Associations between dietary acrylamide intake and plasma sex hormone levels

Acrylamide exposure, sex hormones, and pubertal status in Japanese adolescents

Acrylamide may affect sex hormone levels and the timing of sexual maturation. The present study cross-sectionally examined interrelationship between the urinary metabolite of acrylamide exposure, serum sex hormone levels, and pubertal status in 408 Japanese adolescents aged 13-14 years. Their caregivers completed a questionnaire concerning the health status of their children, including pubertal maturation, and the lifestyles of children and parents. Pubertal status was queried by the Pubertal Development Scale. A major metabolite of acrylamide, N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA) in first-void urine samples. In male students, urinary AAMA was significantly inversely associated with testosterone, puberty stage, and facial hair growth after controlling for covariates. Serum testosterone and DHEAS were significantly positively associated with puberty stage. In female students, urinary AAMA was not associated with puberty stage, the indices, or any measured hormones. The data suggest that exposure to acrylamide may impact the pubertal development of boys through the effects on testosterone level.

Prenatal exposure to acrylamide differently affected the sex ratio, aromatase and apoptosis in female adult offspring of two subsequent generations

In the present study, we investigated the effect of acrylamide (ACR) exposure during pregnancy on the ovary of female adult offspring of two subsequent generations. Sixty-day-old Wistar albino female rats were given different doses of ACR (2.5 and 10 mg/kg/day) from day 6 of pregnancy until giving birth. Females from the first generation (AF1) were fed ad libitum, and thereafter, a subgroup was euthanized at 8 weeks of age and ovary samples were obtained. The remaining females were maintained until they reached sexual maturity (50 days old) and then treated in the same way as the previous generation to obtain the second generation of females (AF2). The histopathological examination indicated a high frequency of corpora lutea along with an increased number of antral follicles that reached the selectable stage mainly at a dose of 2.5 mg/kg/day. Interestingly, ACR exposure significantly increased the mRNA levels of CYP19 gene and its corresponding CYP19 protein expression in AF1 females. The TUNEL assay showed a significantly high rate of apoptosis in stromal cells except for dose of 2.5 mg/kg/day. However, in AF2 females, ACR exposure significantly increased the number of degenerating follicles and cysts while the number of growing follicles was reduced. Moreover, in both ACR-treated groups, estradiol-producing enzyme CYP19A gene and its corresponding protein were significantly reduced, and an excessive apoptosis was produced. We concluded that the ovarian condition of AF1 females had considerable similarity to the typical early perimenopausal stage, whereas that of AF2 females was similar to the late perimenopausal stage in women.

Acrylamide and Glycidamide Hemoglobin Adduct Levels and Breast Cancer Risk in Japanese Women: A Nested Case-Control Study in the JPHC

BACKGROUND

Acrylamide (AA) is classified as "probably carcinogenic to humans (class 2A)" by the International Agency for Research on Cancer. AA causes cancer owing to its mutagenic and genotoxic metabolite, glycidamide (GA), and its effects on sex hormones. Both AA and GA can interact with hemoglobin to hemoglobin adducts (HbAA and HbGA, respectively), which are considered appropriate biomarkers of internal exposure of AA. However, few epidemiologic studies reported an association of HbAA and HbGA with breast cancer.

METHODS

We conducted a nested case-control study within the Japan Public Health Center-based Prospective Study cohort (125 cases and 250 controls). Cases and controls were categorized into tertiles (lowest, middle, and highest) using the distribution of HbAA or HbGA levels in the control group and estimated ORs and 95% confidence intervals (CI) using conditional logistic regression, adjusting for potential confounders.

RESULTS

No association was observed between HbAA (ORHighestvs.Lowest, 1.34; 95% CI, 0.69-2.59), HbGA (ORHighest vs. Lowest, 1.46; 95% CI, 0.79-2.69), their sum HbAA+HbGA (ORHighest vs. Lowest, 1.36; 95% CI, 0.72-2.58) and breast cancer; however, some evidence of positive association was observed between their ratio, HbGA/HbAA, and breast cancer (ORHighest vs. Lowest, 2.19; 95% CI, 1.11-4.31).

CONCLUSIONS

There was no association between biomarkers of AA and breast cancer.

IMPACT

It is unlikely that AA increases breast cancer risk; however, the association of AA with breast cancer may need to be evaluated, with a focus not only on the absolute amount of HbAA or HbGA but also on HbGA/HbAA and the activity of metabolic genes.

Association between acrylamide exposure and sex hormones among premenopausal and postmenopausal women: NHANES, 2013-2016

PURPOSE

Acrylamide (AA) is a potential carcinogen that mainly comes from fried, baked and roasted foods, and Hb adducts of AA (HbAA) and its metabolite glycidamide (HbGA) are the biomarkers of its exposure. Increasing evidence suggests that AA is associated with various hormone-related cancers. This study aims to explore the association of HbAA and HbGA with female serum sex hormone concentrations.

METHODS

942 women from the National Health and Nutrition Examination Survey cycles (2013-2016) were included in this cross-sectional study. The associations between HbAA or HbGA or HbGA/HbAA and sex hormones were assessed by the multiple linear regression. Further stratified analyses were conducted to figure out the effects of menopausal status, BMI and smoking status on sex hormone levels.

RESULTS

Among all participants, 597 were premenopausal and 345 were postmenopausal. HbAA was positively associated with both two androgen indicators. Specifically, a ln-unit increase in HbAA was associated with 0.41 ng/dL higher ln(total testosterone, TT) (95% CI 0.00, 0.27) and 0.14 ng/dL higher ln(free testosterone) (95%CI 0.00, 0.28), respectively. However, HbGA concentrations had no association with sex hormones in the overall population. Additionally, HbGA/HbAA was negatively associated with TT and SHBG in the overall population as well as postmenopausal women. In stratified analysis, higher HbAA was associated with rising TT in postmenopausal women (β = 0.29, 95%CI 0.04, 0.53) and underweight/normal-weight women (β = 0.18, 95%CI 0.03, 0.33). Other indicators had no significant association detected in estradiol and sex hormone-binding globulin.

CONCLUSION

Our results revealed that HbAA was positively associated with androgen concentrations, especially in postmenopausal and BMI < 25 women.

Dietary exposure to acrylamide and breast cancer risk: results from the NutriNet-Santé cohort

BACKGROUND

Acrylamide is classified as a probable human carcinogen by the International Agency for Research on Cancer but epidemiologic evidence on the carcinogenicity of acrylamide from dietary sources is limited.

OBJECTIVES

This study aimed to investigate the associations between dietary acrylamide and breast cancer risk in the NutriNet-Santé cohort, accounting for menopausal and hormone receptor status.

METHODS

This prospective cohort study included 80,597 French females (mean ± SD age at baseline: 40.8 ± 14 y) during a mean ± SD follow-up of 8.8 ± 2.3 y. Acrylamide intake was evaluated using repeated 24-h dietary records (n ± SD = 5.5 ± 3.0), linked to a comprehensive food composition database. Associations between acrylamide intake and breast cancer risk (overall, premenopausal, and postmenopausal) were assessed by Cox hazard models adjusted for known risk factors (sociodemographic, anthropometric, lifestyle, medical history, and nutritional factors).

RESULTS

The mean ± SD dietary acrylamide intake was 30.1 ± 21.9 µg/d (main contributors: coffee, potato fries and chips, pastries, cakes, bread). During follow-up, 1016 first incident breast cancer cases were diagnosed (431 premenopausal, 585 postmenopausal). A borderline significant positive association was observed between dietary acrylamide exposure and breast cancer risk overall (HR for quartile 4 compared with 1: 1.21; 95% CI: 1.00, 1.47) and a positive association was observed with premenopausal cancer (HRQ4vs.Q1: 1.40; 95% CI: 1.04, 1.88). Restricted cubic spline analyses suggested evidence for nonlinearity of these associations, with higher HRs for intermediate (quartile 2) and high (quartile 4) exposures. Receptor-specific analyses revealed positive associations with estrogen receptor-positive breast cancer (total and premenopausal). Acrylamide intake was not associated with postmenopausal breast cancer.

CONCLUSIONS

Results from this large prospective cohort study suggest a positive association between dietary acrylamide and breast cancer risk, especially in premenopausal females, and provide new insights that support continued mitigation strategies to reduce the content of acrylamide in food.This trial was registered at clinicaltrials.gov as NCT03335644.

Associations of Hemoglobin Adducts of Acrylamide and Glycidamide with Prevalent Metabolic Syndrome in a Nationwide Population-Based Study

Environmental and dietary exposures to acrylamide (AA) have been linked with various metabolic-related outcomes, but the results are mixed. However, the association between long-term exposure to AA and the prevalence of metabolic syndrome (MetS) remains unknown. In this study, we aimed to assess the relationship between hemoglobin adducts of AA, biomarkers of internal exposure to AA, and MetS prevalence among a U.S. nationwide population. MetS patients were defined by meeting three or more of the following five characteristics: elevated blood pressure, high fasting glucose, abdominal obesity, hypertriglyceridemia, and lower high-density lipoprotein cholesterol (HDL-C). Multivariate-adjusted logistic regression models and restricted cubic spline models were used to analyze the associations between AA hemoglobin biomarkers and MetS prevalence. A total of 1552 MetS cases were documented. After adjustment for the potential confounders, the odds ratios (95% confidence intervals) of MetS prevalence in the highest quartile of AA hemoglobin biomarkers were 0.60 (0.40-0.89), 1.26 (0.84-1.89), 0.93 (0.71-1.21), and 1.61 (1.18-2.20) for HbAA, HbGA, the sum of HbAA and HbGA (HbAA + HbGA), and the ratio of HbGA to HbAA (HbGA/HbAA), compared with the lowest quartile, respectively. HbAA was significantly and inversely associated with blood pressure, fasting glucose, abdominal obesity, hypertriglyceridemia, and low HDL-C, while the HbGA/HbAA ratio was also positively associated with abdominal obesity, hypertriglyceridemia, and low HDL-C. The restricted cubic spline models revealed a positive relationship between the HbGA/HbAA ratio and the prevalence of MetS, while the HbAA level was inversely associated with MetS prevalence. Our current findings provided epidemiological evidence that HbAA and the HbGA/HbAA ratio were significantly associated with MetS prevalence among general U.S. adults. Further studies should be conducted to examine the association between internal exposure to AA and MetS prevalence.

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.

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.

Association of acrylamide hemoglobin biomarkers with serum lipid levels in general US population: NHANES 2013-2016

The aim of present study was to investigate the association of acrylamide (AA) hemoglobin biomarkers and serum lipids level in a general population. Data set of our study were extracted from an open database - National Health and Nutrition Examination Surveys (NHANES) 2013-2016. In total 2899 participants were enrolled. The associations between AA hemoglobin parameters [hemoglobin adducts of AA (HbAA) and glycidamide (HbGA), total of HbAA and HbGA (HbAA+HbGA), and ratio of HbGA to HbAA (HbGA/HbAA)] and lipid levels [total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C)] were analyzed. Generalized linear models and restricted cubic spline plots were conducted to address the relationship between lipid levels and acrylamide markers. Comparing the lowest quantiles, HbGA and HbGA/HbAA both remained a significant trend regardless of lipid types. Analyses using a generalized linear model with restricted cubic spline and validated with regression models, all 4 AA parameters demonstrated a linear association and positive correlation with TG. Furthermore, there were also opposite nonlinear association between HbGA/HbAA and LDL-C (positive correlation), and HbGA/HbAA and HDL-C (negative correlation). Further analysis with threshold effect analysis or regression analysis showed HbGA and HbGA/HbAA remained significant association with all TC, TG, LDL-C, and HDL-C. The hemoglobin adducts AA parameters as long-term exposure biomarkers are associated with the atherosclerotic lipid changes in a population of US adults.

The Key Characteristics of Carcinogens: Relationship to the Hallmarks of Cancer, Relevant Biomarkers, and Assays to Measure Them

The key characteristics (KC) of human carcinogens provide a uniform approach to evaluating mechanistic evidence in cancer hazard identification. Refinements to the approach were requested by organizations and individuals applying the KCs. We assembled an expert committee with knowledge of carcinogenesis and experience in applying the KCs in cancer hazard identification. We leveraged this expertise and examined the literature to more clearly describe each KC, identify current and emerging assays and in vivo biomarkers that can be used to measure them, and make recommendations for future assay development. We found that the KCs are clearly distinct from the Hallmarks of Cancer, that interrelationships among the KCs can be leveraged to strengthen the KC approach (and an understanding of environmental carcinogenesis), and that the KC approach is applicable to the systematic evaluation of a broad range of potential cancer hazards in vivo and in vitro We identified gaps in coverage of the KCs by current assays. Future efforts should expand the breadth, specificity, and sensitivity of validated assays and biomarkers that can measure the 10 KCs. Refinement of the KC approach will enhance and accelerate carcinogen identification, a first step in cancer prevention.See all articles in this CEBP Focus section, "Environmental Carcinogenesis: Pathways to Prevention."

Association between acrylamide exposure and sex hormones in males: NHANES, 2003-2004

Introduction

Acrylamide is widely present in heat-processed food, cigarette smoke and environment. Reproductive toxicity was reported in animals treated with acrylamide, particularly in males. The reproductive toxicity of acrylamide and its active metabolite, glycidamide, was reported to be mainly mediated through DNA damage in spermatocytes. However, the effect of acrylamide on sex hormones in men is unknown.

Methods

There were 468 male subjects (age ≧ 12 years) enrolled to determine the relationships between hemoglobin adducts of acrylamide (HbAA) and hemoglobin adducts of glycidamide (HbGA) with several sex hormones using the National Health and Nutrition Examination Survey (NHANES), 2003 to 2004. All potential confounding variables in the data set were properly adjusted.

Results

We found that one unit increase in the natural log-transformed HbAA level was associated with an increase in natural log transformed serum inhibin B level by 0.10 (SE = 0.05; P = 0.046), and natural log transformed serum sex hormone binding globulin (SHBG) by 0.15 (SE = 0.15; P = 0.036). With respect to HbGA, one unit increase in the natural log-transformed HbGA level was associated with an increase in natural log transformed serum anti-Müllerian Hormone (AMH) level by 0.31 (SE = 0.00; P = 0.003).

Conclusion

In this representative cohort, we identified positive associations between acrylamide exposure and several sex hormones in men. The HbAA is positively associated with inhibin B and SHBG, and HbGA is positively associated with AMH. Other than genotoxicity, our findings suggested that altered sex hormones might also play a role in acrylamide-related reproductive toxicity in males.

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.

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.

Dietary acrylamide intake and the risk of endometrial or ovarian cancers in Japanese women

A meta-analysis published in 2015 noted a marginally increased risk of endometrial and ovarian cancers in non-smoking women with dietary acrylamide intake, but only a few studies were included, and they were limited to Western countries. The aim of this study was to investigate the association between dietary acrylamide intake and endometrial or ovarian cancer risk in the Japan Public Health Center-based Prospective Study (JPHC Study). In this prospective cohort study, 47 185 participants aged 45-74 years at the follow-up starting point in the JPHC Study were enrolled. Dietary acrylamide intake was assessed using a validated food frequency questionnaire. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI). In participants with endometrial and ovarian cancer, the average follow-up periods were 15.5 and 15.6 years, respectively, and 161 and 122 cases of endometrial and ovarian cancer were diagnosed, respectively. Energy-adjusted dietary acrylamide intake was negatively associated with endometrial cancer, but the association disappeared after adjusting for coffee consumption with an adjusted HR for the highest vs lowest tertile of 0.85 (95%CI: 0.54-1.33). No association was observed, however, for ovarian cancer (adjusted HR, 0.77; 95%CI: 0.49-1.23). Furthermore, after stratifying by smoking status, coffee consumption, alcohol consumption, body mass index, and menopause status, no association was observed. Dietary acrylamide intake was not associated with the risk of endometrial or ovarian cancer in Japanese women with a relatively lower dietary intake of acrylamide compared with Western populations.

Dietary acrylamide intake and risk of breast cancer: The Japan Public Health Center-based Prospective Study

Acrylamide forms during cooking and is classified as a probable carcinogen in humans, mandating the need for epidemiological studies of dietary acrylamide and cancers. However, the risk of dietary acrylamide exposure to breast cancer in Japanese women has not been assessed. We investigated the association between dietary acrylamide intake and risk of breast cancer in the Japan Public Health Center-based Prospective Study. The present study included 48 910 women aged 45-74 years who responded to a 5-year follow-up survey questionnaire. Dietary acrylamide intake was assessed using a validated food frequency questionnaire. Cox proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals. During an average of 15.4 years of follow up, 792 breast cancers were diagnosed. Energy-adjusted dietary acrylamide intake was not associated with the risk of breast cancer (adjusted hazard ratio for highest versus lowest tertile = .95, 95% confidence intervals: 0.79-1.14, P-trend = .58). Further, no significant associations were observed when stratified analyses were conducted by smoking status, coffee consumption, alcohol consumption, body mass index, menopausal status, estrogen receptor status, and progesterone receptor status. In conclusion, dietary acrylamide intake was not associated with the risk of breast cancer in this population-based prospective cohort study of Japanese women.

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.

Dietary acrylamide exposure was associated with increased cancer mortality in Chinese elderly men and women: a 11-year prospective study of Mr. and Ms. OS Hong Kong

AIM

Our study aims to investigate the association between dietary acrylamide exposure and cancer mortality among Chinese elderly.

METHODS

A prospective cohort of 4000 elderly men and women aged 65 years and above (Mr. and Ms. OS Hong Kong study) was recruited from local communities from 2001 to 2003. Dietary exposure to acrylamide was evaluated at baseline based on a validated food frequency questionnaire and an acrylamide database from the 1st Hong Kong Total Diet Study. Data on mortality statistics through March 2014 were obtained from the Death Registry of the Department of Health of Hong Kong with a median follow-up of 11.1 years. Cox proportional hazards models were used to examine the association between the acrylamide exposure and cancer mortality. Sex hormones were assessed in men.

RESULTS

During a median follow-up of 11.1 years (39,271 person-years), we ascertained 330 cancer deaths. Vegetables (43.7%) and cereals (28.9%) products were the major contributors to dietary acrylamide. Compared with the lowest quartile of acrylamide intake (<9.9 µg/day), the multivariable hazard ratios for the highest quartile (>17.1 µg/day) were 1.9 (95% CI 1.3-2.8; P trend < 0.01), 1.9 (95% CI 1.0-3.6; P trend = 0.05), and 2.0 (95% CI 1.0-4.0; P trend = 0.06) for the cancer mortality from overall, digestive and respiratory system, respectively. The associations were attenuated to null after further adjustment for circulating free estradiol in men. No statistically significant interactions were observed between acrylamide exposure and sex, obesity and overall lifestyle pattern scores.

CONCLUSIONS

The longitudinal data provided evidence that dietary acrylamide, in amounts that Chinese elderly are typically exposed to, was associated with increased cancer mortality. Circulating free estradiol may mediate the association in men.

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.

Dietary and lifestyle determinants of acrylamide and glycidamide hemoglobin adducts in non-smoking postmenopausal women from the EPIC cohort

PURPOSE

Acrylamide was classified as 'probably carcinogenic' to humans in 1994 by the International Agency for Research on Cancer. In 2002, public health concern increased when acrylamide was identified in starchy, plant-based foods, processed at high temperatures. The purpose of this study was to identify which food groups and lifestyle variables were determinants of hemoglobin adduct concentrations of acrylamide (HbAA) and glycidamide (HbGA) in 801 non-smoking postmenopausal women from eight countries in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

Biomarkers of internal exposure were measured in red blood cells (collected at baseline) by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) . In this cross-sectional analysis, four dependent variables were evaluated: HbAA, HbGA, sum of total adducts (HbAA + HbGA), and their ratio (HbGA/HbAA). Simple and multiple regression analyses were used to identify determinants of the four outcome variables. All dependent variables (except HbGA/HbAA) and all independent variables were log-transformed (log2) to improve normality. Median (25th-75th percentile) HbAA and HbGA adduct levels were 41.3 (32.8-53.1) pmol/g Hb and 34.2 (25.4-46.9) pmol/g Hb, respectively.

RESULTS

The main food group determinants of HbAA, HbGA, and HbAA + HbGA were biscuits, crackers, and dry cakes. Alcohol intake and body mass index were identified as the principal determinants of HbGA/HbAA. The total percent variation in HbAA, HbGA, HbAA + HbGA, and HbGA/HbAA explained in this study was 30, 26, 29, and 13 %, respectively.

CONCLUSIONS

Dietary and lifestyle factors explain a moderate proportion of acrylamide adduct variation in non-smoking postmenopausal women from the EPIC cohort.

Negative association between acrylamide exposure and body composition in adults: NHANES, 2003-2004

BACKGROUND/OBJECTIVES

Acrylamide is present in mainstream cigarette smoke and in some food prepared at high temperature. Animal studies have shown that acrylamide exposure reduces body weight. Prenatal exposure to acrylamide also has been linked to reduced birth weight in human. Whether acrylamide exposure is associated with altered body compositions in adults is not clear.

SUBJECTS/METHODS

We selected 3623 subjects (aged ⩾20 years) from a National Health and Nutrition Examination Survey (NHANES) in 2003-2004 to determine the relationship among hemoglobin adducts of acrylamide (HbAA), hemoglobin adducts of glycidamide (HbGA) and body composition (body measures, bioelectrical impedance analysis (BIA), dual energy x-ray absorptiometry (DXA)). Data were adjusted for potential confounding variables.

RESULTS

The geometric means and 95% CI concentrations of HbAA and HbGA were 60.48 (59.32-61.65) pmol/g Hb and 55.64 (54.40-56.92) pmol/g Hb, respectively. After weighting for sampling strategy, we identified that one-unit increase in natural log-HbAA, but not HbGA, was associated with reduction in body measures (body weight, body mass index (BMI), subscapular/triceps skinfold), parameters of BIA (fat-free mass, fat mass, percent body fat, total body water) and parameters of DXA (android fat mass, android percent fat, gynoid fat/lean mass, gynoid percent mass, android to gynoid ratio). Subgroup analysis showed that these associations were more evident in subjects at younger age, male gender, whites, lower education level, active smokers and those with lower BMI.

CONCLUSIONS

Higher concentrations of HbAA are associated with a decrease in body composition in the US general population. Further studies are warranted to clarify this association.

Potential Intervention Targets in Utero and Early Life for Prevention of Hormone Related Cancers

Hormone-related cancers have long been thought to be sensitive to exposures during key periods of sexual development, as shown by the vulnerability to such cancers of women exposed to diethylstilbestrol in utero. In addition to evidence from human studies, animal studies using new techniques, such as gene knockout models, suggest that an increasing number of cancers may be hormonally related, including liver, lung, and bladder cancer. Greater understanding of sexual development has also revealed the "mini-puberty" of early infancy as a key period when some sex hormones reach levels similar to those at puberty. Factors driving sex hormones in utero and early infancy have not been systematically identified as potential targets of intervention for cancer prevention. On the basis of sex hormone pathways, we identify common potentially modifiable drivers of sex hormones, including but not limited to factors such as obesity, alcohol, and possibly nitric oxide. We review the evidence for effects of modifiable drivers of sex hormones during the prenatal period and early infancy, including measured hormones as well as proxies, such as the second-to-fourth digit length ratio. We summarize the gaps in the evidence needed to identify new potential targets of early life intervention for lifelong cancer prevention.

Acrylamide and glycidamide hemoglobin adduct levels and endometrial cancer risk: A nested case-control study in nonsmoking postmenopausal women from the EPIC cohort

Acrylamide, classified in 1994 by IARC as "probably carcinogenic to humans," was discovered in 2002 in some heat-treated, carbohydrate-rich foods. Four prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The purpose of this nested case-control study, based on the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, was to evaluate, for the first time, the association between hemoglobin adducts of acrylamide (HbAA) and glycidamide (HbGA) and the risk of developing EC in non-smoking postmenopausal women. Hemoglobin adducts were measured in red blood cells by HPLC/MS/MS. Four exposure variables were evaluated: HbAA, HbGA, their sum (HbAA+HbGA), and their ratio (HbGA/HbAA). The association between hemoglobin adducts and EC was evaluated using unconditional multivariable logistic regression models, and included 383 EC cases (171 were type-I EC), and 385 controls. Exposure variables were analyzed in quintiles based on control distributions. None of the biomarker variables had an effect on overall EC (HRHbAA;Q5vsQ1 : 0.84, 95%CI: 0.49-1.48; HRHbGA;Q5vsQ1 : 0.94, 95%CI: 0.54-1.63) or type-I EC risk. Additionally, none of the subgroups investigated (BMI < 25 vs. ≥25 kg m(-2) , alcohol drinkers vs. never drinkers, oral contraceptive users vs. non-users) demonstrated effect measure modification. Hemoglobin adducts of acrylamide or glycidamide were not associated with EC or type-I EC risk in 768 nonsmoking postmenopausal women from the EPIC cohort.

Acrylamide and Glycidamide Hemoglobin Adducts and Epithelial Ovarian Cancer: A Nested Case-Control Study in Nonsmoking Postmenopausal Women from the EPIC Cohort

BACKGROUND

Acrylamide was classified as "probably carcinogenic to humans (group 2A)" by the International Agency for Research on Cancer. Epithelial ovarian cancer (EOC) is the fourth cause of cancer mortality in women. Five epidemiological studies have evaluated the association between EOC risk and dietary acrylamide intake assessed using food frequency questionnaires, and one nested case-control study evaluated hemoglobin adducts of acrylamide (HbAA) and its metabolite glycidamide (HbGA) and EOC risk; the results of these studies were inconsistent.

METHODS

A nested case-control study in nonsmoking postmenopausal women (334 cases, 417 controls) was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Unconditional logistic regression models were used to estimate ORs and 95% confidence intervals (CI) for the association between HbAA, HbGA, HbAA+HbGA, and HbGA/HbAA and EOC and invasive serous EOC risk.

RESULTS

No overall associations were observed between biomarkers of acrylamide exposure analyzed in quintiles and EOC risk; however, positive associations were observed between some middle quintiles of HbGA and HbAA+HbGA. Elevated but nonstatistically significant ORs for serous EOC were observed for HbGA and HbAA+HbGA (ORQ5vsQ1, 1.91; 95% CI, 0.96-3.81 and ORQ5vsQ1, 1.90; 95% CI, 0.94-3.83, respectively); however, no linear dose-response trends were observed.

CONCLUSION

This EPIC nested case-control study failed to observe a clear association between biomarkers of acrylamide exposure and the risk of EOC or invasive serous EOC.

IMPACT

It is unlikely that dietary acrylamide exposure increases ovarian cancer risk; however, additional studies with larger sample size should be performed to exclude any possible association with EOC risk.

Dietary intake of acrylamide and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Three prospective studies have evaluated the association between dietary acrylamide intake and endometrial cancer (EC) risk with inconsistent results. The objective of this study was to evaluate the association between acrylamide intake and EC risk: for overall EC, for type-I EC, and in never smokers and never users of oral contraceptives (OCs). Smoking is a source of acrylamide, and OC use is a protective factor for EC risk.

METHODS

Cox regression was used to estimate hazard ratios (HRs) for the association between acrylamide intake and EC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Acrylamide intake was estimated from the EU acrylamide monitoring database, which was matched with EPIC questionnaire-based food consumption data. Acrylamide intake was energy adjusted using the residual method.

RESULTS

No associations were observed between acrylamide intake and overall EC (n=1382) or type-I EC risk (n=627). We observed increasing relative risks for type-I EC with increasing acrylamide intake among women who both never smoked and were non-users of OCs (HRQ5vsQ1: 1.97, 95% CI: 1.08-3.62; likelihood ratio test (LRT) P-value: 0.01, n=203).

CONCLUSIONS

Dietary intake of acrylamide was not associated with overall or type-I EC risk; however, positive associations with type I were observed in women who were both non-users of OCs and never smokers.

Risk assessment, formation, and mitigation of dietary acrylamide: current status and future prospects

Acrylamide (AA) was firstly detected in food in 2002, and since then, studies on AA analysis, occurrence, formation, toxicity, risk assessment and mitigation have been extensively carried out, which have greatly advanced understanding of this particular biohazard at both academic and industrial levels. There is considerable variation in the levels of AA in different foods and different brands of the same food; therefore, so far, a general upper limit for AA in food is not available. In addition, the link of dietary AA to human cancer is still under debate, although AA has been known as a potential cause of various toxic effects including carcinogenic effects in experimental animals. Furthermore, the oxidized metabolite of AA, glycidamide (GA), is more toxic than AA. Both AA and GA can form adducts with protein, DNA, and hemoglobin, and some of those adducts can serve as biomarkers for AA exposure; their potential roles in the linking of AA to human cancer, reproductive defects or other diseases, however, are unclear. This review addresses the state-of-the-art understanding of AA, focusing on risk assessment, mechanism of formation and strategies of mitigation in foods. The potential application of omics to AA risk assessment is also discussed.