Daidzein and genistein intakes in England (the EPIC Norfolk cohort).
Explore the source record for details and available documents.
Anticarcinogenic Agents↗
Biomedical subjects
A A Welch
Publications and source records attributed to A A Welch.
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.
Aged↗
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.
Cohort Studies↗
Use of biological markers to validate self-reported dietary intake in a random sample of the European Prospective Investigation into Cancer United Kingdom Norfolk cohort.
BACKGROUND: The validity of dietary assessment methods should be established before diet-disease associations are reported. OBJECTIVE: Our objective was to validate a 7-d food diary and a food-frequency questionnaire (FFQ) against independent biomarkers of intake in urine (nitrogen, potassium, and sodium) and blood (plasma ascorbic acid). DESIGN: A total of 146 healthy middle-aged men and women were recruited from the European Prospective Investigation into Cancer UK Norfolk cohort, a free-living cohort of approximately 25000 persons. Over a 9-mo period, urinary nitrogen, potassium, and sodium were estimated from 2-6 complete 24-h urine collections in 134 subjects and plasma ascorbic acid was estimated from 2-3 fasting blood samples in 118 subjects. Subjects completed 2 FFQs and two 7-d food diaries. RESULTS: In men and women combined, correlations between 24-h urinary nitrogen excretion and dietary intake from the 7-d food diary were high (r = 0.57-0.67) compared with those for the FFQ (r = 0.21-0.29). Similarly, correlations between urinary potassium and dietary potassium were higher for the 7-d food diary (r = 0.51-0.55) than for the FFQ (r = 0.32-0.34). There was no overall difference in correlations between plasma ascorbic acid and dietary vitamin C between the 7-d food diary (r = 0.40-0.52) and the FFQ (r = 0.44-0.45). CONCLUSIONS: These data indicate that, despite increased subject burden, the 7-d food diary provided a better estimate of nitrogen and potassium intakes than did the FFQ in this study population. However, with respect to plasma ascorbic acid, both the FFQ and 7-d food diary provided a similar ranking of subjects according to vitamin C intake.
Aged↗
Validation of dietary intakes measured by diet history against 24 h urinary nitrogen excretion and energy expenditure measured by the doubly-labelled water method in middle-aged women.
A diet history method for estimating energy and N intakes was validated against 24 h urinary N excretion and energy expenditure measured by the doubly-labelled water (DLW) method. Forty-eight women aged 50-65 years were studied over 1 year. Weighed diet records from 4 d and two 24 h urine collections, for measurement of urinary N excretion, were obtained in each of four seasons. At the end of the year, a diet history was obtained, BMR was measured by whole-body calorimetry, and, in sixteen women, total energy expenditure (EE) was measured by DLW. Energy intake (EI) and N intake (NI) were calculated using food tables. Using weighed records and diet history respectively mean NI were 11.21 (SD 2.09) g and 11.47 (SD 2.40) g (NS) and EI were 8.08 (SD 1.54) MJ and 8.20 (SD 1.86) MJ (NS). Mean urine N:NI and EI:BMR values indicated bias to under-reporting by weighed record and diet history techniques in some individuals, but there was no significant difference between these measures at the group level. The Pearson correlation coefficient (r) for urine N v. NI was 0.81 for the weighed record and 0.38 for the diet history. The correlation of EE v. EI was r 0.48 for weighed record and r 0.11 for diet history. In this study the diet history gave the same estimate of mean intake, but the weighed record appeared to perform better in ranking individuals.
Aged↗