Dietary acrylamide and cancer of the large bowel, kidney, and bladder: absence of an association in a population-based study in Sweden

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

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

Dietary Heat-Treatment Contaminants Exposure and Cancer: A Case Study from Turkey

In this study, the 10-year dietary habits of patients diagnosed with cancer (n = 1155) were retrospectively analyzed, and the relationships between dietary (red meat, white meat, fish meat, French fries, bread, instant coffee, ready-to-drink coffee, Turkish coffee, and black tea) heterocyclic amines, polycyclic aromatic hydrocarbons, acrylamide, and N-nitrosamine-based risk scores and cancer types were statistically evaluated. The foods with the highest and lowest mean dietary heat-treatment contaminant risk scores were red meat and ready-to-drink coffee, respectively. There were statistically significant differences in the dietary heat-treatment contamination risk scores based on the cancer patients' demographic characteristics (sex, age, smoking, and body mass index) (p < 0.05). According to the cancer types, the systems with the highest and lowest dietary heat-treatment contaminant risk scores were determined as other (brain, thyroid, lymphatic malignancies, skin, oro- and hypopharynx, and hematology) and the reproductive (breast, uterus, and ovary) system, respectively. The relationship between instant coffee consumption and respiratory system cancer types, the frequency of consumption of French fries and urinary system cancer types and the consumption of meat products and gastrointestinal system cancer types were determined. It is thought that this study contains important findings regarding the relationship between dietary habits and cancer and will be a good source for other studies to be conducted in this context.

Vacuum impregnation pre-treatment: A novel method for incorporating mono- and divalent cations into potato strips to reduce the acrylamide formation in French fries

The effect of different vacuum impregnation (VI) pre-treatments of potato strips [in water (control), NaCl, KCl or CaCl2 (0.1 M) for 10 and 15 min] on acrylamide formation in French fries after deep frying in sunflower oil at 175°C for 5 min was determined. The acrylamide content of fries prepared with potato strips pre-treated by VI in distilled water decreased from 0.82 to 0.24 µg/g when time increased to 15 min. Moreover, the acrylamide content of fries from 10 min-KCl pre-treatment (0.35 µg/g) decreased significantly to 0.04 µg/g when time was 15 min (p < 0.05). In comparison to control (10 min), the VI pre-treatment in KCl and NaCl for 15 min reduced the relative content of acrylamide by 95 and 91%, respectively, and VI in distilled water was able to decrease this value by 71%. Results indicated that monovalent cations (K and Na) were more effective in reducing acrylamide formation than divalent cation (Ca2+) when the VI pre-treatment time increased to 15 min. In conclusion, VI as a pre-treatment for mono- and divalent cations in fried potato production could be a useful technique in industrial applications to reduce acrylamide formation in fries in a short time.

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 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.

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.

Potato Consumption and Risk of Site-Specific Cancers in Adults: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies

The etiology of cancer type may vary significantly due to anatomy, embryology, and physiology of the cancer site. Although the association between potato consumption and colorectal cancer (CRC) was summarized in a 2018 meta-analysis of 5 cohort studies, to the best of our knowledge, no meta-analysis has evaluated potato consumption in relation to multiple cancer sites in adults. Medline/PubMed, ISI Web of Knowledge, Scopus, and the Cochrane Database of Systematic Reviews were searched for relevant publications through August 2020. We selected cohort or case-control studies conducted in adults that reported risk estimates (relative risk [RRs], HRs, and ORs) of potato intake for any cancer type. Random effects meta-analyses compared high and low intake categories. Twenty prospective cohort studies (total n = 785,348) including 19,882 incident cases, and 36 case-control studies (21,822 cases; 66,502 controls) were included. Among cohort studies, we did not find an association between high versus low intake of total potato (white and yellow) consumption and overall cancers: 1.04 (95% CI: 0.96, 1.11; tau2 = 0.005, n = 18). We found no relation between total potato consumption (high compared with low intake) and risk of CRC, pancreatic cancer, colon, gastric, breast, prostate, kidney, lung, or bladder cancer in cohort or case-control studies. We did not find an association between high versus low consumption of potato preparations (boiled/fried/mashed/roasted/baked) and risk of gastrointestinal-, sex-hormone-, or urinary-related cancers in cohort or case-control studies. Certainty of the evidence was low for total cancer, CRC, colon, rectal, renal, pancreatic, breast, prostate, and lung cancer and very low for gastric and bladder cancer. In conclusion, potato intake or potato preparations were not associated with multiple cancer sites when comparing high and low intake categories. This finding was consistent with the findings from the 2018 meta-analysis regarding potato intake and risk of CRC.

Biomedical rationale for acrylamide regulation and methods of detection

Acrylamide is the product of the Maillard reaction, which occurs when starchy, asparagine-rich foods including potato or grain products and coffee are fried, baked, roasted, or heated. Studies in rodents provide evidence that acrylamide is carcinogenic and a male reproductive harmful agent when administered in exceedingly high levels. A 2002 study identified acrylamide in popular consumer food and beverage products, stimulating the European Union (EU) and California to legislate public notice of acrylamide presence in fried and baked foods, and coffee products. The regulatory legislation enacted in the EU and California has scientists working to develop foods and processes aimed at reducing acrylamide formation and advancing rapid and accurate analytical methods for the quantitative and qualitative determination of acrylamide in food and beverage products. The purpose of this review is to survey the studies performed on rodents and humans that identified the potential health impact of acrylamide in the human diet, and provide insight into established and emerging analytical methods used to detect acrylamide in blood, aqueous samples, and food.

Dietary Acrylamide Intake and the Risks of Renal Cell, Prostate, and Bladder Cancers: A Japan Public Health Center-Based Prospective Study

Acrylamide can be carcinogenic to humans. However, the association between the acrylamide and the risks of renal cell, prostate, and bladder cancers in Asians has not been assessed. We aimed to investigate this association in the Japan Public Health Center-based Prospective Study data in 88,818 Japanese people (41,534 men and 47,284 women) who completed a food frequency questionnaire in the five-year follow-up survey in 1995 and 1998. A validated food frequency questionnaire was used to assess the dietary acrylamide intake. Cox proportional hazard regression models were used to estimate hazard ratios and 95% confidence intervals (CIs). During a mean follow-up of 15.5 years (15.2 years of prostate cancer), 208 renal cell cancers, 1195 prostate cancers, and 392 bladder cancers were diagnosed. Compared to the lowest quintile of acrylamide intake, the multivariate hazard ratios for the highest quintile were 0.71 (95% CI: 0.38–1.34, p for trend = 0.294), 0.96 (95% CI: 0.75–1.22, p for trend = 0.726), and 0.87 (95% CI: 0.59–1.29, p for trend = 0.491) for renal cell, prostate, and bladder cancers, respectively, in the multivariate-adjusted model. No significant associations were observed in the stratified analyses based on smoking. Dietary acrylamide intake was not associated with the risk of renal cell, prostate, and bladder cancers.

Mitochondrial, lysosomal and DNA damages induced by acrylamide attenuate by ellagic acid in human lymphocyte

Acrylamide (AA), is an important contaminant formed during food processing under high temperature. Due to its potential neurotoxicity, reproductive toxicity, hepatotoxicity, immunotoxicity, genotoxicity and carcinogenicity effects, this food contaminant has been recognized as a human health concern. Previous studies showed that acrylamide-induced toxicity is associated with active metabolite of acrylamide by cytochrome P450 enzyme, oxidative stress, mitochondrial dysfunction and DNA damage. In the current study, we investigated the role of oxidative stress in acrylamide's genotoxicity and therapeutic potential role of ellagic acid (EA) in human lymphocytes. Human lymphocytes were simultaneously treated with different concentrations of EA (10, 25 and 50 μM) and acrylamide (50 μM) for 4 h at 37°C. After 4 hours of incubation, the toxicity parameters such cytotoxicity, ROS formation, oxidized/reduced glutathione (GSH/GSSG) content, malondialdehyde (MDA) level, lysosomal membrane integrity, mitochondria membrane potential (ΔΨm) collapse and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were analyzed using biochemical and flow cytometry evaluations. It has been found that acrylamide (50 μM) significantly increased cytotoxicity, ROS formation, GSH oxidation, lipid peroxidation, MMP collapse, lysosomal and DNA damage in human lymphocytes. On the other hand, cotreatment with EA (25 and 50 μM) inhibited AA-induced oxidative stress which subsequently led to decreasing of the cytotoxicity, GSH oxidation, lipid peroxidation, MMP collapse, lysosomal and DNA damage. Together, these results suggest that probably the co-exposure of EA with foods containing acrylamide could decrease mitochondrial, lysosomal and DNA damages, and oxidative stress induced by acrylamide in human body.

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.

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.

Dietary Acrylamide Intake and Risk of Esophageal, Gastric, and Colorectal Cancer: The Japan Public Health Center-Based Prospective Study

BACKGROUND

Acrylamide has been classified as a probable human carcinogen based chiefly on laboratory evidence. However, the influence of dietary acrylamide intake on risk of esophageal, gastric, and colorectal cancer has not been extensively studied. We aimed to evaluate the association between dietary acrylamide intake and esophageal, gastric, and colorectal cancer using data from the Japan Public Health Center-based Prospective Study.

METHODS

Our study included 87,628 participants who completed a food-frequency questionnaire at enrollment in 1990 and 1993. We used Cox proportional hazards regression models to estimate hazards ratios and 95% confidence intervals (CI) after adjusting for confounding factors.

RESULTS

After 15.5, 15.3, and 15.3 mean years of follow-up for esophageal, gastric, and colorectal cancer, we identified and analyzed 391 esophageal, 2,218 gastric, and 2,470 colorectal cancer cases, respectively. Compared with the lowest quintile of acrylamide intake, the multivariate HR for the highest quintile was 0.86 (95% CI, 0.53-1.39; P _trend = 0.814), 0.84 (95% CI, 0.69-1.01; P _trend = 0.301), and 0.93 (95% CI, 0.79-1.08; P _trend = 0.165) for esophageal, gastric, and colorectal cancer, respectively, in the multivariable-adjusted model. Furthermore, no significant associations were observed when the participants were stratified by cancer subsites.

CONCLUSIONS

In conclusion, this study demonstrated that dietary acrylamide intake was not associated with increased risk of esophageal, gastric, or colorectal cancer among the Japanese population.

IMPACT

It is the first time to assess the effect of dietary acrylamide intake on risk of digestive system cancer in Asian populations.

Evaluation of the protective effects of Ganoderma atrum polysaccharide on acrylamide-induced injury in small intestine tissue of rats

This research confirmed the protective effects of Ganoderma atrum polysaccharide (PSG-1) on acrylamide (AA) induced intestinal injury in rats.

Non-Occupational Risk Factors for Bladder Cancer a Case-Control Study

Aims

The aim of this study was to determine non-occupational risk factors for bladder cancer in Serbia.

Methods and design

A hospital-based, case-control study included 130 newly diagnosed bladder cancer patients and the same number of individually matched controls with respect to sex, age (± 2 years) and type of residence (rural or urban), from the Clinical Center of Serbia in Belgrade and from the Clinical Center in Kragujevac in central Serbia. The study took place from June 1997 to March 1999.

Results

According to multivariate logistic regression analysis, there was an association between: frequency of daily urination (OR = 0.18; 95% CI = 0.08-0.39); consumption of liver (OR = 13.81; 95% CI = 2.49-76.69), canned meat (OR = 8.38; 95% CI = 1.74-40.36), fruit juices (OR = 0.08; 95% CI = 0.01-0.56); the highest fertile of pork (OR = 4.55; 95% CI = 1.30-15.93), cabbage (OR = 0.25; 95% CI = 0.06-1.01) and vinegar (OR = 4.41; 95% CI = 1.18-16.50) intake and risk for bladder cancer.

Conclusions

Consumption of liver, canned meat, pork (h vs I tertile) and vinegar (m vs I tertile) was indicated as a risk factor for bladder cancer, whereas frequent daily urination, consumption of fruit juices and cabbage (h vs I fertile) were indicated as protective factors.

The Impact of the Roast Levels of Coffee Extracts on their Potential Anticancer Activities

Coffee is one of the most widely consumed beverages in the world and contains numerous phytochemicals that are beneficial to consumer health. The phytochemical profile of coffee, however, can be affected by the roast level. In this study, we compared the effect of roasting level on the growth inhibitory activity of HT-29 (colon) and SCC-25 (oral) cancer cell lines. The different roasting stages selected for this study were green, cinnamon/blonde, city/medium, full city/medium-dark, and full city plus/dark. Cancer cells were treated with various concentrations of coffee extracts for 72 hr. Cell viability was quantified using the thiazolyl blue tetrazolium bromide assay. It was found that the lighter roast extracts, Cinnamon in particular, reduced cell growth more than darker roast extracts. The Cinnamon extract had the greatest amount of total phenolic content and antioxidant activity. Relative levels of gallic, caffeic, and chlorogenic acid in the extracts were also compared. The Cinnamon coffee extract had the highest levels of gallic and caffeic acids, which have both been widely-regarded as bioactive phytochemicals. In conclusion, the consumption of lighter roasted coffee, may contribute to the prevention of certain types of cancer such as oral and colon.

PRACTICAL APPLICATION

Chemical compounds in coffee may reduce the risk for certain types of cancers. These compounds may be particularly abundant in lighter roasted coffee. Therefore, lighter roasted coffee could contribute to the prevention of cancer through a healthy diet.

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.

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.

The red flour beetle Tribolium castaneum allows for the convenient determination of fitness and survival as a measure of toxic effects of the food contaminant acrylamide

Acrylamide  is a toxic ingredient generated as a by-product of the Maillard reaction in starchy foods processed at temperatures above 120°C. Here we used the red flour beetle Tribolium castaneum as a model organism to test the effects of acrylamide on fitness and survival. Beetles were fed on flour spiked with acrylamide between 0.5% and 10% at 32°C over 2 weeks. Fitness of the beetles was tested by measuring the running distance and survival was recorded after 2 weeks of feeding at increased temperatures at 42°C. Both parameters were dose-dependent reduced by acrylamide. Knockdown of gene homologues of ahr, the arylhydrocarbon receptor, and of nrf-2, the nuclear factor erythroid 2-related factor 2, both reduced fitness and survival. Application of 0.5% acrylamide under knockdown of each factor further reduced fitness and survival, suggesting that ahr and nrf-2 are important for an adequate response to the toxicant. RNA-interference for ahr blocked completely the increase in nrf-2 mRNA levels, suggesting that the actions of ahr on acrylamide detoxification are mediated via Nrf-2.

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.

Relation between dietary acrylamide exposure and biomarkers of internal dose in Canadian teenagers

Acrylamide (AA) is a probable human carcinogen found in several foods. Little information is available regarding exposure of adolescents, a subgroup potentially consuming more AA-rich foods. We investigated the relationship between dietary AA intake and levels of biomarkers of exposure (urinary metabolites and hemoglobin adducts) in 195 non-smoking teenagers of Montreal Island aged 10-17 years. Dietary habits and personal characteristics were documented by questionnaire. AA and its metabolites were quantified in 12-h urine collections by LC-MS/MS. Hemoglobin adducts from 165 blood samples were also analyzed by LC-MS/MS. Most prevalent urinary metabolites were NACP and NACP-S, with respective geometric mean concentrations of 31.2 and 14.2 μmol/mol creatinine. Geometric mean concentrations of AAVal and GAVal (hemoglobin adducts of AA and glycidamide (GA) with N-terminal valine residues) were 45.4 and 45.6 pmol/g globin, respectively. AA intake during the 2 days before urine collection was a significant predictor of NACP+NACP-S urinary concentrations (P<0.0001). AA intakes during the month before blood collection (P<0.0001) and passive smoking (P<0.05) were associated with adduct levels. Levels of hemoglobin adducts were above biomonitoring equivalent values corresponding to a 1 × 10(-4) excess cancer risk, which may indicate the need to reduce AA exposure in the population.

Dietary acrylamide intake and the risk of colorectal cancer with specific mutations in KRAS and APC

Acrylamide, a probable human carcinogen, is present in heat-treated carbohydrate-rich foods. Epidemiological studies have not shown a clear association between acrylamide intake and colorectal cancer (CRC) risk. This may be due to the molecular heterogeneity in colorectal tumors, which was not taken into consideration before. Since the acrylamide metabolite glycidamide induces specific DNA mutations in rodents, we investigated whether acrylamide is associated with CRC risk characterized by mutations in Kirsten-ras (KRAS) and adenomatous polyposis coli (APC); key genes in colorectal carcinogenesis. This case-cohort analysis, within the Netherlands Cohort Study on diet and cancer, was based on 7.3 years of follow-up. Acrylamide intake was assessed with a food frequency questionnaire. Mutation analysis of codons 1286-1520 in exon 15 in APC and codons 12 and 13 in exon 1 in KRAS was performed on tumor tissue of 733 cases. Hazard ratios (HR) were calculated using Cox proportional hazards analysis. Among men, acrylamide intake was statistically significantly associated with an increased risk of particularly tumors with an activating KRAS mutation {HR fourth versus first quartile: 2.12 [95% confidence interval (CI): 1.16-3.87], P trend: 0.01}. Among women, acrylamide intake was statistically significantly associated with a decreased risk of particularly tumors with a truncating APC mutation (fourth versus first quartile: 0.47 (95% CI: 0.23-0.94), P trend: 0.02), but only in the highest quartile of intake. This is the first study to show that acrylamide might be associated with CRC with specific somatic mutations, differentially in men and women. More research is needed to corroborate or refute these findings.

Determination of acrylamide levels of "Izmir gevregi" and effects of cooking parameters on acrylamide formation

Acrylamide level of "Izmir gevregi" samples were detected by liquid chromatography-tandem mass spectrometry. Thirty samples of "Izmir gevregi" supplied from bakeries were analyzed to determine acrylamide levels for the first time. The average acrylamide level of "Izmir gevregi" samples was found to be 68.63 μg/kg. In this study, "Izmir gevregi" samples were cooked in laboratory conditions, first at 3 different time intervals at 280, 285, and 290 °C, after immersing in grape molasses. Shapped "Izmir gevregi" dough samples were also immersed in grape molases, mulbery molasses, and burned sugar solutions at different time intervals and cooked. We detected that acrylamide formation was increased by the incease of cooking temperature, time, and by using the same molasses several times. For the reduction of acrylamide level, KCl was added to dough formulations at different levels. Adding of KCl to dough at 25% and 50% of NaCl content decreased acrylamide values from 101.27 μg/kg to 69.88 and 51.91 μg/kg. By reducing sugar, protein, HMF, pH, and moisture content, L*, a*, and b* parameters were also determined in "Izmir gevregi" samples.

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.

The quality of nutrition and cancer reviews: a systematic assessment

The methodological quality of published reviews of nutrition and cancer (2008-2009) and of the carcinogenicity of acrylamide (1999-2009) was systematically assessed. Each review was examined with respect to four characteristics: whether the purpose of the review was explicitly stated, whether a methods section (detailing the methods used to "weigh" the evidence) was included, whether "weight of evidence" methods were described elsewhere in the paper (e.g., in the discussion), and finally, whether references to recognized "weight of evidence" methods were included. In this study, ninety per cent of a systematically selected sample of recent reviews on nutrition and cancer published in 2008-2009 and 74% of reviews on acrylamide on cancer published in 1999-2009 were found to be methodologically troublesome or frankly unsound. Failure of peer review and editorial oversight are possible explanations, suggesting a broad lack of concern about this issue in the scientific community. If peer reviewers in the nutrition and cancer community do not require "weight of evidence" methods, then these methods may not appear in the published reviews. Similarly, if journal editors (or editorial policies) do not require methods sections in literature reviews, then these sections may not appear. The prerogative of the author(s) seems the most likely determinant of whether a systematic approach is used or not in nutrition and cancer reviews.

Molecular mechanism of acrylamide neurotoxicity: lessons learned from organic chemistry

BACKGROUND

Acrylamide (ACR) produces cumulative neurotoxicity in exposed humans and laboratory animals through a direct inhibitory effect on presynaptic function.

OBJECTIVES

In this review, we delineate how knowledge of chemistry provided an unprecedented understanding of the ACR neurotoxic mechanism. We also show how application of the hard and soft, acids and bases (HSAB) theory led to the recognition that the α,β-unsaturated carbonyl structure of ACR is a soft electrophile that preferentially forms covalent bonds with soft nucleophiles.

METHODS

In vivo proteomic and in chemico studies demonstrated that ACR formed covalent adducts with highly nucleophilic cysteine thiolate groups located within active sites of presynaptic proteins. Additional research showed that resulting protein inactivation disrupted nerve terminal processes and impaired neurotransmission.

DISCUSSION

ACR is a type-2 alkene, a chemical class that includes structurally related electrophilic environmental pollutants (e.g., acrolein) and endogenous mediators of cellular oxidative stress (e.g., 4-hydroxy-2-nonenal). Members of this chemical family produce toxicity via a common molecular mechanism. Although individual environmental concentrations might not be toxicologically relevant, exposure to an ambient mixture of type-2 alkene pollutants could pose a significant risk to human health. Furthermore, environmentally derived type-2 alkenes might act synergistically with endogenously generated unsaturated aldehydes to amplify cellular damage and thereby accelerate human disease/injury processes that involve oxidative stress.

CONCLUSIONS

These possibilities have substantial implications for environmental risk assessment and were realized through an understanding of ACR adduct chemistry. The approach delineated here can be broadly applied because many toxicants of different chemical classes are electrophiles that produce toxicity by interacting with cellular proteins.

Critical review of dose-response options for F344 rat mammary tumors for acrylamide - additional insights based on mode of action

Previous risk assessment reviews analyzed the potential for dietary acrylamide to increase breast cancer risk. Here, we critically review acrylamide animal bioassay data on mammary tumors for human relevance. We applied a systematic evaluation using reasonable standards of scientific certainty and a systematic weight of evidence (WOE) approach to evaluate several hypothesized modes of action (MOA), including (1) genotoxicity related to glycidamide formation and oxidative stress, (2) endocrine effects due to age-related hyperprolactinemia or secondary to neurotoxicity, and (3) epigenetic effects. We conclude that the appropriate approach for low-dose extrapolation of the rat mammary tumors can be narrowed to two options: (1) linear low-dose extrapolation (i.e., based on a MOA of mutagenicity from direct DNA interaction) from a point of departure (POD) for the combined incidence of adenomas and adenocarcinomas, since these tumor types are related; or (2) non-linear extrapolation, using uncertainty factors to estimate a Reference Dose (RfD) from a POD for tumor promotion derived using the combined fibroadenoma, adenoma and adenocarcinoma data. Non-linear extrapolation is used in the latter approach because these combined tumor types are unlikely to be exclusively caused by mutagenicity. Comparison of the WOE for each alternative MOA indicates that a non-linear approach (option 2) is more appropriate for evaluation of acrylamide-induced mammary tumors; a linear approach (option 1) is shown for comparison.

Quantifying exploratory low dose compounds in humans with AMS

Accelerator Mass Spectrometry is an established technology whose essentiality extends beyond simply a better detector for radiolabeled molecules. Attomole sensitivity reduces radioisotope exposures in clinical subjects to the point that no population need be excluded from clinical study. Insights in human physiochemistry are enabled by the quantitative recovery of simplified AMS processes that provide biological concentrations of all labeled metabolites and total compound related material at non-saturating levels. In this paper, we review some of the exploratory applications of AMS (14)C in toxicological, nutritional, and pharmacological research. This body of research addresses the human physiochemistry of important compounds in their own right, but also serves as examples of the analytical methods and clinical practices that are available for studying low dose physiochemistry of candidate therapeutic compounds, helping to broaden the knowledge base of AMS application in pharmaceutical research.

Dietary acrylamide and pancreatic cancer risk in an Italian case--control study

BACKGROUND

Information on the relation between acrylamide exposure and risk of pancreatic cancer is scanty and inconsistent.

PATIENTS AND METHODS

We investigated the issue in a case-control study conducted from 1991 to 2008 in Northern Italy. Cases were 326 patients with incident pancreatic cancer, admitted to major teaching and general hospitals. Controls were 652 subjects admitted to the same hospitals with acute non-neoplastic conditions. Acrylamide mean content of various food items was derived from international databases and Italian sources. Odds ratios (ORs) and 95% confidence intervals (CIs) of pancreatic cancer were derived using conditional logistic regression adjusted for several covariates, including energy intake.

RESULTS

The ORs of pancreatic cancer for subsequent quintiles of acrylamide intake, as compared with the lowest one, were 1.48 (95% CI 0.88-2.50), 1.57 (95% CI 0.91-2.69), 1.70 (95% CI 0.98-2.96) and 1.49 (95% CI 0.83-2.70), with no trend in risk (P value 0.21). The OR for an increase in acrylamide intake of 10 μg/day was 1.01 (95% CI 0.92-1.10). No meaningful difference between ORs was found in strata of smoking habit, alcohol drinking, body mass index and other selected covariates.

CONCLUSION

This study found no association between dietary acrylamide and pancreatic cancer in an Italian population.

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.

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.

Epidemiology and risk factors for kidney cancer

After more than two decades of rising rates, in recent years the total kidney cancer incidence worldwide has shown signs of stabilizing, or even decreasing. In adults, kidney cancer consists of renal cell carcinoma (RCC), the predominant form, and renal transitional cell carcinoma (RTCC); these types primarily arise in the renal parenchyma and renal pelvis, respectively. Although temporal trends by kidney cancer type are not well established worldwide, incidence of RCC in the US has continued to rise, mainly for early-stage tumors, while that of RTCC has declined, and total kidney cancer mortality rates have leveled. Stabilization of kidney cancer mortality rates has also been reported in Europe. These trends are consistent with reports of increasing incidental diagnoses and a downward shift in tumor stage and size in clinical series. The changing prevalence of known risk factors for RCC, including cigarette smoking, obesity, and hypertension, is also likely to affect incidence trends, although their relative impact may differ between populations. Accumulating evidence suggests an etiologic role in RCC for physical activity, alcohol consumption, occupational exposure to trichloroethylene, and high parity among women, but further research is needed into the potential causal effects of these factors. Genetic factors and their interaction with environmental exposures are believed to influence risk of developing RCC, but a limited number of studies using candidate-gene approaches have not produced conclusive results. Large consortium efforts employing genome-wide scanning technology are underway, which hold promise for novel discoveries in renal carcinogenesis.

Protective effect of l-carnitine against acrylamide-induced DNA damage in somatic and germ cells of mice

Recent findings of acrylamide (AA) in many common foods have sparked renewed interest in assessing human health hazards. AA was evaluated by the International Agency for Research on Cancer as probably carcinogenic to humans. For this reason, the aim of this study is to evaluate the potential genotoxic effect of AA using chromosomal aberration analysis and micronucleus (MN) test in mouse bone-marrow cells and morphological sperm abnormalities. The result of the present work indicated that treatment with a single dose of 10, 20, or 30 mg/kg b.wt. of AA for 24 h and the repeated dose of 10 mg/kg b.wt. for 1and 2 weeks induced a statistically significant increase in the percentage of chromosomal aberrations and micronuclei in bone- marrow cells. These percentages reduced significantly in all groups treated with AA and the protective agent l-carnitine. Also the results indicated that the dose 10, 20 and 30 mg/kg b.wt. of AA induced a statistically significant percentage of morphological sperm abnormalities compared with the control group. Such effect reached its maximum (7.24 ± 0.61) with the highest tested dose which reduced to (4.02 ± 0.58) in the group treated with the same dose of AA and l-carnitine. In conclusion, the results confirm the protective role of LC against the mutagenicity of AA.

Lack of modifying effects of prepubertal exposure to acrylamide (AA) on N-methyl-N-nitrosourea (MNU)-induced multi-organ carcinogenesis in F344 rats

Acrylamide (AA) has been reported to be formed in fried and baked foods with various concentrations, and exposure levels to AA from cooked foods in children are estimated to be higher than those in adults. In order to evaluate the carcinogenicity of AA exposure during childhood, we conducted a medium-term carcinogenicity study with prepubertal administration of AA followed by treatments of a multi-organ-targeted genotoxic carcinogen and a promoting agent for thyroid carcinogenesis in rats. A total of 36 postpartum F344 rats were given drinking water containing AA at 0, 20, 40 or 80 ppm for 3 weeks during the lactation period, and their weaned offspring received the same AA-containing water for 3 more weeks. Offspring were then injected with N-methyl-N-nitrosourea (MNU; 40 mg/kg body weight, i.p.) once at week 7 after birth. Half the animals of the 0 and 40 ppm groups were additionally treated with the anti-thyroid agent sulfadimethoxine (SDM; 125 ppm) in the drinking water thereafter. Offspring were subjected to complete necropsy at week 50. All the major organs and macroscopic abnormalities were excised and examined histopathologically. There was no significant difference in the incidences of hyperplastic and neoplastic lesions in the target organs of AA and/or MNU, such as the brain, spinal cord, pituitary gland, thyroid, adrenal glands, uterus, mammary glands, clitoral gland and tunica vaginalis. In conclusion, no significant modifying actions of AA on MNU-induced multi-organ carcinogenesis were exhibited in any organs of rats when exposed prepubertally under the present experimental conditions.