Validation of a food frequency questionnaire measurement of dietary acrylamide intake using hemoglobin adducts of acrylamide and glycidamide

Estimation of intake and quantification of hemoglobin adducts of acrylamide in adolescents in Sweden

Blood samples (n = 600) from participants in the Swedish dietary survey Riksmaten Adolescents 2016-17 were analyzed with respect to hemoglobin (Hb) adducts from acrylamide (AA) and its metabolite glycidamide (GA) as biomarkers of internal dose/exposure. The results are presented from statistical analyses of food consumption data (2-day dietary recall and questionnaires) and measured Hb adduct levels. The estimated exposure as well as consumption data were examined in relation to non-dietary factors such as sex, age (group medians of 12, 15, and 18 years), place of residence (urban/rural), smoking status, and parental education level. The median AA adduct level was estimated to be 34 pmol/g Hb (range 14-225). No significant difference was found for place of residence, parental education, sex, or age. A significant difference was found between the median adduct levels of daily smokers (n = 8) and never smokers (n = 323) in the older age groups, but not between occasional smokers (n = 47) and never smokers. The median differences between daily smokers and never smokers were 76, 40, and 128 pmol/g Hb for AA, GA, and AA + GA, respectively. The median AA intake for the whole group of adolescents, as estimated from dietary recall data combined with reported concentrations in food, was 0.40 μg/kg bw/day. The corresponding median intake estimated from measured Hb adduct levels of AA was 0.20 μg/kg bw/day. A significant, although low, positive Spearman correlation was found between the two intake estimates (p-value = 8 × 10-3; ρ = 0.11). From the estimated intake of AA from food frequency questionnaires, significance was found for the 15-year-old children with higher AA adduct levels observed at higher consumption frequencies of fried potatoes/French fries. AA is considered a genotoxic carcinogen. For the estimated intake of AA for any age group and method (dietary recall or AA adduct), both a calculated margin of exposure as well as lifetime quantitative cancer risk estimates indicate health concern. A future study on food consumption designed with respect to AA exposure would provide a better understanding of the correlation between consumption and exposure and should give a more reliable estimate of the contribution of dietary AA to the overall cancer risk.

Estimation of life's essential 8 score with incomplete data of individual metrics

Background

The American Heart Association's Life's Essential 8 (LE8) is an updated construct of cardiovascular health (CVH), including blood pressure, lipids, glucose, body mass index, nicotine exposure, diet, physical activity, and sleep health. It is challenging to simultaneously measure all eight metrics at multiple time points in most research and clinical settings, hindering the use of LE8 to assess individuals' overall CVH trajectories over time.

Materials and methods

We obtained data from 5,588 participants in the Nurses' Health Studies (NHS, NHSII) and Health Professionaĺs Follow-up Study (HPFS), and 27,194 participants in the 2005-2016 National Health and Nutrition Examination Survey (NHANES) with all eight metrics available. Individuals' overall cardiovascular health (CVH) was determined by LE8 score (0-100). CVH-related factors that are routinely collected in many settings (i.e., demographics, BMI, smoking, hypertension, hypercholesterolemia, and diabetes) were included as predictors in the base models of LE8 score, and subsequent models further included less frequently measured factors (i.e., physical activity, diet, blood pressure, and sleep health). Gradient boosting decision trees were trained with hyper-parameters tuned by cross-validations.

Results

The base models trained using NHS, NHSII, and HPFS had validated root mean squared errors (RMSEs) of 8.06 (internal) and 16.72 (external). Models with additional predictors further improved performance. Consistent results were observed in models trained using NHANES. The predicted CVH scores can generate consistent effect estimates in associational studies as the observed CVH scores.

Conclusions

CVH-related factors routinely measured in many settings can be used to accurately estimate individuals' overall CVH when LE8 metrics are incomplete.

Estimation of Life's Essential 8 Score with Incomplete Data of Individual Metrics

Background

The American Heart Association's Life's Essential 8 (LE8) is an updated construct of cardiovascular health (CVH), including blood pressure, lipids, glucose, body mass index, nicotine exposure, diet, physical activity, and sleep health. It is challenging to simultaneously measure all eight metrics at multiple time points in most research and clinical settings, hindering the use of LE8 to assess individuals' overall CVH trajectories over time.

Methods and Results

We obtained data from 5,588 participants in the Nurses' Health Studies (NHS, NHSII) and Health Professional's Follow-up Study (HPFS), and 27,194 participants in the 2005-2016 National Health and Nutrition Examination Survey (NHANES) with all eight metrics available. Individuals' overall cardiovascular health (CVH) was determined by LE8 score (0-100). CVH-related factors that are routinely collected in many settings (i.e., demographics, BMI, smoking, hypertension, hypercholesterolemia, and diabetes) were included as predictors in the base models of LE8 score, and subsequent models further included less frequently measured factors (i.e., physical activity, diet, blood pressure, and sleep health). Gradient boosting decision trees were trained with hyper-parameters tuned by cross-validations. The base models trained using NHS, NHSII, and HPFS had validated root mean squared errors (RMSEs) of 8.06 (internal) and 16.72 (external). Models with additional predictors further improved performance. Consistent results were observed in models trained using NHANES. The predicted CVH scores can generate consistent effect estimates in associational studies as the observed CVH scores.

Conclusions

CVH-related factors routinely measured in many settings can be used to accurately estimate individuals' overall CVH when LE8 metrics are incomplete.

Clinical Perspective

What Is New?: Life's Essential 8 (LE8) has great potential to assess and promote cardiovascular health (CVH) across life course, however, it is challenging to simultaneously collect all eight metrics at multiple time points in most research and clinical settings.We demonstrated that CVH-related factors routinely collected in many research and clinical settings can be used to accurately estimate individuals' overall CVH across time even when LE8 metrics are incomplete.What Are the Clinical Implications?: The approach introduced in this study provides a cost-effective and feasible way to estimate individuals' overall CVH.It can be used to track individuals' CVH trajectories in clinical settings.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

Association of maternal polygenic risk scores for mental illness with perinatal risk factors for offspring mental illness

We examined whether genetic risk for mental illness is associated with known perinatal risk factors for offspring mental illness to determine whether gene-environmental correlation might account for the associations of perinatal factors with mental illness. Among 8983 women with 19,733 pregnancies, we found that genetic risk for mental illness was associated with any smoking during pregnancy [attention-deficit hyperactivity disorder (ADHD) and overall genetic risk], breast-feeding for less than 1 month (ADHD, depression, and overall genetic risk), experience of intimate partner violence in the year before the birth (depression and overall genetic risk), and pregestational overweight or obesity (bipolar disorder). These results indicate that genetic risk may partly account for the association between perinatal conditions and mental illness in offspring.

Machine learning prediction of exposure to acrylamide based on modelling of association between dietary exposure and internal biomarkers

The ubiquitous occurrence of acrylamide in various thermal processing food products poses a potential health risk for the public. An accurate exposure assessment is crucial to the risk evaluation of acrylamide. Machine learning emerging as a powerful computational tool for prediction was employed to establish the association between internal exposure and dietary exposure to acrylamide among a Chinese cohort of middle-aged and elderly population (n = 1,272). Five machine learning regression models were constructed and compared to predict the daily dietary acrylamide exposure based on urinary biomarkers including N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA), N-acetyl-S-(2-carbamoylethyl)-L-cysteine-sulfoxide (AAMA-sul), N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA), and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (iso-GAMA). Other important covariates such as age, gender, physical activities, and total energy intake were also considered as predictors in the models. Average dietary intake of acrylamide among Chinese elderly participants was 8.9 μg/day, while average urinary contents of AAMA, AAMA-sul, GAMA, and iso-GAMA were 52.2, 19.1, 4.4, and 1.7 nmol/g Ucr (urine creatinine), respectively. Support vector regression (SVR) model showed the best prediction performance with a R of 0.415, followed by light gradient boosting machine (LightGBM) model (R = 0.396), adjusted multiple linear regression (MLR) model (R = 0.378), neural networks (NN) model (R = 0.365), MLR model (R = 0.363), and extreme gradient boosting (XGBoost) model (R = 0.337). The present study firstly correlated dietary exposure with internal exposure to acrylamide among Chinese elderly population, providing an innovative perspective for the exposure assessment of acrylamide.

Cigarette smoking is associated with acrylamide exposure among the U.S. population: NHANES 2011-2016

2-carbamoylethyl mercapturic acid (2CaEMA, N-Acetyl-S-carbamoylethyl-L-cysteine) is a urinary metabolite and exposure biomarker of acrylamide, which is a harmful volatile organic compound found in cigarette smoke and in some foods. The goal of this study was to determine the association between cigarette smoking and urinary 2CaEMA concentrations among the U.S. population while considering potential dietary sources of acrylamide intake and demographics. We measured 2CaEMA concentrations in urine specimens collected during the National Health and Nutrition Examination Survey 2011-2012, 2013-2014, and 2015-2016 cycles from eligible participants 18 years and older (n = 5443) using liquid chromatography/tandem mass spectrometry. We developed multiple regression models with urinary 2CaEMA concentrations as the dependent variable and sex, age, race/Hispanic origin, reported primary sources of dietary acrylamide intake, and cigarette smoke exposure as independent variables. This study demonstrates that cigarette smoking is strongly associated with urinary 2CaEMA, suggests that cigarette smoking is likely a primary source of acrylamide exposure, and provides a baseline measure for 2CaEMA in the U.S. population.

Hemoglobin adducts of acrylamide in human blood - What has been done and what is next?

Acrylamide forms in many commonly consumed foods. In animals, acrylamide causes tumors, neurotoxicity, developmental and reproductive effects. Acrylamide crosses the placenta and has been associated with restriction of intrauterine growth and certain cancers. The impact on human health is poorly understood and it is impossible to say what level of dietary exposure to acrylamide can be deemed safe as the assessment of exposure is uncertain. The determination of hemoglobin (Hb) adducts from acrylamide is increasingly being used to improve the exposure assessment of acrylamide. We aim to outline the literature on Hb adduct levels from acrylamide in humans and discuss methodological issues and research gaps. A total of 86 studies of 27,966 individuals from 19 countries were reviewed. Adduct levels were highest in occupationally exposed individuals and smokers. Levels ranged widely from 3 to 210 pmol/g Hb in non-smokers and this wide range suggests that dietary exposure to acrylamide varies largely. Non-smokers from the US and Canada had slightly higher levels as compared with non-smokers from elsewhere, but differences within studies were larger than between studies. Large studies with exposure assessment of acrylamide and related adduct forming compounds from diet during early-life are encouraged for the evaluation of health effects.

Water Intake and Markers of Hydration Are Related to Cardiometabolic Risk Biomarkers in Community-Dwelling Older Adults: A Cross-Sectional Analysis

BACKGROUND

Emerging evidence links underhydration and habitual low water intake to higher cardiometabolic risk, but evidence is limited in community-dwelling older adults.

OBJECTIVES

The objective is to examine if higher water intake and better hydration are associated with better cardiometabolic health.

METHODS

This cross-sectional analysis using general linear models included 2238 participants from the Framingham Heart Study Second Generation and First Generation Omni cohorts with an estimated glomerular filtration rate >30 mL·min-1·1.73 m-2 and a valid FFQ for assessment of water intake. Of these participants, 2219 had fasting spot urinary creatinine data and 950 had 24-h urine creatinine data to assess hydration. Cardiometabolic risk factors included fasting glucose, triglycerides (TGs), total cholesterol (TC), HDL cholesterol, and calculated LDL cholesterol; glycated hemoglobin (HbA1c); C-reactive protein (CRP); and systolic (SBP) and diastolic (DBP) blood pressure.

RESULTS

The combined cohorts were on average aged 70 y; 55% were women. Mean (95% CI) daily total water intakes were 2098 (2048, 2150) mL for men and 2109 (2063, 2156) mL for women. Total daily water, beverage (including plain water), and plain water intakes demonstrated significant positive trends with HDL cholesterol (P < 0.01). TG concentrations were significantly lower among the highest plain water consumers (P < 0.05). The 24-h urine concentration, as measured by creatinine, was positively associated with LDL cholesterol and TG concentrations ( P < 0.01) and inversely associated with HDL cholesterol concentrations (P < 0.002). Neither water intake nor urine concentration was associated with glucose or HbA1c (P > 0.05).

CONCLUSIONS

Our findings of a consistent pattern between circulating lipid concentrations and different water sources and hydration markers support an association between hydration and lipid metabolism in older adults and add to the growing evidence that inadequate water intake and underhydration may lead to higher cardiometabolic risk.

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.

A Metabolomics-Inspired Strategy for the Identification of Protein Covalent Modifications

Identification of protein covalent modifications (adducts) is a challenging task mainly due to the lack of data processing approaches for adductomics studies. Despite the huge technological advances in mass spectrometry (MS) instrumentation and bioinformatics tools for proteomics studies, these methodologies have very limited success on the identification of low abundant protein adducts. Herein we report a novel strategy inspired on the metabolomics workflows for the identification of covalently-modified peptides that consists on LC-MS data preprocessing followed by statistical analysis. The usefulness of this strategy was evaluated using experimental LC-MS data of histones isolated from HepG2 and THLE2 cells exposed to the chemical carcinogen glycidamide. LC-MS data was preprocessed using the open-source software MZmine and potential adducts were selected based on the m/z increments corresponding to glycidamide incorporation. Then, statistical analysis was applied to reveal the potential adducts as those ions are differently present in cells exposed and not exposed to glycidamide. The results were compared with the ones obtained upon the standard proteomics methodology, which relies on producing comprehensive MS/MS data by data dependent acquisition and analysis with proteomics data search engines. Our novel strategy was able to differentiate HepG2 and THLE2 and to identify adducts that were not detected by the standard methodology of adductomics. Thus, this metabolomics driven approach in adductomics will not only open new opportunities for the identification of protein epigenetic modifications, but also adducts formed by endogenous and exogenous exposure to chemical agents.

Validity of Estimated Acrylamide Intake by the Dietary Record Method and Food Frequency Questionnaire in Comparison with a Duplicate Method: A Pilot Study

Acrylamide, classified as a probable carcinogen to humans, forms during high- temperature cooking. Dietary exposure among the Japanese is unknown. To evaluate the validity of estimated acrylamide intake using a dietary record (DR) and the food frequency questionnaire (FFQ) in comparison with the duplicate diet method (DM) in a Japanese population. Design: A validation study was performed with 14 participants (age, 32-50 y; 11 women) from 11 households. Food samples were simultaneously collected for the DM and DR on the same day over 2 consecutive days. The FFQ was administered after collecting samples for the DM and DR. For the DM, dietary acrylamide was calculated from chemical analyses of each food. For the DR and FFQ, acrylamide intake for each food was calculated using the database of acrylamide contents of foods. Correlation coefficients were calculated using the Spearman rank method. Average acrylamide intake values calculated using the DM, DR, and FFQ were 0.106, 0.233, and 0.128 μg/kg body weight/d, respectively; these values showed a marginally positive correlation between the DM and DR (r=0.52), but a low correlation between the DM and FFQ (r=-0.011). For the DR, non-alcoholic drinks had the highest contribution, followed by confectionery and vegetables. For the DM, the contribution of confectionery was the highest, followed by vegetables and non-alcoholic drinks. In conclusion, the validity of acrylamide intake estimation using the DR was reasonably high when compared to the analytical value of the simultaneous DM. However, further improvement is required for estimating acrylamide intake using the FFQ.

Validity of a Self-administered Food Frequency Questionnaire for the Estimation of Acrylamide Intake in the Japanese Population: The JPHC FFQ Validation Study

BACKGROUND

Acrylamide, a probable carcinogen to humans, forms during high temperature cooking. Dietary exposure to acrylamide among the Japanese population is unknown. We aimed to establish and validate a method to assess acrylamide exposure among the Japanese population using a food frequency questionnaire (FFQ) from the Japan Public Health Center-based prospective study.

METHODS

Validation studies for the FFQ were conducted in 1994 (Cohort I, n = 215) and 1996 (Cohort II, n = 350). The 28-day dietary records (DRs) were collected over 1 year. The FFQ was distributed before and after DR collection. Data for acrylamide exposure were based on reported measurements in Japan, and calculations considered the cooking process for specific vegetables in a home setting. Spearman's rank correlation and weighted kappa coefficients were calculated from energy-adjusted data.

RESULTS

Mean acrylamide intake levels estimated from DRs for Cohorts I and II were 6.78 (standard deviation [SD], 3.89) µg/day and 7.25 (SD, 3.33) µg/day, and corresponding levels estimated from the FFQ were 7.03 (SD, 4.30) µg/day and 7.14 (SD, 3.38) µg/day, respectively. Deattenuated correlation coefficients for men and women were 0.54 and 0.48 in Cohort I and 0.40 and 0.37 in Cohort II, respectively. Weighted kappa coefficients were over 0.80 in all cases. The main contributing food groups from DRs were beverages, confectioneries, vegetables, potatoes and starches, and cereals.

CONCLUSIONS

High kappa values validate the use of FFQ in epidemiological studies. The marked contribution of cooked vegetables indicates the importance of considering household cooking methods in assessing acrylamide intake levels in the Japanese population.

Dietary Acrylamide Is Not Associated with Renal Cell Cancer Risk in the CPS-II Nutrition Cohort

BACKGROUND

Acrylamide, an industrial chemical and probable human carcinogen, can be formed in primarily carbohydrate-containing foods during high-heat cooking or processing. Most epidemiologic studies show no associations of dietary acrylamide intake with most cancer outcomes, but limited prospective evidence suggests a positive association with renal cell carcinoma (RCC).

METHODS

In 1999, 102,154 men and women from the Cancer Prevention Study-II Nutrition Cohort completed a questionnaire on diet, lifestyle, and cancer risk factors and were followed through June 30, 2013. Cox proportional hazards regression was used to estimate the HR and 95% confidence interval (CI) for the association between estimated dietary acrylamide intake and risk of RCC.

RESULTS

After 1,137,441 person-years of follow-up, 412 cases of invasive RCC occurred. In multivariable-adjusted models, there was no association between acrylamide intake and risk of RCC (HR = 1.09; 95% CI, 0.82-1.43) for the highest versus lowest quartile of intake. Associations were not modified by sex or smoking history.

CONCLUSIONS

We found no associations between dietary acrylamide exposure and risk of invasive RCC.

IMPACT

The findings from this large, prospective analysis do not support a positive association between higher dietary acrylamide intake and RCC risk.

Dietary Acrylamide Intake and Risk of Renal Cell Carcinoma in Two Large Prospective Cohorts

Background: Accumulating evidence suggests that dietary acrylamide intake is not associated with the risk of most cancers in humans. However, a meta-analysis of five epidemiologic studies found a suggestion of an increased risk of kidney cancer with higher dietary acrylamide intake.Methods: We investigated this association in the prospective Health Professionals Follow-up Study (HPFS; 1986-2014) and Nurses' Health Study (NHS; 1980-2014) cohorts. Dietary acrylamide intake was calculated on the basis of 46 acrylamide-containing foods reported on food frequency questionnaires completed every 4 years. The associations with the incidence of total and fatal renal cell carcinoma (RCC; n = 292/84 HPFS, n = 337/87 NHS) during more than two decades of follow-up were assessed using Cox proportional hazards models adjusting for potential confounders.Results: There was no association between cumulative average or baseline acrylamide intake and the risk of total or fatal RCC risk in men or women. Acrylamide intake was also not associated with RCC risk among never-smokers, nor was it associated with the risk of clear cell RCC.Conclusions: Dietary acrylamide was not associated with risk of RCC in two long-term prospective cohorts with repeated measures of dietary intake.Impact: This analysis of RCC adds to the body of evidence that dietary acrylamide is not an important cancer risk factor in humans. Cancer Epidemiol Biomarkers Prev; 27(8); 979-82. ©2018 AACR.

Polyclonal human antibodies against glycans bearing red meat-derived non-human sialic acid N-glycolylneuraminic acid are stable, reproducible, complex and vary between individuals: Total antibody levels are associated with colorectal cancer risk

BACKGROUND

N-glycolylneuraminic acid (Neu5Gc) is a non-human red-meat-derived sialic acid immunogenic to humans. Neu5Gc can be metabolically incorporated into glycan chains on human endothelial and epithelial surfaces. This represents the first example of a "xeno-autoantigen", against which circulating human "xeno-autoantibodies" can react. The resulting inflammation ("xenosialitis") has been demonstrated in human-like Neu5Gc-deficient mice and contributed to carcinoma progression via antibody-mediated inflammation. Anti-Neu5Gc antibodies have potential as biomarkers for diseases associated with red meat consumption such as carcinomas, atherosclerosis, and type 2 diabetes.

METHODS

ELISA assays measured antibodies against Neu5Gc or Neu5Gc-glycans in plasma or serum samples from the Nurses' Health Studies, the Health Professionals Follow-up Study, and the European Prospective Investigation into Cancer and Nutrition, including inter-assay reproducibility, stability with delayed sample processing, and within-person reproducibility over 1-3 years in archived samples. We also assessed associations between antibody levels and coronary artery disease risk (CAD) or red meat intake. A glycan microarray was used to detected antibodies against multiple Neu5Gc-glycan epitopes. A nested case-control study design assessed the association between total anti-Neu5Gc antibodies detected in the glycan array assay and the risk of colorectal cancer (CRC).

RESULTS

ELISA assays showed a wide range of anti-Neu5Gc responses and good inter-assay reproducibility, stability with delayed sample processing, and within-person reproducibility over time, but these antibody levels did not correlate with CAD risk or red meat intake. Antibodies against Neu5Gc alone or against individual Neu5Gc-bearing epitopes were also not associated with colorectal cancer (CRC) risk. However, a sialoglycan microarray study demonstrated positive association with CRC risk when the total antibody responses against all Neu5Gc-glycans were combined. Individuals in the top quartile of total anti-Neu5Gc IgG antibody concentrations had nearly three times the risk compared to those in the bottom quartile (Multivariate Odds Ratio comparing top to bottom quartile: 2.98, 95% CI: 0.80, 11.1; P for trend = 0.02).

CONCLUSIONS

Further work harnessing the utility of these anti-Neu5Gc antibodies as biomarkers in red meat-associated diseases must consider diversity in individual antibody profiles against different Neu5Gc-bearing glycans. Traditional ELISA assays for antibodies directed against Neu5Gc alone, or against specific Neu5Gc-glycans may not be adequate to define risk associations. Our finding of a positive association of total anti-Neu5Gc antibodies with CRC risk also warrants confirmation in larger prospective studies.

Dietary acrylamide intake during pregnancy and postnatal growth and obesity: Results from the Norwegian Mother and Child Cohort Study (MoBa)

BACKGROUND

Prenatal acrylamide exposure has been negatively associated with fetal growth but the association with child growth is unknown.

OBJECTIVES

We studied the association between prenatal acrylamide exposure and child postnatal growth up to 8 years in the Norwegian Mother and Child Cohort Study (MoBa).

METHODS

In 51,952 mother-child pairs from MoBa, acrylamide intake during pregnancy was estimated by combining maternal food intake with food concentrations of acrylamide. Mothers reported their child's weight and length/height up to 11 times between 6 weeks and 8 years. Weight and height growth trajectories were modelled using Jenss-Bayley's growth model. Logistic regression models were used to study the association with overweight/obese status at 3, 5 and 8 years, as identified using the International Obesity Task Force cut-offs. Linear mixed-effect models were used to explore associations with overall growth.

RESULTS

At 3 years, the adjusted odds ratios (95% Confidence Intervals (CI)) of being overweight/obese were 1.10 (1.02, 1.20), 1.12 (1.04, 1.22) and 1.21 (1.11, 1.31) by increasing prenatal acrylamide exposure quartile. Similar dose-response associations were found at 5 and 8 years. Acrylamide intake during pregnancy was associated with higher weight growth velocity in childhood. Children exposed at the highest level had 22 g (95% CI: 8, 37), 57 g (95% CI: 32, 81), and 194 g (95% CI: 110, 278) higher weight at 0.5, 2, and 8 years, respectively, compared to their low exposed peers.

CONCLUSIONS

Children prenatally exposed to acrylamide in the highest quartile experienced a moderate increase in weight growth velocity during early childhood that resulted in a moderately increased prevalence of overweight/obesity compared to peers in the lowest quartile. Our study is the first to link prenatal acrylamide exposure and postnatal growth.

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

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

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Electronic supplementary material

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

The influence of demographic, physical, behavioral, and dietary factors on hemoglobin adduct levels of acrylamide and glycidamide in the general U.S. population

PURPOSE

This study aims to better understand the individual characteristics and dietary factors that affect the relationship between estimated consumption of acrylamide and measured acrylamide hemoglobin adduct levels (HbAA) and glycidamide hemoglobin adduct levels (HbGA).

METHODS

Acrylamide levels in individual food items, estimated by the U.S. Food and Drug Administration, were linked to data collected in the 2003-2004 National Health and Nutrition Examination Survey. Multivariable linear regression was used to evaluate the relationship between estimated consumption of acrylamide and HbAA.

RESULTS

A significant association between acrylamide intake and HbAA was observed, after adjustment for gender, race/ethnicity, smoking status, age, and BMI (R² = 0.34). Across quartiles of acrylamide consumption, HbAA and HbGA levels increased monotonically. Among nonsmokers, an evaluation of three heavily consumed, high AA concentration foods showed a positive trend between the consumed amount of fried potatoes and HbAA in children, adolescents, and adults. A significant positive trend between the consumed amount of potato chips or coffee was indicated in adolescents, adults, and seniors.

CONCLUSIONS

Consumption of some individual foods affects HbAA concentrations more strongly and in an age-dependent manner. Our results suggest that effective dietary guidelines for controlling acrylamide intake should be subpopulation specific.

Dietary acrylamide exposure was associated with mild cognition decline among non-smoking Chinese elderly men

The aim of the study is to explore the longitudinal association of dietary acrylamide exposure with cognitive performance in Chinese elderly. The analysis was conducted among 2534 non-smoking elderly men and women based on a prospective study, Mr. and Ms. OS Hong Kong. Dietary acrylamide intake was assessed by food frequency questionnaires with data on local food contamination, derived from the first Hong Kong Total Diet Study. Global cognitive function was assessed by Cantonese version of Mini-Mental State Exam (MMSE) at the baseline and the 4^th year of follow-up. Multivariable-adjusted linear and logistic regression models were used to assess the associations of dietary acrylamide with MMSE score changes or risk of poor cognition. The results indicated that among men with MMSE ≥ 18, each one SD increase of acrylamide decreased MMSE score by 7.698% (95%CI: -14.943%, -0.452%; p = 0.037). Logistic regression revealed an increased risk of poor cognition (MMSE ≤ 26) in men with HR of 3.356 (1.064~10.591, p = 0.039). The association became non-significance after further adjustment for telomere length. No significant association was observed in women. Dietary acrylamide exposure was associated with a mild cognitive decline or increased risk of poor cognition over a 4-year period in non-smoking Chinese elderly men.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

IMPACT

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

Dietary intake of acrylamide and epithelial ovarian cancer risk in the european prospective investigation into cancer and nutrition (EPIC) cohort

Acrylamide, classified in 1994 by the International Agency for Research on Cancer (IARC) as "probably carcinogenic" to humans, was discovered in 2002 in some heat-treated, carbohydrate-rich foods. The association between dietary acrylamide intake and epithelial ovarian cancer risk (EOC) has been previously studied in one case-control and three prospective cohort studies which obtained inconsistent results and could not further examine histologic subtypes other than serous EOC. The present study was carried out in the European Prospective Investigation into Cancer and Nutrition (EPIC) subcohort of women (n = 325,006). Multivariate Cox proportional hazards models were used to assess the association between questionnaire-based acrylamide intake and EOC risk. Acrylamide was energy-adjusted using the residual method and was evaluated both as a continuous variable (per 10 μg/d) and in quintiles; when subgroups by histologic EOC subtypes were analyzed, acrylamide intake was evaluated in quartiles. During a mean follow-up of 11 years, 1,191 incident EOC cases were diagnosed. At baseline, the median acrylamide intake in EPIC was 21.3 μg/d. No associations and no evidence for a dose-response were observed between energy-adjusted acrylamide intake and EOC risk (HR10μg/d,1.02; 95% CI, 0.96-1.09; HRQ5vsQ1, 0.97; 95% CI, 0.76-1.23). No differences were seen when invasive EOC subtypes (582 serous, 118 endometrioid, and 79 mucinous tumors) were analyzed separately. This study did not provide evidence that acrylamide intake, based on food intake questionnaires, was associated with risk for EOC in EPIC. Additional studies with more reliable estimates of exposure based on biomarkers may be needed.

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

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

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.

Associations between dietary acrylamide intake and plasma sex hormone levels

BACKGROUND

The rodent carcinogen acrylamide was discovered in 2002 in commonly consumed foods. Epidemiologic studies have observed positive associations between acrylamide intake and endometrial, ovarian, and breast cancer risks, which suggest that acrylamide may have sex-hormonal effects.

METHODS

We cross-sectionally investigated the relationship between acrylamide intake and plasma levels of sex hormones and sex hormone-binding globulin (SHBG) among 687 postmenopausal and 1,300 premenopausal controls from nested case-control studies within the Nurses' Health Studies.

RESULTS

There were no associations between acrylamide and sex hormones or SHBG among premenopausal women overall or among never-smokers. Among normal-weight premenopausal women, acrylamide intake was statistically significantly positively associated with luteal total and free estradiol levels. Among postmenopausal women overall and among never-smokers, acrylamide was borderline statistically significantly associated with lower estrone sulfate levels but not with other estrogens, androgens, prolactin, or SHBG. Among normal-weight women, (borderline) statistically significant inverse associations were noted for estrone, free estradiol, estrone sulfate, DHEA, and prolactin, whereas statistically significant positive associations for testosterone and androstenedione were observed among overweight women.

CONCLUSIONS

Overall, this study did not show conclusive associations between acrylamide intake and sex hormones that would lend unequivocal biologic plausibility to the observed increased risks of endometrial, ovarian, and breast cancer. The association between acrylamide and sex hormones may differ by menopausal and overweight status. We recommend other studies investigate the relationship between acrylamide and sex hormones in women, specifically using acrylamide biomarkers.

IMPACT

The present study showed some interesting associations between acrylamide intake and sex hormones that urgently need confirmation.

Among 10 sociodemographic and lifestyle variables, smoking is strongly associated with biomarkers of acrylamide exposure in a representative sample of the U.S. Population

Hemoglobin adducts of acrylamide (HbAA) and glycidamide (HbGA) have been measured as biomarkers of acrylamide exposure and metabolism in a nationally representative sample of the U.S. population in the NHANES 2003-2004. We assessed the association of sociodemographic (age, sex, race-ethnicity, education, and income) and lifestyle (smoking, alcohol consumption, BMI, physical activity, and dietary supplement use) variables with these biomarkers in U.S. adults (aged ≥ 20 y). We used bivariate and multiple regression models and assessed the magnitude of an estimated change in biomarker concentration with change in a covariable for 2 biomarkers of acrylamide exposure. Smoking was strongly and significantly correlated with HbAA and HbGA concentrations (rs = 0.51 and 0.42, respectively), with biomarker concentrations being 126 and 101% higher in smokers compared with nonsmokers after adjusting for sociodemographic and lifestyle covariates. Age was moderately and significantly correlated with both biomarkers (rs = -0.21 and -0.22, respectively). BMI (rs = -0.11) and alcohol consumption (rs = 0.13) were weakly yet significantly correlated with HbAA concentrations only. The estimated percentage change in biomarker concentration was ≤ 20% for all variables other than smoking after adjusting for sociodemographic and lifestyle covariates. Using multiple regression models, the sociodemographic variables explained 9 and 7% whereas the sociodemographic and lifestyle variables together explained 46 and 25% of the variability in HbAA and HbGA, respectively, showing the importance of considering and adequately controlling for these variables in future studies. Our findings will be useful in the design and analysis of future studies that assess and evaluate exposure to acrylamide and its metabolism to glycidamide.

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 during pregnancy and fetal growth-results from the Norwegian mother and child cohort study (MoBa)

BACKGROUND

Acrylamide has shown developmental and reproductive toxicity in animals, as well as neurotoxic effects in humans with occupational exposures. Because it is widespread in food and can pass through the human placenta, concerns have been raised about potential developmental effects of dietary exposures in humans.

OBJECTIVES

We assessed associations of prenatal exposure to dietary acrylamide with small for gestational age (SGA) and birth weight.

METHODS

This study included 50,651 women in the Norwegian Mother and Child Cohort Study (MoBa). Acrylamide exposure assessment was based on intake estimates obtained from a food frequency questionnaire (FFQ), which were compared with hemoglobin (Hb) adduct measurements reflecting acrylamide exposure in a subset of samples (n = 79). Data on infant birth weight and gestational age were obtained from the Medical Birth Registry of Norway. Multivariable regression was used to estimate associations between prenatal acrylamide and birth outcomes.

RESULTS

Acrylamide intake during pregnancy was negatively associated with fetal growth. When women in the highest quartile of acrylamide intake were compared with women in the lowest quartile, the multivariable-adjusted odds ratio (OR) for SGA was 1.11 (95% CI: 1.02, 1.21) and the coefficient for birth weight was -25.7 g (95% CI: -35.9, -15.4). Results were similar after excluding mothers who smoked during pregnancy. Maternal acrylamide- and glycidamide-Hb adduct levels were correlated with estimated dietary acrylamide intakes (Spearman correlations = 0.24; 95% CI: 0.02, 0.44; and 0.48; 95% CI: 0.29, 0.63, respectively).

CONCLUSIONS

Lowering dietary acrylamide intake during pregnancy may improve fetal growth.

Challenges in estimating the validity of dietary acrylamide measurements

BACKGROUND

Acrylamide is a chemical compound present in tobacco smoke and food, classified as a probable human carcinogen and a known human neurotoxin. Acrylamide is formed in foods, typically carbohydrate-rich and protein-poor plant foods, during high-temperature cooking or other thermal processing. The objectives of this study were to compare dietary estimates of acrylamide from questionnaires (DQ) and 24-h recalls (R) with levels of acrylamide adduct (AA) in haemoglobin.

METHODS

In the European Prospective Investigation into Cancer and Nutrition (EPIC) study, acrylamide exposure was assessed in 510 participants from 9 European countries, randomly selected and stratified by age, sex, with equal numbers of never and current smokers. After adjusting for country, alcohol intake, smoking status, number of cigarettes and energy intake, correlation coefficients between various acrylamide measurements were computed, both at the individual and at the aggregate (centre) level.

RESULTS

Individual level correlation coefficient between DQ and R measurements (r DQ,R) was 0.17, while r DQ,AA and r R,AA were 0.08 and 0.06, respectively. In never smokers, r DQ,R, r DQ,AA and r R,AA were 0.19, 0.09 and 0.02, respectively. The correlation coefficients between means of DQ, R and AA measurements at the centre level were larger (r > 0.4).

CONCLUSIONS

These findings suggest that estimates of total acrylamide intake based on self-reported diet correlate weakly with biomarker AA Hb levels. Possible explanations are the lack of AA levels to capture dietary acrylamide due to individual differences in the absorption and metabolism of acrylamide, and/or measurement errors in acrylamide from self-reported dietary assessments, thus limiting the possibility to validate acrylamide DQ measurements.

Hemoglobin adducts as a measure of variations in exposure to acrylamide in food and comparison to questionnaire data

Measurement of haemoglobin (Hb) adducts from acrylamide (AA) and its metabolite glycidamide (GA) is a possibility to improve the exposure assessment in epidemiological studies of AA intake from food. This study aims to clarify the reliability of Hb-adduct measurement from individual single samples for exposure assessment of dietary AA intake. The intra-individual variations of AA- and GA-adduct levels measured in blood samples collected over 20 months from 13 non-smokers were up to 2-fold and 4-fold, respectively. The corresponding interindividual variations observed between 68 non-smokers, with large differences in AA intake, were 6-fold and 8-fold, respectively. The intra-individual variation of the GA-to-AA-adduct level ratio was up to 3-fold, compared to 11-fold between individuals (n = 68). From AA-adduct levels the average AA daily intake (n = 68) was calculated and compared to that estimated from dietary history methodology: 0.52 and 0.67 μg/kg body weight and day, respectively. At an individual level the measures showed low association (Rs = 0.39).

CONCLUSIONS

Dietary AA is the dominating source to measured AA-adduct levels and corresponding inter- and intra-individual variations in non-smokers. Measurements from single individual samples are useful for calculation of average AA intake and its variation in a cohort, and for identification of individuals only from extreme intake groups.

Pre-diagnostic acrylamide exposure and survival after breast cancer among postmenopausal Danish women

Acrylamide is a probable human carcinogen, with industrial contact, tobacco smoking and foods processed at high temperatures as the main routes of exposure. In animal studies oral intake of acrylamide has been related to cancer development, with indications that the increased cancer occurrence especially regards endocrine related tumors. In human epidemiological studies, dietary exposure to acrylamide has also been suggested related to higher risk of endocrine related tumors, like estrogen sensitive breast cancer. The aim of the present study was to evaluate if pre-diagnostic acrylamide exposure, measured by acrylamide and glycidamide hemoglobin adducts (AA-Hb and GA-Hb), were associated to mortality in breast cancer cases. Among 24,697 postmenopausal women included into a Danish cohort between 1993 and 1997, 420 developed breast cancer before 2001 and 110 died before 2009. AA-Hb and GA-Hb concentrations measured in blood samples were related to mortality by Cox proportional hazard models. Estimates are given per 25 pmol/g globin higher levels. Among non-smokers, higher concentrations of GA-Hb were associated to a higher hazard rate of breast cancer specific mortality (HR (95% CI): 1.63 (1.06-2.51)), the hazard rate among women diagnosed with estrogen receptor positive tumors was (HR (95% CI): 2.23 (1.38-3.61)). For AA-Hb the tendency was similar, but only statistically significant among those with estrogen receptor positive tumors (HR (95% CI): 1.31 (1.02-1.69)). In conclusion, the present study indicates that pre-diagnostic exposure to acrylamide may be related to mortality among breast cancer patients and that this may especially concern the most endocrine related type of breast cancer.

New trends in quantification of acrylamide in food products

Methods applied in acrylamide quantification in foods have been reviewed in this paper. Novel analytical techniques like capillary electrophoresis (CE), immunoenzymatic test (ELISA) and electrochemical biosensors, which can replace traditional methods like high performance liquid chromatography (HPLC) and gas chromatography (GC) were presented. Short time of analysis and high resolution power of electrophoretic techniques caused that they became routinely used in food analysis apart from high performance liquid chromatography and gas chromatography. Application of modern chromatography methods like ultra performance liquid chromatography (UPLC) in acrylamide quantification considerably shortened the time of analysis and decreased the consumption of indispensable reagents. The most promising approaches to acrylamide quantification in foods are electrochemical biosensors and immunoenzymatic tests. In contrast to chromatography and electrophoretic methods they require neither expensive equipment nor time consuming sample preparation and allow for fast screening of numerous samples without the usage of sophisticated apparatuses. Because of many advantages such as miniaturization, rapid and simple analysis, and high sensitivity and selectivity, biosensors are thought to replace conventional methods of acrylamide quantification in food.

Dietary acrylamide and risk of prostate cancer

Acrylamide has been designated by IARC as a "probable human carcinogen." High levels are formed during cooking of many commonly consumed foods including French fries, potato chips, breakfast cereal and coffee. Two prospective cohort studies and two case-control studies in Europe found no association between acrylamide intake and prostate cancer. We examined this association in a large prospective cohort of 47,896 US men in the Health Professionals' Follow-up Study, using updated dietary acrylamide intake from food frequency questionnaires in 1986, 1990, 1994, 1998 and 2002. From 1986 through 2006, we documented 5025 cases of prostate cancer, and 642 lethal cancers. We used Cox proportional hazards models to assess the association between acrylamide intake from diet and prostate cancer risk overall as well as risk of advanced or lethal cancer. Acrylamide intake ranged from a mean of 10.5 mcg/day in the lowest quintile to 40.1 mcg/day in the highest quintile; coffee and potato products were largest contributors to intake. The multivariate-adjusted relative risk of prostate cancer was 1.02 (95% confidence interval: 0.92-1.13) for the highest versus lowest quintile of acrylamide intake (p-value for trend = 0.90). Results were similar when restricted to never smokers and to men who had prostate-specific antigen (PSA) tests. There was no significant association for dietary acrylamide and risk of lethal, advanced or high-grade disease, or for different latency periods ranging from 0-4 years to 12-16 years. We found no evidence that acrylamide intake, within the range of US diets, is associated with increased risk of prostate cancer.

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.

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.

Dietary acrylamide intake and risk of breast cancer in the UK women's cohort

BACKGROUND

No studies to date have demonstrated a clear association with breast cancer risk and dietary exposure to acrylamide.

METHODS

A 217-item food frequency questionnaire was used to estimate dietary acrylamide intake in 33,731 women aged 35-69 years from the UK Women's Cohort Study followed up for a median of 11 years.

RESULTS

In all, 1084 incident breast cancers occurred during follow-up. There was no evidence of an overall association between acrylamide intake and breast cancer (hazard ratio=1.08 per 10 μg day(-1), 95% CI: 0.98-1.18, P(trend)=0.1). There was a suggestion of a possible weak positive association between dietary acrylamide intake and premenopausal breast cancer after adjustment for potential confounders (hazard ratio=1.2, 95% CI: 1.0-1.3, P(trend)=0.008). There was no suggestion of any association for postmenopausal breast cancer (hazard ratio=1.0, 95% CI: 0.9-1.1, P(trend)=0.99).

CONCLUSIONS

There is no evidence of an association between dietary acrylamide intake and breast cancer. A weak association may exist with premenopausal breast cancer, but requires further investigation.