Valeria Pala

Standardization of the 24-hour diet recall calibration method used in the european prospective investigation into cancer and nutrition (EPIC): general concepts and preliminary results.

Objectives: Despite increasing interest in the concept of calibration in dietary surveys, there is still little experience in the use and standardization of a common reference dietary method, especially in international studies. In this paper, we present the general theoretical framework and the approaches developed to standardize the computer-assisted 24 h diet recall method (EPIC-SOFT) used to collect about 37 000 24-h dietary recall measurements (24-HDR) from the 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). In addition, an analysis of variance was performed to examine the level of standardization of EPIC-SOFT across the 90 interviewers involved in the study.Methods: The analysis of variance used a random effects model in which mean energy intake per interviewer was used as the dependent variable, while age, body mass index (BMI), energy requirement, week day, season, special diet, special day, physical activity and the EPIC-SOFT version were used as independent variables. The analysis was performed separately for men and women.Results: The results show no statistical difference between interviewers in all countries for men and five out of eight countries for women, after adjustment for physical activity and the EPIC-SOFT program version used, and the exclusion of one interviewer in Germany (for men), and one in Denmark (for women). These results showed an interviewer effect in certain countries and a significant difference between gender, suggesting an underlying respondent’s effect due to the higher under-reporting among women that was consistently observed in EPIC. However, the actual difference between interviewer and country mean energy intakes is about 10%. Furthermore, no statistical differences in mean energy intakes were observed across centres from the same country, except in Italy and Germany for men, and France and Spain for women, where the populations were recruited from areas scattered throughout the countries.Conclusion: Despite these encouraging results and the efforts to standardize the 24-HDR interview method, conscious or unconscious behaviour of respondents and/or interviewer bias cannot be prevented entirely. Further evaluation of the reliability of EPIC-SOFT measurements will be conducted through validation against independent biological markers (nitrogen, potassium).European Journal of Clinical Nutrition (2000) 54, 900–917

Structure of the standardized computerized 24-h diet recall interview used as reference method in the 22 centers participating in the EPIC project

A computerized 24-h diet recall interview program (EPIC-SOFT) was developed for use in a large European multi-center study, namely the European Prospective Investigation into Cancer and Nutrition (EPIC). This program, which was adapted for each participating country and translated into nine languages, was developed to standardize interviews between the 22 EPIC centers. Common rules were pre-entered into the system to describe, quantify and probe approximately 1500-2200 foods and 150-350 recipes. Common methods used to classify and export the EPIC-SOFT dietary data facilitate their exchange, comparison and analysis. So far, EPIC-SOFT is the only available computerized 24-h diet recall system developed to provide comparable food consumption data between several European countries.

Differences in the prospective association between individual plasma phospholipid saturated fatty acids and incident type 2 diabetes: the EPIC-InterAct case-cohort study

Summary Background Conflicting evidence exists regarding the association between saturated fatty acids (SFAs) and type 2 diabetes. In this longitudinal case-cohort study, we aimed to investigate the prospective associations between objectively measured individual plasma phospholipid SFAs and incident type 2 diabetes in EPIC-InterAct participants. Methods The EPIC-InterAct case-cohort study includes 12 403 people with incident type 2 diabetes and a representative subcohort of 16 154 individuals who were selected from a cohort of 340 234 European participants with 3·99 million person-years of follow-up (the EPIC study). Incident type 2 diabetes was ascertained until Dec 31, 2007, by a review of several sources of evidence. Gas chromatography was used to measure the distribution of fatty acids in plasma phospholipids (mol%); samples from people with type 2 diabetes and subcohort participants were processed in a random order by centre, and laboratory staff were masked to participant characteristics. We estimated country-specific hazard ratios (HRs) for associations per SD of each SFA with incident type 2 diabetes using Prentice-weighted Cox regression, which is weighted for case-cohort sampling, and pooled our findings using random-effects meta-analysis. Findings SFAs accounted for 46% of total plasma phospholipid fatty acids. In adjusted analyses, different individual SFAs were associated with incident type 2 diabetes in opposing directions. Even-chain SFAs that were measured (14:0 [myristic acid], 16:0 [palmitic acid], and 18:0 [stearic acid]) were positively associated with incident type 2 diabetes (HR [95% CI] per SD difference: myristic acid 1·15 [95% CI 1·09–1·22], palmitic acid 1·26 [1·15–1·37], and stearic acid 1·06 [1·00–1·13]). By contrast, measured odd-chain SFAs (15:0 [pentadecanoic acid] and 17:0 [heptadecanoic acid]) were inversely associated with incident type 2 diabetes (HR [95% CI] per 1 SD difference: 0·79 [0·73–0·85] for pentadecanoic acid and 0·67 [0·63–0·71] for heptadecanoic acid), as were measured longer-chain SFAs (20:0 [arachidic acid], 22:0 [behenic acid], 23:0 [tricosanoic acid], and 24:0 [lignoceric acid]), with HRs ranging from 0·72 to 0·81 (95% CIs ranging between 0·61 and 0·92). Our findings were robust to a range of sensitivity analyses. Interpretation Different individual plasma phospholipid SFAs were associated with incident type 2 diabetes in opposite directions, which suggests that SFAs are not homogeneous in their effects. Our findings emphasise the importance of the recognition of subtypes of these fatty acids. An improved understanding of differences in sources of individual SFAs from dietary intake versus endogenous metabolism is needed. Funding EU FP6 programme, Medical Research Council Epidemiology Unit, Medical Research Council Human Nutrition Research, and Cambridge Lipidomics Biomarker Research Initiative.

Fruit and vegetable intake and mortality from ischaemic heart disease: results from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heart study.

AIMS A higher intake of fruits and vegetables has been associated with a lower risk of ischaemic heart disease (IHD), but there is some uncertainty about the interpretation of this association. The objective was to assess the relation between fruit and vegetable intake and risk of mortality from IHD in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heart study. METHODS AND RESULTS After an average of 8.4 years of follow-up, there were 1636 deaths from IHD among 313 074 men and women without previous myocardial infarction or stroke from eight European countries. Participants consuming at least eight portions (80 g each) of fruits and vegetables a day had a 22% lower risk of fatal IHD [relative risk (RR) = 0.78, 95% confidence interval (CI): 0.65-0.95] compared with those consuming fewer than three portions a day. After calibration of fruit and vegetable intake to account for differences in dietary assessment between the participating centres, a one portion (80 g) increment in fruit and vegetable intake was associated with a 4% lower risk of fatal IHD (RR = 0.96, 95% CI: 0.92-1.00, P for trend = 0.033). CONCLUSION Results from this large observational study suggest that a higher intake of fruits and vegetables is associated with a reduced risk of IHD mortality. Whether this association is causal and, if so, the biological mechanism(s) by which fruits and vegetables operate to lower IHD risks remains unclear.

Mediterranean dietary pattern and cancer risk in the EPIC cohort

Background:Although several studies have investigated the association of the Mediterranean diet with overall mortality or risk of specific cancers, data on overall cancer risk are sparse.Methods:We examined the association between adherence to Mediterranean dietary pattern and overall cancer risk using data from the European Prospective Investigation Into Cancer and nutrition, a multi-centre prospective cohort study including 142 605 men and 335 873. Adherence to Mediterranean diet was examined using a score (range: 0–9) considering the combined intake of fruits and nuts, vegetables, legumes, cereals, lipids, fish, dairy products, meat products, and alcohol. Association with cancer incidence was assessed through Cox regression modelling, controlling for potential confounders.Results:In all, 9669 incident cancers in men and 21 062 in women were identified. A lower overall cancer risk was found among individuals with greater adherence to Mediterranean diet (hazard ratio=0.96, 95% CI 0.95–0.98) for a two-point increment of the Mediterranean diet score. The apparent inverse association was stronger for smoking-related cancers than for cancers not known to be related to tobacco (P (heterogeneity)=0.008). In all, 4.7% of cancers among men and 2.4% in women would be avoided in this population if study subjects had a greater adherence to Mediterranean dietary pattern.Conclusion:Greater adherence to a Mediterranean dietary pattern could reduce overall cancer risk.

Use of dietary supplements in the European Prospective Investigation into Cancer and Nutrition calibration study

Background:Dietary supplement use is increasing, but there are few comparable data on supplement intakes and how they affect the nutrition and health of European consumers. The aim of this study was to describe the use of dietary supplements in subsamples of the 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC).Methods:Specific questions on dietary supplement use were asked as a part of single 24-h recalls performed on 36 034 men and women aged 35–74 years from 1995 to 2000.Results:Between countries, the mean percentage of dietary supplement use varied almost 10-fold among women and even more among men. There was a clear north–south gradient in use, with a higher consumption in northern countries. The lowest crude mean percentage of use was found in Greece (2.0% among men, 6.7% among women), and the highest was in Denmark (51.0% among men, 65.8% among women). Use was higher in women than in men. Vitamins, minerals or combinations of them were the predominant types of supplements reported, but there were striking differences between countries.Conclusions:This study indicates that there are wide variations in supplement use in Europe, which may affect individual and population nutrient intakes. The results underline the need to monitor consumption of dietary supplements in Europe, as well as to evaluate the risks and benefits.

Hepatocellular Carcinoma Risk Factors and Disease Burden in a European Cohort: A Nested Case–Control Study

BACKGROUND To date, no attempt has been made to systematically determine the apportionment of the hepatocellular carcinoma burden in Europe or North America among established risk factors. METHODS Using data collected from 1992 to 2006, which included 4,409,809 person-years in the European Prospective Investigation into Cancer and nutrition (EPIC), we identified 125 case patients with hepatocellular carcinoma, of whom 115 were matched to 229 control subjects. We calculated odds ratios (ORs) for the association of documented risk factors for hepatocellular carcinoma with incidence of this disease and estimated their importance in this European cohort. RESULTS Chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection (OR = 9.10, 95% confidence interval [CI] = 2.10 to 39.50 and OR = 13.36, 95% CI = 4.11 to 43.45, respectively), obesity (OR = 2.13, 95% CI = 1.06 to 4.29), former or current smoking (OR = 1.98, 95% CI = 0.90 to 4.39 and OR = 4.55, 95% CI = 1.90 to 10.91, respectively), and heavy alcohol intake (OR = 1.77, 95% CI = 0.73 to 4.27) were associated with hepatocellular carcinoma. Smoking contributed to almost half of all hepatocellular carcinomas (47.6%), whereas 13.2% and 20.9% were attributable to chronic HBV and HCV infection, respectively. Obesity and heavy alcohol intake contributed 16.1% and 10.2%, respectively. Almost two-thirds (65.7%, 95% CI = 50.6% to 79.3%) of hepatocellular carcinomas can be accounted for by exposure to at least one of these documented risk factors. CONCLUSIONS Smoking contributed to more hepatocellular carcinomas in this Europe-wide cohort than chronic HBV and HCV infections. Heavy alcohol consumption and obesity also contributed to sizeable fractions of this disease burden. These contributions may be underestimates because EPIC volunteers are likely to be more health conscious than the general population.

Plasma phospholipid fatty acid profiles and their association with food intakes: results from a cross-sectional study within the European Prospective Investigation into Cancer and Nutrition

BACKGROUND Plasma phospholipid fatty acids have been correlated with food intakes in populations with homogeneous dietary patterns. However, few data are available on populations with heterogeneous dietary patterns. OBJECTIVE The objective was to investigate whether plasma phospholipid fatty acids are suitable biomarkers of dietary intakes across populations involved in a large European multicenter study. DESIGN A cross-sectional study design nested to the European Prospective Investigation into Cancer and Nutrition (EPIC) was conducted to determine plasma fatty acid profiles in >3,000 subjects from 16 centers, who had also completed 24-h dietary recalls and dietary questionnaires. Plasma fatty acids were assessed by capillary gas chromatography. Ecological and individual correlations were calculated between fatty acids and select food groups. RESULTS The most important determinant of plasma fatty acids was region, which suggests that the variations across regions are largely due to different food intakes. Strong ecological correlations were observed between fish intake and long-chain n-3 polyunsaturated fatty acids (r = 0.78, P < 0.01), olive oil and oleic acid (r = 0.73, P < 0.01), and margarine and elaidic acid (r = 0.76, P < 0.01). Individual correlations varied across the regions, particularly between olive oil and oleic acid and between alcohol and the saturation index, as an indicator of stearoyl CoA desaturase activity. CONCLUSIONS These findings indicate that specific plasma phospholipid fatty acids are suitable biomarkers of some food intakes in the EPIC Study. Moreover, these findings suggest complex interactions between alcohol intake and fatty acid metabolism, which warrants further attention in epidemiologic studies relating dietary fatty acids to alcohol-related cancers and other chronic diseases.

Diet in the Italian EPIC cohorts: presentation of data and methodological issues.

One of the aims of the EPIC study is to produce accurate descriptions of the dietary habits of the participants recruited in the 27 EPIC centers of 10 European countries. To do this, different dietary assessment instruments were developed and applied to capture the wide range of diets characterizing the different European populations. Three different food frequency questionnaires were developed for Italy: one for the centers of Varese, Turin and Florence, one for Ragusa and one for Naples. These inquired about eating habits over the previous year and were completed by 46,839 Italian EPIC participants. Specially developed software analyzed the responses and linked them to food composition tables in order to provide a nutritional breakdown of individual and collective diets. A further aim of EPIC was to develop a method of rendering data from different dietary questionnaires comparable. To do this, dietary data were collected from a sample of about 8% of the Italian EPIC cohort, using a standardized computer-driven 24-hour dietary recall interview, and then compared with the dietary data collected by the questionnaires. This paper provides an extensive description of the technical features and performance of the food frequency questionnaires and the 24-hour recall interview, including a comparison of estimates of the intake of different food groups provided by the two instruments. From this comparison, the repeatability and reliability of consumption estimates was assessed, resulting in indications for improving data comparability. The paper also presents food frequency questionnaire estimates of the daily intake of foods and nutrients by center, sex and age group, as well as information on dietary habits such as place and time of intake, and food preparation and preservation methods as provided by the 24-hour recall interview. The picture that emerged is that Italian eating habits are undergoing marked changes, with a tendency to less healthy eating. Documentation of these changes in relation to age, sex and region provides an essential starting point for investigating the influence of diet on the development of cancer and other chronic diseases.

Anthropometric factors and risk of endometrial cancer: the European prospective investigation into cancer and nutrition

ObjectiveTo examine the association between anthropometry and endometrial cancer, particularly by menopausal status and exogenous hormone use subgroups.MethodsAmong 223,008 women in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, there were 567 incident endometrial cancer cases during 6.4 years of follow-up. The analysis was performed with Cox proportional hazards modeling.ResultsWeight, body mass index (BMI), waist and hip circumferences and waist–hip ratio (WHR) were strongly associated with increased risk of endometrial cancer. The relative risk (RR) for obese (BMI 30– < 40 kg/m2) compared to normal weight (BMI < 25) women was 1.78, 95% CI = 1.41–2.26, and for morbidly obese women (BMI ≥ 40) was 3.02, 95% CI = 1.66–5.52. The RR for women with a waist circumference of ≥88 cm vs. <80 cm was 1.76, 95% CI = 1.42–2.19. Adult weight gain of ≥20 kg compared with stable weight (±3 kg) increased risk independent of body weight at age 20 (RR = 1.75, 95% CI = 1.11–2.77). These associations were generally stronger for postmenopausal than premenopausal women, and oral contraceptives never-users than ever-users, and much stronger among never-users of hormone replacement therapy compared to ever-users.ConclusionObesity, abdominal adiposity, and adult weight gain were strongly associated with endometrial cancer risk. These associations were particularly evident among never-users of hormone replacement therapy.