites-associated lung function reductions. For the first time, our findings suggested that exposure to acrylamide in daily life was related to reduced lung function and increased systemic inflammation in general population, and systemic inflammation further mediated acrylamide-associated lung function reduction, indicating a potential mechanistic role of systemic inflammation underlying pulmonary dysfunction from acrylamide exposure.

A Review of Dietary Intake of Acrylamide in Humans

The dietary intake of acrylamide (AA) is a health concern, and food is being monitored worldwide, but the extent of AA exposure from the diet is uncertain. The aim of this review was to provide an overview of estimated dietary intake. We performed a PubMed search identifying studies that used dietary questionnaires and recalls to estimate total dietary AA intake. A total of 101 studies were included, corresponding to 68 original study populations from 26 countries. Questionnaires were used in 57 studies, dietary recalls were used in 33 studies, and 11 studies used both methods. The estimated median AA intake ranged from 0.02 to 1.53 μg/kg body weight/day between studies. Children were represented in 25 studies, and the body-weight-adjusted estimated AA intake was up to three times higher for children than adults. The majority of studies were from Europe (n = 65), Asia (n = 17), and the USA (n = 12). Studies from Asia generally estimated lower intakes than studies from Europe and the USA. Differences in methods undermine direct comparison across studies. The assessment of AA intake through dietary questionnaires and recalls has limitations. The integration of these methods with the analysis of validated biomarkers of exposure/internal dose would improve the accuracy of dietary AA intake exposure estimation. This overview shows that AA exposure is widespread and the large variation across and within populations shows a potential for reduced intake among those with the highest exposure.

Cord blood acrylamide levels and birth size, and interactions with genetic variants in acrylamide-metabolising genes

BACKGROUND

Up to now, 3 epidemiological studies have shown clear inverse associations between prenatal acrylamide exposure and birth size. In addition to studying the association between acrylamide and birth size, we investigated the interaction between acrylamide and polymorphisms in acrylamide-metabolising genes, with the aim of probing the causality of the inverse relationship between acrylamide and fetal growth.

METHODS

We investigated the association between prenatal acrylamide exposure (acrylamide and glycidamide hemoglobin adduct levels (AA-Hb and GA-Hb) in cord blood) and birth weight, length and head circumference in 443 newborns of the ENVIRONAGE (ENVIRonmental influence ON AGEing in early life) birth cohort. In addition, we studied interaction with single nucleotide polymorphisms (SNPs) in CYP2E1, EPHX1 and GSTP1, using multiple linear regression analysis.

RESULTS

Among all neonates, the body weight, length and head circumference of neonates in the highest quartile was - 101 g (95% CI: - 208, 7; p for trend = 0.12), - 0.13 cm (95% CI: - 0.62, 0.36; p for trend = 0.69) and - 0.41 cm (- 0.80, - 0.01; p for trend = 0.06) lower, respectively, compared to neonates in the lowest quartile of AA-Hb in cord blood, For GA-Hb, the corresponding effect estimates were - 222 g (95% CI: - 337, - 108; p for trend = 0.001), - 0.85 (95% CI: - 1.38, - 0.33; p for trend = 0.02) and - 0.55 (95% CI: - 0.98, - 0.11; p for trend = 0.01), respectively. The associations for GA-Hb were similar or stronger in newborns of non-smoking mothers. There was no statistically significant interaction between acrylamide exposure and the studied genetic variations but there was a trend of stronger inverse associations with birth weight and head circumference among newborns with homozygous wildtypes alleles for the CYP2E1 SNPS and with variant alleles for a GSTP1 SNP (rs1138272).

CONCLUSIONS

Prenatal dietary acrylamide exposure, specifically in the form of its metabolite glycidamide, was inversely associated with birth weight, length and head circumference. The interaction pattern with SNPs in CYP2E1, although not statistically significant, is an indication for the causality of this association. Other studies are needed to corroborate this finding.

Does the food processing contaminant acrylamide cause developmental neurotoxicity? A review and identification of knowledge gaps

There is a worldwide concern on adverse health effects of dietary exposure to acrylamide (AA) due to its presence in commonly consumed foods. AA is formed when carbohydrate rich foods containing asparagine and reducing sugars are prepared at high temperatures and low moisture conditions. Upon oral intake, AA is rapidly absorbed and distributed to all organs. AA is a known human neurotoxicant that can reach the developing foetus via placental transfer and breast milk. Although adverse neurodevelopmental effects have been observed after prenatal AA exposure in rodents, adverse effects of AA on the developing brain has so far not been studied in humans. However, epidemiological studies indicate that gestational exposure to AA impair foetal growth and AA exposure has been associated with reduced head circumference of the neonate. Thus, there is an urgent need for further research to elucidate whether pre- and perinatal AA exposure in humans might impair neurodevelopment and adversely affect neuronal function postnatally. Here, we review the literature with emphasis on the identification of critical knowledge gaps in relation to neurodevelopmental toxicity of AA and its mode of action and we suggest research strategies to close these gaps to better protect the unborn child.

Exposure to acrylamide induces skeletal developmental toxicity in zebrafish and rat embryos

Acrylamide is a well-known carcinogen and neurotoxic substance that has been discovered in frying or baking carbohydrate-rich foods and is widely found in soils and groundwater. The purpose of this study was to investigate the adverse effects of exposure to acrylamide on skeletal development. After treatment with acrylamide in zebrafish embryos, the survival and hatching rates decreased, and the body length shortened, with cartilage malformation and a decrease in skeletal area. Exposure to acrylamide in maternal rats during the lactation period disturbed bone mineral density, serum levels of parathyroid hormone, and the expression of skeletal development-related genes in neonates. Exposure to acrylamide in pregnant rats during the pregnancy period decreased the trabecular density and inhibited cartilage formation by delaying the differentiation of osteoblasts and promoting the maturation of osteoclasts in rat embryos. Furthermore, acrylamide intervention downregulated the expression of chondrocyte and osteoblast differentiation-related genes (sox9a, bmp2, col2a1, and runx2), and upregulated the expression of osteoclast marker genes (rankl and mcsf) in zebrafish and rat embryos at different gestational stages. Our results indicated that exposure to acrylamide dysregulated signature gene and protein expression profiles of skeletal development by suppressing the differentiation and maturation of osteoblasts and cartilage matrix and promoting the formation of osteoclasts, and ultimately induced skeletal abnormality in morphology, which brings increasing attention to the intergenerational toxicity of acrylamide via mother-to-child transmission.

Acrylamide-Hemoglobin Adduct Levels in a Japanese Population and Comparison with Acrylamide Exposure Assessed by the Duplicated Method or a Food Frequency Questionnaire

The levels of hemoglobin adducts of acrylamide (AA-Hb), a biomarker of acrylamide exposure, have not been reported for Japanese subjects. Herein, we determined the AA-Hb levels in a Japanese population and compared them with the estimated dietary intake from the duplicate diet method (DM) and a food frequency questionnaire (FFQ). One-day DM samples, FFQ, and blood samples were collected from 89 participants and analyzed for acrylamide. AA-Hb was analyzed using liquid chromatography tandem mass spectrometry and the N-alkyl Edman method. Participants were divided into tertiles of estimated acrylamide intake and geometric means (GMs) of AA-Hb adjusted for sex and smoking status. A stratified analysis according to smoking status was also performed. The average AA-Hb levels for all participants, never, past, and current smokers were 46, 38, 65, and 86 pmol/g Hb, respectively. GMs of AA-Hb levels in all participants were significantly associated with tertiles of estimated acrylamide intake from DM (p for trend = 0.02) and FFQ (p for trend = 0.04), although no association with smokers was observed. AA-Hb levels reflected smoking status, which were similar to values reported in Western populations, and they were associated with estimated dietary intake of acrylamide when adjusted for sex and smoking status.

Estimating the acrylamide exposure of adult individuals from coffee: Turkey

Many researchers have pointed out that coffee contributes significantly to the dietary exposure among the many foods that contain acrylamide. Within the context of this study, the 24 h dietary recall method was employed to obtain the coffee consumption information of 263 individuals with different socio-demographic characteristics, followed by an estimation based on the deterministic model and an analysis of statistical data, in an attempt to estimate acrylamide exposure from coffee. The acrylamide intake of individuals who consume coffee was estimated to be 0.11 ± 0.084 µg/kg bw per day (95th percentile, 0.27 µg/kg bw per day); the exposure of women was estimated to range on an average between 0.12 ± 0.097 µg/kg bw per day while the exposure of men was estimated to range between 0.10 ± 0.065 µg/kg bw per day. A statistically significant difference (p < .05) was detected in the estimated average values between the parameters of age group, education level and coffee types consumed. Dietary acrylamide exposure was not of concern with respect to neurotoxicity and carcinogenicity. This is the first study carried out to estimate acrylamide exposure of individuals in Turkey from coffee.

Acrylamide-Induced Prenatal Programming of Bone Structure in Mammal Model

Acrylamide (AA) is a chemical substance with a potentially carcinogenic effect. Its presence in food or animal food arises from its thermal processing. The experiment was conducted to evaluate the effect of AA exposure (3.0 mg/kg. b.w./day) of pregnant dams during the second half of the pregnancy on bone development in offspring. As an model animal, guinea pig was used. While term body weight of newborns was not influenced by maternal AA treatment, shorter bones with reduced bone diaphysis cross-sectional area were observed in experimental group. Numerous negative, offspring sex-dependent effects of maternal AA exposure were observed in femoral epiphysis and metaphysis as well as the articular and growth plate cartilages. These effects resulted from the AA-induced alterations in bone metabolism, as indicated by the changes in the expression of numerous proteins involved in bone development: receptor activator of nuclear factor kappa-Β ligand (RANKL), tissue inhibitor of metalloproteinases 2 (TIMP-2), bone morphogenetic protein 2 (BMP-2), vascular endothelial growth factor (VEGF), and cartilage oligomeric matrix protein (COMP), all of whose expression was measured as well as distribution of immature collagen fibres was determined. Based on the results, it can be concluded that the exposure of pregnant dams to AA negatively affected the structure of compact bone in bone diaphysis, microarchitecture of trabecular bone in metaphysis and epiphysis as well as the structure of the articular and growth plate cartilages in their offspring. The AA-induced bone impairment increased osteoclast differentiation, as observed through the change in the RANKL/OPG ratio, which in turn inhibited osteoblast function by decreasing the expression of other proteins. The data of the present study suggests that maternal AA exposure can result in insufficient bone gain and even bone loss after the birth.

Are AAMA and GAMA Levels in Urine after Childbirth a Suitable Marker to Assess Exposure to Acrylamide from Passive Smoking during Pregnancy?-A Pilot Study

Introduction: Acrylamide (AA) is a “probably carcinogenic to humans” monomer that can form in heated starchy food and in tobacco smoke. N-Acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA), acrylamide metabolites in urine, are recognized as good markers of exposure to acrylamide. Aim: The aim of the study is a preliminary assessment whether the levels of AAMA and GAMA in urine after childbirth are good markers of acrylamide exposure due to passive smoking during pregnancy. Material and method: The study group consisted 67 non-smokers and 10 passive-smoker women during pregnancy. AAMA and GAMA levels in urine samples were determined using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Results: The median AAMA levels in urine of non-smoking and passively smoking women were 30.7 μg/g creatinine and 25.2 μg/g creatinine, respectively. Much lower values were determined for GAMA: 11.4 μg/g creatinine and 10.3 μg/g creatinine, respectively. There is no significant difference between AAMA and GAMA content in urine samples between both groups of women as well as in the anthropometric parameters of newborns between those two groups of mothers. Conclusion: Our pilot study did not confirm that postpartum AAMA and GAMA concentrations in urine are good markers of exposure to acrylamide from passive smoking during pregnancy. It is probably due to the different ways of acrylamide absorption from tobacco smoke by active and passive smokers. Exposure of pregnant women to acrylamide from passive smoking requires further research.

Acrylamide exposure represses neuronal differentiation, induces cell apoptosis and promotes tau hyperphosphorylation in hESC-derived 3D cerebral organoids

Acrylamide (ACR) is a common food contaminant with neurotoxic effects that are formed in the Maillard browning reaction during the heat processing of food. Importantly, pregnant women are also exposed to ACR in food during pregnancy and thus, the fetus is likely affected. However, the mechanisms of ACR-caused neurotoxicity on human brain development are still unclear. Many recent studies employed cerebral organoids based on human embryonic stem cells (hESC) for investigating human neurodevelopmental disorders and toxicity. Here, we generated hESC-derived cerebral organoids to evaluate the neurodevelopmental toxicity of ACR. The results indicated that exposure to ACR significantly altered the transcriptional profile, increased nuclear factor erythroid 2-related factor 2 (NRF2)-mediated gene expression, induced cell apoptosis, repressed neuronal differentiation, and promoted tau hyperphosphorylation in cerebral organoids, which may contribute to ACR-induced neurodevelopmental toxicity. These results indicate that the risk of transplacental exposure of the fetus to ACR should be evaluated and pregnant mothers should limit their exposure to ACR.

Early exposure to food contaminants reshapes maturation of the human brain-gut-microbiota axis

Early childhood growth and development is conditioned by the consecutive events belonging to perinatal programming. This critical window of life will be very sensitive to any event altering programming of the main body functions. Programming of gut function, which is starting right after conception, relates to a very well-established series of cellular and molecular events associating all types of cells present in this organ, including neurons, endocrine and immune cells. At birth, this machinery continues to settle with the establishment of extra connection between enteric and other systemic systems and is partially under the control of gut microbiota activity, itself being under the densification and the diversification of microorganisms’ population. As thus, any environmental factor interfering on this pre-established program may have a strong incidence on body functions. For all these reasons, pregnant women, fetuses and infants will be particularly susceptible to environmental factors and especially food contaminants. In this review, we will summarize the actual understanding of the consequences of repeated low-level exposure to major food contaminants on gut homeostasis settlement and on brain/gut axis communication considering the pivotal role played by the gut microbiota during the fetal and postnatal stages and the presumed consequences of these food toxicants on the individuals especially in relation with the risks of developing later in life non-communicable chronic diseases.

Microbial-host molecular exchange and its functional consequences in early mammalian life

Molecules from symbiotic microorganisms pervasively infiltrate almost every organ system of a mammalian host, marking the initiation of microbial-host mutualism in utero, long before the newborn acquires its own microbiota. Starting from in utero development, when maternal microbial molecules can penetrate the placental barrier, we follow the different phases of adaptation through the life events of birth, lactation, and weaning, as the young mammal adapts to the microbes that colonize its body surfaces. The vulnerability of early-life mammals is mitigated by maternal detoxification and excretion mechanisms, the protective effects of maternal milk, and modulation of neonatal receptor systems. Host adaptations to microbial exposure during specific developmental windows are critical to ensure organ function for development, growth, and immunity.

Relationship between gestational acrylamide exposure and offspring's growth: a systematic review and meta-analysis of cohort studies

OBJECTIVE

To estimate the current evidence regarding the association between gestational acrylamide (AA) exposure and offspring's growth.

DESIGN

Systematic review and meta-analysis.

SETTING

A systematic literature search for relevant publications was conducted using PubMed, Medline, Embase, Web of Science databases from inception to 26 April 2019. The standardised mean difference (SMD) or OR with 95 % CI was selected as the effect sizes and was calculated using a random effects model.

RESULTS

Five cohort studies including 54 728 participants were identified. Offspring's birth weight was significantly lower in high AA exposure group than in low AA exposure group (SMD -0·05, 95 % CI -0·09, -0·02, P = 0·005). There was also an association between maternal AA exposure and small for gestational age (OR 1·14, 95 % CI 1·06, 1·23, P < 0·001). In addition, pooled ORs suggested that children had a high risk of developing overweight/obesity in the future in maternal high AA exposure group (OR 1·14, 95 % CI 1·08, 1·21, P < 0·001 at age 3; OR 1·13, 95 % CI 1·07, 1·19, P < 0·001 at age 5; OR 1·09, 95 % CI 1·02, 1·16, P = 0·020 at age 8).

CONCLUSIONS

These findings have important implications for conducting health education, providing guidance on maternal diet and developing an appropriate dietary strategy for pregnant women to reduce dietary AA exposure.

Exposure to acrylamide inhibits uterine decidualization via suppression of cyclin D3/p21 and apoptosis in mice

Acrylamide (ACR), a neurotoxicity and carcinogenic chemical, has attracted considerable attention since it is present at high concentrations in thermally cooked carbohydrate-rich foods. ACR exposure significantly increased rate of fetal resorption, and decreased fetal body weights in mice. However, no detailed information is available about the effect of ACR on uterine decidualization, which is a vital process in the establishment of successful pregnancy. Thus, our aim of this study was to explore the effect and mechanism of ACR on uterine decidualization in vivo during mice pregnancy. Mice were gavaged with 0, 10, and 50 mg ACR /kg/day from gestational days (GD) 1 until GD 8, whereas pseudopregnant mice from pseudopregnant day (PPD) 4 until PPD 8. Results indicated ACR treatment dramatically reduced numbers of implanted embryos, and decreased the weights of implantation site and oil-induced uterus. Nevertheless, no significant difference was observed in the weights of no oil-induced uterus between control and ACR-treated group. Furthermore, ACR significantly reduced numbers of polyploidy and PCNA-positive decidual cells and expression of cyclin D3 and p21 proteins, and induced apoptosis of decidua, as presented by up-regulation of Bax and cleaved-caspase-3, and decreased Bcl-2 protein during normal pregnant and pseudopregnant process. In summary, ACR exposure significantly inhibited uterine endometrial decidualization via the apoptosis and suppression of cyclin D3/p21 in mice.

Environmental contaminants and child's growth

Experimental data have suggested that some contaminants in the environment may increase the risk of obesity. Infants can be exposed to chemicals either prenatally, by trans-placental passage of chemicals, or postnatally by their own diet and by other external pathways (air inhalation, dust, hand-to-mouth exposure) after birth. To provide a review of epidemiological evidence on the association between prenatal exposure to chemicals and prenatal and postnatal growth, we present the literature from systematic review articles and international meta-analyses, when available, or recent research articles when summarizing articles were not available. The most studied contaminants in this field were persistent organic pollutants (e.g. organochlorinated pesticides, polychlorinated biphenyls), non-persistent pollutants (e.g. phthalates, bisphenol A), toxic heavy metals (i.e. cadmium, lead and mercury), arsenic, mycotoxins and acrylamide. Mounting evidence suggests that child's growth may be associated with prenatal or postnatal exposures to environmental contaminants. Improving exposure assessment and studying the contaminants as mixtures should allow to gain knowledge about the environmental determinants of growth and obesity.

Biological interactions between nanomaterials and placental development and function following oral exposure

We summarize the literature involving the deposition of nanomaterials within the placenta following oral exposure and the biological interactions between nanomaterials and placental development and function. The review focuses on the oral exposure of metal and metal oxide engineered nanomaterials (ENMs), carbon-based ENMs, and nanoplastics in animal models, with a minor discussion of intravenous injections. Although the literature suggests that the placenta is an efficient barrier in preventing nanomaterials from reaching the fetus, nanomaterials that accumulate in the placenta may interfere with its development and function. Furthermore, some studies have demonstrated a decrease in placental weight and association with adverse fetal health outcomes following oral exposure to nanomaterials. Since nanomaterials are increasingly used in food, food packaging, and have been discovered in drinking water, the risk for adverse impacts on placental development and functions, with secondary effects on embryo-fetal development, following unintentional maternal ingestion of nanomaterials requires further investigation.

French infant total diet study: Dietary exposure to heat-induced compounds (acrylamide, furan and polycyclic aromatic hydrocarbons) and associated health risks

A total diet study (TDS) was conducted between 2010 and 2016 to assess the risk associated with chemicals in food of non-breast-fed children from 1 to 36 months living in France. Food samples were collected, prepared "as consumed", and analyzed for chemicals of public health interest. Acrylamide, furan and polycyclic aromatic hydrocarbons (PAHs) were analyzed as heat-induced compounds produced mainly during thermal processing of foods. Dietary exposure was assessed for 705 representative children using food consumptions recorded through a 3-consecutive-days record. As all calculated margins of exposure (MOE) for PAHs exceeded 10 000, dietary exposure of the infant and toddler population was deemed tolerable with regard to the carcinogenic risk. Conversely, the exposure levels to acrylamide and furan were considered as of concern, requiring management measures to reduce the exposure essentially by reducing the formation of heat-induced compounds during food production or preparation processes. Efforts should mainly focus on major contributors to the exposure, i.e. sweet and savoury biscuits and bars, and potatoes and potato products for acrylamide, baby jars of vegetables, with or without meat or fish for acrylamide and furan.

Gestational exposure to acrylamide inhibits mouse placental development in vivo

Acrylamide, a carcinogen and neurotoxic substance, recently has been discovered in various heat-treated carbohydrate-rich foods. The aim of this study was to investigate the effects of acrylamide exposure on placental development. Pregnant mice received acrylamide by gavage at dosages of 0, 10, and 50 mg/kg/day from gestational days (GD) 3 until GD 8 or GD 13. The results showed that acrylamide feeding significantly decreased the numbers of viable embryos and increased the numbers of resorbed embryos on GD 13. Acrylamide exposure reduced the absolute and relative weight of placentas and embryos, and inhibited the development of ectoplacental cone (EPC) and placenta, as shown by the atrophy of EPC and reduced placental area. Acrylamide markedly reduced the numbers of labyrinth vessels. Expression levels of most placental key genes such as Esx1, Hand1, and Hand2 mRNA dramatically decreased in acrylamide-treated placentas. Furthermore, acrylamide treatment inhibited proliferation and induced apoptosis of placentas, as shown by decreased Ki67-positive cells and Bcl-2 protein, and increased the expression of Bax, cleaved-caspase-3, and cleaved-caspase-8 proteins. In conclusion, our results indicated that gestational exposure to acrylamide inhibits placental development through dysregulation of placental key gene expression and labyrinth vessels, suppression of proliferation, and apoptosis induction in mice.

Exposure to acrylamide disrupts cardiomyocyte interactions during ventricular morphogenesis in zebrafish embryos

Acrylamide (AA), a ubiquitous chemical that is present in surrounding environment and baked or fried carbohydrate-rich food, has recently been linked to cardiac developmental toxicity. However, the toxicological role of AA exposure in the cardiac development remains largely unknown. Here we showed the cardiotoxicity of AA and its role in cardiomyocyte interactions in zebrafish embryos during ventricular morphogenesis. Using the embryo model of transgenic zebrafish Tg(Tp1:d2GFP;myl7:mCherry), we found AA interfered the dynamics of Notch signaling in the endocardium during early cardiogenesis. Prolonged exposure to AA thickened the chamber wall and prevented the trabeculae from extending into the lumen of ventricular chamber. As a result, AA reduced the ventricular shortening fraction and spatial dimension via excessively activating the Notch signal in myocardium during cardiac maturation. Moreover, exposure to AA inhibited the re-distribution of N‑cadherin and failed to coordinate cardiomyocyte interactions between the myocardium layers due to the lack of delaminated cardiomyocytes. Therefore, AA-treated embryos exhibited subcellular pathological states including disarrayed myofibrils and abnormal morphology of mitochondria despite normal proliferation of cardiomyocytes. In addition, we found overexpression of some cardiac-specific transcription factors, such as hand2 and nkx2.5, in hearts of AA-treated embryos compared with those in control group. Our study provided the evidence that the period of ventricular chamber morphogenesis might be a vulnerable window in zebrafish, and revealed new insights into how AA might exert cardiac developmental toxicity.

Acrylamide Content of Experimental and Commercial Flatbreads

Acrylamide, formed in baked and fried plant-based foods, is reported to induce numerous adverse effects in cells, animals, and humans. Examples from the literature show that processed potato- and cereal-based products are two major food types that seem to contribute the highest amounts of acrylamide to the diet worldwide. To meet both the demand for gluten-free products and the interest in alternative grains, we previously developed recipes for flatbreads using a variety of different grains. In this study, we determined the acrylamide content of 15 experimental flatbreads made from a variety of flours and 21 commercial flatbreads. The application of a validated, highly sensitive HPLC/MS method revealed that flatbreads made with the following flours baked at 195.5 °C for 2 min had very low (<10 μg/kg) levels of acrylamide: brown rice, buckwheat, cornmeal, millet, oat, and quinoa. The acrylamide levels of the following flatbreads were 14 to 59 μg/kg: rye, sorghum, soy, wheat, commercial pita, pita crackers, pizza, naan, and lavash. Wheat-based matzo breads, which are rapidly baked to a crisp texture at high heat (∼400 °C), contained 101 to 504 μg/kg acrylamide. Potato-based products were some of the highest of the products tested, ranging from 153 (potato pancakes) to 2,070 (potato-containing gluten-free matzos) μg/kg acrylamide. Except for the potato-containing products, the flatbreads made in this study were lower in acrylamide content (<3 to 21.3 μg/kg) than any of the commercial products tested. Of these experimental flatbreads, wheat- and sorghum-based products were the highest. Flatbreads from alternative grains can result in gluten-free products with high nutritional value and less acrylamide. PRACTICAL APPLICATION: Acrylamide formation is dependent on both the composition of the food product and the method of cooking. Flatbreads have the potential to be high in acrylamide due to cooking methods which lead to the development of desirable browning products. Flatbreads developed in this study using alternative and ancient grains were mostly lower in acrylamide content than their wheat counterpart, suggesting that they can serve as a low-acrylamide, gluten-free functional food.

Maternal Acrylamide Intake during Pregnancy and Sex Hormone Levels in Maternal and Umbilical Cord Blood and Birth Size of Offspring

Exposure to acrylamide during pregnancy may disturb pregnancy hormones and the growth of the fetus. The present study aimed to examine the association of maternal acrylamide intake with maternal and cord sex hormone levels during pregnancy and at birth and birth size of offspring. The study subjects were 204 pregnant Japanese women and their newborn girls. Intake of acrylamide was assessed based on 5-day diet records at approximately the 29th week of pregnancy. The concentrations of estradiol, estriol, and testosterone were measured in maternal serum at the 29th weeks of pregnancy and at delivery and umbilical cord blood at delivery. Birth weight, length, and head circumference were measured at the delivery. After controlling for covariates, higher intake of acrylamide was significantly positively associated with higher level of umbilical cord estradiol at the delivery (p for trend = .01), but not with any hormone levels measured in maternal blood. A positive association between acrylamide intake and head circumference was of borderline significance (p for trend = .06). Overall, there were no consistent associations between maternal acrylamide intake and sex hormone levels during pregnancy. However, as this is the first study to examine these associations, additional studies are needed.

Association of acrylamide hemoglobin biomarkers with obesity, abdominal obesity and overweight in general US population: NHANES 2003-2006

Exposure to chemical contaminants is considered as one of risk factors to the current epidemic of obesity. Acrylamide (AA) is a ubiquitous chemical contaminant in environmental waste, mainstream cigarette smoke and carbohydrate-rich foods, and widely used in industrial manufacturers and cosmetics. Few studies have highlighted the association of daily exposure to AA with obesity-related outcomes. We analyzed data from 8364 participants who aged 20-85years and were recruited in National Health and Nutrition Examination Surveys (NHANES) 2003-2006. We established the model of PROC Survey Logistic regressions via using AA biomarkers in blood, hemoglobin adducts of acrylamide and glycidamide (HbAA and HbGA), as the measure of internal exposure to AA, and assessing obesity, abdominal obesity and overweight with body mass index (BMI) or waist circumference (WC). After the adjustment of sociodemographic variables, lifestyle behaviors, and health-related factors, the ratio of HbGA to HbAA (HbGA/HbAA) was significantly associated with obesity (p for trend<0.0001). The odd ratios (ORs) with 95% confidence intervals (CIs) of HbGA/HbAA across increasing quartiles were 1.740 (1.413-2.144), 2.604 (2.157-3.144), and 2.863 (2.425-3.380) compared with the lowest quartile. HbGA was positively associated with obesity [OR (95% CI): 1.226 (1.041-1.443), 1.283 (1.121-1.468), and 1.398 (1.165-1.679); p for trend=0.0004], while HbAA was inversely associated with obesity [OR (95% CI): 0.839 (0.718-0.980), 0.713 (0.600-0.848), and 0.671 (0.554-0.811); p for trend<0.0001]. Negative associations were found between the sum of HbAA and HbGA (HbAA+HbGA) and the body weight outcomes. Similar associations were also observed between the hemoglobin biomarkers of AA and abdominal obesity as well as overweight. Thus, the hemoglobin adducts of AA as long-term internal exposure biomarkers are strongly associated with obesity-related outcomes in a population of US adults.

Associations of hemoglobin biomarker levels of acrylamide and all-cause and cardiovascular disease mortality among U.S. adults: National Health and Nutrition Examination Survey 2003-2006

BACKGROUND

The potential hazards of acrylamide (AA) have been proposed due to its lifelong exposure. However, the association between AA exposure and mortality remains unclear.

OBJECTIVES

We evaluated the prospective association of AA hemoglobin adducts (HbAA and HbGA) with all-cause and cardiovascular disease (CVD) mortality in U.S. population from National Health and Nutrition Examination Survey (NHANES) 2003-2006.

METHODS

We followed 5504 participants who were ≥25 years of age for an average of 6.7 years at the baseline examination with annual linkage to the NHANES statistics database. Using AA hemoglobin biomarkers [HbAA, HbGA, sum of HbAA and HbGA (HbAA + HbGA), and ratio of HbGA to HbAA (HbGA/HbAA)], we determined mortality from all-causes and CVD through Cox proportional hazard regression analysis with multivariable adjustments both in non-smoker group and smoker group. In addition, subgroup analyses and sensitivity analyses were further conducted.

RESULTS

After adjusting for sociodemographic, life behavioral and cardiovascular risk factors in non-smoker group, HbAA was positively associated with all-cause mortality (p for trend = 0.0197) and non-CVD mortality (p for trend = 0.0124). HbGA and HbGA/HbAA were inversely associated with all-cause mortality (p for trend = 0.0117 and 0.0098, respectively) and CVD mortality (p for trend=0.0009 and 0.0036, respectively). The multivariable adjusted hazard ratios (HRs) [95% confidence intervals (CIs)] of the upper three quartiles were 0.472 (95% CI: 0.283-0.786), 0.517 (95% CI: 0.299-0.894) and 0.470 (95% CI: 0.288-0.766) between HbGA/HbAA and all-cause mortality comparing with the lowest quartile, respectively. No significant associations were found between HbAA + HbGA and mortality in non-smoker group, and between all AA hemoglobin biomarkers and mortality in smoker group.

CONCLUSIONS

Hemoglobin biomarker levels of AA were strongly associated with mortality in general U.S. non-smoker adults. These findings proposed a continuous public health concern in relation to environmental and dietary exposure to AA.

Characterization of acrylamide-induced oxidative stress and cardiovascular toxicity in zebrafish embryos

Acrylamide (AA) is a high production volume chemical in industrial applications and widely found in baked or fried carbohydrate-rich foods. In this study, we unravelled that AA induced developmental toxicity associated with oxidative stress status and disordered lipid distribution in heart region of developing zebrafish. Treatment with AA caused a deficient cardiovascular system with significant heart malformation and dysfunction. We also found that AA could reduce the number of cardiomyocytes through the reduced capacity of cardiomyocyte proliferation rather than cell apoptosis. The cardiac looping and ballooning appeared abnormal though cardiac chamber-specific identity in the differentiated myocardium was maintained well after AA treatment through MF20/S46 immunofluorescence assay. Furthermore, treatment with AA disturbed the differentiation of atrioventricular canal, which was demonstrated by the disordered expressions of the atrioventricular boundary markers bmp4, tbx2b and notch1b and further confirmed by the ectopic expressions of the cardiac valve precursor markers has2, klf2a and nfatc1 through whole-mount in situ hybridization. Thus, our studies provide the evidence of cardiac developmental toxicity of AA in the cardiovascular system, and also raised health concern about the harm of trans-placental exposure to high level of AA for foetuses and the risk of high exposure to AA for the pregnant women.

Dietary acrylamide intake during pregnancy and postnatal growth and obesity: Results from the Norwegian Mother and Child Cohort Study (MoBa)

BACKGROUND

Prenatal acrylamide exposure has been negatively associated with fetal growth but the association with child growth is unknown.

OBJECTIVES

We studied the association between prenatal acrylamide exposure and child postnatal growth up to 8 years in the Norwegian Mother and Child Cohort Study (MoBa).

METHODS

In 51,952 mother-child pairs from MoBa, acrylamide intake during pregnancy was estimated by combining maternal food intake with food concentrations of acrylamide. Mothers reported their child's weight and length/height up to 11 times between 6 weeks and 8 years. Weight and height growth trajectories were modelled using Jenss-Bayley's growth model. Logistic regression models were used to study the association with overweight/obese status at 3, 5 and 8 years, as identified using the International Obesity Task Force cut-offs. Linear mixed-effect models were used to explore associations with overall growth.

RESULTS

At 3 years, the adjusted odds ratios (95% Confidence Intervals (CI)) of being overweight/obese were 1.10 (1.02, 1.20), 1.12 (1.04, 1.22) and 1.21 (1.11, 1.31) by increasing prenatal acrylamide exposure quartile. Similar dose-response associations were found at 5 and 8 years. Acrylamide intake during pregnancy was associated with higher weight growth velocity in childhood. Children exposed at the highest level had 22 g (95% CI: 8, 37), 57 g (95% CI: 32, 81), and 194 g (95% CI: 110, 278) higher weight at 0.5, 2, and 8 years, respectively, compared to their low exposed peers.

CONCLUSIONS

Children prenatally exposed to acrylamide in the highest quartile experienced a moderate increase in weight growth velocity during early childhood that resulted in a moderately increased prevalence of overweight/obesity compared to peers in the lowest quartile. Our study is the first to link prenatal acrylamide exposure and postnatal growth.

Exposure to acrylamide induces cardiac developmental toxicity in zebrafish during cardiogenesis

Acrylamide (AA), an environmental pollutant, has been linked to neurotoxicity, genotoxicity and carcinogenicity. AA is widely used to synthesize polymers for industrial applications, is widely found in Western-style carbohydrate-rich foods and cigarette smoke, and can also be detected in human umbilical cord blood and breast milk. This is the first study that demonstrated the cardiac developmental toxicity of AA in zebrafish embryos. Post-fertilization exposure to AA caused a clearly deficient cardiovascular system with a shrunken heart and abortive morphogenesis and function. Disordered expression of the cardiac genes, myl7, vmhc, myh6, bmp4, tbx2b and notch1b, as well as reduced number of myocardial cells and endocardial cells, indicated the collapsed development of ventricle and atrium and failed differentiation of atrioventricular canal (AVC). Although cell apoptosis was not affected, the capacity of cardiomyocyte proliferation was significantly reduced by AA exposure after fertilization. Further investigation showed that treatment with AA specifically reduced the expressions of nkx2.5, myl7 and vmhc in the anterior lateral plate mesoderm (ALPM) during the early cardiogenesis. In addition, AA exposure disturbed the restricted expressions of bmp4, tbx2b and notch1b during atrioventricular (AV) valve development and cardiac chambers maturation. Our results showed that AA-induced cardiotoxicity was related to decreased cardiac progenitor genes expression, reduced myocardium growth, abnormal cardiac chambers morphogenesis and disordered AVC differentiation. Our study demonstrates that AA exposure during a time point analogous to the first trimester in humans has a detrimental effect on early heart development in zebrafish. A high ingestion rate of AA-containing products may be an underlying risk factor for cardiogenesis in fetuses.