1.
Identifying sources of measurement error in assessing dietary intakes - Results of a multi-country ring-trial.
Gavrieli, A, Trichopoulou, A, Valsta, LM, Ioannidou, S, Berry, R, Roe, M, Harvey, L, Finglas, P, Glibetic, M, Gurinovic, M, et al
Nutrition, metabolism, and cardiovascular diseases : NMCD. 2019;(2):127-134
Abstract
BACKGROUND AND AIMS Epidemiological investigations include dietary intakes as primary exposures or potential confounders. To reduce bias, data collection protocols include the administration of questionnaires together with measurements of biomarkers. Some error, however, remains and needs to be considered in the analysis and interpretation of results. The European Food Safety Authority supported a ring-trial to compare the precision and reproducibility of dietary assessment methods applied in Europe. METHODS AND RESULTS Software applications used to collect 24-hour recalls and food records in six countries (Estonia, Italy, Latvia, Portugal, Spain, and Sweden) were assessed. The intake of 256 foods was identically reported to each method. Experienced interviewers participated and were instructed to repeat national protocols closely. The error in recording quantities, compared with reference values, was variable but in about 60% of recorded quantities was in the range of ±20%. Errors were however unsystematic and independent of the food type or quantification method used - although food pictures performed better. The reproducibility of some tools was limited. The methods generally captured additional ingredients (usually flavoring agents), but not sweetening agents or fortification and failed to record packaging information in about 60% of the cases. CONCLUSION In a design that eliminated respondent bias, this study indicates that softwares, supporting databases and interviewers generally introduce random error in dietary assessments. The inclusion of large sample sizes and food pictures to quantify portions, together with enhanced attention on interviewers' training, standardisation of procedures and regular tool upgrades are essential in assuring a study's quality and comparability.
2.
Combined impact of lifestyle factors on prospective change in body weight and waist circumference in participants of the EPIC-PANACEA study.
May, AM, Romaguera, D, Travier, N, Ekelund, U, Bergmann, MM, Kaaks, R, Teucher, B, Steffen, A, Boeing, H, Halkjaer, J, et al
PloS one. 2012;(11):e50712
Abstract
BACKGROUND The evidence that individual dietary and lifestyle factors influence a person's weight and waist circumference is well established; however their combined impact is less well documented. Therefore, we investigated the combined effect of physical activity, nutrition and smoking status on prospective gain in body weight and waist circumference. METHODS We used data of the prospective EPIC-PANACEA study. Between 1992 and 2000, 325,537 participants (94,445 men and 231,092 women, aged between 25-70) were recruited from nine European countries. Participants were categorised into two groups (positive or negative health behaviours) for each of the following being physically active, adherent to a healthy (Mediterranean not including alcohol) diet, and never-smoking for a total score ranging from zero to three. Anthropometric measures were taken at baseline and were mainly self-reported after a medium follow-up time of 5 years. RESULTS Mixed-effects linear regression models adjusted for age, educational level, alcohol consumption, baseline body mass index and follow-up time showed that men and women who reported to be physically active, never-smoking and adherent to the Mediterranean diet gained over a 5-year period 537 (95% CI -706, -368) and 200 (-478, -87) gram less weight and 0.95 (-1.27, -0.639) and 0.99 (-1.29, -0.69) cm less waist circumference, respectively, compared to participants with zero healthy behaviours. CONCLUSION The combination of positive health behaviours was associated with significantly lower weight and waist circumference gain.
3.
Are dietary influences on the risk of prostate cancer mediated through the insulin-like growth factor system?
Mucci, LA, Tamimi, R, Lagiou, P, Trichopoulou, A, Benetou, V, Spanos, E, Trichopoulos, D
BJU international. 2001;(9):814-20
Abstract
OBJECTIVES To investigate whether dietary factors that appear to affect the risk of prostate cancer may be similarly associated with serum levels of insulin-like growth factor 1 (IGF-1). Patients and methods In the context of a case-control study, 112 men were admitted to three teaching hospitals in Athens, Greece, for disorders other than cancer. Sociodemographic data and detailed histories of smoking, alcohol and coffee consumption were recorded. A validated food-frequency questionnaire was administered by an interviewer and serological measurements of IGF-1 and its binding protein-3 conducted. RESULTS IGF-1 declined significantly by almost 25% among men aged >75 years and there was a small reduction in IGF-1 levels with increased alcohol intake, with a mean (95% confidence interval, CI) change of -1.6 (- 2.2 to -0.9)% for an increment of one drink per day. There was no evidence for an effect of either smoking or coffee consumption on IGF-1 level. Among foods, the consumption of cooked tomatoes was substantially and significantly inversely associated with IGF-1 levels, with a mean (95% CI) change of -31.5 (- 49.1 to -7.9)% for an increment of one serving per day. CONCLUSIONS The strongest known dietary risk factor for prostate cancer (lycopene deficit, as reflected in a reduced intake of cooked tomatoes) and an important endocrine factor in the aetiology of this disease (IGF-1) seem to be related in a way that suggests that at least one, and perhaps more, exogenous factors in the development of prostate cancer may be mediated through the IGF-1 system.