Introduction: The kinetics of protein oxidation, monitored in breath, and its contribution to the whole body protein status is not well established. Objectives: To analyze protein oxidation in various metabolic conditions we developed/validated a 13C-protein oxidation breath test using low enriched milk proteins. Method/Design: 30 g of naturally labeled 13C-milk proteins were consumed by young healthy volunteers. Breath samples were taken every 10 min and 13CO2 was measured by Isotope Ratio Mass Spectrometry. To calculate the amount of oxidized substrate we used: substrate dose, molecular weight and 13C enrichment of the substrate, number of carbon atoms in a substrate molecule, and estimated CO2-production of the subject based on body surface area. Results: We demonstrated that in 255 min 20% ± 3% (mean ± SD) of the milk protein was oxidized compared to 18% ± 1% of 30 g glucose. Postprandial kinetics of oxidation of whey (rapidly digestible protein) and casein (slowly digestible protein) derived from our breath test were comparable to literature data regarding the kinetics of appearance of amino acids in blood. Oxidation of milk proteins was faster than that of milk lipids (peak oxidation 120 and 290 minutes, respectively). After a 3-day protein restricted diet (~10 g of protein/day) a decrease of 31% ± 18% in milk protein oxidation was observed compared to a normal diet. Conclusions: Protein oxidation, which can be easily monitored in breath, is a significant factor in protein metabolism. With our technique we are able to characterize changes in overall protein oxidation under various meta-bolic conditions such as a protein restricted diet, which could be relevant for defining optimal protein intake under various conditions. Measuring protein oxidation in new-born might be relevant to establish its contribution to the protein status and its age-dependent development.
LINK
Voor het eerst in de geschiedenis van de mensheid zijn er meer mensen met overgewicht dan met ondervoeding. Overgewicht is in snel tempo toegenomen en is een van de grootste maatschappelijke (gezondheids)problemen van deze tijd. Overgewicht heeft ondervoeding overschaduwd. In "The land of plenty"’ is geen gebrek meer, en dus geen ondervoeding zou je verwachten. Ondervoeding blijkt echter ook in deze tijd nog steeds een van de grootste maatschappelijke (gezondheids). Door inactiviteit of door ziekte kan spiermassa afnemen en wordt het steeds lastiger ondervoeding door de laag vet heen te ontdekken. Het aanpakken van overgewicht en ondervoeding door de professional vergt goed gewichtsmanagement. Voeding en beweging spelen hierbij een cruciale rol. Energie uit de voeding is gerelateerd aan vetmassa, en eiwit uit de voeding en beweging is gerelateerd aan spiermassa
Een van de instrumenten voor de bepaling van de kwaliteit en van de aanwezigheid van opgetreden schade vormt het niet-destructief onderzoek (NDO), waarvan vele uitvoeringsvormen zijn ontwikkeld en waaraan binnen de kaders van de wetgeving en de in gebruik zijnde Codes zowel aan de apparatuur als aan de bediening eisen worden gesteld. Zo moeten ook de uitvoerders van NDO in de praktijk gecertificeerd zijn.
Along with the rapidly growing number of disabled people participating in competitive sports, there is an increased need for (para)medical support in disability sports. Disabled athletes experience differences in body composition, metabolism, training load and habitual activity patterns compared with non-disabled athletes. Moreover, it has been suggested that the well-recognized athlete triad, and low energy availability and low bone mineral density in particular, is even a greater challenge in disabled athletes. Therefore, it is not surprising that sport nutritionists of disabled athletes have expressed an urgency for increased knowledge and insights on the nutritional demands of this group. This project aims to investigate energy expenditure, dietary intake, body composition and bone health of disabled athletes, ultimately leading to nutritional guidelines that promote health and optimal sports performance for this unique population. For this purpose, we will conduct a series of studies and implementation activities that are inter-related and build on the latest insights from sports practice, technology and science. Our international consortium is highly qualified to achieve this goal. It consists of knowledge institutes including world-leading experts in sport and nutrition research, complemented with practical insights from nutritionists working with disabled athletes and the involvement of athletes and teams through the Dutch and Norwegian Olympic committees. The international collaboration, which is a clear strength of this project, is not only focused on research, but also on the optimization of professional practice and educational activities. In this regard, the outcomes of this project will be directly available for practical use by the (para)medical staff working with disabled athletes, and will be extensively communicated to sport teams to ensure that the new insights are directly embedded into daily practice. The project outcomes will also be incorporated in educational activities for dietetics and sport and exercise students, thereby increasing knowledge of future practitioners.
