Within- and between-cohort variation in measured macronutrient intakes, taking account of measurement errors, in the European Prospective Investigation into Cancer and Nutrition study

Inflammatory potential of diet and risk of lymphoma in the European Prospective Investigation into Cancer and Nutrition

INTRODUCTION

Chronic inflammation plays a critical role in lymphomagenesis and several dietary factors seem to be involved its regulation. The aim of the current study was to assess the association between the inflammatory potential of the diet and the risk of lymphoma and its subtypes in the European Investigation into Cancer and Nutrition (EPIC) study.

METHODS

The analysis included 476,160 subjects with an average follow-up of 13.9 years, during which 3,136 lymphomas (135 Hodgkin lymphoma (HL), 2606 non-Hodgkin lymphoma (NHL) and 395 NOS) were identified. The dietary inflammatory potential was assessed by means of an inflammatory score of the diet (ISD), calculated using 28 dietary components and their corresponding inflammatory weights. The association between the ISD and lymphoma risk was estimated by hazard ratios (HR) and 95% confidence intervals (CI) calculated by multivariable Cox regression models adjusted for potential confounders.

RESULTS

The ISD was not associated with overall lymphoma risk. Among lymphoma subtypes, a positive association between the ISD and mature B-cell NHL (HR for a 1-SD increase: 1.07 (95% CI 1.01; 1.14), p trend = 0.03) was observed. No statistically significant association was found among other subtypes. However, albeit with smaller number of cases, a suggestive association was observed for HL (HR for a 1-SD increase = 1.22 (95% CI 0.94; 1.57), p trend 0.13).

CONCLUSIONS

Our findings suggested that a high ISD score, reflecting a pro-inflammatory diet, was modestly positively associated with the risk of B-cell lymphoma subtypes. Further large prospective studies on low-grade inflammation induced by diet are warranted to confirm these findings.

Coffee and tea drinking in relation to the risk of differentiated thyroid carcinoma: results from the European Prospective Investigation into Cancer and Nutrition (EPIC) study

PURPOSE

Coffee and tea constituents have shown several anti-carcinogenic activities in cellular and animal studies, including against thyroid cancer (TC). However, epidemiological evidence is still limited and inconsistent. Therefore, we aimed to investigate this association in a large prospective study.

METHODS

The study was conducted in the EPIC (European Prospective Investigation into Cancer and Nutrition) cohort, which included 476,108 adult men and women. Coffee and tea intakes were assessed through validated country-specific dietary questionnaires.

RESULTS

During a mean follow-up of 14 years, 748 first incident differentiated TC cases (including 601 papillary and 109 follicular TC) were identified. Coffee consumption (per 100 mL/day) was not associated either with total differentiated TC risk (HRcalibrated 1.00, 95% CI 0.97-1.04) or with the risk of TC subtypes. Tea consumption (per 100 mL/day) was not associated with the risk of total differentiated TC (HRcalibrated 0.98, 95% CI 0.95-1.02) and papillary tumor (HRcalibrated 0.99, 95% CI 0.95-1.03), whereas an inverse association was found with follicular tumor risk (HRcalibrated 0.90, 95% CI 0.81-0.99), but this association was based on a sub-analysis with a small number of cancer cases.

CONCLUSIONS

In this large prospective study, coffee and tea consumptions were not associated with TC risk.

Adherence to the mediterranean diet and lymphoma risk in the european prospective investigation into cancer and nutrition

There is a growing evidence of the protective role of the Mediterranean diet (MD) on cancer. However, no prospective study has yet investigated its influence on lymphoma. We evaluated the association between adherence to the MD and risk of lymphoma and its subtypes in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The analysis included 476,160 participants, recruited from 10 European countries between 1991 and 2001. Adherence to the MD was estimated through the adapted relative MD (arMED) score excluding alcohol. Cox proportional hazards regression models were used while adjusting for potential confounders. During an average follow-up of 13.9 years, 3,136 lymphomas (135 Hodgkin lymphoma [HL], 2,606 non-HL and 395 lymphoma not otherwise specified) were identified. Overall, a 1-unit increase in the arMED score was associated with a 2% lower risk of lymphoma (95% CI: 0.97; 1.00, p-trend = 0.03) while a statistically nonsignificant inverse association between a high versus low arMED score and risk of lymphoma was observed (hazard ratio [HR]: 0.91 [95% CI 0.80; 1.03], p-trend = 0.12). Analyses by lymphoma subtype did not reveal any statistically significant associations. Albeit with small numbers of cases (N = 135), a suggestive inverse association was found for HL (HR 1-unit increase = 0.93 [95% CI: 0.86; 1.01], p-trend = 0.07). However, the study may have lacked statistical power to detect small effect sizes for lymphoma subtype. Our findings suggest that an increasing arMED score was inversely related to the risk of overall lymphoma in EPIC but not by subtypes. Further large prospective studies are warranted to confirm these findings.

Combining biomarker and self-reported dietary intake data: A review of the state of the art and an exposition of concepts

Classical approaches to assessing dietary intake are associated with measurement error. In an effort to address inherent measurement error in dietary self-reported data there is increased interest in the use of dietary biomarkers as objective measures of intake. Furthermore, there is a growing consensus of the need to combine dietary biomarker data with self-reported data. A review of state of the art techniques employed when combining biomarker and self-reported data is conducted. Two predominant methods, the calibration method and the method of triads, emerge as relevant techniques used when combining biomarker and self-reported data to account for measurement errors in dietary intake assessment. Both methods crucially assume measurement error independence. To expose and understand the performance of these methods in a range of realistic settings, their underpinning statistical concepts are unified and delineated, and thorough simulation studies are conducted. Results show that violation of the methods' assumptions negatively impacts resulting inference but that this impact is mitigated when the variation of the biomarker around the true intake is small. Thus there is much scope for the further development of biomarkers and models in tandem to achieve the ultimate goal of accurately assessing dietary intake.

The role of diet in the aetiopathogenesis of inflammatory bowel disease

Crohn's disease and ulcerative colitis, collectively known as IBD, are chronic inflammatory disorders of the gastrointestinal tract. Although the aetiopathogenesis of IBD is largely unknown, it is widely thought that diet has a crucial role in the development and progression of IBD. Indeed, epidemiological and genetic association studies have identified a number of promising dietary and genetic risk factors for IBD. These preliminary studies have led to major interest in investigating the complex interaction between diet, host genetics, the gut microbiota and immune function in the pathogenesis of IBD. In this Review, we discuss the recent epidemiological, gene-environment interaction, microbiome and animal studies that have explored the relationship between diet and the risk of IBD. In addition, we highlight the limitations of these prior studies, in part by explaining their contradictory findings, and review future directions.

Coffee and Tea Consumption and the Contribution of Their Added Ingredients to Total Energy and Nutrient Intakes in 10 European Countries: Benchmark Data from the Late 1990s

BACKGROUND

Coffee and tea are among the most commonly consumed nonalcoholic beverages worldwide, but methodological differences in assessing intake often hamper comparisons across populations. We aimed to (i) describe coffee and tea intakes and (ii) assess their contribution to intakes of selected nutrients in adults across 10 European countries.

METHOD

Between 1995 and 2000, a standardized 24-h dietary recall was conducted among 36,018 men and women from 27 European Prospective Investigation into Cancer and Nutrition (EPIC) study centres. Adjusted arithmetic means of intakes were estimated in grams (=volume) per day by sex and centre. Means of intake across centres were compared by sociodemographic characteristics and lifestyle factors.

RESULTS

In women, the mean daily intake of coffee ranged from 94 g/day (~0.6 cups) in Greece to 781 g/day (~4.4 cups) in Aarhus (Denmark), and tea from 14 g/day (~0.1 cups) in Navarra (Spain) to 788 g/day (~4.3 cups) in the UK general population. Similar geographical patterns for mean daily intakes of both coffee and tea were observed in men. Current smokers as compared with those who reported never smoking tended to drink on average up to 500 g/day more coffee and tea combined, but with substantial variation across centres. Other individuals' characteristics such as educational attainment or age were less predictive. In all centres, coffee and tea contributed to less than 10% of the energy intake. The greatest contribution to total sugar intakes was observed in Southern European centres (up to ~20%).

CONCLUSION

Coffee and tea intake and their contribution to energy and sugar intake differed greatly among European adults. Variation in consumption was mostly driven by geographical region.

Consumption of fruits, vegetables and fruit juices and differentiated thyroid carcinoma risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Fruit and vegetable (F&V) intake is considered as probably protective against overall cancer risk, but results in previous studies are not consistent for thyroid cancer (TC). The purpose of this study is to examine the association between the consumption of fruits, vegetables, fruit juices and differentiated thyroid cancer risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The EPIC study is a cohort including over half a million participants, recruited between 1991 and 2000. During a mean follow-up of 14 years, 748 incident first primary differentiated TC cases were identified. F&V and fruit juice intakes were assessed through validated country-specific dietary questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models adjusted for potential confounding factors. Comparing the highest versus lowest quartile of intake, differentiated TC risk was not associated with intakes of total F&V (HR: 0.89; 95% CI: 0.68-1.15; p-trend = 0.44), vegetables (HR: 0.89; 95% CI: 0.69-1.14; p-trend = 0.56), or fruit (HR: 1.00; 95% CI: 0.79-1.26; p-trend = 0.64). No significant association was observed with any individual type of vegetable or fruit. However, there was a positive borderline trend with fruit juice intake (HR: 1.23; 95% CI: 0.98-1.53; p-trend = 0.06). This study did not find any significant association between F&V intakes and differentiated TC risk; however a positive trend with fruit juice intake was observed, possibly related to its high sugar content.

Dietary fat, fat subtypes and hepatocellular carcinoma in a large European cohort

The role of amount and type of dietary fat consumption in the etiology of hepatocellular carcinoma (HCC) is poorly understood, despite suggestive biological plausibility. The associations of total fat, fat subtypes and fat sources with HCC incidence were investigated in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, which includes 191 incident HCC cases diagnosed between 1992 and 2010. Diet was assessed by country-specific, validated dietary questionnaires. A single 24-hr diet recall from a cohort subsample was used for measurement error calibration. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated from Cox proportional hazard models. Hepatitis B and C viruses (HBV/HCV) status and biomarkers of liver function were assessed separately in a nested case-control subset with available blood samples (HCC = 122). In multivariable calibrated models, there was a statistically significant inverse association between total fat intake and risk of HCC (per 10 g/day, HR = 0.80, 95% CI: 0.65-0.99), which was mainly driven by monounsaturated fats (per 5 g/day, HR = 0.71, 95% CI: 0.55-0.92) rather than polyunsaturated fats (per 5 g/day, HR = 0.92, 95% CI: 0.68-1.25). There was no association between saturated fats (HR = 1.08, 95% CI: 0.88-1.34) and HCC risk. The ratio of polyunsaturated/monounsaturated fats to saturated fats was not significantly associated with HCC risk (per 0.2 point, HR = 0.86, 95% CI: 0.73-1.01). Restriction of analyses to HBV/HCV free participants or adjustment for liver function did not substantially alter the findings. In this large prospective European cohort, higher consumption of monounsaturated fats is associated with lower HCC risk.

Fruit and vegetable consumption in relation to hepatocellular carcinoma in a multi-centre, European cohort study

BACKGROUND

Vegetable and/or fruit intakes in association with hepatocellular carcinoma (HCC) risk have been investigated in case-control studies conducted in specific European countries and cohort studies conducted in Asia, with inconclusive results. No multi-centre European cohort has investigated the indicated associations.

METHODS

In 486,799 men/women from the European Prospective Investigation into Cancer and nutrition, we identified 201 HCC cases after 11 years median follow-up. We calculated adjusted hazard ratios (HRs) for HCC incidence for sex-specific quintiles and per 100 g d(-1) increments of vegetable/fruit intakes.

RESULTS

Higher vegetable intake was associated with a statistically significant, monotonic reduction of HCC risk: HR (100 g d(-1) increment): 0.83; 95% CI: 0.71-0.98. This association was consistent in sensitivity analyses with no apparent heterogeneity across strata of HCC risk factors. Fruit intake was not associated with HCC incidence: HR (100 g d(-1) increment): 1.01; 95% CI: 0.92-1.11.

CONCLUSIONS

Vegetable, but not fruit, intake is associated with lower HCC risk with no evidence for heterogeneity of this association in strata of important HCC risk factors. Mechanistic studies should clarify pathways underlying this association. Given that HCC prognosis is poor and that vegetables are practically universally accessible, our results may be important, especially for those at high risk for the disease.

A multilevel model to estimate the within- and the between-center components of the exposure/disease association in the EPIC study

In a multicenter study, the overall relationship between exposure and the risk of cancer can be broken down into a within-center component, which reflects the individual level association, and a between-center relationship, which captures the association at the aggregate level. A piecewise exponential proportional hazards model with random effects was used to evaluate the association between dietary fiber intake and colorectal cancer (CRC) risk in the EPIC study. During an average follow-up of 11.0 years, 4,517 CRC events occurred among study participants recruited in 28 centers from ten European countries. Models were adjusted by relevant confounding factors. Heterogeneity among centers was modelled with random effects. Linear regression calibration was used to account for errors in dietary questionnaire (DQ) measurements. Risk ratio estimates for a 10 g/day increment in dietary fiber were equal to 0.90 (95%CI: 0.85, 0.96) and 0.85 (0.64, 1.14), at the individual and aggregate levels, respectively, while calibrated estimates were 0.85 (0.76, 0.94), and 0.87 (0.65, 1.15), respectively. In multicenter studies, over a straightforward ecological analysis, random effects models allow information at the individual and ecologic levels to be captured, while controlling for confounding at both levels of evidence.

Meat and fish consumption and the risk of renal cell carcinoma in the European prospective investigation into cancer and nutrition

Renal cell cancer (RCC) incidence varies worldwide with a higher incidence in developed countries and lifestyle is likely to contribute to the development of this disease. We examined whether meat and fish consumption were related to the risk of RCC in the European Prospective Investigation into Cancer and Nutrition (EPIC). The analysis included 493,179 EPIC participants, recruited between 1992 and 2000. Until December 2008, 691 RCC cases have been identified. Meat and fish consumption was assessed at baseline using country-specific dietary assessment instruments; 24-hour recalls were applied in an 8% subsample for calibration purposes. Cox proportional hazards regression was used to calculate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI). Women with a high consumption of red meat (HR = 1.36, 95% CI 1.14-1.62; calibrated, per 50 g/day) and processed meat (HR = 1.78, 95% CI 1.05-3.03; calibrated, per 50 g/day) had a higher risk of RCC, while no association existed in men. For processed meat, the association with RCC incidence was prominent in premenopausal women and was lacking in postmenopausal women (p interaction = 0.02). Neither poultry nor fish consumption were statistically significantly associated with the risk of RCC. The results show a distinct association of red and processed meat consumption with incident RCC in women but not in men. A biological explanation for these findings remains unclear.

Fish consumption and mortality in the European Prospective Investigation into Cancer and Nutrition cohort

Fish is a source of important nutrients and may play a role in preventing heart diseases and other health outcomes. However, studies of overall mortality and cause-specific mortality related to fish consumption are inconclusive. We examined the rate of overall mortality, as well as mortality from ischaemic heart disease and cancer in relation to the intake of total fish, lean fish, and fatty fish in a large prospective cohort including ten European countries. More than 500,000 men and women completed a dietary questionnaire in 1992-1999 and were followed up for mortality until the end of 2010. 32,587 persons were reported dead since enrolment. Hazard ratios and their 99% confidence interval were estimated using Cox proportional hazard regression models. Fish consumption was examined using quintiles based on reported consumption, using moderate fish consumption (third quintile) as reference, and as continuous variables, using increments of 10 g/day. All analyses were adjusted for possible confounders. No association was seen for fish consumption and overall or cause-specific mortality for both the categorical and the continuous analyses, but there seemed to be a U-shaped trend (p < 0.000) with fatty fish consumption and total mortality and with total fish consumption and cancer mortality (p = 0.046).

The association of pattern of lifetime alcohol use and cause of death in the European prospective investigation into cancer and nutrition (EPIC) study

BACKGROUND

There is limited evidence for an association between the pattern of lifetime alcohol use and cause-specific risk of death.

METHODS

Multivariable hazard ratios were estimated for different causes of death according to patterns of lifetime alcohol consumption using a competing risks approach: 111 953 men and 268 442 women from eight countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study were included. Self-reported alcohol consumption at ages 20, 30, 40 or 50 years and at enrollment were used for the analysis; 26 411 deaths were observed during an average of 12.6 years of follow-up.

RESULTS

The association between lifetime alcohol use and death from cardiovascular diseases was different from the association seen for alcohol-related cancers, digestive, respiratory, external and other causes. Heavy users (>5 drinks/day for men and >2.5 drinks/day for women), regardless of time of cessation, had a 2- to 5-times higher risk of dying due to alcohol-related cancers, compared with subjects with lifetime light use (≤1 and ≤0.5 drink/week for men and women, respectively). Compared with lifetime light users, men who used <5 drinks/day throughout their lifetime had a 24% lower cardiovascular disease mortality (95% confidence interval 2-41). The risk of death from coronary heart disease was also found to be 34-46% lower among women who were moderate to occasionally heavy alcohol users compared with light users. However, this relationship was only evident among men and women who had no chronic disease at enrollment.

CONCLUSIONS

Limiting alcohol use throughout life is associated with a lower risk of death, largely due to cardiovascular disease but also other causes. However, the potential health benefits of alcohol use are difficult to establish due to the possibility of selection bias and competing risks related to diseases occurring later in life.

Use of two-part regression calibration model to correct for measurement error in episodically consumed foods in a single-replicate study design: EPIC case study

In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.

Fruit, vegetable, and fiber intake in relation to cancer risk: findings from the European Prospective Investigation into Cancer and Nutrition (EPIC)

Fruit, vegetables, and certain components of plant foods, such as fiber, have long been thought to protect against cancer. The European Prospective Investigation into Cancer and Nutrition (EPIC) is a prospective cohort that includes >500,000 participants from 10 European countries and has made a substantial contribution to knowledge in this research area. The purpose of this article is to summarize the findings published thus far from the EPIC study on the associations between fruit, vegetable, or fiber consumption and the risk of cancer at 14 different sites. The risk of cancers of the upper gastrointestinal tract was inversely associated with fruit intake but was not associated with vegetable intake. The risk of colorectal cancer was inversely associated with intakes of total fruit and vegetables and total fiber, and the risk of liver cancer was also inversely associated with the intake of total fiber. The risk of cancer of the lung was inversely associated with fruit intake but was not associated with vegetable intake; this association with fruit intake was restricted to smokers and might be influenced by residual confounding due to smoking. There was a borderline inverse association of fiber intake with breast cancer risk. For the other 9 cancer sites studied (stomach, biliary tract, pancreas, cervix, endometrium, prostate, kidney, bladder, and lymphoma) there were no reported significant associations of risk with intakes of total fruit, vegetables, or fiber.

Meat and heme iron intake and esophageal adenocarcinoma in the European Prospective Investigation into Cancer and Nutrition study

Although recent studies suggest that high intakes of meat and heme iron are risk factors for several types of cancer, studies in relation to esophageal adenocarcinoma (EAC) are scarce. Previous results in the European Prospective Investigation into Cancer and Nutrition (EPIC) based on a relatively small number of cases suggested a positive association between processed meat and EAC. In this study, we investigate the association between intake of different types of meats and heme iron intake and EAC risk in a larger number of cases from EPIC. The study included 481,419 individuals and 137 incident cases of EAC that occurred during an average of 11 years of follow-up. Dietary intake of meat (unprocessed/processed red and white meat) was assessed by validated center-specific questionnaires. Heme iron was calculated as a type-specific percentage of the total iron content in meat. After adjusting for relevant confounders, we observed a statistically significant positive association of EAC risk with heme iron and processed meat intake, with HR: 1.67, 95% CI: 1.05-2.68 and HR: 2.27, 95% CI:1.33-3.89, respectively, for comparison of the highest vs. lowest tertile of intake. Our results suggest a potential association between higher intakes of processed meat and heme iron and risk of EAC.

Meat consumption and mortality--results from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Recently, some US cohorts have shown a moderate association between red and processed meat consumption and mortality supporting the results of previous studies among vegetarians. The aim of this study was to examine the association of red meat, processed meat, and poultry consumption with the risk of early death in the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

Included in the analysis were 448,568 men and women without prevalent cancer, stroke, or myocardial infarction, and with complete information on diet, smoking, physical activity and body mass index, who were between 35 and 69 years old at baseline. Cox proportional hazards regression was used to examine the association of meat consumption with all-cause and cause-specific mortality.

RESULTS

As of June 2009, 26,344 deaths were observed. After multivariate adjustment, a high consumption of red meat was related to higher all-cause mortality (hazard ratio (HR) = 1.14, 95% confidence interval (CI) 1.01 to 1.28, 160+ versus 10 to 19.9 g/day), and the association was stronger for processed meat (HR = 1.44, 95% CI 1.24 to 1.66, 160+ versus 10 to 19.9 g/day). After correction for measurement error, higher all-cause mortality remained significant only for processed meat (HR = 1.18, 95% CI 1.11 to 1.25, per 50 g/d). We estimated that 3.3% (95% CI 1.5% to 5.0%) of deaths could be prevented if all participants had a processed meat consumption of less than 20 g/day. Significant associations with processed meat intake were observed for cardiovascular diseases, cancer, and 'other causes of death'. The consumption of poultry was not related to all-cause mortality.

CONCLUSIONS

The results of our analysis support a moderate positive association between processed meat consumption and mortality, in particular due to cardiovascular diseases, but also to cancer.

Glycemic index, glycemic load, dietary carbohydrate, and dietary fiber intake and risk of liver and biliary tract cancers in Western Europeans

BACKGROUND

The type and quantity of dietary carbohydrate as quantified by glycemic index (GI) and glycemic load (GL), and dietary fiber may influence the risk of liver and biliary tract cancers, but convincing evidence is lacking.

PATIENTS AND METHODS

The association between dietary GI/GL and carbohydrate intake with hepatocellular carcinoma (HCC; N = 191), intrahepatic bile duct (IBD; N = 66), and biliary tract (N = 236) cancer risk was investigated in 477 206 participants of the European Prospective Investigation into Cancer and Nutrition cohort. Dietary intake was assessed by country-specific, validated dietary questionnaires. Hazard ratios and 95% confidence intervals were estimated from proportional hazard models. HBV/HCV status was measured in a nested case-control subset.

RESULTS

Higher dietary GI, GL, or increased intake of total carbohydrate was not associated with liver or biliary tract cancer risk. For HCC, divergent risk estimates were observed for total sugar = 1.43 (1.17-1.74) per 50 g/day, total starch = 0.70 (0.55-0.90) per 50 g/day, and total dietary fiber = 0.70 (0.52-0.93) per 10 g/day. The findings for dietary fiber were confirmed among HBV/HCV-free participants [0.48 (0.23-1.01)]. Similar associations were observed for IBD [dietary fiber = 0.59 (0.37-0.99) per 10 g/day], but not biliary tract cancer.

CONCLUSIONS

Findings suggest that higher consumption of dietary fiber and lower consumption of total sugars are associated with lower HCC risk. In addition, high dietary fiber intake could be associated with lower IBD cancer risk.

Fiber intake and total and cause-specific mortality in the European Prospective Investigation into Cancer and Nutrition cohort

BACKGROUND

Previous studies have shown that high fiber intake is associated with lower mortality. However, little is known about the association of dietary fiber with specific causes of death other than cardiovascular disease (CVD).

OBJECTIVE

The aim of this study was to assess the relation between fiber intake, mortality, and cause-specific mortality in a large European prospective study of 452,717 men and women.

DESIGN

HRs and 95% CIs were estimated by using Cox proportional hazards models, stratified by age, sex, and center and adjusted for education, smoking, alcohol consumption, BMI, physical activity, total energy intake, and, in women, ever use of menopausal hormone therapy.

RESULTS

During a mean follow-up of 12.7 y, a total of 23,582 deaths were recorded. Fiber intake was inversely associated with total mortality (HR(per 10-g/d increase): 0.90; 95% CI: 0.88, 0.92); with mortality from circulatory (HR(per 10-g/d increase): 0.90 and 0.88 for men and women, respectively), digestive (HR: 0.61 and 0.64), respiratory (HR: 0.77 and 0.62), and non-CVD noncancer inflammatory (HR: 0.85 and 0.80) diseases; and with smoking-related cancers (HR: 0.86 and 0.89) but not with non-smoking-related cancers (HR: 1.05 and 0.97). The associations were more evident for fiber from cereals and vegetables than from fruit. The associations were similar across BMI and physical activity categories but were stronger in smokers and participants who consumed >18 g alcohol/d.

CONCLUSIONS

Higher fiber intake is associated with lower mortality, particularly from circulatory, digestive, and non-CVD noncancer inflammatory diseases. Our results support current recommendations of high dietary fiber intake for health maintenance.

Assessment of a school-based intervention in eating habits and physical activity in school children: the AVall study

BACKGROUND

Obesity has become a global public health problem, which also affects children. It has been proposed that the educational interventions during childhood could be a key strategy in the prevention of obesity.

OBJECTIVE

To evaluate the efficacy of an intervention on food habits and physical activity in school children.

METHODS

A 2-year cluster-randomised prospective study with two parallel arms was used to evaluate an intervention programme in children in their first year of primary schooling (5-6 years of age) in schools in the city of Granollers. The intervention consisted of the promotion of healthy eating habits and physical activity by means of the educational methodology Investigation, Vision, Action and Change (IVAC). At the beginning and at the end of the study (2006 and 2008) the weight and height of each child was measured in situ, while the families were given a self-report physical activity questionnaire and the Krece Plus quick test.

RESULTS

Two years after the beginning of the study, the body mass index of the children in the control group was 0.8 kg/m(2) higher than that of the intervention schools. The intervention reduced by 62% the prevalence of overweight children. Similarly, the proportion of children that ate a second piece of fruit and took part in an after-school physical activity increased in the intervention group. In the control group, the weekly consumption of fish was reduced.

CONCLUSIONS

The educational intervention in healthy eating habits and physical activity in the school could contribute to lessen the current increase in child obesity.

Dietary intake of heme iron and risk of gastric cancer in the European prospective investigation into cancer and nutrition study

Even though recent studies suggest that a high intake of heme iron is associated with several types of cancer, epidemiological studies in relation to gastric cancer (GC) are lacking. Our previous results show a positive association between red and processed meat and non cardia gastric cancer, especially in Helicobacter pylori infected subjects. The aim of the study is to investigate the association between heme iron intake and GC risk in the European prospective investigation into cancer and nutrition (EURGAST-EPIC). Dietary intake was assessed by validated center-specific questionnaires. Heme iron was calculated as a type-specific percentage of the total iron content in meat intake, derived from the literature. Antibodies of H. pylori infection and vitamin C levels were measured in a sub-sample of cases and matched controls included in a nested case-control study within the cohort. The study included 481,419 individuals and 444 incident cases of GC that occurred during an average of 8.7 years of followup. We observed a statistically significant association between heme iron intake and GC risk (HR 1.13 95% CI: 1.01-1.26 for a doubling of intake) adjusted by sex, age, BMI, education level, tobacco smoking and energy intake. The positive association between heme iron and the risk of GC was statistically significant in subjects with plasma vitamin C <39 mmol/l only (log2 HR 1.54 95% CI (1.01-2.35). We found a positive association between heme iron intake and gastric cancer risk.

Estimated dietary intakes of flavonols, flavanones and flavones in the European Prospective Investigation into Cancer and Nutrition (EPIC) 24 hour dietary recall cohort

Flavonols, flavanones and flavones (FLAV) are sub-classes of flavonoids that exert cardioprotective and anti-carcinogenic propertiesin vitroandin vivo. We aimed to estimate the FLAV dietary intake, their food sources and associated lifestyle factors in ten European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. FLAV intake and their food sources for 36 037 subjects, aged between 35 and 74 years, in twenty-seven study centres were obtained using standardised 24 h dietary recall software (EPIC-SOFT). Anad hocfood composition database on FLAV was compiled using data from US Department of Agriculture and Phenol-Explorer databases and was expanded using recipes, estimations and flavonoid retention factors in order to increase its correspondence with the 24 h dietary recall. Our results showed that the highest FLAV-consuming centre was the UK health-conscious group, with 130·9 and 97·0 mg/d for men and women, respectively. The lowest FLAV intakes were 36·8 mg/d in men from Umeå and 37·2 mg/d in women from Malmö (Sweden). The flavanone sub-class was the main contributor to the total FLAV intake ranging from 46·6 to 52·9 % depending on the region. Flavonols ranged from 38·5 to 47·3 % and flavones from 5·8 to 8·6 %. FLAV intake was higher in women, non-smokers, increased with level of education and physical activity. The major food sources were citrus fruits and citrus-based juices (especially for flavanones), tea, wine, other fruits and some vegetables. We concluded that the present study shows heterogeneity in intake of these three sub-classes of flavonoids across European regions and highlights differences by sex and other sociodemographic and lifestyle factors.

Consumption of meat and fish and risk of lung cancer: results from the European Prospective Investigation into Cancer and Nutrition

Evidence from case-control studies, but less so from cohort studies, suggests a positive association between meat intake and risk of lung cancer. Therefore, this association was evaluated in the frame of the European Prospective Investigation into Cancer and Nutrition, EPIC. Data from 478,021 participants, recruited from 10 European countries, who completed a dietary questionnaire in 1992-2000 were evaluated; 1,822 incident primary lung cancer cases were included in the present evaluation. Relative risk estimates were calculated for categories of meat intake using multi-variably adjusted Cox proportional hazard models. In addition, the continuous intake variables were calibrated by means of 24-h diet recall data to account for part of the measurement error. There were no consistent associations between meat consumption and the risk of lung cancer. Neither red meat (RR = 1.06, 95% CI 0.89-1.27 per 50 g intake/day; calibrated model) nor processed meat (RR = 1.13, 95% CI 0.95-1.34 per 50 g/day; calibrated model) was significantly related to an increased risk of lung cancer. Also, consumption of white meat and fish was not associated with the risk of lung cancer. These findings do not support the hypothesis that a high intake of red and processed meat is a risk factor for lung cancer.

Food intake of individuals with and without diabetes across different countries and ethnic groups

BACKGROUND/OBJECTIVES

Given the importance of nutrition therapy in diabetes management, we hypothesized that food intake differs between individuals with and without diabetes. We investigated this hypothesis in two large prospective studies including different countries and ethnic groups.

SUBJECTS/METHODS

Study populations were the European Prospective Investigation into Cancer and Nutrition Study (EPIC) and the Multiethnic Cohort Study (MEC). Dietary intake was assessed by food frequency questionnaires, and calibrated using 24h-recall information for the EPIC Study. Only confirmed self-reports of diabetes at cohort entry were included: 6192 diabetes patients in EPIC and 13 776 in the MEC. For the cross-sectional comparison of food intake and lifestyle variables at baseline, individuals with and without diabetes were matched 1:1 on sex, age in 5-year categories, body mass index in 2.5 kg/m(2) categories and country.

RESULTS

Higher intake of soft drinks (by 13 and 44% in the EPIC and MEC), and lower consumption of sweets, juice, wine and beer (>10% difference) were observed in participants with diabetes compared with those without. Consumption of vegetables, fish and meat was slightly higher in individuals with diabetes in both studies, but the differences were <10%. Findings were more consistent across different ethnic groups than countries, but generally showed largely similar patterns.

CONCLUSIONS

Although diabetes patients are expected to undergo nutritional education, we found only small differences in dietary behavior in comparison with cohort members without diabetes. These findings suggest that emphasis on education is needed to improve the current behaviors to assist in the prevention of complications.

Consumption of meat and dairy and lymphoma risk in the European Prospective Investigation into Cancer and Nutrition

The consumption of meat and other foods of animal origin is a risk factor for several types of cancer, but the results for lymphomas are inconclusive. Therefore, we examined these associations among 411,097 participants of the European Prospective Investigation into Cancer and Nutrition. During a median follow-up of 8.5 years, 1,334 lymphomas (1,267 non-Hodgkin lymphoma (NHL) and 67 Hodgkin lymphomas) were identified. Consumption of red and processed meat, poultry, milk and dairy products was assessed by dietary questionnaires. Cox proportional hazard regression was used to evaluate the association of the consumption of these food groups with lymphoma risk. Overall, the consumption of foods of animal origin was not associated with an increased risk of NHLS or HL, but the associations with specific subgroups of NHL entities were noted. A high intake of processed meat was associated with an increased risk of B-cell chronic lymphocytic leukemia (BCLL) [relative risk (RR) per 50 g intake = 1.31, 95% confidence interval (CI) 1.06-1.63], but a decreased risk of follicular lymphomas (FL) (RR = 0.58; CI 0.38-0.89). A high intake of poultry was related to an increased risk of B-cell lymphomas (RR = 1.22; CI 1.05-1.42 per 10 g intake), FL (RR = 1.65; CI 1.18-2.32) and BCLL (RR = 1.54; CI 1.18-2.01) in the continuous models. In conclusion, no consistent associations between red and processed meat consumption and lymphoma risk were observed, but we found that the consumption of poultry was related to an increased risk of B-cell lymphomas. Chance is a plausible explanation of the observed associations, which need to be confirmed in further studies.

Fitting a bivariate measurement error model for episodically consumed dietary components

There has been great public health interest in estimating usual, i.e., long-term average, intake of episodically consumed dietary components that are not consumed daily by everyone, e.g., fish, red meat and whole grains. Short-term measurements of episodically consumed dietary components have zero-inflated skewed distributions. So-called two-part models have been developed for such data in order to correct for measurement error due to within-person variation and to estimate the distribution of usual intake of the dietary component in the univariate case. However, there is arguably much greater public health interest in the usual intake of an episodically consumed dietary component adjusted for energy (caloric) intake, e.g., ounces of whole grains per 1000 kilo-calories, which reflects usual dietary composition and adjusts for different total amounts of caloric intake. Because of this public health interest, it is important to have models to fit such data, and it is important that the model-fitting methods can be applied to all episodically consumed dietary components.We have recently developed a nonlinear mixed effects model (Kipnis, et al., 2010), and have fit it by maximum likelihood using nonlinear mixed effects programs and methodology (the SAS NLMIXED procedure). Maximum likelihood fitting of such a nonlinear mixed model is generally slow because of 3-dimensional adaptive Gaussian quadrature, and there are times when the programs either fail to converge or converge to models with a singular covariance matrix. For these reasons, we develop a Monte-Carlo (MCMC) computation of fitting this model, which allows for both frequentist and Bayesian inference. There are technical challenges to developing this solution because one of the covariance matrices in the model is patterned. Our main application is to the National Institutes of Health (NIH)-AARP Diet and Health Study, where we illustrate our methods for modeling the energy-adjusted usual intake of fish and whole grains. We demonstrate numerically that our methods lead to increased speed of computation, converge to reasonable solutions, and have the flexibility to be used in either a frequentist or a Bayesian manner.

Meat consumption and prospective weight change in participants of the EPIC-PANACEA study

BACKGROUND

Meat intake may be related to weight gain because of its high energy and fat content. Some observational studies have shown that meat consumption is positively associated with weight gain, but intervention studies have shown mixed results.

OBJECTIVE

Our objective was to assess the association between consumption of total meat, red meat, poultry, and processed meat and weight gain after 5 y of follow-up, on average, in the large European population who participated in the European Prospective Investigation into Cancer and Nutrition-Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home and Obesity (EPIC-PANACEA) project.

DESIGN

A total of 103,455 men and 270,348 women aged 25-70 y were recruited between 1992 and 2000 in 10 European countries. Diet was assessed at baseline with the use of country-specific validated questionnaires. A dietary calibration study was conducted in a representative subsample of the cohort. Weight and height were measured at baseline and self-reported at follow-up in most centers. Associations between energy from meat (kcal/d) and annual weight change (g/y) were assessed with the use of linear mixed models, controlled for age, sex, total energy intake, physical activity, dietary patterns, and other potential confounders.

RESULTS

Total meat consumption was positively associated with weight gain in men and women, in normal-weight and overweight subjects, and in smokers and nonsmokers. With adjustment for estimated energy intake, an increase in meat intake of 250 g/d (eg, one steak at approximately 450 kcal) would lead to a 2-kg higher weight gain after 5 y (95% CI: 1.5, 2.7 kg). Positive associations were observed for red meat, poultry, and processed meat.

CONCLUSION

Our results suggest that a decrease in meat consumption may improve weight management.

Region-specific nutrient intake patterns exhibit a geographical gradient within and between European countries

Until recently, the study of nutrient patterns was hampered at an international level by a lack of standardization of both dietary methods and nutrient databases. We aimed to describe the diversity of nutrient patterns in the European Prospective Investigation into Cancer and Nutrition (EPIC) study at population level as a starting point for future nutrient pattern analyses and their associations with chronic diseases in multi-center studies. In this cross-sectional study, 36,034 persons aged 35-74 y were administered a single, standardized 24-h dietary recall. Intake of 25 nutrients (excluding intake from dietary supplements) was estimated using a standardized nutrient database. We used a graphic presentation of mean nutrient intakes by region and sex relative to the overall EPIC means to contrast patterns within and between 10 European countries. In Mediterranean regions, including Greece, Italy, and the southern centers of Spain, the nutrient pattern was dominated by relatively high intakes of vitamin E and monounsaturated fatty acids (MUFA), whereas intakes of retinol and vitamin D were relatively low. In contrast, in Nordic countries, including Norway, Sweden, and Denmark, reported intake of these same nutrients resulted in almost the opposite pattern. Population groups in Germany, The Netherlands, and the UK shared a fatty acid pattern of relatively high intakes of PUFA and SFA and relatively low intakes of MUFA, in combination with a relatively high intake of sugar. We confirmed large variability in nutrient intakes across the EPIC study populations and identified 3 main region-specific patterns with a geographical gradient within and between European countries.

Fruits and vegetables consumption and the risk of histological subtypes of lung cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC)

Objective

To examine the association between fruit and vegetable consumption and risk of different histological subtypes of lung cancer among participants of the European Prospective Investigation into Cancer and Nutrition study.

Methods

Multivariable Cox proportional hazard models were used to analyze the data. A calibration study in a subsample was used to reduce dietary measurement errors.

Results

During a mean follow-up of 8.7 years, 1,830 incident cases of lung cancer (574 adenocarcinoma, 286 small cell, 137 large cell, 363 squamous cell, 470 other histologies) were identified. In line with our previous conclusions, we found that after calibration a 100 g/day increase in fruit and vegetables consumption was associated with a reduced lung cancer risk (HR 0.94; 95% CI 0.89–0.99). This was also seen among current smokers (HR 0.93; 95% CI 0.90–0.97). Risks of squamous cell carcinomas in current smokers were reduced for an increase of 100 g/day of fruit and vegetables combined (HR 0.85; 95% CI 0.76–0.94), while no clear effects were seen for the other histological subtypes.

Conclusion

We observed inverse associations between the consumption of vegetables and fruits and risk of lung cancer without a clear effect on specific histological subtypes of lung cancer. In current smokers, consumption of vegetables and fruits may reduce lung cancer risk, in particular the risk of squamous cell carcinomas.

Alcohol consumption patterns, diet and body weight in 10 European countries

BACKGROUND/OBJECTIVES

Europe has the highest level of alcohol consumption in the world. As drinking patterns are important determinants of the beneficial and harmful effects of alcohol consumption, we investigated alcohol consumption in relation to nutrient intake, place of consumption, education and body weight in a sample of adults from 10 European countries.

METHODS

A 24-h dietary recall interview was conducted on 13 025 men and 23 009 women, aged 35-74 years, from 27 centres participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Means and standard errors of alcohol consumption, adjusted for age, were calculated, stratified by gender and centre.

RESULTS

In many centres, higher level drinkers (males consuming >24 g of ethanol/day, equivalent to >2 standard drinks and females consuming >12 g of ethanol/day equivalent to >1 standard drink) obtained more energy from fat and protein and less from sugar than did abstainers. The proportion of energy from starch tended to be higher for male and lower for female higher level drinkers than for abstainers. Female higher level drinkers had a lower body mass index than did abstainers, whereas male higher level drinkers generally weighed more. Male higher level drinkers were less educated than abstainers in Mediterranean countries, but were more educated elsewhere. Female higher level drinkers were usually more educated than were abstainers. Outside the home, consumption (both genders) tended to be at friends' homes, particularly among men in Northern and Central Europe, and in bars in Spain.

CONCLUSIONS

This study reveals clear geographical differences in drinking habits across Europe, and shows that the characteristics of different alcohol consumption categories also vary.

Energy intake and sources of energy intake in the European Prospective Investigation into Cancer and Nutrition

OBJECTIVES

To describe energy intake and its macronutrient and food sources among 27 regions in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

Between 1995 and 2000, 36 034 subjects aged 35-74 years were administered a standardized 24-h dietary recall. Intakes of macronutrients (g/day) and energy (kcal/day) were estimated using standardized national nutrient databases. Mean intakes were weighted by season and day of the week and were adjusted for age, height and weight, after stratification by gender. Extreme low- and high-energy reporters were identified using Goldberg's cutoff points (ratio of energy intake and estimated basal metabolic rate <0.88 or >2.72), and their effects on macronutrient and energy intakes were studied.

RESULTS

Low-energy reporting was more prevalent in women than in men. The exclusion of extreme-energy reporters substantially lowered the EPIC-wide range in mean energy intake from 2196-2877 to 2309-2866 kcal among men. For women, these ranges were 1659-2070 and 1873-2108 kcal. There was no north-south gradient in energy intake or in the prevalence of low-energy reporting. In most centres, cereals and cereal products were the largest contributors to energy intake. The food groups meat, dairy products and fats and oils were also important energy sources. In many centres, the highest mean energy intakes were observed on Saturdays.

CONCLUSIONS

These data highlight and quantify the variations and similarities in energy intake and sources of energy intake among 10 European countries. The prevalence of low-energy reporting indicates that the study of energy intake is hampered by the problem of underreporting.

Variation in intakes of calcium, phosphorus, magnesium, iron and potassium in 10 countries in the European Prospective Investigation into Cancer and Nutrition study

BACKGROUND/OBJECTIVES

Adequate mineral intake is important for the maintenance of bone health, cellular function and general metabolism, and possibly in the aetiology of cancer and other chronic diseases. This study aimed at investigating variation in intakes of selected minerals across 10 European countries participating in the EPIC (European Prospective Investigation into Cancer and Nutrition) study.

METHODS

Nutrient intakes for 36 034 subjects, aged between 35 and 74 years, in 27 centres were obtained using standardized 24-h dietary recall software (EPIC-SOFT). Mean intakes of calcium, phosphorus, magnesium, iron and potassium were calculated by centre and weighted by season and day of the week and were also stratified by age group. The contribution of food groups to total nutrient intake was calculated.

RESULTS

There was clear geographical variability in intakes, with differences ranging from 35% for magnesium to 90% for iron in men and 36% for potassium to 75% for calcium in women, and a twofold difference in sources of haem iron (meat and fish). There was a geographical gradient in iron intake, with higher intakes in Southern than in Northern Europe and also around a twofold north-south gradient in the contribution of fruits and vegetables to potassium intake. Compared with reference intakes, the majority of age groups and centres had intakes above the recommended levels. Dairy foods and products contributed the most to calcium and phosphorus intake in almost all centres. Cereals and cereal products contributed the most to magnesium and iron intakes, except in Greece and Germany.

CONCLUSIONS

Intakes of minerals vary substantially throughout Europe, with some geographical variability in their food sources.

Dietary intake of the water-soluble vitamins B1, B2, B6, B12 and C in 10 countries in the European Prospective Investigation into Cancer and Nutrition

OBJECTIVES

To describe the intake of vitamins thiamine (B1), riboflavin (B2), B6 (pyridoxine), B12 (cobalamine) and C (ascorbic acid) and their food sources among 27 centres in 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

Between 1995 and 2000, 36 034 persons aged between 35 and 74 years were administered a standardized 24-h dietary recall using a computerized interview software programme (EPIC-SOFT). Intakes of the four B vitamins and vitamin C were estimated using the standardized EPIC Nutrient Database (ENDB). Mean intakes were adjusted for age and weighted by season and day of recall.

RESULTS

Intake of B vitamins did not vary considerably between centres, except in the UK health-conscious cohort, in which substantially higher intakes of thiamine and lower intakes of vitamin B12 were reported compared with other centres. Overall, meat was the most important contributor to the B vitamins in all centres except in the UK health-conscious group. Vitamin C showed a clear geographical gradient, with higher intakes in the southern centres as compared with the northern ones; this was more pronounced in men than in women. Vegetables and fruits were major contributors to vitamin C in all centres, but juices and potatoes were also important sources in the northern centres.

CONCLUSIONS

This study showed no major differences across centres in the mean intakes of B vitamins (thiamine, riboflavin, B6, B12), whereas a tendency towards a north-south gradient was observed for vitamin C.

Adherence to a Mediterranean diet and risk of gastric adenocarcinoma within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study

BACKGROUND

The Mediterranean dietary pattern is believed to protect against cancer, although evidence from cohort studies that have examined particular cancer sites is limited.

OBJECTIVE

We aimed to explore the association between adherence to a relative Mediterranean diet (rMED) and incident gastric adenocarcinoma (GC) within the European Prospective Investigation into Cancer and Nutrition study.

DESIGN

The study included 485,044 subjects (144,577 men) aged 35-70 y from 10 European countries. At recruitment, dietary and lifestyle information was collected. An 18-unit rMED score, incorporating 9 key components of the Mediterranean diet, was used to estimate rMED adherence. The association between rMED and GC with respect to anatomic location (cardia and noncardia) and histologic types (diffuse and intestinal) was investigated. A calibration study in a subsample was used to control for dietary measurement error.

RESULTS

After a mean follow-up of 8.9 y, 449 validated incident GC cases were identified and used in the analysis. After stratification by center and age and adjustment for recognized cancer risk factors, high compared with low rMED adherence was associated with a significant reduction in GC risk (hazard ratio: 0.67; 95% CI: 0.47, 0.94). A 1-unit increase in the rMED score was associated with a decreased risk of GC of 5% (95% CI: 0.91, 0.99). There was no evidence of heterogeneity between different anatomic locations or histologic types. The calibrated results showed similar trends (overall hazard ratio for GC: 0.93; 95% CI: 0.89, 0.99).

CONCLUSION

Greater adherence to an rMED is associated with a significant reduction in the risk of incident GC.

Dietary fat intake and subsequent weight change in adults: results from the European Prospective Investigation into Cancer and Nutrition cohorts

BACKGROUND

It is unclear from the inconsistent epidemiologic evidence whether dietary fat intake is associated with future weight change.

OBJECTIVE

The objective was to assess the association between the amount and type of dietary fat and subsequent weight change (follow-up weight minus baseline weight divided by duration of follow-up).

DESIGN

We analyzed data from 89,432 men and women from 6 cohorts of the EPIC (European Prospective Investigation into Cancer and Nutrition) study. Using country-specific food-frequency questionnaires, we examined the association between baseline fat intake (amount and type of total, saturated, polyunsaturated, and monounsaturated fats) and annual weight change by using the residual, nutrient density, and energy-partition methods. We used random-effects meta-analyses to obtain pooled estimates across centers.

RESULTS

Mean total fat intake as a percentage of energy intake ranged between 31.5% and 36.5% across the 6 cohorts (58% women; mean +/- SD age: 53.2 +/- 8.6 y). The mean (+/-SD) annual weight change was 109 +/- 817 g/y in men and 119 +/- 823 g/y in women. In pooled analyses adjusted for anthropometric, dietary, and lifestyle factors and follow-up period, no significant association was observed between fat intake (amount or type) and weight change. The difference in mean annual weight change was 0.90 g/y (95% CI: -0.54, 2.34 g/y) for men and -1.30 g/y (95% CI: -3.70, 1.11 g/y) for women per 1 g/d energy-adjusted fat intake (residual method).

CONCLUSIONS

We found no significant association between the amount or type of dietary fat and subsequent weight change in this large prospective study. These findings do not support the use of low-fat diets to prevent weight gain.

Nonparametric Prediction in Measurement Error Models

Predicting the value of a variable Y corresponding to a future value of an explanatory variable X, based on a sample of previously observed independent data pairs (X(1), Y(1)), …, (X(n), Y(n)) distributed like (X, Y), is very important in statistics. In the error-free case, where X is observed accurately, this problem is strongly related to that of standard regression estimation, since prediction of Y can be achieved via estimation of the regression curve E(Y|X). When the observed X(i)s and the future observation of X are measured with error, prediction is of a quite different nature. Here, if T denotes the future (contaminated) available version of X, prediction of Y can be achieved via estimation of E(Y|T). In practice, estimating E(Y|T) can be quite challenging, as data may be collected under different conditions, making the measurement errors on X(i) and X non-identically distributed. We take up this problem in the nonparametric setting and introduce estimators which allow a highly adaptive approach to smoothing. Reflecting the complexity of the problem, optimal rates of convergence of estimators can vary from the semiparametric n(-1/2) rate to much slower rates that are characteristic of nonparametric problems. Nevertheless, we are able to develop highly adaptive, data-driven methods that achieve very good performance in practice.

A Bayesian multilevel model for estimating the diet/disease relationship in a multicenter study with exposures measured with error: the EPIC study

In a multicenter study, the overall relationship between diet and cancer risk can be broken down into: (a) within-center relationships, which reflect the relationships at the individual level in each of the centers, and (b) a between-center relationship, which captures the association between exposure and disease risk at the aggregate level. In this work, we propose the use of a Bayesian multilevel model that takes into account the within- and between-center levels of evidence, using information at the individual and aggregate level. Correction for measurement error is performed in order to correct for systematic between-center measurement error in dietary exposure, and for attenuation biases in relative risk estimates within centers. The estimation of the parameters is carried out in a Bayesian framework using Gibbs sampling. The model entails a measurement, an exposure, and a disease component. Within the European Prospective Investigation into Cancer and Nutrition (EPIC) the association between lipid intake, assessed through dietary questionnaire and 24-hour dietary recall, and breast cancer incidence was evaluated. This analysis involved 21 534 women and 334 incident breast cancer cases from the EPIC calibration study. In this study, total energy intake was positively associated with breast cancer incidence at the aggregate level, whereas no effect was observed for fat. At the individual level, height was positively related to breast cancer incidence, whereas a weaker association was observed for fat. The use of multilevel models, which constitute a very powerful approach to estimating individual vs aggregate levels of evidence should be considered in multicenter studies.

Fruit and vegetable intakes and subsequent changes in body weight in European populations: results from the project on Diet, Obesity, and Genes (DiOGenes)

BACKGROUND

High fruit and vegetable intakes may limit weight gain, particularly in susceptible persons, such as those who stop smoking.

OBJECTIVE

The objective was to assess the association of fruit and vegetable intake with subsequent weight change in a large-scale prospective study.

DESIGN

The data used were from 89,432 men and women from 5 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). The association between fruit and vegetable intake and weight change after a mean follow-up of 6.5 y was assessed by linear regression. Polytomous logistic regression was used to evaluate whether fruit and vegetable intake relates to weight gain, weight loss, or both.

RESULTS

Per 100-g intake of fruit and vegetables, weight change was -14 g/y (95% CI: -19, -9 g/y). In those who stopped smoking during follow-up, this value was -37 g/y (95% CI: -58, -15 g/y; P for interaction < 0.0001). When weight gain and loss were analyzed separately per 100-g intake of fruit and vegetables in a combined model, the odds ratios (95% CIs) were 0.97 (0.95, 0.98) for weight gain > or =0.5 and <1 kg/y, 0.94 (0.92, 0.96) for weight gain > or =1 kg/y, and 0.97 (0.95, 0.99) for weight loss > or =0.5 kg/y. In those who stopped smoking during follow-up, the odds ratios (95% CIs) were 0.93 (0.88, 0.99), 0.87 (0.81, 0.92), and 0.97 (0.88, 1.07), respectively (P for interaction < 0.0001).

CONCLUSIONS

Fruit and vegetable intake relates significantly, albeit weakly inversely, to weight change. For persons who stop smoking, high fruit and vegetable intakes may be recommended to reduce the risk of weight gain.

Fruit and vegetable consumption and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition

Many case-control studies have suggested that higher consumption of fruit and vegetables is associated with a lower risk of pancreatic cancer, whereas cohort studies do not support such an association. We examined the associations of the consumption of fruits and vegetables and their main subgroups with pancreatic cancer risk within the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is comprised of over 520,000 subjects recruited from 10 European countries. The present study included 555 exocrine pancreatic cancer cases after an average follow-up of 8.9 years. Estimates of risk were obtained by Cox proportional hazard models, stratified by age at recruitment, gender, and study center, and adjusted for total energy intake, weight, height, history of diabetes mellitus, and smoking status. Total consumption of fruit and vegetables, combined or separately, as well as subgroups of vegetables and fruits were unrelated to risk of pancreatic cancer. Hazard ratios (95% CI) for the highest versus the lowest quartile were 0.92 (0.68-1.25) for total fruit and vegetables combined, 0.99 (0.73-1.33) for total vegetables, and 1.02 (0.77-1.36) for total fruits. Stratification by gender or smoking status, restriction to microscopically verified cases, and exclusion of the first 2 years of follow-up did not materially change the results. These results from a large European prospective cohort suggest that higher consumption of fruit and vegetables is not associated with decreased risk of pancreatic cancer.