In Vivo Investigation of the Effect of Dietary Acrylamide and Evaluation of Its Clinical Relevance in Colon Cancer

Dietary exposure to acrylamide (AA) has been linked with carcinogenicity in the gastrointestinal (GI) tract. However, epidemiologic data on AA intake in relation to cancer risk are limited and contradictory, while the potential cancer-inducing molecular pathways following AA exposure remain elusive. In this study, we collected mechanistic information regarding the induction of carcinogenesis by dietary AA in the colon, using an established animal model. Male Balb/c mice received AA orally (0.1 mg/kg/day) daily for 4 weeks. RNA was extracted from colon tissue samples, followed by RNA sequencing. Comparative transcriptomic analysis between AA and mock-treated groups revealed a set of differentially expressed genes (DEGs) that were further processed using different databases through the STRING-DB portal, to reveal deregulated protein-protein interaction networks. We found that genes implicated in RNA metabolism, processing and formation of the ribosomal subunits and protein translation and metabolism are upregulated in AA-exposed colon tissue; these genes were also overexpressed in human colon adenocarcinoma samples and were negatively correlated with patient overall survival (OS), based on publicly available datasets. Further investigation of the potential role of these genes during the early stages of colon carcinogenesis may shed light into the underlying mechanisms induced by dietary AA exposure.

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.

Acrylamide levels in smoke from conventional cigarettes and heated tobacco products and exposure assessment in habitual smokers

Acrylamide (AA) is a neurotoxic, genotoxic, and carcinogenic compound developed during heating at high temperatures. Foods such as potatoes, biscuits, bread and coffee are the main foodstuffs containing AA. Cigarette smoke may be a significant additional source of exposure. However, AA content may vary among different types of cigarettes. The study aimed to evaluate the AA content in conventional cigarettes (CC) and heated tobacco products (HTP) and its resulting exposure through their use. AA levels from the two types of cigarettes were determined by GC-MS and the daily exposure to AA was also ascertained. The margin of exposure (MOE) was calculated for neurotoxic and carcinogenic risk based on benchmark dose lower confidence limit for a 10% response (BMDL10) of 0.43 and 0.17, 0.30, and 1.13 mg/kgbw/day. AA level in CC ranged from 235 to 897 ng/cigarette, whereas HTP reported AA levels in the range of 99-187 ng/cigarette. The data showed a low neurotoxic risk for either CC or HTP, whereas a carcinogenic risk emerged through the smoking of CC based on different Benchmark doses. The carcinogenic risk for CC based on the highest Benchmark dose that was considered showed unsafe levels, as little as 10 CC cigarettes/day, whereas it was almost always of low concern for HTP. Another approach based upon the incremental lifetime cancer risk (ILCR) analysis led to similar results, exceeding, in some cases, the safety value of 10-4, as far as CC are concerned. Overall, the results confirmed that CC are a significant source of AA, and its levels were five times higher than in HTP.

Dietary Acrylamide Exposure and Risk of Site-Specific Cancer: A Systematic Review and Dose-Response Meta-Analysis of Epidemiological Studies

Diet is a main source of acrylamide exposure to humans. Existing observational data on the relationship between dietary exposure to acrylamide and risk of cancer are inconsistent. We performed a systematic review and dose-response meta-analysis of epidemiological studies evaluating the association between dietary acrylamide exposure and several site-specific cancer. A systematic literature search was conducted in PubMed, Scopus, and Web of Science databases until March 7, 2022. Studies were eligible if they were carried out in non-occupationally exposed adults, assessed dietary acrylamide exposure (μg/day) and reported risk estimates of cancer incidence (all but gynecological cancers). Using a random-effects model, we performed a meta-analysis of site-specific cancer risk comparing the highest vs. lowest category of dietary acrylamide exposure. We also carried out a one-stage dose-response meta-analysis assessing the shape of the association. Out of 1,994 papers screened, 31 were eligible (total of 16 studies), which included 1,151,189 participants in total, out of whom 48,175 developed cancer during the median follow-up period of 14.9 years (range 7.3–33.9). The mean estimated dose of dietary acrylamide across studies was 23 μg/day. Pooled analysis showed no association between the highest vs. lowest dietary acrylamide exposure and each site-specific cancer investigated, with no evidence of thresholds in the dose-response meta-analysis. There were also no associations between dietary acrylamide exposure and the risk of cancers when stratifying by smoking status, except for increased risk of lung cancer in smokers. In conclusion, high dietary acrylamide exposure was not associated with an increased risk of site-specific non-gynecological cancer.

Long-term acrylamide exposure exacerbates brain and lung pathology in a mouse malaria model

The consumption of dietary acrylamide (ACR), a carcinogen, results in the dysfunction of various organs and the immune system. However, the impact of ACR exposure on the progression of infectious diseases is unknown. This study investigated the effect of ACR on the progression of malaria infection using a mouse model of malaria. C57BL/6 mice were continuously treated with ACR at a dose of 20 mg/kg bodyweight/day for six weeks (long-term exposure) or phosphate-buffered saline (PBS). Next, the mice were infected with the rodent malaria parasite, Plasmodium berghei NK65 (PbNK). Parasitemia and survival rate were analyzed in the different treatment groups. Magnetic resonance imaging (MRI) and histopathological analyses were performed to evaluate the effect of ACR exposure on the morphology of various organs. Long-term ACR exposure exacerbated PbNK-induced multiorgan dysfunction. MRI and histopathological analysis revealed signs of encephalomeningitis and acute respiratory distress syndrome in the PbNK-infected long-term ACR exposure mice, which decreased the survival rate of mice, but not in the PbNK-infected long-term PBS exposure group. These findings enhance our understanding of the impact of ACR on the progression of infectious diseases, such as malaria.

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

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

The Coffee-Acrylamide Apparent Paradox: An Example of Why the Health Impact of a Specific Compound in a Complex Mixture Should Not Be Evaluated in Isolation

The health implications of acrylamide in food are a matter of concern based on toxicological studies in rodents, which showed that doses of acrylamide more than 100 times higher than those estimated to result from dietary exposure in humans are carcinogenic; however, the cancer types reported in rodents are species-specific, and whether these results can be extrapolated to humans is still in question. In fact, human epidemiological studies revealed a general lack of association between dietary acrylamide exposure and the incidence of different cancer types. Even occupational exposure to acrylamide, resulting in acrylamide exposure nearly 10 times higher than dietary exposure, did not increase tumor occurrence. Furthermore, the consumption of coffee, which is a main contributor of dietary acrylamide exposure, actually decreases the overall incidence of cancer in humans and afford global health benefits, increasing both lifespan and healthspan on ageing. This paradox clearly illustrates the risk of evaluating an individual molecule independently of its complete food matrix, which may have other components that completely override the effects of the considered molecule.

Dietary Acrylamide Intake and Risk of Lung Cancer: The Japan Public Health Center Based Prospective Study

Acrylamide, which forms in heat-treated foods with high carbohydrate content, is a probable human carcinogen. This study aimed to evaluate the association between dietary acrylamide intake and lung cancer using data from the Japan Public Health Center based Prospective Study. Our study included 85,303 participants who completed a food frequency questionnaire. Cox proportional hazards regression models were used to assess hazard ratios and 95% confidence intervals (CIs) after adjusting for confounders. After 14.3 years and 15.4 years of mean follow-up period, 1187 and 485 lung cancer cases were identified in men and women, respectively. The multivariable-adjusted hazard ratios of 10-µg/day increment in acrylamide intake were 1.01 (95% CI, 0.99–1.02) in men and 0.98 (95% CI, 0.95–1.02) in women. Compared with the lowest quartile of acrylamide intake, the hazard ratios for the highest quartile were 1.13 (95% CI, 0.95–1.33; p for trend = 0.12) in men and 1.03 (95% CI, 0.78–1.36; p for trend = 0.86) in women in the multivariable-adjusted model. Moreover, there was also no significant association observed in the stratified analysis for histological subtypes of lung cancer. This study demonstrated that dietary acrylamide intake was not associated with increased lung cancer risk in the Japanese population.

No association between dietary acrylamide and renal cell carcinoma: an updated meta-analysis

BACKGROUND

The relationship between dietary acrylamide intake and renal cell carcinoma risk is inconclusive. In consideration of the recent findings, we conducted an updated meta-analysis to assess the association between acrylamide intake and renal cell carcinoma risk.

RESULTS

PubMed, EMBASE, and Cochrane databases have been used to identify epidemiological studies on dietary acrylamide intake and renal cell carcinoma risk. This meta-analysis study included eight studies, 2843 cases, and 309 920 controls/participants. We performed meta-analyses to calculate the summary relative risk (RR) for the highest versus lowest intake of dietary acrylamide. No meaningful association was found for renal cell carcinoma; RR was 1.12 (95% confidence interval (CI): 0.97-1.28). Among participants who never smoked, no association was found between dietary acrylamide and renal cell carcinoma; the RR for highest versus lowest intake of dietary acrylamide was 1.11 (95% CI: 0.93-1.32).

CONCLUSION

This meta-analysis study indicates that dietary acrylamide is not related to the risk of renal cell carcinoma. © 2020 Society of Chemical Industry.

Glycidamide Promotes the Growth and Migratory Ability of Prostate Cancer Cells by Changing the Protein Expression of Cell Cycle Regulators and Epithelial-to-Mesenchymal Transition (EMT)-Associated Proteins with Prognostic Relevance

Acrylamide (AA) and glycidamide (GA) can be produced in carbohydrate-rich food when heated at a high temperature, which can induce a malignant transformation. It has been demonstrated that GA is more mutagenic than AA. It has been shown that the proliferation rate of some cancer cells are increased by treatment with GA; however, the exact genes that are induced by GA in most cancer cells are not clear. In the present study, we demonstrated that GA promotes the growth of prostate cancer cells through induced protein expression of the cell cycle regulator. In addition, we also found that GA promoted the migratory ability of prostate cancer cells through induced epithelial-to-mesenchymal transition (EMT)-associated protein expression. In order to understand the potential prognostic relevance of GA-mediated regulators of the cell cycle and EMT, we present a three-gene signature to evaluate the prognosis of prostate cancer patients. Further investigations suggested that the three-gene signature (CDK4, TWIST1 and SNAI2) predicted the chances of survival better than any of the three genes alone for the first time. In conclusion, we suggested that the three-gene signature model can act as marker of GA exposure. Hence, this multi-gene panel may serve as a promising outcome predictor and potential therapeutic target in prostate cancer patients.

Genotoxic and Epigenotoxic Alterations in the Lung and Liver of Mice Induced by Acrylamide: A 28 Day Drinking Water Study

Acrylamide has been classified as a "Group 2A carcinogen" (probably carcinogenic to humans) by the International Agency for Research on Cancer. The carcinogenicity of acrylamide is attributed to its well-recognized genotoxicity. In the present study, we investigated the effect of acrylamide on epigenetic alterations in mice. Female B6C3F1 mice received acrylamide in drinking water for 28 days, at doses previously used in a 2 year cancer bioassay (0, 0.0875, 0.175, 0.35, and 0.70 mM), and the genotoxic and epigenetic effects were investigated in lungs, a target organ for acrylamide carcinogenicity, and livers, a nontarget organ. Acrylamide exposure resulted in a dose-dependent formation of N7-(2-carbamoyl-2-hydroxyethyl)guanine and N3-(2-carbamoyl-2-hydroxyethyl)adenine in liver and lung DNA. In contrast, the profiles of global epigenetic alterations differed between the two tissues. In the lungs, acrylamide exposure resulted in a decrease of histone H4 lysine 20 trimethylation (H4K20me3), a common epigenetic feature of human cancer, while in the livers, there was increased acetylation of histone H3 lysine 27 (H3K27ac), a gene transcription activating mark. Treatment with 0.70 mM acrylamide also resulted in substantial alterations in the DNA methylation and whole transcriptome in the lungs and livers; however, there were substantial differences in the trends of DNA methylation and gene expression changes between the two tissues. Analysis of differentially expressed genes showed a marked up-regulation of genes and activation of the gene transcription regulation pathway in livers, but not lungs. This corresponded to increased histone H3K27ac and DNA hypomethylation in livers, in contrast to hypermethylation and transcription silencing in lungs. Our results demonstrate that acrylamide induced global epigenetic alterations independent of its genotoxic effects, suggesting that epigenetic events may determine the organ-specific carcinogenicity of acrylamide. Additionally this study provides strong support for the importance of epigenetic alterations, in addition to genotoxic events, in the mechanism of carcinogenesis induced by genotoxic chemical carcinogens.

Estimation of exposure to dietary acrylamide based on mercapturic acids level in urine of Polish women post partum and an assessment of health risk

We determined metabolites of acrylamide and glycidamide concentrations (AAMA and GAMA, respectively) in urine of 93 women within the first days after delivery, using LC-MS/MS. The median AAMA and GAMA levels in urine were 20.9 μg/l (2.3÷399.0 μg/l) and 8.6 μg/l (1.3÷85.0 μg/l), respectively. In smokers we found significantly (P<0.01) higher levels of metabolites in comparison with the non-smoking women. As demonstrated by the 24-h dietary recall, acrylamide intake was low (median: 7.04 μg/day). Estimated exposure to acrylamide based on AAMA and GAMA levels in the whole group of women was 0.16 μg/kg b.w./day (1.15 μg/kg b.w./day, P95). We found significantly (P<0.05) higher exposure in women who consumed higher amount of acrylamide in the diet (≥10 μg/day vs <10 μg/day). A weak but significant positive correlation between acrylamide intake calculated on the basis of urinary levels of AAMA and GAMA and estimated on the basis of 24-h dietary recall (r=0.26, P<0.05) was found. The estimated margin of exposure values were below 10 000 and ranged from 156 for 95th percentile to 1938 for median acrylamide intake. Our results have shown that even a low dietary acrylamide intake may be associated with health risk.

Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans

Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

Dietary acrylamide and cancer risk: an updated meta-analysis

The debate on the potential carcinogenic effect of dietary acrylamide is open. In consideration of the recent findings from large prospective investigations, we conducted an updated meta-analysis on acrylamide intake and the risk of cancer at several sites. Up to July 2014, we identified 32 publications. We performed meta-analyses to calculate the summary relative risk (RR) of each cancer site for the highest versus lowest level of intake and for an increment of 10 µg/day of dietary acrylamide, through fixed-effects or random-effects models, depending on the heterogeneity test. Fourteen cancer sites could be examined. No meaningful associations were found for most cancers considered. The summary RRs for high versus low acrylamide intake were 0.87 for oral and pharyngeal, 1.14 for esophageal, 1.03 for stomach, 0.94 for colorectal, 0.93 for pancreatic, 1.10 for laryngeal, 0.88 for lung, 0.96 for breast, 1.06 for endometrial, 1.12 for ovarian, 1.00 for prostate, 0.93 for bladder and 1.13 for lymphoid malignancies. The RR was of borderline significance only for kidney cancer (RR = 1.20; 95% confidence interval, CI, 1.00-1.45). All the corresponding continuous estimates ranged between 0.95 and 1.03, and none of them was significant. Among never-smokers, borderline associations with dietary acrylamide emerged for endometrial (RR = 1.23; 95% CI, 1.00-1.51) and ovarian (RR = 1.39; 95% CI, 0.97-2.00) cancers. This systematic review and meta-analysis of epidemiological studies indicates that dietary acrylamide is not related to the risk of most common cancers. A modest association for kidney cancer, and for endometrial and ovarian cancers in never smokers only, cannot be excluded.

Dietary acrylamide and human cancer: a systematic review of literature

Cancer remains the second leading cause of death in the United States, and the number of cases is expected to continue to rise worldwide. Cancer prevention strategies are crucial for reducing the cancer burden. The carcinogenic potential of dietary acrylamide exposure from cooked foods is unknown. Acrylamide is a by-product of the common Maillard reaction where reducing sugars (i.e., fructose and glucose) react with the amino acid, asparagine. Based on the evidence of acrylamide carcinogenicity in animals, the International Agency for Research on Cancer has classified acrylamide as a group 2A carcinogen for humans. Since the discovery of acrylamide in foods in 2002, a number of studies have explored its potential as a human carcinogen. This article outlines a systematic review of dietary acrylamide and human cancer, acrylamide exposure and internal dose, exposure assessment methods in the epidemiologic studies, existing data gaps, and future directions. A majority of the studies reported no statistically significant association between dietary acrylamide intake and various cancers, and few studies reported increased risk for renal, endometrial, and ovarian cancers; however, the exposure assessment has been inadequate leading to potential misclassification or underestimation of exposure. Future studies with improved dietary acrylamide exposure assessment are encouraged.

Current issues in dietary acrylamide: formation, mitigation and risk assessment

Acrylamide (AA) is known as a neurotoxin in humans and it is classified as a probable human carcinogen by the International Agency of Research on Cancer. AA is produced as by-product of the Maillard reaction in starchy foods processed at high temperatures (>120 °C). This review includes the investigation of AA precursors, mechanisms of AA formation and AA mitigation technologies in potato, cereal and coffee products. Additionally, most relevant issues of AA risk assessment are discussed. New technologies tested from laboratory to industrial scale face, as a major challenge, the reduction of AA content of browned food, while still maintaining its attractive organoleptic properties. Reducing sugars such as glucose and fructose are the major contributors to AA in potato-based products. On the other hand, the limiting substrate of AA formation in cereals and coffee is the free amino acid asparagine. For some products the addition of glycine or asparaginase reduces AA formation during baking. Since, for potatoes, the limiting substrate is reducing sugars, increases in sugar content in potatoes during storage then introduce some difficulties and potentially quite large variations in the AA content of the final product. Sugars in potatoes may be reduced by blanching. Levels of AA in different foods show large variations and no general upper limit is easily applicable, since some formation will always occur. Current policy is that practical measures should be taken voluntarily to reduce AA formation in vulnerable foods since AA is considered a health risk at the concentrations found in foods.

Urinary levels of N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA), an acrylamide metabolite, in Korean children and their association with food consumption

Acrylamide (AA), a probable human carcinogen, is present in high-temperature-processed foods, and has frequently been detected in humans worldwide. In the present study, the levels of a major AA metabolite, N-acetyl-S-(2-carbamoylethyl)-cysteine (AAMA) were measured in urine samples collected in two separate events with 3d interval from Korean children (n=31, 10-13 years old), and their diets were surveyed for 4d period prior to the second urine sampling. Daily AA intake was estimated from AAMA urinary levels and the influence of food consumption on urinary AAMA levels was investigated. The concentrations of metabolite AAMA in urine ranged between 15.4 and 196.3 ng/mL, with a median level of 68.1 ng/mL, and the levels varied by day considerably even in a given child. Children who were exposed to environmental smoke at home exhibited significantly higher levels of AAMA in urine, suggesting the importance of passive smoking as a source of AA exposure among children. Median (95th percentile) values of daily AA intake in Korean children were 1.04 (2.47)μg/kgbodyweight/day, which is higher than those reported elsewhere. After adjustment for gender, body mass index, and smoking status of family members, the consumptions of cracker and chocolate were identified to be significantly associated with the concentrations of AAMA in urine. The result of this study will provide information useful for developing public health and safety management for AA.

Acrylamide hemoglobin adduct levels and ovarian cancer risk: a nested case-control study

BACKGROUND

Acrylamide is a probable human carcinogen formed during cooking of starchy foods. Two large prospective cohort studies of dietary acrylamide intake and ovarian cancer risk observed a positive association, although two other studies reported no association.

METHODS

We measured acrylamide exposure using red blood cell acrylamide and glycidamide hemoglobin adducts among women in two large prospective cohorts: the Nurses' Health Study and Nurses' Health Study II. Between blood collection and 2010, we identified 263 incident cases of epithelial ovarian cancer, matching two controls per case. We used logistic regression models to examine the association between acrylamide exposure and ovarian cancer risk, adjusting for matching factors, family history of ovarian cancer, tubal ligation, oral contraceptive use, body mass index, parity, alcohol intake, smoking, physical activity, and caffeine intake.

RESULTS

The multivariate-adjusted relative risk (RR) of ovarian cancer comparing the highest versus lowest tertile of total acrylamide adducts was 0.79 (95% CI, 0.50-1.24, P trend = 0.08). The comparable RR of ovarian cancer among non-smokers at blood draw was 0.85 (95% CI, 0.57-1.27, P trend = 0.14). The association did not differ by tumor histology (serous invasive versus not), P for heterogeneity = 0.86. Individual adduct types (acrylamide or glycidamide) were not associated with risk.

CONCLUSIONS

We observed no evidence that acrylamide exposure as measured by adducts to hemoglobin is associated with an increased risk of ovarian cancer.

IMPACT

Our finding indicates that acrylamide intake may not increase risk of ovarian cancer.

Dietary acrylamide intake and the risk of lymphatic malignancies: the Netherlands Cohort Study on diet and cancer

Background

Acrylamide, a probable human carcinogen, is present in many everyday foods. Since the finding of its presence in foods in 2002, epidemiological studies have found some suggestive associations between dietary acrylamide exposure and the risk of various cancers. The aim of this prospective study is to investigate for the first time the association between dietary acrylamide intake and the risk of several histological subtypes of lymphatic malignancies.

Methods

The Netherlands Cohort Study on diet and cancer includes 120,852 men and women followed-up since September 1986. The number of person years at risk was estimated by using a random sample of participants from the total cohort that was chosen at baseline (n  = 5,000). Acrylamide intake was estimated from a food frequency questionnaire combined with acrylamide data for Dutch foods. Hazard ratios (HRs) were calculated for acrylamide intake as a continuous variable as well as in categories (quintiles and tertiles), for men and women separately and for never-smokers, using multivariable-adjusted Cox proportional hazards models.

Results

After 16.3 years of follow-up, 1,233 microscopically confirmed cases of lymphatic malignancies were available for multivariable-adjusted analysis. For multiple myeloma and follicular lymphoma, HRs for men were 1.14 (95% CI: 1.01, 1.27) and 1.28 (95% CI: 1.03, 1.61) per 10 µg acrylamide/day increment, respectively. For never-smoking men, the HR for multiple myeloma was 1.98 (95% CI: 1.38, 2.85). No associations were observed for women.

Conclusion

We found indications that acrylamide may increase the risk of multiple myeloma and follicular lymphoma in men. This is the first epidemiological study to investigate the association between dietary acrylamide intake and the risk of lymphatic malignancies, and more research into these observed associations is warranted.

Dietary acrylamide exposure among Finnish adults and children: the potential effect of reduction measures

A deterministic exposure assessment using the Nusser method that adjusts for within-subject variation and for nuisance effects among Finnish children and adults was carried out. The food consumption data covered 2038 adults (25-74 years old) and 1514 children of 1, 3 and 6 years of age, with the data on foods' acrylamide content obtained from published Finnish studies. We found that acrylamide exposure was highest among the 3-year-old children (median = 1.01 µg kg(-1) bw day(-1), 97.5th percentile = 1.95 µg kg(-1) bw day(-1)) and lowest among 65-74-year-old women (median = 0.31 µg kg(-1) bw day(-1), 97.5th percentile = 0.69 µg kg(-1) bw day(-1)). Among adults, the most important source of acrylamide exposure was coffee, followed by casseroles rich in starch, then rye bread. Among children, the most important sources were casseroles rich in starch and then biscuits and, finally, chips and other fried potatoes. Replacing lightly roasted coffee with dark-roasted, swapping sweet wheat buns for biscuits, and decreasing the acrylamide content of starch-based casseroles and rye bread by 50% would result in a 50% decrease in acrylamide exposure in adults. Among children, substituting boiled potatoes for chips and other friend potatoes and replacing biscuits with sweet wheat buns while lowering the acrylamide content of starch-based casseroles by 50% would lead to acrylamide exposure that is only half of the original exposure. In conclusions, dietary modifications could have a large impact in decreasing acrylamide exposure.

Dietary determinants for Hb-acrylamide and Hb-glycidamide adducts in Danish non-smoking women

Acrylamide (AA) is a probable human carcinogen that is formed in heat-treated carbohydrate-rich foods. The validity of FFQ to assess AA exposure has been questioned. The aim of the present cross-sectional study was to investigate dietary determinants of Hb-AA and Hb-glycidamide (GA) adducts. The study included 537 non-smoking women aged 50–65 years who participated in the Diet, Cancer and Health cohort (1993–97). At study baseline, blood samples and information on dietary and lifestyle variables obtained from self-administered questionnaires were collected. From blood samples, Hb-AA and Hb-GA in erythrocytes were analysed by liquid chromatography/MS/MS. Dietary determinants were evaluated by multiple linear regression analyses adjusted for age and smoking behaviour among ex-smokers. The median for Hb-AA was 35 pmol/g globin (5th percentile 17, 95th percentile 89) and for Hb-GA 21 pmol/g globin (5th percentile 8, 95th percentile 49). Of the dietary factors studied, intakes of coffee and chips were statistically significantly associated with a 4 % per 200 g/d (95 % CI 2, 7; P < 0·0001) and an 18 % per 5 g/d (95 % CI 6, 31; P = 0·002) higher Hb-AA, respectively. This model explained 17 % of the variation in Hb-AA. Intakes of coffee and biscuits/crackers were statistically significantly associated with a 3 % per 200 g/d (95 % CI 1, 6; P = 0·005) and 12 % per 10 g/d (95 % CI 3, 23; P = 0·01) higher Hb-GA, respectively. This model explained 12 % of the variation in Hb-GA. In conclusion, only a few dietary determinants of Hb-AA and Hb-GA were identified. Thus, the present study implies that dietary intake measured by an FFQ explains only to a limited extent the variation in Hb-AA and Hb-GA concentrations.

Dietary acrylamide intake and the risk of cancer among Finnish male smokers

OBJECTIVE

To assess the association between dietary acrylamide intake and the risk of cancer among male smokers.

METHODS

The study consisted of 27,111 male smokers, aged 50-69 years, without history of cancer. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in Finland. The men completed a validated dietary questionnaire and a questionnaire on general background characteristics (including smoking habits) at baseline. Incident cases of cancer were identified through the national Finnish Cancer Registry.

RESULTS

During an average 10.2 year follow-up, 1,703 lung cancers, 799 prostate cancers, 365 urothelial cancers, 316 colorectal cancers, 224 stomach cancers, 192 pancreatic cancers, 184 renal cell cancers, and 175 lymphomas were diagnosed. Dietary acrylamide intake was positively associated with the risk of lung cancer; relative risk (RR) in the highest versus the lowest quintile in the multivariable-adjusted model was 1.18 ((95% confidence interval (CI) 1.01-1.38, p for trend 0.11). Other cancers were not associated with acrylamide intake.

CONCLUSIONS

High acrylamide intake is associated with increased risk of lung cancer but not with other cancers in male smokers.

Modification of major plasma proteins by acrylamide and glycidamide: Preliminary screening by nano liquid chromatography with tandem mass spectrometry

Environmental and food-borne acrylamide is a suspected carcinogen in humans and is associated with several cancer types. Its biological metabolite, glycidamide, is also harmful to human health. The presence of acrylamide in the living environment makes this toxic chemical an important public health issue. Acrylamide and glycidamide bind with proteins to form protein adducts in metabolic processes. These metabolic adducts can be considered environmental modifications of proteins. This study used a simple proteomic strategy to identify acrylamide and glycidamide adducts bound in major plasma proteins. After simple sample preparation, new protein modifications by acrylamide and glycidamide were identified using nano LC combined with quadruple time-of-flight (Q-TOF) mass spectrometry. This method required only 10 μL of human plasma sample for protein modification survey. Hopefully, this strategy can help to discover protein-acrylamide (or glycidamide) adducts that are biomarkers of human exposure to high-dose acrylamide. These biomarkers may also elucidate the metabolic pathways of acrylamide and glycidamide.

The carcinogenicity of dietary acrylamide intake: a comparative discussion of epidemiological and experimental animal research

Since 2002, it is known that the probable human carcinogen acrylamide is present in commonly consumed carbohydrate-rich foods, such as French fries and potato chips. In this review, the authors discuss the body of evidence on acrylamide carcinogenicity from both epidemiological and rodent studies, including variability, strengths and weaknesses, how both types of evidence relate, and possible reasons for discrepancies. In both rats and humans, increased incidences of various cancer types were observed. In rats, increased incidences of mammary gland, thyroid tumors and scrotal mesothelioma were observed in both studies that were performed. In humans, increased risks of ovarian and endometrial cancers, renal cell cancer, estrogen (and progesterone) receptor-positive breast cancer, and oral cavity cancer (the latter in non-smoking women) were observed. Some cancer types were found in both rats and humans, e.g., endometrial cancer (observed in one of the two rat studies), but there are also some inconsistencies. Interestingly, in humans, some indications for inverse associations were observed for lung and bladder cancers in women, and prostate and oro- and hypopharynx cancers in men. These latter observations indicate that genotoxicity may not be the only mechanism by which acrylamide causes cancer. The estimated risks based on the epidemiological studies for the sites for which a positive association was observed were considerably higher than those based on extrapolations from the rat studies. The observed pattern of increased risks in the rat and epidemiological studies and the decreased risks in the epidemiological studies suggests that acrylamide might influence hormonal systems, for which rodents may not be good models.

Determination of acrylamide level in popular Iranian brands of potato and corn products

Acrylamide is a chemical found in starchy foods that have been cooked at high temperatures. These include crisps, chips, bread and crisp breads. It was first discovered by scientists in Sweden in 2002. The Objective of this study is to determine the level of acrylamide in popular Iranian brands of potato crisps and corn products, produced by domestic food industrial factories. For this reason 7 brands of potato and 8 brands of corn products (10 each) were collected, crashed and after preparing the extracts of each sample, using LC-MS-MS spectrometry for measuring acrylamide amount. Results showed that in different brands of potato and corn products there were different amounts (244-1688 microg/kg) and (<30-410 microg/kg) of acrylamide, respectively. As acrylamide is a dangerous toxin for human health, so it needs to reduce the level of acrylamide in these products that are used extensively by people specially children.

Dietary acrylamide intake and the risk of head-neck and thyroid cancers: results from the Netherlands Cohort Study

Acrylamide exposure has been related to an increased incidence of oral and thyroid tumors in animal studies. In 1986, 120,852 persons (aged 55-69 years) were included in the Netherlands Cohort Study. Dietary acrylamide intake was assessed with a food frequency questionnaire and was based on chemical analysis of all relevant Dutch foods. Hazard ratios were adjusted for smoking and other confounders. After 16.3 years of follow-up, there were 101, 83, 180, and 66 cases of oral cavity, oro-hypopharynx, larynx, and thyroid cancer, respectively. Average daily dietary acrylamide intake was 21.8 microg (standard deviation, 12.1). Dietary acrylamide intake was not associated with increased risk of oral cavity (hazard ratio (HR) per 10-microg intake/day = 0.90, 95% confidence interval (CI): 0.73, 1.10), oro-hypopharynx (HR = 0.74, 95% CI: 0.53, 1.03), larynx (HR = 1.05, 95% CI: 0.91, 1.21), or thyroid (HR = 1.03, 95% CI: 0.82, 1.27) cancer. For nonsmokers, hazard ratios were not increased either. Dietary acrylamide was statistically significantly associated with increased risk of oral cavity cancer in female nonsmokers, but case numbers were small. Dietary acrylamide intake was not positively associated with risk of head-neck and thyroid cancer, except with oral cavity cancer risk for female nonsmokers. A negative association for males was indicated.