Intake Of Heterocyclic Amines Research Articles

A Prospective Pooled Analysis of Meat Mutagens and Colorectal Adenoma and Cancer in the US and EPIC Studies: Findings with an Emphasis on Improving Exposure Measurements.

In animal studies, heterocyclic amines (HCAs) are recognized as having strong carcinogenicity, therefore we have hypothesized that HCAs might be associated with the risk of colorectal adenoma (CRA) and cancer (CRC). We used the Keywords of "Heterocyclic amines and colorectal cancer" to search, there were showing published articles (n=200). After reviews of titles, abstracts, and full articles, seven prospective cohort studies were included in the pooled analysis. Exposures to HCAs 2-amino-3,8-dimethylimidazo(4,5-j)quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo(4,5-f)quinoxaline (DiMeIQx), meat-derived mutagenicity (MDM), and the risk of CRA and CRC were examined. The estimated HCA intake as ng/day and ng/1,000 kcal/day by participants and by studies were examined. The ln(HR) and se(ln(HR)) were estimated from the multivariable-adjusted HR, 95%CI derived from seven published prospective studies in the US and EPIC. The random pooled multivariable-adjusted HR, 95%CI was analyzed using ln(HR) and se(ln(HR)) by STATA-10. For CRC and HCA intake, the null association was observed for MDM, the random pooled multivariable-adjusted HR, (95%CI): 1.11, (1.00, 1.23); for PhIP: 1.00, (0.91, 1.09); and for DiMeIQx: 1.03, (0.87, 1.22). A significant positive association was seen for MeIQx, the random pooled multivariable-adjusted HR, (95%CI):1.12, (1.03, 1.22). For CRA and HCA intake, the null association was observed for MDM, randomly pooled multivariable-adjusted HR, (95%CI): 1.15, (0.99, 1.34), and for DiMeIQx: 1.09, (0.97, 1.23). A significant positive association was seen for PhIP, the random pooled multivariable-adjusted HR, (95%CI): 1.19, (1.02, 1.39), and for MeIQx: 1.17, (1.01, 1.35). The major instances of HCAs were contributed by chicken (54%-74%) for PhIP and by red meat (83%-92%) for MeIQx. However, the estimated PhIP intake (ng/1,000 kcal/day) was remarkably different between studies. We observed a positive association between exposures to MeIQx and the risk of both CRC and CRA which supports the hypothesis of the role of HCAs in developing CRA and CRC. Improving the quality of the estimated HCA intake would be highly concerned for further investigation.

Pilot Study for the Dietary Assessment of Xenobiotics Derived from Food Processing in an Adult Spanish Sample.

Background: Although xenobiotics from food processing have gained support as possible drivers of the relationship between diet and some types of cancer, there are still few studies characterizing the intake of these compounds among different populations. Aim: To describe the intake of heterocyclic amines (HAs), polycyclic aromatic hydrocarbons (PAHs), nitrates, nitrites, nitrosamines, and acrylamide; and to identify dietary and lifestyle related factors. Methods: This was a descriptive cross-sectional study in 70 adult volunteers. Intake was registered by means of a food frequency questionnaire, including cooking methods, temperature, and degree of browning. The European Prospective Investigation into Cancer (EPIC) and the Computerized Heterocyclic Amines Resource for Research in Epidemiology of Disease (CHARRED) databases were used for xenobiotic estimation in conjunction with data from the European Food Safety Authority (EFSA) and U.S. Food and Drug Administration (FDA). Results: Dietary HAs (amino-alpha-carboline (AαC), 2-amino-3-methylimidazo (4,5,f) quinoline (IQ), 2-amino-3,8 dimethylimidazo (4,5,f) quinoxaline (MeIQx), 2-amino-3,4,8 trime-thylimidazo (4,5,f) quinoxaline (DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo (4,5,b) pyridine (PhIP)) were mainly derived from meat and meat products, while benzo (a) pyrene (B(a)P), dibenzo (a) anthracene (DiB(a)A), and total PAHs were explained by oils and fats, alcoholic beverages, and milk, respectively. Microwaved, fried, grilled, broiled, barbecued, and braised cooking methods were mainly responsible for HAs and PAHs consumption. Conclusion: Based on the wide presence and levels of intake of these compounds in different sources, more efforts should be made to adjust their intake to the levels recommended by health agencies.

Assessment of dietary exposure to heterocyclic amines based on the Korean total diet study

ABSTRACT Heterocyclic amines (HCAs) are contaminants in proteinaceous foods produced by cooking at high temperatures. This study was the first assessment of exposure to HCAs using the Korean total diet study. Twelve HCAs were analysed in 1,232 pooled samples using six isotope-labelled internal standards and HPLC-MS/MS. The daily intake of HCAs in the Korean population was estimated based on the concentration of HCAs in the total diet study samples and individual food consumption data from the Korean National Health and Nutrition Examination Survey. Among HCAs, the intake of β-carbolines, such as harman and norharman, was the highest, followed by the intake of PhIP. The primary sources of HCA intake were meat, fish, shellfish, and beverages, including alcohol. The margin of exposure to PhIP was 2,349,000 at the average level and 373,000 at the 95th percentile in the Korean population. The estimated daily intake of all HCAs in the Korean population was considered safe.

Changes in Insulin Signaling and Gluconeogenic Gene Expression in Human Hepatocytes Following Exposure to Heterocyclic Amines

Humans are exposed to heterocyclic amine (HCA) mutagens produced in meats cooked at high temperatures or until well-done. A recent epidemiological study documented associations of high HCA intake with increased prevalence of insulin resistance, which is one of the hallmarks of type II diabetes mellitus and metabolic syndrome. However, it is unknown if HCAs directly induce insulin resistance. To investigate the effects of HCA exposure on insulin sensitivity, we subjected HepG2 (hepatocellular carcinoma) cells and primary human hepatocytes to 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and measured changes in insulin signaling, gluconeogenic gene expression, and glucose production. HepG2 cells were treated with varying concentrations of MeIQ (0-100 μM), then treated with insulin and analyzed for changes in insulin signaling via p-AKT induction on Western blot. MeIQ exposure decreased insulin-induced p-AKT levels in low glucose conditions, suggesting that the cells become insulin resistant in the presence of MeIQ. Additionally, the MeIQ treatment significantly upregulated the transcripts of genes involved in gluconeogenesis (e.g., G6PC and PCK1) in HepG2 cells. Similarly, primary human hepatocytes exposed to MeIQ also showed significant increases in gluconeogenic genes, compared to the vehicle treated cells. These results suggest that MeIQ impairs insulin signaling and potentially induces glucose production in hepatocytes. We then tested if the gene expression changes induced by MeIQ leads to increases in glucose production in primary hepatocytes. Despite upregulation of gluconeogenic genes, there were no significant changes in glucose production between control and MeIQ-treated cells. Future studies will examine whether MeIQ exposure alters the suppressive effects of insulin on gluconeogenic gene expression and glucose production and test additional HCAs. The alterations in insulin signaling and gluconeogenic gene expression following MeIQ exposure in hepatocytes indicate that MeIQ may directly alter insulin sensitivity.

Dietary Heterocyclic Amine Intake and Risk of Esophageal Squamous Cell Carcinoma in Rural Uganda.

Dietary exposure to 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in cooked meats maybe responsible for the high burden of Esophageal squamous cell carcinoma (ESCC) in southwestern Uganda.We conducted a pilot case-control study among 31 histologically confirmed ESCC cases and 54 age, gender, and residence matched healthy community controls sampled from the general population at the time of accrual of each case in southwestern Uganda. We collected data including smoking, alcohol consumption, diet, and scalp hair samples analyzed for normalized PhlP (adjusted per gram of melanin). We used logistic regression to determine the association of PhlP and ESCC.Overall, the mean normalized PhIP (ng/g melanin) was 44.79 (SD 148.08), higher among women compared to men (130.68 vs. 9.00, p = 0.03), lowest among healthy men [8.31 (SD 8.52) ng/g melanin] and highest among healthy women 158.39 (SD 288.75) ng/g melanin.In fully adjusted models, covariates associated with greater odds of ESCC included ever smoking 2 to 3 pack years of cigarettes (aOR 7.75 (95% CI 1.90, 31.50) and those 3 or more pack years (aOR5.82, 95%CI 1.25, 27.11), drinking 3 to 4 alcoholic drinks daily (aOR8.00, 95%CI 2.31, 27.74), and normalized PhIP above 75th percentile (8.65 ng/g of melanin) (aOR4.27, 95%CI 1.12, 16.24).In conclusion, high PhIP levels maybe associated with ESCC in a rural Uganda, a high ESCC burden setting. Further study with larger sample with a wider geographical representation is needed to validate scalp hair PhIP for assessment of ESCC risk.

Heterocyclic amine intake along with high fat diet may trigger predisposition to atherosclerosis

Background and Aims: The potential effects of polycyclic aromatic hydrocarbons on cardiovascular disease are well known. Despite their structural similarities; different types of heterocyclic aromatic amines are not considered enough on the basis of cardiovascular disease. Therefore, we aimed to investigate the effects of various heterocyclic aromatic amines exposure via diet on lipid profile and atherosclerosis.

Meat intake, meat cooking methods, and meat-derived mutagen exposure and risk of sessile serrated lesions

Red and processed meat, recognized carcinogens, are risk factors for colorectal neoplasia, including polyps, the precursor for colorectal cancer. The mechanism is unclear. One possible explanation is the mutagenic activity of these foods, perhaps due to generation during cooking [e.g., heterocyclic amine (HCA) intake]. Few studies have evaluated meat intake and sessile serrated lesion (SSL) risk, a recently recognized precursor, and no study has evaluated meat cooking methods and meat-derived mutagens with SSL risk. We evaluated intakes of meat, meat cooking methods, and inferred meat mutagens with SSL risk and in comparison to risk of other polyps. Meat, well-done meat, and inferred meat mutagen intakes were evaluated. Polytomous logistic regression models were used to estimate ORs and 95% CIs among cases (556 hyperplastic polyp, 1753 adenoma, and 208 SSL) and controls (3804) in the large colonoscopy-based, case-control study, the Tennessee Colorectal Polyp Study. The highest quartile intakes of red meat (OR: 2.38; 95% CI: 1.44, 3.93), processed meat (OR: 2.03; 95% CI: 1.30, 3.17), well-done red meat (OR: 2.19; 95% CI: 1.34, 3.60), and the HCA 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQX; OR: 2.48; 95% CI: 1.49, 4.16) were associated with increased risk of SSLs in comparison to the lowest quartile intake. High intakes of red and processed meats are strongly and especially associated with SSL risk and part of the association may be due to HCA intake. Future studies should evaluate other mechanism(s) and the potential for primary prevention.

Abstract C043: Meat and fish intake and the risk of breast cancer in the Carolina Breast Cancer Study (CBCS)

Abstract Introduction: Cooking meat at high temperatures and charring of meat increases the production of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), which are implicated in breast carcinogenesis. Several epidemiologic studies have reported increased risk of breast cancer with higher intake of HCAs or red meat intake. However, few studies have examined these associations in racially diverse populations. The goal of the study was to examine the associations between various meat and fish preparation methods and breast cancer using the Carolina Breast Cancer Study (CBCS) Phase 2. Methods: African American (AA) and European American (EA) women aged 20-74 years with a first diagnosis of invasive or in situ breast cancers were enrolled. Controls were identified through the DMV and Medicare lists and were frequency matched to cases by race and age group (AA: 548 cases and 452 controls; EA: 858 cases and 748 controls). Preparation methods and intake frequencies were obtained through self-report questionnaires. Multivariable logistic regression analysis was used to obtain odds ratios and 95% CIs of breast cancer by frequency of intake of meat and fish cooked by various preparation methods. Results: Using no reported meat intake as the referent, positive associations with breast cancer were observed for intakes of grilled/barbecued hamburger (one or more times per week, OR: 1.30; 95% CI: 1.02, 1.66), and for pan-fried/oven-broiled beef steak (one or more times per week, OR: 1.38; 95% CI: 1.09, 1.74). Inverse associations with breast cancer were observed for pan-fried fish (one or more times per week, OR: 0.77; 95% CI: 0.61, 0.99) and for grilled/barbecued pork chops (OR: 0.82, 95% CI: 0.69, 0.98). Overall, the associations appeared to be stronger among EA women but showed inconsistency within meat categories (fish, pork, beef) depending upon method of cooking. Conclusion: Among AA and EA women, more frequently consuming beef prepared with high-temperature methods (such as grilling or oven-broiling) was associated with higher odds of breast cancer, and the associations were stronger among EA women compared to AA women. In contrast, consuming pan-fried fish or grilled/barbecued pork chops weekly was associated with lower odds of breast cancer compared to less frequent consumption. Citation Format: Omonefe Omofuma, Susan Steck, Melissa Troester, Andrew Olshan. Meat and fish intake and the risk of breast cancer in the Carolina Breast Cancer Study (CBCS) [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C043.

Doneness preferences, meat and meat-derived heterocyclic amines intake, and N-acetyltransferase 2 polymorphisms: association with colorectal adenoma in Japanese Brazilians.

Intake of heterocyclic amines (HCAs) and other mutagenic compounds formed during cooking has been hypothesized to be responsible for the positive association observed between red meat and colorectal cancer. We evaluated whether well-done/very well-done preferences for various meat and fish items, higher intakes of meat and fish, and meat-derived and fish-derived HCA are associated with the risk of colorectal adenoma (CRA) in a Japanese-Brazilian population. We selected 302 patients with adenoma and 403 control individuals who underwent total colonoscopy between 2007 and 2013, and collected information on aspects of meat intake using a detailed questionnaire. We also estimated HCA intake of the study participants using an HCA database that matched the cooking methods of this population. Latent class analysis on the basis of response to doneness preferences for different cooking methods of commonly consumed meat and fish items identified four distinct subgroups. Compared with the subgroup characterized by a preference for rare/medium well-done cooking for most meat and fish items, the odds ratio of CRA for the well-done/very well-done preference subgroup was 1.19 (95% confidence interval: 0.51-2.75). High intake of mixed-meat dishes was suggestively associated inversely with CRA, whereas a high intake of poultry was associated positively with CRA. No clear association with intake of total or specific HCAs and no effect modification by N-acetyltransferase 2 acetylation genotype were observed. We found no statistically significant associations between meat and HCA intake and CRA. These findings do not support a positive association between meat and meat-derived HCA intake and the risk of CRA.

Meat intake and risk of hepatocellular carcinoma in two large US prospective cohorts of women and men.

Epidemiological evidence on the associations between meat intake and risk of hepatocellular carcinoma (HCC) was limited and inconsistent. We prospectively examined the association between consumption of meats and meat mutagens with HCC risk using data from the Nurses' Health Study and the Health Professionals Follow-up Study. Cox proportional-hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) after adjusting for known liver-cancer risk factors. During up to 32 years of follow-up, we documented 163 incident HCC cases. The HRs of HCC for the highest vs the lowest tertile intake levels were 1.84 (95% CI: 1.16-2.92, Ptrend = 0.04) for processed red meats and 0.61 (95% CI: 0.40-0.91, Ptrend = 0.02) for total white meats. There was a null association between unprocessed red meats and HCC risk (HR = 1.06, 95% CI: 0.68-1.63, Ptrend = 0.85). We found both poultry (HR = 0.60, 95% CI: 0.40-0.90, Ptrend = 0.01) and fish (HR = 0.70, 95% CI: 0.47-1.05, Ptrend = 0.10) were inversely associated with HCC risk. The HR for HCC risk was 0.79 (95% CI: 0.61-1.02) when 1standard deviation of processed red meats was substituted with an equivalent amount of poultry or fish intake. We also found a suggestive positive association of intake of meat-derived mutagenicity or heterocyclic amines with risk of HCC. Processed red meat intake might be associated with higher, whereas poultry or possibly fish intake might be associated with lower, risk of HCC. Replacing processed red meat with poultry or fish might be associated with reduced HCC risk.

Abstract 964: The association of meat intake, meat cooking methods, and meat-derived mutagen exposure with the risk of sessile serrated polyps

Abstract Colorectal polyps are the precursors of colorectal cancer, the second leading cause of cancer death in the United States. Red and processed meat intakes have been associated with an increased risk of conventional colorectal adenomas and are classified as carcinogens by the World Health Organization. The mechanism for the relationship between red and processed meat intakes and adenoma risk remains unclear. An explanation may be the exposure to mutagens derived from meat including heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) which are formed by cooking meats at high temperatures. Although intakes of these meats and mutagens has been associated with risks of conventional adenomas including in our study, no previous study has evaluated risk of sessile serrated polyp (SSPs). SSPs, a more recently recognized precursor lesion for microsatellite instable cancer, were strongly associated with red meat intake in our earlier study. This new study builds on that work by evaluating the associations between meat intake, meat cooking methods, and meat mutagens with risks of SSPs and compares the risks to conventional adenomas and hyperplastic polyps. The analysis is conducted in the Tennessee Colorectal Polyp Study, using polytomous logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CI). Dietary information was collected by a self-administered food frequency questionnaire and telephone interview to ascertain meat intake and doneness. This information was used to estimate the intakes of meats, well-done meats, PAHs, HCAs, and mutagenic activity. Several measures of meat intake were strongly associated with risk of SSPs. Highest quartile levels of total meat intake (OR=2.04; 95% CI: 1.24-3.36, p for trend=0.002), red meat intake (OR=2.32; 95% CI: 1.37-3.91, p for trend<0.001), processed meat intake (OR=1.99, 95% CI: 1.24-3.20, p for trend=0.004), well-done red meat (OR=2.13, 95% CI: 1.28-3.55, p for trend=0.002), well-done processed meat (OR=1.60, 95% CI: 1.06-2.4, p for trend=0.03), and the HCA MeIQx (OR=2.55, 95% CI: 1.50-4.33, p for trend=0.003) were associated with statistically significantly increased risks of SSP in comparison to the lowest intake levels. Most of these associations were stronger for risk of SSP than for the other types of polyps. In particular, MeIQx intake was not associated with risk of conventional adenomas suggesting that the mechanisms by which red meat intake affects polyp risk may be different between the conventional adenoma and serrated pathways. Future studies are needed to confirm the relationship between meat and meat mutagen intake with SSP risk and to further define the mechanism(s) by which intake of these factors affects SSP risk. Citation Format: Dominique A. Mosley, Harvey J. Murff, Reid M. Ness, Walter E. Smalley, Wei Zheng, Martha J. Shrubsole. The association of meat intake, meat cooking methods, and meat-derived mutagen exposure with the risk of sessile serrated polyps [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 964.

Dietary Heterocyclic Amine Intake and Colorectal Adenoma Risk: A Systematic Review and Meta-analysis.

Heterocyclic amines (HCA) are potent carcinogenic substances formed in meat. Because of their mutagenic activity, they may increase the risk of colorectal adenomas, which are the precursors of colorectal cancer, one of the most prevalent cancers worldwide. The aim of this meta-analysis was to synthesize the knowledge about the intake of HCAs and its associations with CRA. We conducted a systematic search in PubMed and EMBASE. We used odds ratios (OR); or relative risks, RR) from every reported intake and compared the highest versus lowest level of dietary HCAs. In addition, we assessed a dose-response relationship. Twelve studies on HCA intake and risk of CRA were included in our analysis. We observed a statistically significant association when comparing top versus bottom intake category of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine [PhIP; OR = 1.20; 95% confidence interval (CI) = 1.12-1.29], 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx; OR = 1.20; 95% CI = 1.08-1.34), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx; OR = 1.16; 95% CI = 1.05-1.27), benzo(a)pyrene (BaP; OR = 1.15; 95% CI = 1.04-1.27), and mutagenicity index (OR = 1.22; 95% CI = 1.06-1.41). Furthermore, we observed a significant dose-response effect for PhIP, MeIQx, and mutagenicity index. This meta-analysis suggests that there is a positive association of HCAs, BaP, mutagenicity index with risk of CRA. In addition, our dose-response analyses showed an increased risk of CRA for PhIP, MeIQx, and mutagenicity index. This study provides evidence for a positive association between the dietary intake of meat mutagens and CRA risk.

Rapid determination of heterocyclic amines in ruminant meats using accelerated solvent extraction and ultra-high performance liquid chromatograph–mass spectrometry

Cooking techniques such as grilling confer several benefits to meat during food preparation including improved palatability, digestibility, preservation, and safety, as well as enhancing the sensory characteristics and net nutritional gain. However, grilling can lead to the formation of harmful compounds such heterocyclic amines (HCAs). HCAs are potent carcinogenic and mutagenic nitrogen containing compounds produced during certain cooking conditions of protein rich foods. Dietary intake of HCAs is associated with increased risk factors for cancers in humans. As such, there is overwhelming interest in identifying improved methods for rapid and accurate determination of heterocyclic amines in food matrices that is sensitive and avoids exhaustive sample preparation steps. Herein, we describe an approach that involves first extracting HCAs by pressurized accelerated solvent extractor using methanol as solvent, followed by addition of internal standard and quantification of HCAs by ultra-high performance liquid chromatography-high resolution accurate mass spectrometric detection (UHPLC-HRAMS). This method is fast, accurate, reproducible and does not require exhaustive sample pre-treatments prior to UHPLC-HRAMS analysis compared to existing/traditional methods for HCA analysis.•The method is automated, fast and uses tunable pressurized liquid extractor to selectively extract HCAs•Method does not require exhaustive cleanup and preconcentration steps prior to UHPLC/HRAMS analysis of HCAs•Validation showed method to be accurate, precise, and useful for routine multi-sample HCA analyses

Occurrence of Heterocyclic Amines in Commercial Fast-Food Meat Products Available on the Chinese Market and Assessment of Human Exposure to these Compounds.

Heterocyclic amines (HCAs) have been identified as highly mutagenic and are risk factors for human cancer. In recent years, the intake of fast-food meat products has increased exponentially due to their convenience. Therefore, it is important to assess the health risks of HCAs and provide useful public dietary guidelines. Eight fast-food meat products were selected from the Chinese market, including chicken, beef, and fish, to evaluate their health risk in conjunction with HCAs. Crispy chicken drumsticks contained the maximum level of total HCAs (24.18±3.57 ng/g), followed by crispy fried chicken burgers (19.99±1.41 ng/g) and traditional Chinese nuggets (19.17±1.23 ng/g), whereas shrimp cake burgers had the lowest levels (13.17±1.77 ng/g). Crispy chicken drumsticks (men: 169.12 ng/day, women: 108.70 ng/day), hot chicken wings (men: 126.32 ng/day, women: 142.11 ng/day), and crispy fried chicken burgers (men: 129.78 ng/day, women: 59.91 ng/day) were found to provide the highest dietary intake of HCAs in both genders, which may lead to an increase in colorectal and breast cancers. PRACTICAL APPLICATIONS: The rapid expansion of the Chinese fast-food industry has promoted serious health problems, such as colorectal cancer and some cardiovascular diseases. Several epidemiological studies revealed that a high intake of processed meats may increase the risk of cancer in humans because cooking food proteins, such as meat, at high temperatures could produce high levels of carcinogenic compounds, such as HCAs. Because of the vast variation in eating habits, preparation methods and the frequency of meat consumption, it is important to evaluate the accurate level of HCAs in commercially available fast-food meat products with the aim to clarify the association between processed meats and the health risk.

English

Dietary intake of polycyclic aromatic hydrocarbons (PAH) and heterocyclic amines (HCA) has posted a great health risk as they have been identified as a most potent human carcinogen. Microbial quality of food is also of concern as they contribute to food poisoning and infection. Sixty food samples comprising roasted yam, plantain, grilled and smoked fish and meat were randomly sampled from Lagos and Ogun State, Nigeria, and the PAHs, HCAs contents and microbial load were determined. Isolates were subjected to antibiogram assay. The pH of the samples ranged between 5.08 and 7.49, titrable acidity was in the range of 0.50 and 1.20.  Staphylococcus, Bacillus, Micrococcus, Proteus, Pseudomonas, Citrobacter and Klebsiella sp. had been identified. Antibiogram revealed that the isolates were multi-resistant and most resistant to ceftazidime, cloxacillin and tetracycline and more susceptible to ofloxacin. PAHs were detected in some grilled, roasted and smoked samples and with the highest concentrations 314.85 and 139.97 µg/g Dibenzene[a,h]anthracene established in roasted yam and smoked fish samples. Only 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was detected in grilled fish and meat samples. This study therefore established the presence of chemical and microbial contaminants in some of the food items investigated. It recommended that strict sanitary practices and appropriate cooking methods be enforced during food preparation.   Key words: Antibiogram, carcinogens, hazard analysis and critical control point (HACCP), heterocyclic amines, polycyclic aromatic hydrocarbons, Nigeria.

Current Achievement and Challenges of Food, Cooking Methods and Cancer Control: A Pooled Multivariable-Adjusted Analysis for the Association Between Meat Mutagens Intake and Colorectal Adenoma and Cancer

Background: Heterocyclic amines (HCAs), a group of dietary carcinogens, have been hypothesized to increase risk of colorectal adenoma (CRA) cancer (CRC). However, previous findings have been inconsistences. Aim: The aim was to pool analysis of multivariable-adjusted relative risks from published articles for the association between HCAs intake and the risk of CRD and CRC. Methods: We used all available 34 published articles to access the multivariable-adjusted relative risk (hazard ratio or odds ratio) and their 95% confidence interval (95% CI) to estimate ln(RR) and se(ln(RR)). The HCAs 2-amino-3,8-dimethylimidazo[4,5,-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo[4,5,-f]quinoxaline (DiMeIQx), and meat-derived mutagenicity (MDM) were examined. The random pooled RR, 95% CI was analyzed in using ln(RR) and se(ln(RR)) for separated prospective cohort studies and case-control studies by STATA-10. Results: Prospective cohort studies have examined for 5,684 CRC occurred among 528,111 registered participants; and for 2,484 CRA occurred among 136,902 registered participants. Case-control studies have examined for 12,753 CRC and 17,152 matched controls; and for 10,821 CRA and 45,099 matched controls. PhIP was majority contributed by cooked chicken (54%–74%). MeIQx was mainly contributed by red meat (83%–92%). For prospective cohort studies on CRC, fifth versus first-quintile, the random pooled RR, (95% CI) was 1.11, (1.00, 1.23), P = 0.052 for MDM; 1.00, (0.91, 1.09), P = 0.958 for PhIP; 1.12, (1.03, 1.22), P = 0.009 for MeIQx; 1.03, (0.87, 1.22), P = 0.763 for DiMeIQx. For CRA, third versus first-quintile, the random pooled RR, (95% CI) was 1.13, (0.92, 1.39), P = 0.237 for MDM; 1.11, (0.96, 1.29), P = 0.169 for PhIP; 1.14, (1.00, 1.30), P = 0.048 for MeIQx; 1.00, (0.87, 1.15), P = 0.999 for DiMeIQx. For case-control studies, the null association was observed for PhIP, DiMeIQx and CRC. A positive association was significantly seen for MeIQx, MDM and both CRC and CRA. Conclusion: Because intake of MeIQx significantly increased the risk of both CRC and CRA in both prospective cohort and case-control studies, the findings support to the hypothesis of the role of underlying mechanisms of red meat induced CRC.

High red and processed meat consumption is associated with non-alcoholic fatty liver disease and insulin resistance

High red and processed meat consumption is related to type 2 diabetes. In addition, cooking meat at high temperatures for a long duration forms heterocyclic amines (HCAs), which are related to oxidative stress. However, the association between meat consumption and non-alcoholic fatty liver disease (NAFLD) is yet to be thoroughly tested. Therefore, we aimed to test the association of meat type and cooking method with NAFLD and insulin resistance (IR). This was a cross-sectional study in individuals who were 40-70 years old and underwent screening colonoscopy between 2013 and 2015 in a single center in Israel. NAFLD and IR were evaluated by ultrasonography and homeostasis model assessment. Meat type and cooking method were measured by a food frequency questionnaire (FFQ) and a detailed meat questionnaire. Unhealthy cooking methods were considered as frying and grilling to a level of well done and very well done. Dietary HCA intake was calculated. A total of 789 individuals had a valid FFQ and 357 had a valid meat questionnaire. High consumption of total meat (portions/day above the median) (odds ratio [OR] 1.49; 95% CI 1.05-2.13; p = 0.028; OR 1.63; 1.12-2.37; p = 0.011), red and/or processed meat (OR1.47; 95% CI 1.04-2.09; p = 0.031; OR1.55; 1.07-2.23; p = 0.020) was independently associated with higher odds of NAFLD and IR, respectively, when adjusted for: body mass index, physical activity, smoking, alcohol, energy, saturated fat and cholesterol intake. High intake of meat cooked using unhealthy methods (OR1.92; 95% CI 1.12-3.30; p = 0.018) and HCAs (OR2.22; 95% CI 1.28-3.86; p = 0.005) were independently associated with higher odds of IR. High consumption of red and/or processed meat is associated with both NAFLD and IR. High HCA intake is associated with IR. If confirmed in prospective studies, limiting the consumption of unhealthy meat types and improving preparation methods may be considered as part of NAFLD lifestyle treatment. High red and processed meat consumption is related to several diseases. In addition, cooking meat at high temperatures for a long duration forms heterocyclic amines, which have harmful health effects. Non-alcoholic fatty liver disease is a significant public health burden and its formation is strongly related to insulin resistance. In this study, both were found to be more frequent in people who consume relatively high quantities of red and processed meat. In addition, a high intake of heterocyclic amines was associated with insulin resistance.

Abstract P184: Meat Cooking Methods and Risk of Hypertension: Results From Three Prospective Cohort Studies

Background: The role of open-flame and/or high-temperature cooking (grilling/barbequing, broiling, or roasting) and doneness preferences (rare, medium, or well-done) in the association between meat consumption and risk of hypertension remains unknown. This study aimed to examine cooking methods for meats (red meats, chicken, or fish) in relation to hypertension risk among men and women who consumed meat regularly (≥2 servings/week). Methods: Study population consisted of 32,925 women from the Nurses’ Health Study (NHS 1996-2012), 53,852 women from the NHSII (2001-2013), and 17,104 men from the Health Professionals Follow-Up Study (HPFS 1996-2012), who were free of hypertension, diabetes, cardiovascular disease, and cancer at baseline. Results: We documented 37,123 incident hypertension cases during 1.06 million person-years of follow-up. After multivariate adjustments of covariates including total consumption of red meats, chicken, and fish, a higher frequency of open-flame and/or high-temperature cooking and a preference for higher meat doneness level were both independently associated with an increased hypertension risk. When comparing open-flame and/or high-temperature cooking >15 times/month with <4 times/month, the pooled hazard ratio (HR) and 95% confidence interval (CI) of hypertension was 1.17 (1.12, 1.21; P trend <0.001). When comparing the extreme quartiles of meat doneness level score, the pooled HR (95% CI) of hypertension was 1.15 (1.12, 1.19; P trend <0.001). The associations persisted when data were analyzed by individual meat groups: comparing extreme groups, for red meats, the pooled HR (95% CI) of hypertension was 1.18 (1.13, 1.23; P trend <0.001) for open-flame and/or high-temperature cooking and 1.15 (1.12, 1.19; P trend <0.001) for high meat doneness level; for white meats (chicken and fish), the pooled HR (95% CI) of hypertension was 1.12 (1.08, 1.16; P trend <0.001) for open-flame and/or high-temperature cooking and 1.10 (1.07, 1.14; P trend <0.001) for high meat doneness level. Moreover, levels of estimated intake of heterocyclic aromatic amines (HAAs) were also independently associated with an increased risk of hypertension. Comparing extreme quintiles of HAAs, the pooled HR (95% CI) of hypertension was 1.16 (1.13, 1.21; P trend <0.001). These associations were attenuated but remained significant when further adjusting for baseline body mass index. Conclusions: Our results suggest that, independent of the amount of meat consumption, open-flame and/or high-temperature cooking and high doneness level for both red meats and white meats are associated with an increased risk of hypertension.

Meat Cooking Methods and Risk of Type 2 Diabetes: Results From Three Prospective Cohort Studies.

To examine open-flame and/or high-temperature cooking (grilling/barbecuing, broiling, or roasting) and doneness preferences (rare, medium, or well done) for red meat, chicken, and fish in relation to type 2 diabetes (T2D) risk among U.S. adults who consumed animal flesh regularly (≥2 servings/week). The prospective studies included 52,752 women from the Nurses' Health Study (NHS) (followed during 1996-2012), 60,809 women from NHS II (followed during 2001-2013), and 24,679 men from the Health Professionals Follow-Up Study (HPFS) (followed during 1996-2012) who were free of diabetes, cardiovascular disease, and cancer at baseline. Incident cases of T2D were confirmed by validated supplementary questionnaires. We documented 7,895 incident cases of T2D during 1.74 million person-years of follow-up. After multivariate adjustments including baseline BMI and total consumption of red meat, chicken, and fish, higher frequency of open-flame and/or high-temperature cooking was independently associated with an elevated T2D risk. When comparing open-flame and/or high-temperature cooking >15 times/month with <4 times/month, the pooled hazard ratio (HR) (95% CI) of T2D was 1.28 (1.18, 1.39; Ptrend <0.001). When comparing the extreme quartiles of doneness-weighted frequency of high-temperature cooking, the pooled HR (95% CI) of T2D was 1.20 (1.12, 1.28; Ptrend <0.001). These associations remained significant when red meat and chicken were examined separately. In addition, estimated intake of heterocyclic aromatic amines was also associated with an increased T2D risk. Independent of consumption amount, open-flame and/or high-temperature cooking for both red meat and chicken is associated with an increased T2D risk among adults who consume animal flesh regularly.

Red Meat and Colorectal Cancer: Exploring the Potential HCA Connection.

Epidemiological studies have found that eating red meat, especially if it is grilled or processed, is associated with increased risk for colorectal cancer. 1 Heterocyclic amines (HCAs) and other cooking-related mutagens in meat are among several possible culprits that trigger carcinogenesis. In a new study, researchers focused on consumption of three key HCAs in the human diet, known as MeIQx, DiMeIQx, and PhIP. Although estimated HCA intake was not associated with colorectal cancer overall, people classified as having the greatest intake of PhIP from red meat (but not white meat) had a slightly increased risk of proximal colon cancers, which include tumors of the cecum and the ascending and transverse colon. 2