Tonje Braaten

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.

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.

Abdominal obesity, weight gain during adulthood and risk of liver and biliary tract cancer in a European cohort

General obesity has been positively associated with risk of liver and probably with biliary tract cancer, but little is known about abdominal obesity or weight gain during adulthood. We used multivariable Cox proportional hazard models to investigate associations between weight, body mass index, waist and hip circumference, waist‐to‐hip and waist‐to‐height ratio (WHtR), weight change during adulthood and risk of hepatocellular carcinoma (HCC), intrahepatic (IBDC) and extrahepatic bile duct system cancer [EBDSC including gallbladder cancer (GBC)] among 359,525 men and women in the European Prospective Investigation into Cancer and Nutrition study. Hepatitis B and C virus status was measured in a nested case–control subset. During a mean follow‐up of 8.6 years, 177 cases of HCC, 58 cases of IBDC and 210 cases of EBDSC, including 76 cases of GBC, occurred. All anthropometric measures were positively associated with risk of HCC and GBC. WHtR showed the strongest association with HCC [relative risk (RR) comparing extreme tertiles 3.51, 95% confidence interval (95% CI): 2.09–5.87; ptrend < 0.0001] and with GBC (RR: 1.56, 95% CI: 1.12–2.16 for an increment of one unit in WHtR). Weight gain during adulthood was also positively associated with HCC when comparing extreme tertiles (RR: 2.48, 95% CI: 1.49–4.13; <0.001). No statistically significant association was observed between obesity and risk of IBDC and EBDSC. Our results provide evidence of an association between obesity, particularly abdominal obesity, and risk of HCC and GBC. Our findings support public health recommendations to reduce the prevalence of obesity and weight gain in adulthood for HCC and GBC prevention in Western populations.

Social Inequalities and Mortality in Europe - Results from a Large Multi-National Cohort

Background Socio-economic inequalities in mortality are observed at the country level in both North America and Europe. The purpose of this work is to investigate the contribution of specific risk factors to social inequalities in cause-specific mortality using a large multi-country cohort of Europeans. Methods A total of 3,456,689 person/years follow-up of the European Prospective Investigation into Cancer and Nutrition (EPIC) was analysed. Educational level of subjects coming from 9 European countries was recorded as proxy for socio-economic status (SES). Cox proportional hazard models with a step-wise inclusion of explanatory variables were used to explore the association between SES and mortality; a Relative Index of Inequality (RII) was calculated as measure of relative inequality. Results Total mortality among men with the highest education level is reduced by 43% compared to men with the lowest (HR 0.57, 95% C.I. 0.52–0.61); among women by 29% (HR 0.71, 95% C.I. 0.64–0.78). The risk reduction was attenuated by 7% in men and 3% in women by the introduction of smoking and to a lesser extent (2% in men and 3% in women) by introducing body mass index and additional explanatory variables (alcohol consumption, leisure physical activity, fruit and vegetable intake) (3% in men and 5% in women). Social inequalities were highly statistically significant for all causes of death examined in men. In women, social inequalities were less strong, but statistically significant for all causes of death except for cancer-related mortality and injuries. Discussion In this European study, substantial social inequalities in mortality among European men and women which cannot be fully explained away by accounting for known common risk factors for chronic diseases are reported.

The Role of Smoking and Diet in Explaining Educational Inequalities in Lung Cancer Incidence

BACKGROUND Studies in many countries have reported higher lung cancer incidence and mortality in individuals with lower socioeconomic status. METHODS To investigate the role of smoking in these inequalities, we used data from 391,251 participants in the European Prospective Investigation into Cancer and Nutrition study, a cohort of individuals in 10 European countries. We collected information on smoking (history and quantity), fruit and vegetable consumption, and education through questionnaires at study entry and gathered data on lung cancer incidence for a mean of 8.4 years. Socioeconomic status was defined as the highest attained level of education, and participants were grouped by sex and region of residence (Northern Europe, Germany, or Southern Europe). Relative indices of inequality (RIIs) of lung cancer risk unadjusted and adjusted for smoking were estimated using Cox regression models. Additional analyses were performed by histological type. RESULTS During the study period, 939 men and 692 women developed lung cancer. Inequalities in lung cancer risk (RII(men) = 3.62, 95% confidence interval [CI] = 2.77 to 4.73, 117 vs 52 per 100,000 person-years for lowest vs highest education level; RII(women) = 2.39, 95% CI = 1.77 to 3.21, 46 vs 25 per 100,000 person-years) decreased after adjustment for smoking but remained statistically significant (RII(men) = 2.29, 95% CI = 1.75 to 3.01; RII(women) = 1.59, 95% CI = 1.18 to 2.13). Large RIIs were observed among men and women in Northern European countries and among men in Germany, but inequalities in lung cancer risk were reverse (RIIs < 1) among women in Southern European countries. Inequalities differed by histological type. Adjustment for smoking reduced inequalities similarly for all histological types and among men and women in all regions. In all analysis, further adjustment for fruit and vegetable consumption did not change the estimates. CONCLUSION Self-reported smoking consistently explains approximately 50% of the inequalities in lung cancer risk due to differences in education.

Explaining the Socioeconomic Variation in Cancer Risk in the Norwegian Women and Cancer Study

Associations between level of education and cancer risk is well supported by scientific evidence, but previous studies could only partly adjust for relevant confounding factors. In this article, we examined how risk of cancer varies with level of education and identified factors that explain this variation using data from a prospective cohort study, including 93,638 Norwegian women who responded to an extensive questionnaire in 1991/1992 or 1996/1997. A total of 3,259 incident primary invasive cancer cases were diagnosed during follow-up, which ended in December 2001. We used Cox proportional hazards model to calculate relative risks (RR) with 95% confidence intervals (95% CI). Besides a similar overall risk of female cancers by level of education, we observed differing risks between educational groups for cancers of the lung, breast, cervix, kidney, and skin melanoma. Women with >16 years of education had an increased risk of breast cancer (RR, 1.46; 95% CI, 1.19-1.79) and a decreased risk of lung cancer (RR, 0.30; 95% CI, 0.13-0.70) and cervical cancer (RR, 0.38; 95% CI, 0.17-0.85) compared with the lowest educated women (7-9 years). The middle educated (13-16 years) had the lowest risk of kidney cancer (RR, 0.24; 95% CI, 0.08-0.71), whereas the risk of skin melanoma was highest among women with 10 to 12 years of education (RR, 1.53; 95% CI, 1.05-2.24) compared with the lowest educated women. After multivariate adjustment for potential confounders related to level of education, the variation in cancer risk according to educational levels declined into nonsignificance for all these sites.

Tobacco smoke and bladder cancer-in the European prospective investigation into cancer and nutrition

The purpose of the present study was to investigate the association between smoking and the development of bladder cancer. The study population consisted of 429,906 persons participating in the European Prospective Investigation into Cancer and Nutrition (EPIC), 633 of whom developed bladder cancer during the follow‐up period. An increased risk of bladder cancer was found for both current‐ (incidence rate ratio 3.96, 95% confidence interval: 3.07–5.09) and ex‐ (2.25, 1.74–2.91) smokers, compared to never‐smokers. A positive association with intensity (per 5 cigarettes) was found among current‐smokers (1.18, 1.09–1.28). Associations (per 5 years) were observed for duration (1.14, 1.08–1.21), later age at start (0.75, 0.66–0.85) and longer time since quitting (0.92, 0.86–0.98). Exposure to environmental tobacco smoke (ETS) during childhood increased the risk of bladder cancer (1.38, 1.00–1.90), whereas for ETS exposure as adult no effect was detected. The present study confirms the strong association between smoking and bladder cancer. The indication of a higher risk of bladder cancer for those who start smoking at a young age and for those exposed to ETS during childhood adds to the body of evidence suggesting that children are more sensitive to carcinogens than adults.

Active and passive cigarette smoking and breast cancer risk: results from the EPIC cohort.

Recent cohort studies suggest that increased breast cancer risks were associated with longer smoking duration, higher pack‐years and a dose‐response relationship with increasing pack‐years of smoking between menarche and first full‐term pregnancy (FFTP). Studies with comprehensive quantitative life‐time measures of passive smoking suggest an association between passive smoking dose and breast cancer risk. We conducted a study within the European Prospective Investigation into Cancer and Nutrition to examine the association between passive and active smoking and risk of invasive breast cancer and possible effect modification by known breast cancer risk factors. Among the 322,988 women eligible for the study, 9,822 developed breast cancer (183,608 women with passive smoking information including 6,264 cases). When compared to women who never smoked and were not being exposed to passive smoking at home or work at the time of study registration, current, former and currently exposed passive smokers were at increased risk of breast cancer (hazard ratios (HR) [95% confidence interval (CI)] 1.16 [1.05–1.28], 1.14 [1.04–1.25] and 1.10 [1.01–1.20], respectively). Analyses exploring associations in different periods of life showed the most important increase in risk with pack‐years from menarche to FFTP (1.73 [1.29–2.32] for every increase of 20 pack‐years) while pack‐years smoked after menopause were associated with a significant decrease in breast cancer risk (HR = 0.53, 95% CI: 0.34–0.82 for every increase of 20 pack‐years). Our results provide an important replication, in the largest cohort to date, that smoking (passively or actively) increases breast cancer risk and that smoking between menarche and FFTP is particularly deleterious.

Predictors for cod-liver oil supplement use — the Norwegian Women and Cancer Study

Objective: To assess the use of cod-liver oil supplements among Norwegian women and to examine dietary, lifestyle, demographic, and health factors associated with use of this supplement.Design: Cross-sectional study.Setting and subjects: The study is based on data from a food frequency questionnaire from 1998 answered by 37 226 women aged 41–55 y, who in 1991/1992 participated in the Norwegian component of the European Prospective Investigation into Cancer and Nutrition (EPIC). The Norwegian EPIC cohort was based on a random nation-wide sample of Norwegian women.Results: Cod-liver oil supplement use was reported by 44.7% of the participating women. Subjects with higher education, high physical activity level, and body mass index (BMI) in the normal range were more likely to use cod-liver oil supplements. Consumption did also increase with increased age as well as with increased reported consumption of fruits, vegetables, fatty fish, lean fish, and vitamin D (excluding the vitamin D contribution from cod-liver oil). Energy intake was higher among cod-liver oil users than nonusers. Whole-year daily users of cod-liver oil were also more likely to take other dietary supplements (OR=2.45, 95% CI: 2.28–2.62). Never smokers were more likely to use cod-liver oil supplements than current smokers.Conclusion: Use of cod-liver oil is associated with several sociodemographic factors, self-reported health issues, and intake of fish, fruit, and vegetables. When assessing the relationship between cod-liver oil use and occurrence of chronic diseases potential confounders need to be considered. Cod-liver oil use seemed not to be matched with vitamin D needs. Thus, emphasis on assessing vitamin D status by measuring levels in blood should be investigated further, in particular, among people living in northern latitudes.

Fruit and vegetable consumption and prospective weight change in participants of the European Prospective Investigation into Cancer and Nutrition–Physical Activity, Nutrition, Alcohol, Cessation of Smoking, Eating Out of Home, and Obesity study

BACKGROUND Fruit and vegetable consumption might prevent weight gain through their low energy density and high dietary fiber content. OBJECTIVE We assessed the association between the baseline consumption of fruit and vegetables and weight change in participants from 10 European countries participating in the European Prospective Investigation into Cancer and Nutrition study. DESIGN Diet was assessed at baseline in 373,803 participants by using country-specific validated questionnaires. Weight was measured at baseline and self-reported at follow-up in most centers. Associations between baseline fruit and vegetable intakes (per 100 g/d) and weight change (g/y) after a mean follow-up of 5 y were assessed by using linear mixed-models, with age, sex, total energy intake, and other potential confounders controlled for. RESULTS After exclusion of subjects with chronic diseases at baseline and subjects who were likely to misreport energy intakes, baseline fruit and vegetable intakes were not associated with weight change overall. However, baseline fruit and vegetable intakes were inversely associated with weight change in men and women who quit smoking during follow-up. We observed weak positive associations between vegetable intake and weight change in women who were overweight, were former smokers, or had high prudent dietary pattern scores and weak inverse associations between fruit intake and weight change in women who were >50 y of age, were of normal weight, were never smokers, or had low prudent dietary pattern scores. CONCLUSIONS In this large study, higher baseline fruit and vegetable intakes, while maintaining total energy intakes constant, did not substantially influence midterm weight change overall but could help to reduce risk of weight gain in persons who stop smoking. The interactions observed in women deserve additional attention.