The influence of single nucleotide polymorphisms on the association between dietary acrylamide intake and endometrial cancer risk

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 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.

Dietary acrylamide intake and risk of women's cancers: a systematic review and meta-analysis of prospective cohort studies

This systematic review and meta-analysis was done to review earlier publications on the association between dietary acrylamide intake and risk of breast, endometrial and ovarian cancers. We performed a systematic search in the online databases of PubMed, ISI Web of Science and Scopus for relevant publications up to August 2020. Prospective cohort studies that considered dietary acrylamide as the exposure variable and breast, endometrial or ovarian cancer as the main outcome variable or as one of the outcome variables were included in this systematic review and meta-analysis. A total of fourteen cohort studies were included in the meta-analysis. We found no significant association between dietary acrylamide intake and the risk of breast (relative risk (RR) 0·95; 95 % CI 0·90, 1·01), endometrial (RR 1·03; 95 % CI 0·89, 1·19) and ovarian cancers (RR 1·02; 95 % CI 0·84, 1·24). In addition, we observed no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers in different subgroup analyses by smoking status, menopausal status, BMI status and different types of breast cancer. In conclusion, no significant association was found between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers.

Acrylamide in non-centrifugal sugars and syrups

BACKGROUND

Acrylamide in foods has been widely studied because of its possible carcinogenicity. Most of the foods investigated were prepared using low moisture and high temperature conditions. Non-centrifugal sugars (NCSs), which have been promoted as 'non-chemical' natural sweeteners, contain precursors of acrylamide and their production processes involved prolonged heating. The acrylamide content in 32 commercial NCSs from coconut, cane and palmyra palm purchased in Asian countries was investigated. Additionally, syrups (80 ^o Brix) produced from coconut and palmyra raw saps and cane juice were prepared by evaporation with prolonged heating (2.5 h to reach 100 °C, 1 h to increase to 110 °C, held at 110 °C for 30 min). The compositions and contents of sugars, amino acids and minerals, as well as the physical characteristics of the raw saps, juice and syrups, were determined.

RESULTS

The acrylamide content of these 32 products ranged from < 15 to 4011 μg kg^-1 . The raw saps and juice were mildly acidic (pH 5.14-5.66) and similar values were observed for their syrups (4.73-5.73). The contents of sucrose, fructose and glucose in the saps and juice from these plants were similar, whereas their compositions varied with respect to amino acids. The variation of the ornithine content was significant, demonstrating a striking influence on the extent of acrylamide formation (867-1564 μg kg^-1 ) in the syrups prepared from these materials.

CONCLUSION

The present study emphasizes the importance of a careful monitoring and control of the critical steps invloved in the manufacturing process of NCSs (particularly the evaporation phase), aiming to protect the health and safety of consumers. © 2021 Society of Chemical Industry.

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.

Science and Healthy Meals in the World: Nutritional Epigenomics and Nutrigenetics of the Mediterranean Diet

The Mediterranean Diet (MD), UNESCO Intangible Cultural Heritage of Humanity, has become a scientific topic of high interest due to its health benefits. The aim of this review is to pick up selected studies that report nutrigenomic or nutrigenetic data and recapitulate some of the biochemical/genomic/genetic aspects involved in the positive health effects of the MD. These include (i) the antioxidative potential of its constituents with protective effects against several diseases; (ii) the epigenetic and epigenomic effects exerted by food components, such as Indacaxanthin, Sulforaphane, and 3-Hydroxytyrosol among others, and their involvement in the modulation of miRNA expression; (iii) the existence of predisposing or protective human genotypes due to allelic diversities and the impact of the MD on disease risk. A part of the review is dedicated to the nutrigenomic effects of the main cooking methods used in the MD and also to a comparative analysis of the nutrigenomic properties of the MD and other diet regimens and non-MD-related aliments. Taking all the data into account, the traditional MD emerges as a diet with a high antioxidant and nutrigenomic modulation power, which is an example of the “Environment-Livings-Environment” relationship and an excellent patchwork of interconnected biological actions working toward human health.

Strawberry-like SiO2/Ag nanocomposites immersed filter paper as SERS substrate for acrylamide detection

In this work, based on the strawberry-like SiO₂/Ag nanocomposites (SANC) immersed filter paper, a newly surface-enhanced Raman scattering (SERS) substrate was constructed for the detection of acrylamide (AAm) in food products. To construct filter paper-based SANC (F-SANC) SERS substrates, SiO₂ nanoparticles (SNP) were firstly synthesized and acted as carriers. After that, the in-situ preparation of silver nanoparticles (Ag NP) on SNP surface was carried out to form the strawberry-like three-dimensional (3D) structure of SANC. Finally, SANC were entangled into the filter paper to produce nanoarchitecture, thus providing enhanced plasmon resonance between SANC with strong SERS signal. Under the optimized conditions, the method exhibited good performance toward AAm with a vast linear response from 0.1 nM to 50 μM (R = 0.9935), limit of detection (LOD) of 0.02 nM (S/N = 3), and the recoveries of 80.5%~105.6% for practical samples. This strategy showed good robustness in the rapid and sensitive detection of AAm, which could be a promising strategy in food analysis and verification.

Dietary Intake of Acrylamide and Risk of Breast, Endometrial, and Ovarian Cancers: A Systematic Review and Dose-Response Meta-analysis

Acrylamide is a probable human carcinogen. Aside from occupational exposures and smoking, diet is the main source of exposure in humans. We performed a systematic review of the association between estimated dietary intake of acrylamide and risk of female breast, endometrial, and ovarian cancers in nonexperimental studies published through February 25, 2020, and conducted a dose-response meta-analysis. We identified 18 papers covering 10 different study populations: 16 cohort and two case-control studies. Acrylamide intake was associated with a slightly increased risk of ovarian cancer, particularly among never smokers. For endometrial cancer, risk was highest at intermediate levels of exposure, whereas the association was more linear and positive among never smokers. For breast cancer, we found evidence of a null or inverse relation between exposure and risk, particularly among never smokers and postmenopausal women. In a subgroup analysis limited to premenopausal women, breast cancer risk increased linearly with acrylamide intake starting at 20 μg/day of intake. High acrylamide intake was associated with increased risks of ovarian and endometrial cancers in a relatively linear manner, especially among never smokers. Conversely, little association was observed between acrylamide intake and breast cancer risk, with the exception of premenopausal women.

Processing effects on acrylamide content in roasted coffee production

Acrylamide is a toxic compound that develops during the roasting process of coffee beans. According to literature, the levels of acrylamide in coffee vary with the percentage of Robusta type in the mix and with the time-temperature parameters during the roasting process. Therefore, this study aimed to find the best roasting conditions in order to mitigate acrylamide formation. Two types of roasted coffee (Arabica and Robusta) were analyzed through GC-MS and two clean-up methods were compared. The best roasting conditions were optimized on an industrial scale and the median levels of acrylamide decreased from the range 170-484 µg kg^-1 to 159-351 µg kg^-1, after the optimization of roasting parameters. Therefore, the choice of the best conditions, according to the percentage of Robusta type in the finished product, could be an efficient mitigation strategy for acrylamide formation in coffee, maintaining the manufacturer's requirements of the finished product.

Acrylamide Induced Toxicity and the Propensity of Phytochemicals in Amelioration: A Review

Acrylamide is widely found in baked and fried foods, produced in large amount in industries and is a prime component in toxicity. This review highlights various toxicities that are induced due to acrylamide, its proposed mode of action including oxidative stress cascades and ameliorative mechanisms using phytochemicals. Acrylamide formation, the mechanism of toxicity and the studies on the role of oxidative stress and mitochondrial dysfunctions are elaborated in this paper. The various types of toxicities caused by Acrylamide and the modulation studies using phytochemicals that are carried out on various type of toxicity like neurotoxicity, hepatotoxicity, cardiotoxicity, immune system, and skeletal system, as well as embryos have been explored. Lacunae of studies include the need to explore methods for reducing the formation of acrylamide in food while cooking and also better modulators for alleviating the toxicity and associated dysfunctions along with identifying its molecular mechanisms.

The Effects of the Dietary and Nutrient Intake on Gynecologic Cancers

The contribution of diet to cancer risk has been considered to be higher in advanced countries than in developing countries. In this paper, I review the current issues (a review of the relevant literature), and the effects of the dietary and nutrient intake on three types of gynecologic cancer (cervical, endometrial and ovarian cancers). In cervical cancer, the most important roles of diet/nutrition in relation to cancer are prophylaxis and countermeasures against human papillomavirus (HPV) infection. The main preventive and reductive factors of cervical cancer are antioxidants, such as vitamin A, C, D and E, carotenoids, vegetables and fruits. These antioxidants may have different abilities to intervene in the natural history of diseases associated with HPV infection. For endometrial cancer, the increase in peripheral estrogens as a result of the aromatization of androgens to estrogens in adipose tissue in obese women and insulin resistance are risk factors. Thus, we must mainly take care to avoid the continuous intake of fat energy and sugar. In ovarian cancer, the etiology has not been fully understood. To the best of our knowledge, the long-term consumption of pro-inflammatory foods, including saturated fat, carbohydrates and animal proteins is a risk factor. The intake of acrylamide is also a risk factor for both endometrial and ovarian cancer. Most papers have been epidemiological studies. Thus, further research using in vitro and in vivo approaches is needed to clarify the effects of the dietary and nutrient intake in detail.

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.

Effects of Formulation and Baking Process on Acrylamide Formation in Kolompeh, a Traditional Cookie in Iran

Thermal treatments and recipes are two critical aspects for the formation of acrylamide at ordinary household cooking conditions and industrial level. Kolompeh is a traditional Iranian cookie, and the aim of this study was to monitor acrylamide formation in four different recipes: traditional sugary Kolompeh (TSK), traditional simple Kolompeh (TSIK), industrial sugary Kolompeh (ISK), and industrial simple Kolompeh (ISIK). Along with the measurement of reducing sugars, moisture, and pH, acrylamide was quantified by gas chromatography mass spectrometry (GC-MS). Results indicated that acrylamide content was 1758, 1048, 888, and 560 μg/kg for TSK, TSIK, ISK, and ISIK, respectively, revealing that the kind of thermal treatment in combination with higher concentrations of reducing sugars were the major driver for acrylamide formation. In particular, acrylamide concentration in TSIK direct heating was 1.87 times higher than industrial indirect heating treatment, highlighting that domestic preparation of Kolompeh required a specific attention as a source of potential toxic molecule formation.

Genetic polymorphisms of 3'-untranslated region of SULT1A1 and their impact on tamoxifen metabolism and efficacy

Purpose

Tamoxifen has a wide inter-variability. Recently, two SNPs in the 3′-untranslated region (UTR) of the SULT1A1 gene, rs6839 and rs1042157, have been associated with decreased SULT1A1 activity. The aim of this study is to investigate the role of the rs6839 and rs1042157 on tamoxifen metabolism and relapse-free survival (RFS) in women diagnosed with early-breast cancer receiving tamoxifen.

Methods

Samples from 667 patients collected in the CYPTAM study (NTR1509) were used for genotyping (CYP2D6, SULT1A1 rs6839 and rs1042157) and measurements of tamoxifen and metabolites. Patients were categorized in three groups depending on the decreased SULT1A1 activity due to rs6839 and rs1042157: low activity group (rs6839 (GG) and rs1042157 (TT)); high activity group (rs6839 (AA) and rs1042157 (CC)); and medium activity group (all the other combinations of rs6839 and rs1042157). Associations between SULT1A1 phenotypes and clinical outcome (RFS) were explored.

Results

In the low SULT1A1 activity group, higher endoxifen and 4-hydroxy-tamoxifen concentrations were found, compared to the medium and high activity group (endoxifen: 31.23 vs. 30.51 vs. 27.00, p value: 0.016; 4-hydroxy-tamoxifen: 5.55 vs. 5.27 vs. 4.94, p value:0.05). In terms of relapse, the low activity group had a borderline better outcome compared to the medium and high SULT1A1 activity group (adjusted Hazard ratio: 0.297; 95% CI 0.088–1.000; p value: 0.05).

Conclusion

Our results suggested that rs6839 and rs1042157 SNPs have a minor effect on the concentrations and metabolic ratios of tamoxifen and its metabolites, and RFS in women receiving adjuvant tamoxifen.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4923-7) contains supplementary material, which is available to authorized users.

The polymorphism rs2480258 within CYP2E1 is associated with different rates of acrylamide metabolism in vivo in humans

In a recent study, we demonstrated that the variant allele of rs2480258 within intron VIII of CYP2E1 is associated with reduced levels of mRNA, protein, and enzyme activity. CYP2E1 is the most important enzyme in the metabolism of acrylamide (AA) by operating its oxidation into glycidamide (GA). AA occurs in food, is neurotoxic and classified as a probable human carcinogen. The goal of the present study was to further assess the role of rs2480258 by measuring the rate of AA > GA biotransformation in vivo. In blood samples from a cohort of 120 volunteers, the internal doses of AA and GA were assessed by AA and GA adducts to hemoglobin (Hb) measured by mass spectrometry. The rate of biotransformation was assessed by calculating the GA-Hb/AA-Hb ratio. To maximize the statistical power, 60 TT was compared to 60 CC-homozygotes and the results showed that TT homozygotes had a statistically significant reduced rate of biotransformation. Present results reinforced the notion that T-allele of rs2480258 is a marker of low functional activity of CYP2E1. Moreover, we studied the role of polymorphisms (SNPs) within glutathione-S-transferases (GSTs) enzymes and epoxide hydrolase (EPHX), verifying previous findings that SNPs within GSTs and EPHX influence the metabolism rate.

Dietary Acrylamide and the Risks of Developing Cancer: Facts to Ponder

Acrylamide (AA) is a water soluble white crystalline solid commonly used in industries. It was listed as an industrial chemical with potential carcinogenic properties. However to date, AA was used to produce polyacrylamide polymer, which was widely used as a coagulant in water treatment; additives during papermaking; grouting material for dams, tunnels, and other underground building constructions. AA in food could be formed during high-temperature cooking via several mechanisms, i.e., formation via acrylic acid which may be derived from the degradation of lipid, carbohydrates, or free amino acids; formation via the dehydration/decarboxylation of organic acids (malic acid, lactic acid, and citric acid); and direct formation from amino acids. The big debate is whether this compound is toxic to human beings or not. In the present review, we discuss the formation of AA in food products, its consumption, and possible link to the development of any cancers. We discuss the body enzymatic influence on AA and mechanism of action of AA on hormone, calcium signaling pathways, and cytoskeletal filaments. We also highlight the deleterious effects of AA on nervous system, reproductive system, immune system, and the liver. The present and future mitigation strategies are also discussed. The present review on AA may be beneficial for researchers, food industry, and also medical personnel.

Interaction between dietary acrylamide intake and genetic variants for estrogen receptor-positive breast cancer risk

Purpose

The association between dietary acrylamide intake and estrogen receptor-positive (ER+) breast cancer risk in epidemiological studies is inconsistent. By analyzing gene-acrylamide interactions for ER+ breast cancer risk, we aimed to clarify the role of acrylamide intake in ER+ breast cancer etiology.

Methods

The prospective Netherlands Cohort Study on diet and cancer includes 62,573 women, aged 55–69 years. At baseline, a random subcohort of 2589 women was sampled from the total cohort for a case–cohort analysis approach. Dietary acrylamide intake of subcohort members (n = 1449) and ER+ breast cancer cases (n = 844) was assessed with a food frequency questionnaire. We genotyped single nucleotide polymorphisms (SNPs) in genes in acrylamide metabolism, sex steroid systems, oxidative stress and DNA repair. Multiplicative interaction between acrylamide intake and SNPs was assessed with Cox proportional hazards analysis, based on 20.3 years of follow-up.

Results

Unexpectedly, there was a statistically non-significant inverse association between acrylamide and ER+ breast cancer risk among all women but with no clear dose–response relationship, and no association among never smokers. Among the results for 57 SNPs and 2 gene deletions, rs1056827 in CYP1B1, rs2959008 and rs7173655 in CYP11A1, the GSTT1 gene deletion, and rs1052133 in hOGG1 showed a statistically significant interaction with acrylamide intake for ER+ breast cancer risk.

Conclusions

This study did not provide evidence for a positive association between acrylamide intake and ER+ breast cancer risk. If anything, acrylamide was associated with a decreased ER+ breast cancer risk. The interaction with SNPs in CYP1B1 and CYP11A1 suggests that acrylamide may influence ER+ breast cancer risk through sex hormone pathways.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1619-z) contains supplementary material, which is available to authorized users.

Determination of acrylamide levels in potato crisps and other snacks and exposure risk assessment through a Margin of Exposure approach

Potato crisps, corn-based extruded snacks and other savoury snacks are very popular products especially among younger generations. These products could be a potential source of acrylamide (AA), a toxic compound which could develop during frying and baking processes. The purpose of this study was the assessment of the dietary intake to AA across six groups of consumers divided according to age through the consumption of potato crisps and other snacks, in order to eventually evaluate the margin of exposure (MOE) related to neurotoxic and carcinogenic critical endpoints. Different brands of potato crisps and other popular snacks were analyzed through a matrix solid-phase dispersion method followed by a bromination step and GC-MS quantification. The concentration of detected AA ranged from 21 to 3444 ng g^-1 and the highest level occurred in potato crisps samples which showed a median value of 968 ng g^-1. The risk characterization through MOE assessment revealed that five out of six consumers groups showed higher exposure values associated with an augmented carcinogenic risk.

Interactions between dietary acrylamide intake and genes for ovarian cancer risk

Some epidemiological studies observed a positive association between dietary acrylamide intake and ovarian cancer risk but the causality needs to be substantiated. By analyzing gene-acrylamide interactions for ovarian cancer risk for the first time, we aimed to contribute to this. The prospective Netherlands Cohort Study on diet and cancer includes 62,573 women, aged 55–69 years. At baseline in 1986, a random subcohort of 2589 women was sampled from the total cohort for a case cohort analysis approach. Dietary acrylamide intake of subcohort members and ovarian cancer cases (n = 252, based on 20.3 years of follow-up) was assessed with a food frequency questionnaire. We selected single nucleotide polymorphisms (SNPs) in genes in acrylamide metabolism and in genes involved in the possible mechanisms of acrylamide-induced carcinogenesis (effects on sex steroid systems, oxidative stress and DNA damage). Genotyping was done on DNA from toenails through Agena’s MassARRAY iPLEX platform. Multiplicative interaction between acrylamide intake and SNPs was assessed with Cox proportional hazards analysis. Among the results for 57 SNPs and 2 gene deletions, there were no statistically significant interactions between acrylamide and gene variants after adjustment for multiple testing. However, there were several nominally statistically significant interactions between acrylamide intake and SNPs in the HSD3B1/B2 gene cluster: (rs4659175 (p interaction = 0.04), rs10923823 (p interaction = 0.06) and its proxy rs7546652 (p interaction = 0.05), rs1047303 (p interaction = 0.005), and rs6428830 (p interaction = 0.05). Although in need of confirmation, results of this study suggest that acrylamide may cause ovarian cancer through effects on sex hormones.

Metabolomics analysis of serum from subjects after occupational exposure to acrylamide using UPLC-MS

Since occupational exposure to acrylamide (ACR) may cause nerve damage, sensitive biomarkers to evaluate the early effects of ACR on human health are needed. In the present study, we have compared a group of individuals with occupational exposure to ACR (contact group, n = 65) with a group of individuals with no exposure (non-contact group, n = 60). Serum metabolomics analysis of the contact and non-contact groups was carried out using ultra performance liquid chromatograph/time of flight mass spectrometry, combined with multivariate analysis, to identify potential metabolites. Serum biochemical indexes of the contact and non-contact groups were also determined using an automatic biochemistry analyzer. There was a clear separation between the contact group and the non-contact group; receiver operator characteristic curve analysis suggested that phytosphingosine, 4E,15Z-bilirubin IXa and tryptophan were the best metabolites to use as biomarkers. Liver function was also found to be abnormal in the contact group. Important, ACR-related, metabolic changes were seen in the contact group and new biomarkers for assessing the toxicity of ACR on the central nervous system have been proposed. This study will provide a sound basis for exploring the toxic mechanisms and metabolic pathways of ACR.