Executive summary and conclusions from the European Hydration Institute Expert Conference on human hydration, health, and performance.

On April 7-8, 2014, the European Hydration Institute hosted a small group of experts at Castle Combe Manor House, United Kingdom, to discuss a range of issues related to human hydration, health, and performance. The meeting included 18 recognized experts who brought a wealth of experience and knowledge to the topics under review. Eight selected topics were addressed, with the key issues being briefly presented before an in-depth discussion. Presented here is the executive summary and conclusions from this meeting.

Evaluation of seasonality on total water intake, water loss and water balance in the general population in Greece.

BACKGROUND: Water balance is achieved when water intake from solid and fluid foods and drinking water meets water losses, mainly in sweat, urine and faeces. Seasonality, particularly in Mediterranean countries that have a hot summer, may affect water loss and consequently water balance. Water balance has not been estimated before on a population level and the effect of seasonality has not been evaluated. The present study aimed to compare water balance, intake and loss in summer and winter in a sample of the general population in Greece. METHODS: The Water Balance Questionnaire (WBQ) was used to evaluate water balance, estimating water intake and loss in summer (n = 480) and in winter (n = 412) on a stratified sample of the general population in Athens, Greece. RESULTS: In winter, mean (SD) water balance was -63 (1478) mL/day(-1) , mean (SD)water intake was 2892 (987) mL/day(-1) and mean (quartile range) water loss was 2637 (1810-3922) mL/day(-1) . In summer, mean (SD) water balance was -58 (2150) mL/day(-1) , mean (SD) water intake was 3875 (1373) mL/day(-1) and mean (quartile range) water loss was 3635 (2365-5258) mL/day(-1) . Water balance did not differ between summer and winter (P = 0.96); however, the data distribution was different; in summer, approximately 8% more participants were falling in the low and high water balance categories. Differences in water intake from different sources were identified (P < 0.05). CONCLUSIONS: Water balance in summer and winter was not different. However, water intake and loss were approximately 40% higher in summer than in winter. More people were falling in the low and high water balance categories in summer when comparing the distribution on water balance in winter.

Phytosterols supplementation decreases plasma small and dense LDL levels in metabolic syndrome patients on a westernized type diet.

BACKGROUND AND AIMS: Several studies have observed a hypocholesterolemic effect of plant sterols in hypercholesterolemic patients on a balanced diet. The aim of this study was to examine the effect of phytosterol supplementation on risk factors of coronary artery disease in metabolic syndrome patients on a Westernized type diet. METHODS AND RESULTS: In a randomized placebo-controlled design 108 patients with metabolic syndrome were assigned to consume either 2 plant sterol-enriched yogurt mini drink which provided 4 g phytosterols per day, or a yogurt beverage without phytosterols (control). The duration of the study was 2 months and the patients in both groups followed their habitual westernized type diet and recording it on food diaries. Blood samples were drawn at baseline and after 2 months of intervention. After 2 months supplementation with phytosterols, a significant reduction in total cholesterol, LDL-cholesterol, small and dense LDL (sdLDL) levels, as well as, apoB and triglycerides concentrations were observed in the intervention group (P < 0.05) compared to the control group. In addition, phytosterol supplementation lowered serum total cholesterol by 15.9%, LDL-cholesterol by 20.3% and triglyceride levels by 19.1% (P = 0.02, P < 0.001 and P < 0.001, respectively), although the patients kept their habitual westernized type diet. No differences were observed in HDL cholesterol, apoA1, glucose, C-reactive protein, fibrinogen levels and blood pressure. CONCLUSIONS: Phytosterol supplementation improves risk factors of coronary artery disease even if the diet is a westernized type.

Iron or zinc dialyzability obtained from a modified in vitro digestion procedure compare well with iron or zinc absorption from meals.

The dialyzability method has been considered a convenient option for screening a large number of samples for iron bioavailability. A new setup that allows the rapid and efficient application of the dialyzability method has been recently proposed. To evaluate the new setup for its applicability in predicting iron and zinc bioavailability, dialyzable iron or zinc were compared with iron or zinc absorption. A series of solutions and meals that have been employed in published studies on iron or zinc absorption were prepared as described in the literature and digested in vitro using the new setup. Dialyzability was measured and correlated with published data on absorption. Iron or zinc dialyzability measured with the proposed setup correlated well with iron or zinc absorption. These results suggest that the new setup can be employed in the future applications for the prediction of iron or zinc bioavailability.

EuroFIR eBASIS: application for health claims submissions and evaluations.

BACKGROUND: The European Food Information Resource (EuroFIR) network has established the eBASIS (Bioactive Substances in Food Information System) online food composition and biological effects database for plant-derived bioactive compounds (phytochemicals). On the basis of submitted evidence, the European Food Safety Authority (EFSA) expert panel on Dietetic Products, Nutrition and Allergies assesses whether claims made under articles 13.1, 13.5 or 14 of the Regulation (EC) 1924/2006, which governs the use of nutrition and health claims on foods, are scientifically justified. This report evaluates the eBASIS biological effects database in the preparation and evaluation of health claims dossiers. METHODS: The eBASIS biological effects database is a compilation of expert-evaluated data extracted from the literature, prioritizing human intervention studies to investigate health effects of phytochemicals. Currently included are >750 records from 445 studies providing data on 56 validated biomarkers, mainly relating to cardio-metabolic and bone health outcomes. The data cover 144 bioactive compounds from 17 compound classes. Using the EFSA Register of Questions and the database of general function health claims, we identified claims relating to phytochemicals made under articles 13.1, 13.5 and 14 and compared them with the eBASIS database to identify overlap between them. RESULTS: The EFSA online health claims database contains 4240 submissions under article 13.1, of which 2157 pertain to plants or plant-based bioactive compounds; 496 of these relate to plants or bioactive compounds included in the eBASIS biological effects database. Out of the 18 current 13.5 'new function' claims on EFSA's register of questions, 7 are for plants or plant-based bioactive compounds, of which 6 are included in eBASIS. Of the 222 defined article 14 claims, 21 pertain to plants or plant-based bioactive compounds, of which 19 are in eBASIS. CONCLUSIONS: There is extensive overlap between eBASIS and the submitted health claims that relate to plant-based bioactive compounds. EuroFIR eBASIS is a useful tool for regulators to independently check completeness of health claims applications relating to phytochemicals and is a potentially valuable resource to assist claimants in the compilation of dossiers on functional foods and health claims.

Iron loading and large doses of intravenous ascorbic acid promote lipid peroxidation in whole serum in guinea pigs.

Large doses of ascorbic acid may mobilise Fe from Fe-binding proteins in vivo which in turn could catalyse lipid peroxidation, a process associated with degenerative diseases. This hypothesis was tested in vitro in the serum of Fe-loaded animals. Eighteen male guinea pigs weighing about 500 g on arrival were allocated to two groups of nine. Fe loading was induced in one group by two intraperitoneal injections of 200 mg iron dextran given on days 1 and 5. Blood (6 ml) was drawn from all animals on day 12 by cardiac puncture. Serum and LDL were separated. Serum was tested for loosely-bound Fe (bleomycin assay) and lipid peroxidation (thiobarbituric acid reactive substances (TBARS) assay) and LDL for susceptibility to in vitro oxidation (TBARS and conjugated diene assays). On day 12, another intraperitoneal injection of 200 mg iron dextran was given to the animals in the Fe-loaded group. On day 19, all animals were given 75 mg ascorbic acid by intraperitoneal injection. Blood (6 ml) was drawn 4 h later by cardiac puncture. Serum and LDL assays were repeated. Ascorbic acid increased loosely-bound Fe and in vitro oxidation in the serum from animals of the Fe-loaded group but not in the serum from animals of the control group. Susceptibility of LDL to in vitro oxidation increased after the ascorbic acid injection in the control group but there was no further increase in the Fe-loaded group. These data suggest that large doses of ascorbic acid promote Fe mobilisation and in vitro oxidation in the serum of Fe-loaded animals.

Aqueous infusions of Mediterranean herbs exhibit antioxidant activity towards iron promoted oxidation of phospholipids, linoleic acid, and deoxyribose.

Reactive oxygen species (ROS) have been widely known to inflict biological damage upon a variety of biological sites. The ability to counteract any such activity has been the subject of this work, in an attempt to comprehend prooxidant metal ion induced oxidation and its possible physiological consequences. Five Mediterranean aqueous herb infusions have been employed in the investigation of possible pro/antioxidant activity promoted by prooxidant iron ions. In the presence of phospholipid liposomes or linoleic acid micelles or 2-deoxy-D-ribose, it was shown that all of the aqueous infusions used exhibited antioxidant activity in comparison to the iron control. The antioxidant activity, studied on 2-deoxy-D-ribose, at three concentration levels in each herb, appears to be dose dependent, albeit non-linear. The total polyphenol content of the investigated herb infusions, however, does not directly correlate with the observed antioxidant activity. The variable, yet effective, antioxidant capacity of the aqueous infusions indicates that their antioxidant components can quench ROS generating activity, brought on different substrates and likely arisen by variable mechanisms involving different ROS.

Lean beef and beef fat interact to enhance nonheme iron absorption in rats.

Nonheme iron absorption is enhanced when meat replaces non-meat protein sources in a meal. Our objective was to examine the hypothesis that both lean and fat fractions of meat contribute to this enhancement. Weanling rats were assigned, according to a 3 x 3 factorial design, to one of nine nutritionally complete diets formulated to contain various combinations of protein (lean beef, skim milk or egg white) and fat sources (beef fat, milk fat or partially hydrogenated vegetable fat). Diets contained 20% protein and 20% fat. After 4 d of consuming the assigned diets, the rats were deprived of food overnight and offered a meal of their respective diet labeled extrinsically with 59FeCl3. Feeding of the unlabeled diets was continued for 14 d. Iron absorption was estimated from 59Fe retention, monitored by whole-body counting over the 14-d period. Absorption was highest from diets containing beef regardless of the fat source, but the combination of beef and beef fat was highest of all. In the comparison of absorption from the lean beef and other diets, there was significant interaction between lean beef and fat source on iron absorption. These results suggest that the iron absorption-enhancing properties of meat may involve an interaction between the lean and fat fractions of meat.