Reproducibility, validity, and responsiveness to change of a short questionnaire for measuring fruit and vegetable intake

The reproducibility, relative validity, and responsiveness to change of an eight-item food frequency questionnaire designed to measure fruit and vegetable consumption was assessed among 157 women (mean age = 41 years) in the Netherlands from spring 2001 to spring 2002. Plasma concentrations of vitamin C and total and specific carotenoids served as biomarkers against which validity was assessed. The questionnaire was completed and biomarker concentrations were determined three times: immediately preceding and following a controlled intervention of 1 month aimed at increasing fruit and vegetable consumption and 1 year after the start of the intervention. The 1-month and 1-year reproducibility of total fruit and vegetable consumption assessed in the control group was 0.80 and 0.79 (Spearman's r ). Correlations between consumption and plasma carotenoids and vitamin C at baseline were 0.39 and 0.37, respectively, for fruits and 0.24 and 0.26, respectively, for vegetables. Correlations between changes in consumption and plasma carotenoids and vitamin C were 0.32 and 0.33, respectively, for fruits and 0.28 and 0.30, respectively, for vegetables. On the basis of similar correlations reported in the literature, the authors conclude that the questionnaire appears to be suitable for ranking individuals according to their consumption of fruits and vegetables and according to changes in their consumption. However, the validity of the questionnaire remains to be established in males, other age groups, and populations of lower educational levels

Explaining fruit and vegetable consumption: the theory of planned behaviour and misconception of personal intake levels

The influence of individuals' misconceptions in assessing fruit and vegetable consumption on the ability of the theory of planned behaviour to explain variance in the consumption of these foods was studied. Dutch women (mean age 41, n=159) completed a questionnaire assessing the theory's constructs with regard to the daily consumption of at least two pieces of fruit and 200 gram of vegetables. Consumption was assessed using a self-rated measure and more objectively with a food-frequency questionnaire. Both measures were combined to classify participants according to the accuracy of their self-assessed intake levels ('realists' vs. 'overestimators'). The model explained variation in objective fruit and vegetable intake much better among realists (R2 = 45% for fruits and 39% for vegetables) than among overestimators (R2 = 18% and 5%, respectively). Perceived behavioural control was the strongest predictor of intentions and behaviour. When plasma vitamin C and carotenoid concentrations were used as objective indicators for fruit and vegetable intake, the explanatory value of the model was lower, but again more variance was explained among realists than among overestimators. We conclude that awareness of personal behaviour should be taken into account when applying the theory of planned behaviour to explain dietary behaviours as well as to design health education interventions

Psychosocial Predictors of Increases in Fruit and Vegetable Consumption

Objectives: To examine psychosocial predictors of changes in fruit and vegetable consumption. Methods: Baseline psychosocial variables were used to explain differences in changes in consumption in 83 healthy women with children after they received free fruit and vegetables for one month. Results: One-month changes in fruit consumption (mean 144; SE 16 g/day) were positively associated with perceived costs and perceived health benefits for the children, and negatively associated with perceived behavioral control. Changes in vegetable consumption (68 (11) g/day) were positively related with the intention to eat at least 200 g of vegetables and taste preferences of the children. Conclusions: Fruit and vegetable consumption may be encouraged by influencing the above variables

Cancer incidence in Dutch Balkan veterans

Item does not contain fulltextSuspicion has been raised about an increased cancer risk among Balkan veterans because of alleged exposure to depleted uranium. The authors conducted a historical cohort study to examine cancer incidence among Dutch Balkan veterans. Male military personnel (n=18,175, median follow-up 11 years) of the Army and Military Police who had been deployed to the Balkan region (1993-2001) was compared with their peers not deployed to the Balkans (n=135,355, median follow-up 15 years) and with the general Dutch population of comparable age and sex. The incidence of all cancers and 4 main cancer subgroups was studied in the period 1993-2008. The cancer incidence rate among Balkan deployed military men was 17% lower than among non-Balkan deployed military men (hazard ratio 0.83 (95% confidence interval 0.69, 1.00)). For the 4 main cancer subgroups, hazard ratios were statistically non-significantly below 1. Also compared to the general population cancer rates were lower in Balkan deployed personnel (standardised incidence rate ratio (SIR) 0.85 (0.73, 0.99). The SIR for leukaemia was 0.63 (0.20, 1.46). The authors conclude that earlier suggestions of increased cancer risks among veterans are not supported by empirical data. The lower risk of cancer might be explained by the 'healthy warrior effect'

The impact of body mass index in old age on cause-specific mortality

Objectives: To assess the association between Body Mass Index (BMI) and cause-specific mortality in older adults and to assess which BMI was associated with lowest mortality. Design: Prospective study. Setting: European towns. Participants: 1,980 older adults, aged 70-75 years from the SENECA (Survey in Europe on Nutrition and the Elderly: a concerted action) study. Measurements: BMI, examined in 1988/1989, and mortality rates and causes of death during 10 years of follow-up. Results: Cox proportional hazards model including both BMI and BMI2, accounting for sex, smoking status, educational level and age at baseline showed that BMI was associated with all-cause mortality (p0.3). The lowest all-cause mortality risk was found at 27.1 (95%CI 24.1, 29.3) kg/m2, and this risk was increased with statistical significance when higher than 31.4 kg/m2 and lower than 21.1 kg/m2. The lowest cardiovascular mortality risk was found at 25.6 (95%CI 17.1, 28.4) kg/m2, and was increased with statistical significance when higher than 30.9 kg/m2. Conclusion: In this study, BMI was associated with all-cause mortality risk in older people. This risk was mostly driven by an increased cardiovascular mortality risk, as no association was found for mortality risk from cancer or respiratory disease. Our results indicate that the WHO cut-off point of 25 kg/m2 for overweight might be too low in old age, but more studies are needed to define specific cut-off points

Effect of increased vegetable and fruit consumption on plasma folate and homocysteine concentrations

OBJECTIVE: We assessed the effects of an intervention aimed at increasing the consumption of fruits and vegetables on plasma folate and homocysteine concentrations. METHODS: Seventy-one healthy non-smoking women (mean +/- SD 41 +/- 4 y of age) were randomized to an intervention or a control group. Participants in the intervention group (n = 36) received weekly packets containing fruits and vegetables free of charge and were asked to consume a daily amount of >/=200 g of vegetables and two pieces of fruit (the Dutch recommended intake level) over a period of 1 mo. Control subjects did not receive any intervention. RESULTS: Compared with the control group, reported fruit and vegetable intakes in the intervention group increased by 133 g/d (95% confidence interval [CI] 87-179, P < 0.001) for fruits and juice and 64 g/d (95% CI 37-91, P < 0.001) for vegetables and estimated folate intake from fruits and vegetables increased by 40 mug/d (95% CI 22-58, P < 0.001). However, no effect was observed on plasma folate concentrations (intervention effect 0.3 nmol/L, 95% CI -1.8 to 2.8, P = 0.77) or homocysteine concentrations (intervention effect 0.26 mumol/L, 95% CI -0.34 to 0.87, P = 0.39). CONCLUSION: The results suggest that 4 wk of increased fruit and vegetable consumption to the recommended amounts may be insufficient to change plasma folate and homocysteine concentrations

Using a correction factor to correct for overreporting in a food-frequency questionnaire does not improve biomarker-assessed validity of estimates for fruit and vegetable consumption

To correct for overreporting of fruit and vegetable (FV) consumption in a food-frequency questionnaire, summary questions about consumption of main FV groups are often used to calculate correction factors. This study compared the ability to rank people according to their FV intake of those summary questions and the sum of questions on individual FV items within categories, and of corrected or uncorrected estimates of specific sorts of FV. Healthy middle-age women (n = 161) completed a food-frequency questionnaire about FV consumption during the previous month and gave a single fasting blood sample. Correction factors were calculated as the reported frequency on a summary question divided by the summed frequencies of all items in a category. Plasma carotenoids and vitamin C served as biomarkers of FV consumption. Significant correlations between FV consumption and biomarkers were observed (e.g., Spearman's correlation coefficient r with total carotenoids/vitamin C: 0.32/0.34 for vegetables, 0.30/0.25 for fruits). Summary estimates of cooked, raw and total vegetable consumption correlated higher with biomarkers than sum estimates. For fruits no differences in correlations between sum and summary estimates were observed. Applying a correction factor on the consumption of carrots and total cabbage resulted in lower correlations with relevant biomarkers. For broccoli/cauliflower, Brussels sprouts and citrus fruits, correlations with biomarkers did not change after correction. We conclude that summary questions may suffice to rank individuals according to their intake of main FV categories, and that correction for overreporting of individual FV items is probably not advisable when ranking individuals according to intake of these items