Objective: The main purpose of the study was to investigate the feasibility of using workplaces to increase the fruit consumption of participants by increasing fruit availability and accessibility by a minimal fruit programme. Furthermore, it was investigated whether a potential increase in fruit intake would affect vegetable, total energy and nutrient intake. Design: A 5-month, controlled, workplace study where workplaces were divided into an intervention group (IG) and a control group (CG). At least one piece of free fruit was available per person per day in the IG. Total fruit and dietary intake was assessed, using two 24 h dietary recalls at baseline and at endpoint. Setting: Eight Danish workplaces were enrolled in the study. Five workplaces were in the IG and three were in the CG. Subjects: One hundred and twenty-four (IG, n 68; CG, n 56) healthy, mainly normal-weight participants were recruited. Results: Mean daily fruit intake increased significantly from baseline to endpoint only in the IG by 112 (SE 35) g. In the IG, mean daily intake of added sugar decreased significantly by 10?7 (SE 4?4) g, whereas mean daily intake of dietary fibre increased significantly by 3?0 (SE 1?1) g. Vegetable, total energy and macronutrient intake remained unchanged through the intervention period for both groups. Conclusions: The present study showed that it is feasible to increase the average fruit intake at workplaces by simply increasing fruit availability and accessibility. Increased fruit intake possibly substituted intake of foods containing added sugar. In this study population the increased fruit intake did not affect total energy intake.

To gain better insight into the potential health effects of fruits and vegetables, reliable biomarkers of intake are needed. The main purpose of this study was to investigate the ability of flavonoid excretion in both 24-h and morning urine samples to reflect a low intake and moderate changes in fruit and vegetable consumption. Furthermore, the urinary excretions of 4-pyridoxic acid (4-PA) and potassium were investigated as other potential biomarkers of fruit and vegetable intake. The study was designed as a 5-d randomized, controlled crossover study. On d 1-3, the men (n = 12) consumed a self-restricted flavonoid-free diet. On d 4, they were provided a strictly controlled diet containing no fruits or vegetables (basic diet). On d 5, they consumed the basic diet supplemented with 300 or 600 g of fruits and vegetables. The total excretion of flavonoids in 24-h urine samples increased linearly with increasing fruit and vegetable intakes (r(s) = 0.86, P < 1 x 10(-6)). The total excretion of flavonoids in morning urine also increased, but the association was weaker (r(s) = 0.59, P < 0.0001). Urinary 4-PA in 24-h and morning urine samples increased significantly only with the 600-g increase in fruit and vegetable intake, whereas the excretion of potassium in urine did not reflect the changes in fruit and vegetable intake. We conclude that the total excretion of flavonoids in 24-h urine may be used as a new biomarker for fruit and vegetable intake.

Background/Objectives: To validate 24 h dietary recall of fruit intake by measuring the total 24 h excretion of 10 different flavonoids in 24 h urine during an intervention with free fruit at workplaces. Subjects/Methods: Employees at workplaces offering a free-fruit program, consisting of daily free and easy access to fresh fruit, and controls employees at workplaces with no free-fruit program were enrolled in this validation study (n ¼ 103). Dietary intake was assessed by using a 24 h dietary recall questionnaire at baseline and approximately 5 months later. Ten flavonoids, quercetin, isorhamnetin, tamarixetin, kaempferol, hesperetin, naringenin, eriodictyol, daidzein, genistein, and phloretin, were measured using HPLC-electrospray ionization-MS. Results: The 24 h urinary excretion of total flavonoids and the estimated intake of fruits were significantly correlated (r s ¼ 0.31, Po0.01). The dietary intake of citrus fruits and citrus juices was significantly correlated with total excretion of citrus specific flavonoids (r s ¼ 0.28, Po0.01), and orange was positively correlated with naringenin (r s ¼ 0.24, Po0.01) and hesperetin (r s ¼ 0.24, Po0.01). Phloretin in urine was correlated with apple intake (r s ¼ 0.22, Po0.01) and also with overall estimated intake of fruit (r s ¼ 0.22, Po0.01). Conclusions: This study shows that a 24 h dietary recall can be used as a valid estimate of the intake of fruits in agreement with an objective biomarker of fruit intake in free fruit at workplace interventions.

The bioavailability and urinary excretion of three dietary flavonoids, quercetin, hesperetin and naringenin, were investigated. Ten healthy men were asked to consume a 'juice mix' containing equal amounts of the three flavonoids, and their urine and plasma samples were collected. The resulting mean plasma area under the curve (AUC) 0À48h and C max values for quercetin and hesperetin were similar, whereas the AUC 0À48h of naringenin and, thus, the relative bioavailability were higher after consumption of the same dose. The study consolidates a significantly lower urinary excretion of quercetin (1.5 ± 1%) compared with hesperetin (14.2±9.1%) and naringenin (22.6±11.5%) and shows that this is not due to a lower bioavailability of quercetin, but rather reflects different clearance mechanisms. ( To compare the impact of dietary important flavonoids, it is necessary to study them in the same food matrix and at similar realistic doses. The present study investigates the bioavailability and urinary excretion of the flavonoids, quercetin, hesperetin and naringenin, in a 48-h intervention study with a single dose (6.3 ml/kg b.w.) of 'juice mix' containing the three flavonoids. European Journal of Clinical NutritionComplete urine and plasma samples were obtained from 10 healthy men, aged 21-28 years. The study was approved by the ethics committee of Copenhagen and Frederiksberg municipality (J.No.(KF)01-161/01). The 'juice mix' was provided to fasting individuals in the morning, along with a standardized flavonoid-free diet (0-24 h), after which the individuals maintained a flavonoid-free diet (24-48 h). Blood and urine samples were collected as described previously (Nielsen et al., 2006). Flavonoid aglycones were quantified in the 'juice mix' (30 mg/l quercetin, 28 mg/l naringenin and 32 mg/l hesperetin) and flavonoid glycosides in the 'juice mix' were identified according to Breinholt et al. (2003).Flavonoids in plasma were completely hydrolysed as described in Nielsen et al. (2006). Plasma samples were added 25 ml aqueous ascorbic acid (20 mg/ml) and 0.5% formic acid to pH ¼ 4 and applied to Evolute ABN columns (25 mg, Mikrolab, Aarhus, Denmark). The eluted flavonoid aglycones were evaporated to dryness and re-dissolved in 200 ml 0.5% formic acid and 10% methanol, and 250 ng 13 C-daidzein was added as external standard.Determination of flavonoids in urine is essentially described elsewhere (Nielsen et al., 2006), except for the inclusion of solid-phase extraction (Isolute SPE 100, Mikrolab) before injection into the liquid chromatographymass spectrometry system. Statistical analyses were performed using Wilcoxon matched pair tests (SPSS version 14.0). The relative

The results in this study indicate that the urinary excretion of ITCs, measured by use of the cyclocondesation reaction, is a useful and precise tool that may be used as a biomarker of ITC exposure in population based studies.