Alison McTaggart

Nutritional methods in the European Prospective Investigation of Cancer in Norfolk.

OBJECTIVE To describe methods and dietary habits of a large population cohort. DESIGN Prospective assessment of diet using diet diaries and food-frequency questionnaires, and biomarkers of diet in 24-h urine collections and blood samples. SETTING Free living individuals aged 45 to 75 years living in Norfolk, UK. SUBJECTS Food and nutrient intake from a food-frequency questionnaire on 23 003 men and women, and from a 7-day diet diary from 2117 men and women. Nitrogen, sodium and potassium excretion was obtained from single 24-h urine samples from 300 individuals in the EPIC cohort. Plasma vitamin C was measured for 20 846 men and women. RESULTS The food-frequency questionnaire (FFQ) and the food diary were able to determine differences in foods and nutrients between the sexes and were reliable as judged by repeated administrations of each method. Plasma vitamin C was significantly higher in women than men. There were significant differences in mean intake of all nutrients measured by the two different methods in women but less so in men. The questionnaire overestimated dairy products and vegetables in both men and women when compared with intakes derived from the diary, but underestimated cereal and meat intake in men. There were some consistent trends with age in food and nutrient intakes assessed by both methods, particularly in men. Correlation coefficients between dietary intake assessed from the diary and excretion of nitrogen and potassium in a single 24-h urine sample ranged from 0.36 to 0.47. Those comparing urine excretion and intake assessed from the FFQ were 0.09 to 0.26. The correlations between plasma vitamin C and dietary intake from the first FFQ, 24-h recall or diary were 0.28, 0.35 and 0.40. CONCLUSIONS EPIC Norfolk is one of the largest epidemiological studies of nutrition in the UK and the largest on which plasma vitamin C has been obtained. Methods for obtaining food and nutrient intake are described in detail. The results shown here for food and nutrient intakes can be compared with results from other population studies utilising different methods of assessing dietary intake. The utility of different methods used in different settings within the main EPIC cohort is described. The FFQ is to be used particularly in pooled analyses of risk from diet in relation to cancer incidence within the larger European EPIC study, where measurement error is more likely to be overcome by large dietary heterogeneity on an international basis. Findings in the UK, where dietary variation between individuals is smaller and hence the need to use a more accurate individual method greater, will be derived from the 7-day diary information on a nested case-control basis. 24-h recalls can be used in the event that diary information should not be forthcoming from some eventual cases. Combinations of results utilising all dietary methods and biomarkers may also be possible.

DINER (Data Into Nutrients for Epidemiological Research) – a new data-entry program for nutritional analysis in the EPIC–Norfolk cohort and the 7-day diary method

BACKGROUND AND OBJECTIVE A new data-entry system (DINER - Data Into Nutrients for Epidemiological Research) for food record methods has been devised for the European Prospective Investigation into Cancer (EPIC) cohort study of 25,000 men and women in Norfolk. DINER has been developed to address the problems of efficiency and consistency of data entry, comparability of data, maximising information and future flexibility in large long-term population studies of diet and disease that use record methods to assess dietary intakes. DINER captures more detail than traditional systems and enables provision of new variables for specific food types or groups. The system has been designed to be fully flexible and easy to update. Analysis of consistency of data entry was tested in a group of 3525 participants entered by 25 coders. RESULTS A food list of 9000 food items and values for 24,000 portion sizes have been incorporated into the database, using information from the 5979 diaries coded since 1995. Analysis of consistency of entry indicated that this has largely been achieved. The effect of coders in a multivariate regression model was significant only if the three coders involved in early use of the program were included (P < 0.013). CONCLUSIONS The development of DINER has facilitated the use of more accurate record methods in large-scale epidemiological studies of diet and disease. Furthermore, the retention of original information as an extensive food list allows greater flexibility in later analyses of data of multiple dietary hypotheses.

Urinary Sucrose and Fructose as Biomarkers for Sugar Consumption

The use of 24-hour urinary sucrose and fructose as potential biomarkers for sugars consumption was investigated in two studies of 21 healthy participants living in a volunteer suite where dietary intake was known and all specimens collected. The dose-response was assessed in 12 males using a randomized crossover design of three diets containing constant levels of 63, 143, and 264 g of sugars for 10 days each. Both sugars and sucrose intake were significantly correlated with the sum of sucrose and fructose concentration in urine (0.888; P < 0.001). To assess effects with volunteers consuming their habitual varying diets, seven males and six females were fed their usual diet (assessed beforehand from four consecutive self-completed 7-day food diaries) for 30 days under controlled conditions in the volunteer suite. The mean (±SD) calculated total sugars intake was 202 ± 69 g/d, 41% from sucrose. Mean (±SD) urinary sucrose and fructose were 36.6 ± 16.6 and 61.8 ± 61.3 mg/d, respectively. The sum of sucrose and fructose in urine was significantly correlated with sugars (0.841; P < 0.001) and sucrose intake (0.773; P = 0.002). In the regression, 200 g of sugars intake predicted ∼100 mg of sucrose and fructose in urine. The correlation between individual means of randomized 16 days of sugars intake and 8 days of sugars excretion data (as used in validation studies) remained as high as that obtained with the means of 30-day measurements and the regression estimates were very similar. Twenty-four–hour urinary sucrose and fructose could be grouped into a new category of biomarkers, predictive biomarkers, that can be used in studies determining the structure of dietary measurement error in free living individuals and to relate sugars intake to disease risk.

Soy product consumption in 10 European countries: the European Prospective Investigation into Cancer and Nutrition (EPIC) study

OBJECTIVE The aim of this study was to describe the variation of soy product intake in 10 European countries by using a standardised reference dietary method. A subsidiary aim was to characterise the pattern of soy consumption among a sub-group of participants with a habitual health-conscious lifestyle (HHL), i.e. non-meat eaters who are fish eaters, vegetarians and vegans. DESIGN A 24-hour dietary recall interview (24-HDR) was conducted among a sample (5-12%) of all cohorts in the European Prospective Investigation into Cancer and Nutrition (EPIC). Study participants totalled 35 955 after exclusion of subjects younger than 35 or older than 74 years of age. Soy products were subdivided into seven sub-groups by similarity. Distribution of consumption and crude and adjusted means of intake were computed per soy product group across countries. Intake of soy products was also investigated among participants with an HHL. RESULTS In total, 195 men and 486 women reported consuming soy products in the 24-HDR interview. Although soy product intake was generally low across all countries, the highest intake level was observed in the UK, due to over-sampling of a large number of participants with an HHL. The most frequently consumed soy foods were dairy substitutes in the UK and France and beans and sprouts among mid-European countries. For both genders, the sub-group of soy dairy substitutes was consumed in the highest quantities (1.2 g day-1 for men; 1.9 g day-1 for women). Participants with an HHL differed substantially from others with regard to demographic, anthropometric and nutritional factors. They consumed higher quantities of almost all soy product groups. CONCLUSIONS Consumption of soy products is low in centres in Western Europe. Soy dairy substitutes are most frequently consumed. Participants with an HHL form a distinct sub-group with higher consumptions of fruit, vegetables, legumes, cereals and soy products compared with the other participants.

Eating out of home: energy, macro- and micronutrient intakes in 10 European countries. The European Prospective Investigation into Cancer and Nutrition

Objectives:To assess the contribution of out-of-home (OH) energy and nutrient intake to total dietary intake, and to compare out- versus in-home nutrient patterns 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 participants aged between 35–74 years completed a standardized 24-h dietary recall using a software programme (EPIC-Soft) that recorded the place of food/drink consumption. Eating OH was defined as the consumption of foods and beverages anywhere other than in household premises, irrespective of the place of purchase/preparation. Nutrient intakes were estimated using a standardized nutrient database. Mean intakes were adjusted for age and weighted by season and day of recall.Results:Among women, OH eating contributed more to total fat intake than to intakes of protein and carbohydrates. Among both genders, and particularly in southern Europe, OH eating contributed more to sugar and starch intakes and less to total fibre intake. The contribution of OH eating was also lower for calcium and vitamin C intakes. The composition of diet at home was different from that consumed out of home in southern countries, but was relatively similar in the north.Conclusions:In northern Europe, OH and in-home eating are homogeneous, whereas southern Europeans consider OH eating as a distinctive occasion. In most centres, women selected more fat-rich items when eating out.

Total dietary carbohydrate, sugar, starch and fibre intakes in the European Prospective Investigation into Cancer and Nutrition

Objective:To describe dietary carbohydrate intakes 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 subjects, aged between 35–74 years, were administered a standardized, 24-h dietary recall using a computerized interview software programme (EPIC-SOFT). Intakes (g/day) of total carbohydrate, sugars, starch and fibre were estimated using the standardized EPIC Nutrient Database (ENDB). Mean intakes were adjusted for age, total energy intake, height and weight, and were weighted by season and day of recall.Results:Adjusted mean total carbohydrate intakes were highest in Italy and in the UK health-conscious cohort, and were lowest in Spain, Greece and France. Total fibre intakes were highest in the UK health-conscious cohort and lowest in Sweden and the UK general population. Bread contributed the highest proportion of carbohydrates (mainly starches) in every centre. Fruit consumption contributed a greater proportion of total carbohydrates (mainly sugars) among women than among men, and in southern centres compared with northern centres. Bread, fruits and vegetables represented the largest sources of fibre, but food sources varied considerably between centres. In stratified analyses, carbohydrate intakes tended to be higher among subjects who were physically active, never-smokers or non-drinkers of alcohol.Conclusions:Dietary carbohydrate intakes and in particular their food sources varied considerably between these 10 European countries. Intakes also varied according to gender and lifestyle factors. These data will form the basis for future aetiological analyses of the role of dietary carbohydrates in influencing health and disease.

Intakes and sources of soya foods and isoflavones in a UK population cohort study (EPIC-Norfolk).

Background:It has been suggested that the consumption of a diet rich in phytoestrogens might protect against a variety of diseases common in Western societies. However, there are little available data on the food sources or distribution of intake in the UK diet.Objective:To estimate the average intake and range of soya foods and isoflavones in a population-based cohort and to provide data on isoflavone consumption by food group.Subjects:Men and women (11 843) from the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC).Methods:Dietary daidzein and genistein intakes were obtained from 7-day food diaries, completed by participants between 1993 and 1998 and calculated from an in-house food composition database. Energy and anthropometric measurements were also carried out.Results:Average daily isoflavone intakes for both men and women were less than 1 mg (interquartile range (IQR) men: 0.39–0.82 mg; women: 0.30–0.64 mg). However, in soya-consumers, average daily intakes were higher: 8.6 mg in women (IQR: 2.28–10.72 mg) and 7.5 mg in men (IQR: 2.22–9.17 mg). In both men and women, bread and bread rolls made the highest contribution to isoflavone intake – 62.5 and 53.0%, respectively. In soya-consuming men and women, vegetable dishes and milks were the main contributors – 25.0 and 38.5% in men and 38.5% and 26.0% in women, respectively.Conclusions:Isoflavone intake is low in the UK but may be an underestimate due to soya added to commercial products. Future analyses of the isoflavone and lignan content of basic ingredient foods and commercial items commonly consumed in the UK diet will enable more accurate estimates of phytoestrogen intake to be made. The ability to estimate isoflavone intake in Western populations more accurately will enable investigations to be conducted into the suggested beneficial effects of phytoestrogens on health.

Consumption of dairy products in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort: data from 35 955 24-hour dietary recalls in 10 European countries.

OBJECTIVES To describe and compare the consumption of dairy products in cohorts included in the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS Data from single 24-hour dietary recall interviews collected through a highly standardised computer-based program (EPIC-SOFT) in 27 redefined centres in 10 European countries between 1995 and 2000. From a total random sample of 36 900, 22 924 women and 13 031 men were selected after exclusion of subjects under 35 and over 74 years of age. RESULTS A high total consumption of dairy products was reported in most of the centres in Spain and in the UK cohort sampled from the general population, as well as in the Dutch, Swedish and Danish centres. A somewhat low consumption was reported in the Greek centre and in some of the Italian centres (Ragusa and Turin). In all centres and for both sexes, milk constituted the dairy sub-group with the largest proportion (in grams) of total dairy consumption, followed by yoghurt and other fermented milk products, and cheese. Still, there was a wide range in the contributions of the different dairy sub-groups between centres. The Spanish and Nordic centres generally reported a high consumption of milk, the Swedish and Dutch centres reported a high consumption of yoghurt and other fermented milk products, whereas the highest consumption of cheese was reported in the French centres. CONCLUSION The results demonstrate both quantitative and qualitative disparities in dairy product consumption among the EPIC centres. This offers a sound starting point for analyses of associations between dairy intake and chronic diseases such as cancer.

Food sources of carbohydrates in a European cohort of adults

OBJECTIVE To describe the average consumption of carbohydrate-providing food groups among study centres of the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS Of the 27 redefined EPIC study centres, 19 contributed subjects of both genders and eight centres female participants only (men, women, after exclusion of subjects under 35 and over 74 years of age from the original 36 900 total). Dietary data were obtained using the 24-hour recall methodology using the EPIC-SOFT software. The major sources of dietary carbohydrate were identified, and 16 food groups were examined. RESULTS The 10 food groups contributing most carbohydrate were bread; fruit; milk and milk products; sweet buns, cakes and pies; potato; sugar and jam; pasta and rice; vegetables and legumes; crispbread; and fruit and vegetable juices. Consumption of fruits as well as vegetables and legumes was higher in southern compared with northern centres, while soft drinks consumption was higher in the north. Italian centres had high pasta and rice consumption, but breakfast cereal, potato, and sweet buns, cakes and pies were higher in northern centres. In Sweden, lower bread consumption was balanced with a higher consumption of crispbread, and with sweet buns, cakes and pies. Overall, men consumed higher amounts of vegetables and legumes, bread, soft drinks, potatoes, pasta and rice, breakfast cereal and sugar and jam than women, but fruit consumption appeared more frequent in women. CONCLUSION The study supports the established idea that carbohydrate-rich foods chosen in northern Europe are different from those in the Mediterranean region. When comparing and interpreting diet-disease relationships across populations, researchers need to consider all types of foods.

Dietary antioxidants and the aetiology of pancreatic cancer: a cohort study using data from food diaries and biomarkers

Objective To investigate whether the dietary antioxidants vitamins C and E, selenium and zinc decrease the risk of developing pancreatic cancer, for the first time using 7-day food diaries, the most accurate dietary methodology in prospective work. Design 23 658 participants, aged 40–74 years, recruited into the EPIC-Norfolk Study completed 7-day food diaries which recorded foods, brands and portion sizes. Nutrient intakes were calculated in those later diagnosed with pancreatic cancer and in 3970 controls, using a computer program with information on 11 000 foods. Vitamin C was measured in serum samples. The HRs of developing pancreatic cancer were estimated across quartiles of intake and thresholds of the lowest quartile (Q1) against a summation of the three highest (Q2–4). Results Within 10 years, 49 participants (55% men), developed pancreatic cancer. Those eating a combination of the highest three quartiles of all of vitamins C and E and selenium had a decreased risk (HR=0.33, 95% CI 0.13 to 0.84, p<0.05). There were threshold effects (Q2–4 vs Q1) for selenium (HR=0.49, 95% CI 0.26 to 0.93, p<0.05) and vitamin E (HR=0.57, 95% CI 0.29 to 1.09, p<0.10). The HRs of quartiles for antioxidants, apart from zinc, were <1, but not statistically significant. For vitamin C, there was an inverse association with serum measurements (HR trend=0.67, 95% CI 0.49 to 0.91, p=0.01), but the threshold effect from diaries was not significant (HR=0.68, 95% CI 0.37 to 1.26). Conclusion The results support measuring antioxidants in studies investigating the aetiology of pancreatic cancer. If the association is causal, 1 in 12 cancers might be prevented by avoiding the lowest intakes.