Dietary intake of different types and characteristics of processed meat which might be associated with cancer risk Πresults from the 24-hour diet recalls in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Objective: There is increasing evidence for a significant effect of processed meat (PM) intake on cancer risk. However, refined knowledge on how components of this heterogeneous food group are associated with cancer risk is still missing. Here, actual data on the intake of PM subcategories is given; within a food-based approach we considered preservation methods, cooking methods and nutrient content for stratification, in order to address most of the aetiologically relevant hypotheses. Design and setting: Standardised computerised 24-hour diet recall interviews were collected within the framework of the European Prospective Investigation into Cancer and Nutrition (EPIC), a prospective cohort study in 27 centres across 10 European countries. q The Authors 2006 *Corresponding author: Email [email protected] Public Health Nutrition: 9(4), 449–464 DOI: 10.1079/PHN2005861 https:/www.cambridge.org/core/terms. https://doi.org/10.1079/PHN2005861 Downloaded from https:/www.cambridge.org/core. IP address: 54.191.40.80, on 09 Apr 2017 at 05:54:05, subject to the Cambridge Core terms of use, available at Subjects: Subjects were 22 924 women and 13 031 men aged 35–74 years. Results: Except for the so-called ‘health-conscious’ cohort in the UK, energy-adjusted total PM intake ranged between 11.1 and 47.9 g day in women and 18.8 and 88.5 g day in men. Ham, salami-type sausages and heated sausages contributed most to the overall PM intake. The intake of cured (addition of nitrate/nitrite) PM was highest in the German, Dutch and northern European EPIC centres, with up to 68.8 g day in men. The same was true for smoked PM (up to 51.8 g day). However, due to the different manufacturing practice, the highest average intake of NaNO2 through PM consumption was found for the Spanish centres (5.4mg day in men) as compared with German and British centres. Spanish centres also showed the highest intake of NaCl-rich types of PM; most cholesteroland iron-rich PM was consumed in central and northern European centres. Possibly hazardous cooking methods were more often used for PM preparation in central and northern European centres. Conclusions: We applied a food-based categorisation of PM that addresses aetiologically relevant mechanisms for cancer development and found distinct differences in dietary intake of these categories of PM across European cohorts. This predisposes EPIC to further investigate the role of PM in cancer aetiology. Several studies have already shown a positive association between meat consumption and different types of cancer, especially colorectal cancer. In a recent review a higher risk of colorectal cancer was calculated for a high intake of processed meat (PM) and red meat; additionally, a strong dose–response relationship between PM intake and colorectal cancer risk (1.36, 95% confidence interval 1.15–1.61, for consumption of 30 g day vs. no consumption) existed. An even stronger association was provided by a recent meta-analysis, where Sandhu et al. showed a significant 49% increased risk for a daily increase of 25 g of PM. In addition, associations between PM consumption and gastric cancer, lung cancer, cancer of the upper aerodigestive tract, prostate cancer and cancer of the lower urinary tract have been observed. There are also reports linking maternal intake of cured meat to the risk of brain tumours in childhood. Several mechanisms have been hypothesised to explain associations between the consumption of PM and cancer risk; not all of them, however, are specific for PM. In general, it may be mediated through (1) an increased intake of (pre-)carcinogens or their precursors as well as (2) a high intake of specific nutrients enhancing the development of carcinogenic processes. Suggested mechanisms include the production of heterocyclic aromatic amines (HCA) during cooking, an increased content of polycyclic aromatic hydrocarbons (PAH) by certain cooking and smoking methods applied to PM, the presence of preformed N-nitroso compounds (NOC) from nitrates and nitrites added for preservation purposes, endogenous production of NOC by means of the high haem content in PM produced from red meat, and the content of lipid (fatty acids, cholesterol) oxidation products arising during processing and storage. Concerning nutrient effects, curing increases drastically the originally low NaCl content of fresh meat and a high intake of salted food is associated with the risk of gastric cancer. Further, high haem iron intake may be linked to carcinogenesis via enhancement of endogenous NOC production and oxidative damage to macromolecules, including lipids and DNA. Therefore, also categorisation of PM by lipid content seems a promising approach. In particular, formation of cholesterol oxidation products during preparation and storage of PM has been described and a link between 7b-hydroxycholesterol and lung cancer risk has been suggested. To the best of our knowledge, a systematic analysis of factors that might contribute to a higher cancer risk due to high PM consumption has not been conducted so far. The European Prospective Investigation into Cancer and Nutrition (EPIC) offers the opportunity to study the diversity of food and nutrition habits in Europe because detailed nutrition information on type and preparation of the consumed PM is available for a subset of EPIC participants. Therefore, the aim of the present work is to describe PM intake in categories which reflect suggested aetiological factors and mechanisms that might help to explain the association of PM intake and cancer risk. We applied a food-based approach considering preservation methods, cooking methods and nutrient content for stratification; the definition of the subgroups and categories that we were able to build is given in the following section. The results may be the basis for more refined aetiological analyses in EPIC to disentangle the different mechanistic hypotheses on the effect of PM. Material and methods Subjects TheEPIC cohort study includes about half amillion subjects from 10 European countries (France, Italy, Spain, Greece, The Netherlands, the United Kingdom, Germany, Denmark, Sweden, Norway). Information on the usual