Development of a physiologically-based toxicokinetic model of acrylamide and glycidamide in rats and humans

The Application of a Physiologically Based Toxicokinetic Model in Health Risk Assessment

Toxicokinetics plays a crucial role in the health risk assessments of xenobiotics. Classical compartmental models are limited in their ability to determine chemical concentrations in specific organs or tissues, particularly target organs or tissues, and their limited interspecific and exposure route extrapolation hinders satisfactory health risk assessment. In contrast, physiologically based toxicokinetic (PBTK) models quantitatively describe the absorption, distribution, metabolism, and excretion of chemicals across various exposure routes and doses in organisms, establishing correlations with toxic effects. Consequently, PBTK models serve as potent tools for extrapolation and provide a theoretical foundation for health risk assessment and management. This review outlines the construction and application of PBTK models in health risk assessment while analyzing their limitations and future perspectives.

Evaluation of the genotoxic potential of acrylamide: Arguments for the derivation of a tolerable daily intake (TDI value)

This opinion of the Senate Commission on Food Safety (SKLM) of the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) presents arguments for an updated risk assessment of diet-related exposure to acrylamide (AA), based on a critical review of scientific evidence relevant to low dose exposure. The SKLM arrives at the conclusion that as long as an appropriate exposure limit for AA is not exceeded, genotoxic effects resulting in carcinogenicity are unlikely to occur. Based on the totality of the evidence, the SKLM considers it scientifically justified to derive a tolerable daily intake (TDI) as a health-based guidance value.

Development of physiologically based toxicokinetic models for 3-monochloropropane-1,2-diol and glycidol

3-Monochloropropane-1,2-diol (3-MCPD), glycidol, together with their fatty acid esters are commonly presented in various food and have shown carcinogenicity in various laboratory animals. Public health risk assessment of 3-MPCD and glycidol exposure relies on quantitative tools that represent their in vivo toxicokinetics. In order to better understand the absorption, distribution, metabolism, and excretion profiles of 3-MCPD and glycidol in male rats, a physiologically based pharmacokinetic (PBTK) model was developed. The model's predictive power was evaluated by comparing in silico simulations to in vivo time course data obtained from experimental studies. Results indicate that our PBTK model successfully captured the toxicokinetics of both free chemicals in key organs, and their metabolites in accessible biological fluids. With the validated PBTK model, we then gave an animal-free example on how to extrapolate the toxicological knowledge acquired from a single gavage to a realistic dietary intake scenario. Three biomarkers, free compound in serum, urinary metabolite DHPMA, and glycidol-hemoglobin adduct (diHOPrVal) were selected for in silico simulation following constant dietary intakes, and their internal levels were correlated with proposed external daily exposure via reverse dosimetry approaches. Taken together, our model provides a computational approach for extrapolating animal toxicokinetic experiments to biomonitoring measurement and risk assessment.

Literature review and evaluation of biomarkers, matrices and analytical methods for chemicals selected in the research program Human Biomonitoring for the European Union (HBM4EU)

Humans are potentially exposed to a large amount of chemicals present in the environment and in the workplace. In the European Human Biomonitoring initiative (Human Biomonitoring for the European Union = HBM4EU), acrylamide, mycotoxins (aflatoxin B1, deoxynivalenol, fumonisin B1), diisocyanates (4,4'-methylenediphenyl diisocyanate, 2,4- and 2,6-toluene diisocyanate), and pyrethroids were included among the prioritized chemicals of concern for human health. For the present literature review, the analytical methods used in worldwide biomonitoring studies for these compounds were collected and presented in comprehensive tables, including the following parameter: determined biomarker, matrix, sample amount, work-up procedure, available laboratory quality assurance and quality assessment information, analytical techniques, and limit of detection. Based on the data presented in these tables, the most suitable methods were recommended. According to the paradigm of biomonitoring, the information about two different biomarkers of exposure was evaluated: a) internal dose = parent compounds and metabolites in urine and blood; and b) the biologically effective = dose measured as blood protein adducts. Urine was the preferred matrix used for deoxynivalenol, fumonisin B1, and pyrethroids (biomarkers of internal dose). Markers of the biological effective dose were determined as hemoglobin adducts for diisocyanates and acrylamide, and as serum-albumin-adducts of aflatoxin B1 and diisocyanates. The analyses and quantitation of the protein adducts in blood or the metabolites in urine were mostly performed with LC-MS/MS or GC-MS in the presence of isotope-labeled internal standards. This review also addresses the critical aspects of the application, use and selection of biomarkers. For future biomonitoring studies, a more comprehensive approach is discussed to broaden the selection of compounds.

The construction and application of physiologically based toxicokinetic models for acrylamide, glycidamide and their biomarkers in rats and humans

Acrylamide (AA), a class 2A probable carcinogen to humans classified by the International Agency for Research on Cancer, has attracted extensive attention worldwide since it was widely used in industrial and domestic water treatment and detected in thermal processing foods. The metabolic adducts of AA and its primary metabolite glycidamide (GA) have been served as biomonitoring markers of AA intake, but the physiologically based toxicokinetics (PBTK) models to estimate internal dosimetry still remain unclear. An updated PBTK model for AA, GA and their metabolic biomarkers in rats and humans was developed and extended with time-course datasets from both literatures and our experiments. With adjustments to the model parameters, linear regression correlation coefficient (R²) between the fitting values and the validation datasets of rats and humans was greater than 0.76. The current model fits well with the experimental datasets of urinary N-acetyl-S-(2-carbamoylethyl)-l-cysteine (AAMA) and (N-(R,S)-acetyl-S-(carbamoyl-2-hydroxyethyl)-l-cysteine) (GAMA) of rats exposed to AA from 0.1 to 50 mg/kg b.w. and humans exposed to AA from 0.0005 to 0.020 mg/kg b.w., indicating the robustness of the current models. Parameters for adduct of AA with N-terminal valine of hemoglobin (AAVal) were extended to humans and validated. Kinetic parameters for rats were assessed and validated based upon fit to the experimental datasets for liver N3-(2-carbamoyl-2-hydroxyethyl)-adenine (N3-GA-Ade) and N7-(2-carbamoyl-2-hydroxyethyl)-guanine (N7-GA-Gua) adducts. Compared with the previous model, the developed model included the correlation between AA intake and its mercapturic acid adducts, AAMA and GAMA, in a larger dose range with new experimental data, and parameters for AAVal, N3-GA-Ade and N7-GA-Gua were improved and verified. The current multi-component PBTK models provide a superior foundation for the estimation of short-term to medium and long-term intake levels of human exposure to AA.

Simultaneous toxicokinetics characterization of acrylamide and its primary metabolites using a novel microdialysis isotope-dilution liquid chromatography mass spectrometry method

Acrylamide (AA) is a toxicant in high-temperature processed foods and an animal carcinogen. Upon absorption, AA is metabolized to glycidamide (GA) or conjugates with glutathione (AA-GSH). Important advantages of microdialysis coupled with liquid chromatography-tandem mass spectrometry (MD-LC-MS/MS) include its minimization of potential losses during sample collection, storage and preparation, as well as an improvement in temporal resolution for toxicokinetics (TKs). We aimed to simultaneously study the TKs of AA and products of its primary metabolism using an isotope-dilution (ID) MD-LC-MS/MS method. MD probes implanted into the jugular vein/right atrium of anesthetized Sprague Dawley rats were connected to the ID-LC-MS/MS for continuous monitoring of AA, GA and AA-GSH in the blood every 15 min over 8 h following intraperitoneal AA administration (0.1 mg/kg or 5 mg/kg). AA, GA, and AA-GSH TKs followed linear kinetics: GA AUC/AA AUC = 0.11 and AA-GSH AUC/AA AUC = 0.011 at 5 mg/kg. Elimination half-life (T_e1/2) values were 2.44 ± 0.70, 4.93 ± 2.37 and 3.47 ± 1.47 h for AA, GA and AA-GSH, respectively. GA TKs reached a plateau at 3-6 h, suggesting that metabolic saturation of AA and T_e1/2 values of the analytes were prolonged with AA at 5 mg/kg. Our results demonstrate that oxidation of AA to GA overwhelmed the conjugation of AA with GSH. Our innovative MD-ID-LC-MS/MS method facilitates the simultaneous characterization of multiple TKs associated with toxicants and their active metabolites with excellent temporal resolution to capture metabolic saturation of AA to GA.

Characterization of primary glutathione conjugates with acrylamide and glycidamide: Toxicokinetic studies in Sprague Dawley rats treated with acrylamide

Acrylamide (AA) is classified as a probable human carcinogen and is ubiquitous in foods processed at high temperatures. The carcinogenicity of AA has been attributed to its active metabolite, glycidamide (GA). Both AA and GA can spontaneously or enzymatically conjugate with glutathione (GSH) to form their corresponding GSH conjugates. Profiling AA-glutathione conjugate (AA-GSH) and GA-glutathione conjugates (2 isomers: GA2-GSH and GA3-GSH) in serum would better illustrate AA detoxification compared with urinary metabolite analysis. However, the lack of AA-, GA2, and GA3-GSH study remains a critical data gap. Our study aimed to investigate the toxicokinetics of AA-, GA2-and GA3-GSH in Sprague Dawley rats treated with 0.1 mg/kg, 1.0 mg/kg, or 5.0 mg/kg AA. Blood samples were collected for LC-MS/MS analysis of the GSH conjugate products. Within 24 h of treatment, we observed rapid formation, elimination, and linear kinetics of AA-, GA2-and GA3-GSH. The ∑GA-GSH AUC/AA-GSH AUC ratios were 0.14-0.29, similar to ∑GA/AA AUC in serum but different from ∑GA/AA-derived urinary mercapturic acids in rodents. Our analysis of AA- and GA-GSHs values represents direct detoxification of AA and GA in vivo. This study advances our understanding of sex and inter-species differences in AA detoxification and may refine the existing kinetic models for a more relevant risk extrapolation.

Metabolic profiles for the pyrrolizidine alkaloid neopetasitenine and its metabolite petasitenine in humans extrapolated from rat in vivo and in vitro data sets using a simplified physiologically based pharmacokinetic model

Naturally occurring food substances may constitute safety hazards. The risks associated with plant-derived pyrrolizidine alkaloids have been extensively evaluated. Petasites japonicus (common Japanese name, fuki) is a widely consumed water-soluble pyrrolizidine alkaloid-producing plant. In this study, neopetasitenine (acetylfukinotoxin) was selected as a model food substrate (for which human pharmacokinetics were estimated) because of its high concentration in fuki, along with petasitenine (fukinotoxin), its carcinogenic deacetylated metabolite. Although neopetasitenine was rapidly absorbed and converted to petasitenine after oral administration of 1.0 mg/kg in rats, petasitenine was slowly cleared from plasma. Forward dosimetry was conducted using in silico simplified physiologically based pharmacokinetic (PBPK) modeling formulated on experimental pharmacokinetic rat data. From ~2 hr after the oral administration of neopetasitenine in rats, the plasma concentrations of petasitenine were higher than those of neopetasitenine under the present conditions. A human PBPK model was established following an allometric scaling approach applied to rat parameters (without considering interspecies factors) to estimate human intrinsic hepatic clearances from empirical rat values. Human in silico neopetasitenine and petasitenine plasma concentration curves were simulated after daily oral administrations of 3.0 and 1.3 mg/kg neopetasitenine. These doses were taken from reported acute/short-term cases of pyrrolizidine alkaloid toxicity. In vitro hepatotoxicity of neopetasitenine and petasitenine was caused by their high concentrations in the medium for human hepatocyte-like cell line HepaRG cells as an index of lactate dehydrogenase leakage. Neopetasitenine was estimated to be rapidly absorbed and converted to deacetylated carcinogenic petasitenine, even after hepatotoxic doses of 1.0 mg/kg in humans. If the water-soluble pyrrolizidine alkaloid-producing plant P. japonicus were daily consumed as food, current simulation results suggest that dangerous amounts of deacetylated petasitenine could be continuously present in human plasma.

Accelerated Repurposing and Drug Development of Pulmonary Hypertension Therapies for COVID-19 Treatment Using an AI-Integrated Biosimulation Platform

The COVID-19 pandemic has reached over 100 million worldwide. Due to the multi-targeted nature of the virus, it is clear that drugs providing anti-COVID-19 effects need to be developed at an accelerated rate, and a combinatorial approach may stand to be more successful than a single drug therapy. Among several targets and pathways that are under investigation, the renin-angiotensin system (RAS) and specifically angiotensin-converting enzyme (ACE), and Ca²⁺-mediated SARS-CoV-2 cellular entry and replication are noteworthy. A combination of ACE inhibitors and calcium channel blockers (CCBs), a critical line of therapy for pulmonary hypertension, has shown therapeutic relevance in COVID-19 when investigated independently. To that end, we conducted in silico modeling using BIOiSIM, an AI-integrated mechanistic modeling platform by utilizing known preclinical in vitro and in vivo datasets to accurately simulate systemic therapy disposition and site-of-action penetration of the CCBs and ACEi compounds to tissues implicated in COVID-19 pathogenesis.

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.

Metabolic profiles of coumarin in human plasma extrapolated from a rat data set with a simplified physiologically based pharmacokinetic model

Coumarin is a dietary-derived substance that is extensively metabolized by human liver to excretable 7-hydroxycoumarin. Although coumarin under daily dietary consumption is generally regarded as nontoxic, the substance is of toxicological and clinical interest because of its potential association with hepatotoxicity, which is especially evident in rats. In this study, the pharmacokinetics of coumarin were modeled after virtual oral administration in humans. The adjusted monitoring equivalents of coumarin, along with the biotransformation of coumarin to o-hydroxyphenylacetic acid (via 3,4-epoxidation) based on reported plasma concentrations from rat studies, were scaled to human coumarin equivalents using known species allometric scaling factors. Using rat and human liver preparations, data on the rapid in vitro metabolic clearance for humans (~50-fold faster than in rats) were obtained for in vitro-in vivo extrapolation. For human physiologically based pharmacokinetic (PBPK) modeling, the metabolic ratios to o-hydroxyphenylacetic acid and 7-hydroxycoumarin were set at minor (0.1) and major (0.9) levels for the total disappearance of coumarin. The resulting modeled plasma concentration curves in humans generated by simple PBPK models were consistent with reported simulated coumarin maximum concentrations. These results provide basic information to simulate plasma levels of coumarin and its primary metabolite 7-hydroxycoumarin or its secondary activated metabolite o-hydroxyphenylacetic acid (via 3,4-epoxidation) resulting from dietary foodstuff consumption. Under the current assumptions, little toxicological impact of coumarin was evident in humans, thereby indicating the usefulness of forward dosimetry using PBPK modeling for human risk assessment.

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.

Derivation of a No significant risk level (NSRL) for acrylamide

Acrylamide is included on the State of California's Proposition 65 list as a carcinogen. Acrylamide is found in cigarette smoke and in many types of foods, including breads, cereals, coffee, cookies, French fries, and potato chips. In 1990, California's Office of Environmental Health Hazard Assessment (OEHHA) established a no significant risk level (NSRL) of 0.2 μg/day for acrylamide. Since then, multiple cancer studies have been published. In this report, we developed an updated NSRL for acrylamide. Using benchmark dose modeling and a weight-of-evidence, non-threshold approach to identify the most sensitive species, cancer slope factors (CSFs) were derived based on combined incidences of statistically significant neoplastic lesions in the Harderian gland, lung, and stomach in male mice. We then used a toxicokinetic (TK)-based scaling approach to convert the animal CSF to a human equivalent CSF, which served as the basis for the NSRL of 1.1 μg/day at the cancer risk level of 1 in 100,000. This NSRL can be used in quantitative exposure assessments to assess compliance with Proposition 65 to ascertain either the need for or exemption from the Proposition 65 labeling requirement and drinking water discharge prohibition.

Association of urinary acrylamide concentration with lifestyle and demographic factors in a population of South Korean children and adolescents

Acrylamide (AA) has been identified as probably carcinogenic to humans and thus represents a potential public health threat. This study aimed to determine the urinary concentrations of AA and N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) in a nationally representative sample (n = 1025) of children and adolescents (age range 3-18 years) in South Korea. The AA and AAMA detection rates and geometric mean concentrations were 97%, 19.1 ng/mL, and 98.7%, 26.4 ng/mL, respectively. Although urinary AA levels did not vary widely by age (17.2 ng/mL at 3-6 years, 19.9 ng/mL at 7-18 years), the urinary concentration of AAMA increased with age (18.3 ng/mL at 3-6 years, 30.4 ng/mL at 7-18 years). A multiple linear regression analysis revealed that the urinary levels of AA and AAMA varied significantly by sex, with the adjusted proportional changes indicating rates of 1.47- to 1.48-fold higher at 3-6 years and 1.36- to 1.68-fold higher at 7-18 years among males relative to females. Furthermore, the urinary levels of AA and AAMA correlated with the consumption of certain foods (doughnuts, hotdogs, popcorn, and nachos) among male subjects aged 7-18 years. The urinary concentrations of AA and AAMA increased significantly with the smoking status and passive smoking exposure, with adjusted proportional changes of 1.51 to 1.71-fold higher among smokers relative to non-smokers in the age range of 7-18 years. Exposure to smoking for > 30 min led to adjusted proportional increases in AA and AAMA of 1.51 and 1.77 times in the non-smoking group aged 3-6 years and a 1.52-fold increase in AAMA in the non-smoking group aged 7-18 years. In conclusion, the urinary levels of AA and AAMA were found to associate with age, sex, smoking, and food consumption in a population of Korean children and adolescents.

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.

Parallelogram based approach for in vivo dose estimation of genotoxic metabolites in humans with relevance to reduction of animal experiments

When employing metabolism studies of genotoxic compounds/metabolites and cancer tests for risk estimation, low exposure doses in humans are roughly extrapolated from high exposure doses in animals. An improvement is to measure the in vivo dose, i.e. area under concentration-time curve (AUC), of the causative genotoxic agent. In the present work, we propose and evaluate a parallelogram based approach for estimation of the AUC of genotoxic metabolites that incorporates in vitro metabolic data and existing knowledge from published in vivo data on hemoglobin (Hb) adduct levels, using glycidamide (GA) as a case study compound that is the genotoxic metabolite of acrylamide (AA). The estimated value of AUC of GA per AUC of AA from the parallelogram approach vs. that from Hb adduct levels measured in vivo were in good agreement; 0.087 vs. 0.23 in human and 1.4 vs. 0.53 in rat, respectively. The described parallelogram approach is simple, and can be useful to provide an approximate estimation of the AUC of metabolites in humans at low exposure levels for which sensitive methods for analyzing the metabolites are not available, as well as aid in reduction of animal experiments for metabolism studies that are to be used for cancer risk assessment.

Dose-dependent DNA adduct formation by cinnamaldehyde and other food-borne α,β-unsaturated aldehydes predicted by physiologically based in silico modelling

Genotoxicity of α,β-unsaturated aldehydes shown in vitro raises a concern for the use of the aldehydes as food flavourings, while at low dose exposures the formation of DNA adducts may be prevented by detoxification. Unlike many α,β-unsaturated aldehydes for which in vivo data are absent, cinnamaldehyde was shown to be not genotoxic or carcinogenic in vivo. The present study aimed at comparing dose-dependent DNA adduct formation by cinnamaldehyde and 18 acyclic food-borne α,β-unsaturated aldehydes using physiologically based kinetic/dynamic (PBK/D) modelling. In rats, cinnamaldehyde was predicted to induce higher DNA adducts levels than 6 out of the 18 α,β-unsaturated aldehydes, indicating that these 6 aldehydes may also test negative in vivo. At the highest cinnamaldehyde dose that tested negative in vivo, cinnamaldehyde was predicted to form at least three orders of magnitude higher levels of DNA adducts than the 18 aldehydes at their respective estimated daily intake. These results suggest that for all the 18 α,β-unsaturated aldehydes DNA adduct formation at doses relevant for human dietary exposure may not raise a concern. The present study illustrates a possible use of physiologically based in silico modelling to facilitate a science-based comparison and read-across on the possible risks posed by DNA reactive agents.

Acrylamide in foods: a review of the science and future considerations

Acrylamide occurs in foods commonly consumed in diets worldwide. It is formed from the reaction of reducing sugars (e.g., glucose or fructose) with the amino acid asparagine via the Maillard reaction, which occurs during heat processing of foods, primarily those derived from plant origin, such as potato and cereal products, above 120°C (248°F). The majority of epidemiological studies concerning potential relationships between acrylamide consumption and different types of cancer have indicated no increased risk, except with a few types that warrant further study. Efforts to reduce the formation of acrylamide in food products have resulted in some successes, but there is no common approach that works for all foods. Reduction in some foods is probably not possible. The results from a major toxicological study (aqueous intake of acrylamide by rats and mice) are in the process of being released. The status of current knowledge in these areas is reviewed.