Development of a food frequency questionnaire module and databases for compounds in cooked and processed meats

There is ample evidence from basic research and animal carcinogenicity studies that heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are mutagens and carcinogens. However, there was a paucity of human data due to a lack of appropriate investigative tools. We developed the first validated cooked meat module within a food frequency questionnaire (FFQ) in the United States of America and created databases to be used in conjunction with this FFQ to estimate intake of HCAs and benzo[a]pyrene, a marker of PAHs. It became clear that other aspects of meat may also contribute to carcinogenesis; in particular, we are pursuing two additional areas: processed meat and iron exposure in relation to cancer risk. To investigate these hypotheses, we have expanded the cooked meat module to include detailed information on processed meats and fish. In addition, we are developing two databases, one for total iron and heme iron in cooked meat and the other for nitrite, nitrate, and N-nitroso compounds in processed meats. In this report, we will outline the methods used to develop the meat questionnaires, the databases, a software package for generating the intake values, and the methods used to generate nutritional data from nationally representative samples.     

Meat and cancer

An increasing literature associates high intake of meat, especially red meat and processed meat with an increased risk of cancers, especially colorectal cancer. There is evidence that this risk may not be a function of meat per se, but may reflect high-fat intake, and/or carcinogens generated through various cooking and processing methods. The cancer risk may be modulated by certain genotypes. Cancers associated with high meat consumption may be reduced by the addition of anticarcinogens in the diet, especially at the same time as meat preparation or meat consumption, or modification of food preparation methods. Meat contains potential anticarcinogens, including omega-3 polyunsaturated fatty acids, and conjugated linoleic acid (CLA). Red meat, in particular, is an important source of micronutrients with anticancer properties, including selenium, vitamin B6 and B12, and vitamin D. Adjusting the balance between meat and other dietary components may be critical to protecting against potential cancer risks.     

The relationship of red meat with cancer: Effects of thermal processing and related physiological mechanisms

Red meat is consumed globally and plays an important role in the Western diet. Its consumption is however linked with various types of diseases. This review focuses on the relationship of red meat with cancer, its dependency on the thermal processing methodology and the subsequent physiological effects. The epidemiological evidence is discussed, followed by introduction of the species that were hypothesized to contribute to these carcinogenic effects including polycyclic aromatic hydrocarbons (PAHs), heterocyclic amines (HCAs), N-nitroso compounds (NOCs), heme iron, and macromolecular oxidation products. Their carcinogenic mechanisms were then addressed with further emphasis on the involvement of inflammation and oxidative stress. The thermal processing dependency of the carcinogen generation and the partially elucidated carcinogenic mechanism both represent doorways of opportunities available for the scientific manipulation of their impact after human consumption, to minimize the cancer risks associated with red meat.     

Dietary exposure to heterocyclic amines in high-temperature cooked meat and fish in Malaysia

The intake of heterocyclic amines is influenced by the amount and type of meat and fish ingested, frequency of consumption, cooking methods, cooking temperature, and duration of cooking. In this study, the dietary intake of heterocyclic amines in Malaysia and their main sources were investigated. Forty-two samples of meat and fish were analysed by high-performance liquid chromatography with photodiode array detector to determine the concentration of the six predominant heterocyclic amines, namely: 2-amino-3-methylimidazo[4,5-f] quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f] quinoline(MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f] quinoxaline (4,8-DiMeIQx), 2-amino-3,7,8-trimethylimidazo[4,5-f] quinoxaline (7,8-DiMeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Dietary intake data were obtained using a food-frequency questionnaire when interviewing 600 Malaysian respondents. The level of total heterocyclic amines in food samples studies ranged from not detected to 38.7 ng g^?1. The average daily intake level of heterocyclic amine was 553.7 ng per capita day^?1. The intake of PhIP was the highest, followed by MeIQx and MeIQ. The results reveal that fried and grilled chicken were the major dietary source of heterocyclic amines in Malaysia. However, the heterocyclic amine intake by the Malaysian population was lower than those reported from other regions.     

Heterocyclic amine content in commercial ready to eat meat products

Heterocyclic amines (HCAs) are produced in meats cooked at high temperature, which are potent mutagens and a risk factor for human cancers. The aim of this study was to estimate the amount of HCAs in some commonly consumed ready-to-eat (RTE) meat products. The RTE products were purchased from a local grocery store, and HCA were analyzed using an analytical method based on solid-phase extraction followed by HPLC. The primary HCAs in these samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) (not detected-7.9 ng/g) and MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (not detected-3.6 ng/g). Products ranked in order of increasing total HCA content: pepperoni (0.05 ng/g)相似文献   

Update on the relationship of fish intake with prostate, breast, and colorectal cancers

A systematic review of prospective cohort and case-control studies investigating relationships between the intake of fish and incidence of prostate, breast, or colorectal cancers was conducted. A total of 106 studies fulfilled the requirements stated in the "Search strategy and selection criteria." Among 273 estimates of association reported by these studies, 53 indicated decreased risk while 12 indicated increased risk associated with fish intake. The hypothesis linking fish consumption and low cancer incidence appears to be supported by little epidemiological data. However, there are several factors that may mask potential protective associations with fish intake. The type and the amount of fish eaten, the cooking method, the stage of the cancer and, amongst women, menopausal status may all be important factors that relate to whether fish is protective or not. Future epidemiologic studies with a clearer assessment of these factors are needed to know more about the effects of fish consumption on cancer risk. Therefore, until there are better measures of dietary exposure or biomarkers to correlate self-report, no conclusion can be drawn regarding the recommendation for increasing fish consumption in general to reduce the risk of developing the most common cancers in Western societies.     

Controversy on the correlation of red and processed meat consumption with colorectal cancer risk: an Asian perspective

Abstract

This study aimed to investigate the relationship between meat intake and colorectal cancer risk from an Asian, particularly Korean, perspective. A report by the International Agency for Research on Cancer (IARC) published in 2015 concluded that intake of processed and red meat increases the risk of developing colorectal cancer. We conducted an in-depth analysis of prospective, retrospective, case-control and cohort studies, systematic review articles, and IARC monograph reports, which revealed that the IARC/WHO report weighted the results of studies based in Western countries more and that the correlation between intake of processed meat products and colorectal cancer incidence in Asians is not clearly supported. Among 73 epidemiological studies, approximately 76% were conducted in Western countries, whereas only 15% of studies were conducted in Asia. Furthermore, most studies conducted in Asia showed that processed meat consumption is not related to the onset of cancer. Moreover, there have been no reports showing significant correlation between various factors that directly or indirectly affect colorectal cancer incidence, including processed meat products types, raw meat types, or cooking methods. Further epidemiological studies taking each country’s food culture into consideration are required to reliably elucidate the effects of processed meat product intake, especially on cancer incidence.     

Red meat and colon cancer: Should we become vegetarians,or can we make meat safer?

The effect of meat consumption on cancer risk is a controversial issue. However, recent meta-analyses show that high consumers of cured meats and red meat are at increased risk of colorectal cancer. This increase is significant but modest (20-30%). Current WCRF-AICR recommendations are to eat no more than 500 g per week of red meat, and to avoid processed meat. Moreover, our studies show that beef meat and cured pork meat promote colon carcinogenesis in rats. The major promoter in meat is heme iron, via N-nitrosation or fat peroxidation. Dietary additives can suppress the toxic effects of heme iron. For instance, promotion of colon carcinogenesis in rats by cooked, nitrite-treated and oxidized high-heme cured meat was suppressed by dietary calcium and by α-tocopherol, and a study in volunteers supported these protective effects in humans. These additives, and others still under study, could provide an acceptable way to prevent colorectal cancer.     

Exposure to heterocyclic aromatic amines from the consumption of cooked red meat and its effect on human cancer risk: A review

This review covers the bibliographic data from the last 10 years on the possible carcinogenicity of heterocyclic aromatic amines (HAAs) in humans. Aspects such as red meat intake, cooking methods applied to red meat, and doneness of cooking are discussed from an epidemiological point of view. The role in the carcinogenicity of the HAAs has been assigned to two main factors: first, the very high frequency of consumption of red meat; and, second, very darkly browned meats from cooking. However, there are some uncertainties associated with epidemiological results such as the presence of other carcinogens, co-carcinogens and anti-carcinogens in the diet, analytical results on the content of HAAs in foods, food frequency questionnaires, and mainly genetic susceptibility to HAAs. It is concluded that there is not sufficient scientific evidence to support the hypothesis that human cancer risk is due specifically to the intake of HAAs in the diet.     

Exposure to heterocyclic aromatic amines from the consumption of cooked red meat and its effect on human cancer risk: A review

This review covers the bibliographic data from the last 10 years on the possible carcinogenicity of heterocyclic aromatic amines (HAAs) in humans. Aspects such as red meat intake, cooking methods applied to red meat, and doneness of cooking are discussed from an epidemiological point of view. The role in the carcinogenicity of the HAAs has been assigned to two main factors: first, the very high frequency of consumption of red meat; and, second, very darkly browned meats from cooking. However, there are some uncertainties associated with epidemiological results such as the presence of other carcinogens, co-carcinogens and anti-carcinogens in the diet, analytical results on the content of HAAs in foods, food frequency questionnaires, and mainly genetic susceptibility to HAAs. It is concluded that there is not sufficient scientific evidence to support the hypothesis that human cancer risk is due specifically to the intake of HAAs in the diet.     

Enhancement of colon and stomach carcinogenesis in 1,2-dimethylhydrazine-treated rats fed a diet high in heterocyclic amines

 Epidemiological studies have linked the consumption of red meat and the consumption of highly browned meats containing high levels of heterocyclic aromatic amines (HCAs) to increased risk of colorectal cancer or polyps. We have examined the effects of long-term feeding of beef-containing diets with low and high levels of HCAs (in the context of a low- or high-beef tallow diet) on a standard 1,2-dimethylhydrazine (DMH)-induced colon tumorigenesis protocol. Feeding of a beef diet high in HCAs resulted in more DMH-induced colon adenocarcinomas, but only in the context of a low fat diet. The high HCA diets increased stomach tumors in all DMH-treated rats. An apparent interaction of high HCA levels with a high fat level reduced the colon tumor incidence and tumor numbers in those rats on diets containing both these factors. These results support the epidemiological data linking well-cooked meat to increased risk for colon and stomach cancer, but the role of the dietary fat level remains puzzling. Additionally, we examined the DNA of liver, colon, and stomach from control rats (not treated with DMH) fed a high level of HCAs for 27 weeks. The genomic DNA was analyzed for the presence of 2-amino-1-methyl-6-phenylimidazo[4,5-f]pyridine (PhIP) adducts by ³²P-postlabeling analysis and was also used in PCR to amplify the rat p53 and Apc genes, followed by direct dye-terminator DNA sequencing. Results showed that no PhIP adducts were present in any tissue. In addition, there were no signature p53 or Apc gene mutations seen in the colon or stomach DNA. These results indicate that the high level of HCAs present in a diet of well-cooked meat does not cause (1) persistent PhIP adducts similar to those produced by feeding pure PhIP at high doses or (2) p53 and Apc gene mutations in nontumor tissue. Received: 23 April 1998     

Red meat,diseases, and healthy alternatives: A critical review

Meat is an important food for human nutrition, by especially providing high-quality protein and also some essential micronutrients, in front iron, zinc, and vitamin B₁₂. However, a high intake of red and processed meat is associated with an increased risk for diseases, especially type 2 diabetes and colorectal cancer, as several epidemiological studies and meta-analyses have shown. This review summarizes meta-analyses of publications studying the association between red and processed meat intake and type 2 diabetes, cardiovascular diseases, colorectal and other cancers, and all-cause mortality. Various potential mechanisms involved in the increased disease risk are discussed. Furthermore, the beneficial effects of healthy alternatives for meat, like fish, nuts, vegetables and fruits, pulses and legumes, whole grains, and dairy products are reviewed by including selected papers and recent meta-analyses.     

Changes in l-carnitine content of fish and meat during domestic cooking

Human adults store around 20g of l-carnitine. In the human body, l-carnitine is not metabolized but excreted through the kidney. Lost l-carnitine has to be replenished either by a biosynthetic mechanism or by the consumption of foods containing l-carnitine. Today, there is no "official" recommended daily allowance for l-carnitine but the daily need for l-carnitine intake has been estimated in the wide range of 2-12μmol/day/kg body weight for an adult human. In this study we evaluated the effect of freezing and of different cooking methods on the l-carnitine content of red meat and fish. l-carnitine was abundantly present in all beef products analyzed. The amounts in the various cuts were similar and our data showed that freezing or cooking did not modify l-carnitine content. Salmon contained about 12 times less l-carnitine than beef but except in smoked salmon, cooking or freezing did not alter l-carnitine content. This study confirms the important role that meet products play for providing adequate amount of l-carnitine to the human body.     

Effect of tea and other dietary factors on iron absorption

Iron deficiency is a major world health problem, that is, to a great extent, caused by poor iron absorption from the diet. Several dietary factors can influence this absorption. Absorption enhancing factors are ascorbic acid and meat, fish and poultry; inhibiting factors are plant components in vegetables, tea and coffee (e.g., polyphenols, phytates), and calcium. After identifying these factors their individual impact on iron absorption is described. Specific attention was paid to the effects of tea on iron absorption. We propose a calculation model that predicts iron absorption from a meal. Using this model we calculated the iron absorption from daily menus with varying amounts of enhancers and inhibitors. From these calculations we conclude that the presence of sufficient amounts of iron absorption enhancers (ascorbic acid, meat, fish, poultry, as present in most industrialized countries) overcomes inhibition of iron absorption from even large amounts of tea. In individuals with low intakes of heme iron, low intakes of enhancing factors and/or high intakes of inhibitors, iron absorption may be an issue. Depletion of iron stores enhances iron absorption, but this effect is not adequate to compensate for the inhibition of iron absorption in such an inadequate dietary situation. For subjects at risk of iron deficiency, the following recommendations are made. Increase heme-iron intake (this form of dietary iron present in meat fish and poultry is hardly influenced by other dietary factors with respect to its absorption); increase meal-time ascorbic acid intake; fortify foods with iron. Recommendations with respect to tea consumption (when in a critical group) include: consume tea between meals instead of during the meal; simultaneously consume ascorbic acid and/or meat, fish and poultry.     

Red meat consumption: An overview of the risks and benefits

Red meat is long established as an important dietary source of protein and essential nutrients including iron, zinc and vitamin B12, yet recent reports that its consumption may increase the risk of cardiovascular disease (CVD) and colon cancer have led to a negative perception of the role of red meat in health. The aim of this paper is to review existing literature for both the risks and benefits of red meat consumption, focusing on case–control and prospective studies. Despite many studies reporting an association between red meat and the risk of CVD and colon cancer, several methodological limitations and inconsistencies were identified which may impact on the validity of their findings. Overall, there is no strong evidence to support the recent conclusion from the World Cancer Research Fund (WCRF) report that red meat has a convincing role to play in colon cancer. A substantial amount of evidence supports the role of lean red meat as a positive moderator of lipid profiles with recent studies identifying it as a dietary source of the anti-inflammatory long chain (LC) n−3 PUFAs and conjugated linoleic acid (CLA). In conclusion, moderate consumption of lean red meat as part of a balanced diet is unlikely to increase risk for CVD or colon cancer, but may positively influence nutrient intakes and fatty acid profiles, thereby impacting positively on long-term health.     

A population-based dietary inventory of cooked meat and assessment of the daily intake of food mutagens

Frequent consumption of meat has been associated with an increased risk of colorectal cancer. Such a risk may be due to naturally occurring compounds in the meat, substances added to the meat, or agents formed during cooking. Concerning the latter alternative, mutagenic heterocyclic amines are multi-site animal carcinogens, but their relevance to human cancer has yet to be determined. In the present study, we made a population-based inventory of cooked meat dishes consumed in the county of Stockholm, ranked dishes according to cooking method and frequency of consumption and, in addition, determined levels of mutagenic activity in six commonly consumed fried meat dishes. Meat was consumed, on average, 493 times per year, giving 1.4 daily servings. Frying was the most common way to cook meat. When ranking meat dishes according to intake frequency, the top eight dishes were as follows: sausage, steak casserole, meatballs, pork chops, pork belly, bacon, ground beef patties, and, finally, mincemeat sauce. The frying sessions were performed under controlled conditions at four different temperatures, and we documented the degree of surface browning and measured mutagenic activity in six frequently eaten dishes (sausage, meatballs, pork chops, pork belly, ground beef patties, and minute beef). We found extracts from all six dishes to be mutagenic, and a mean daily dose of exposure was calculated, giving 862 revertants. This investigation leaves no doubt that a major portion of the total meat consumption is fried before ingestion and that fried meat dishes frequently consumed by an elderly population in Stockholm contain mutagenic substances. Furthermore, the study provides usable information for future epidemiological research in which it is necessary to disentangle the effect of meat per se from the effect of potentially carcinogenic heterocyclic amines.     

不同工艺即食烤鱼多环芳烃检测方法及变化研究

目的:建立即食烤鱼16种多环芳烃（Polycyclic aromatic hydrocarbons, PAHs）检测方法,分析不同工艺对烤鱼PAHs种类及含量的影响。方法:样品经正己烷提取,采用固相萃取柱净化,二氯甲烷洗脱,高效液相色谱法测定。结果:16种PAH_S相关系数为0.9993~0.9998,检出限为0.20~2.50 μg/kg;加标回收率为64.25%~122.8%,相对标准偏差为1.38%~7.13%。在碳烤、油炸、电烤三种不同熟化方式下,烤鱼中调味料的添加可减少PAHs的生成量;烤鱼中PAHs的种类和含量为碳烤>油炸>电烤,样品中萘、苊烯、菲和芘检出含量较高,碳烤样品PAHs总量高达58.74 μg/kg,明显高于油炸和电烤样品组;熟化时间和温度对烤鱼PAHs种类及含量均有影响,随油炸时间延长、油炸温度增高,样品PAHs检出种类和含量增加明显,其中,萘、苊烯、菲、荧蒽和芘含量增高达3~5倍;随电烤时间和温度的增加,样品中PAHs种类增多,PAHs总量亦提高;通过风险评估,烤鱼加热时间控制在6 min,温度200 ℃以内,摄入频率小于每月2次,食用风险低。结论:建立了烤鱼中16种PAHs的检测方法;进行了不同工艺烤鱼样品中PAHs的种类、含量变化分析及风险评估,为即食烤鱼熟化工艺选择提供依据。     

Formation of protein adducts of 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine in cooked foods

Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds found in cooked meat and fish. Although HCAs are known to form adducts with protein after metabolic activation, adduct formation during cooking has not been elucidated. In this study, we showed that 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) is released from high molecular weight compounds by acid or enzymatic hydrolysis of cooked foods. Formation of free and protein adduct forms of PhIP was dependent on cooking temperature and time, and PhIP–protein adducts were estimated to form after formation of free PhIP. We also demonstrated that PhIP–protein adduct is formed by heating of PhIP and albumin as a model protein. A new adduct peak including [M+H]⁺ (m/z=225) of PhIP as a fragment ion was detected in the high molecular weight fraction of heat‐treated protein by LC–MS analysis. From model experiments by heating of PhIP and amino acids, the adduct was estimated to be produced by condensation of the amino group of PhIP and the carboxyl group of protein. PhIP–protein adducts were detected in several cooked meat and fish at ng/g food level as PhIP content. These results suggest that food‐borne protein adducts of HCAs may influence human HCA exposure and carcinogenic risk.     

Occurrence of heterocyclic amines in cooked meat products

Heterocyclic amines (HCAs), potent mutagens and a risk factor for human cancers, are produced in meats cooked at high temperature. The aim of this study was to determine the HCA content in cooked meat products (beef, chicken, pork, fish) prepared by various cooking methods (pan frying, oven broiling, and oven baking at 170 to 230 °C) that are preferred by U.S. meat consumers. The primary HCAs in these samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) (1.49-10.89 ng/g), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (not detected-4.0 ng/g), and DiMeIQx (2-amino-3,4,8-trimethyl-imidazo [4,5-f]quinoxaline) (not detected-3.57 ng/g). Type and content of HCAs in cooked meat samples were highly dependent on cooking conditions. The total HCA content in well-done meat was 3.5 times higher than that of medium-rare meat. Fried pork (13.91 ng/g) had higher levels of total HCAs than fried beef (8.92 ng/g) and fried chicken (7.00 ng/g). Among the samples, fried bacon contained the highest total HCA content (17.59 ng/g).     

Oxidation During Digestion of Meat: Interactions with the Diet and Helicobacter pylori Gastritis,and Implications on Human Health

The last decade has seen epidemiological evidence of a positive association between high consumption of red meat and processed meat and the risk of developing a range of chronic diseases, such as colorectal cancer, cardiovascular disease, and type 2 diabetes. Oxidative stress is potentially involved in this association; however, oxidative stress is likely limited if red meat and processed meat are consumed in moderation, and combined with high intake of fruits and vegetables and low intake of refined sugars. In addition, it appears that some subgroups of the population are more prone to developing oxidative stress‐related diseases as a consequence of high red and processed meat consumption. For example, the gastric juice in the inflamed stomach of individuals infected with Helicobacter pylori may be an excellent site for enhanced oxidation following meat consumption. Similarly, patients with inflammatory bowel disease may be at increased risk. Oxidative stress resulting from red or processed meat consumption may mediate the onset and/or progression of a wide range of diseases through various mechanisms, which are discussed in this review.