Implementation of a microplate based assay for the assessment of the oxygen radical absorbance capacity (ORAC)

Das erste Ziel der Diplomarbeit war die Entwicklung einer auf Mikrotiterplatten basierten Methode zur Erfassung der Oxygen-radical-absorbance-capacity (ORAC).Der zweite Ansatz umfasste die Bestimmung der antioxidativen Kapazität im Plasma von Ironmantriathleten innherhalb des FWF finanzierten Projektes "Risk- assessment of Ironman-triathlon participants". Die Verwendung des Mikroplattenlesegerätes FLUOstar Optima in Kombination mit 96-well Platten ermöglichte eine hohe Probendurchsatzrate, 100 Proben/Tag. Mit Hilfe der gewählten Methode wurde die antioxidative Aktivität im Plasma von 42 Ironmantriathleten bestimmt. Die erfaßten ORAC Werte trugen zur Aufklärung der komplexen Beziehung zwischen freien Radikalen und Antioxidantien nach intensiver physischer Belastung bei. Dafür wurden Blutproben von gut trainierten Triathleten entnommen und die Oxygen-radical-absorbance-capacity 2 Tage vor dem Ironmantriathlon, 20 Minuten, 1, 5, und 19 Tage nach dem Bewerb gemessen. Der ORAC Test liefert reproduzierbare Ergebnisse und zeigt eine gute Linearität zwischen Konzentration und Fluoreszenz. Bezieht man die ORAC Werte auf das Studienkollektiv, zeigte sich ein Anstieg der antioxidativen Kapazität unmittelbar nach dem Bewerb. Einen Tag nach dem Bewerb lagen die Werte immer noch signifikant über den Ausgangswert. Nach fünf Tagen näherten sie sich wieder dem Ausgangsniveau.Die eingesetzte Methode ist für die Erfassung der antioxidativen Kapazität im Plasma gut geeignet und ist mit der standardmäßigen Ausstattung eines Labors durchführbar. Außerdem erwies sich die Methode als kostengünstig, schnell und einfach in der Handhabung. Die vorliegende Arbeit zeigt, dass gut trainierte Athle- ten nach einem Ironmantriathlon keinen persistenten oxidativen Stress ausgesetzt sind. Dieser Effekt ist wahrscheinlich auf eine trainingsinduzierte Adaptierung des antioxidativen Systems zurückzuführen.The first objective of the thesis was the application of a microplate based assay for the assessment of the oxygen radical absorbance capacity (ORAC). The second objective was referred to the detection and validation of the antioxidant capacity in plasma samples of well trained Ironman-triathletes, within the FWF fundend project "Risk-assessment of Ironman-triathlon participants". The use of the device FLUOstar Optima in combination with 96-well microplates allowed a high sample throughput of 100 samples a day. Within the applied method we determined the antioxidant capacity in plasma of 42 Ironman-triathletes. The measured ORAC values contributed to the elucidation of the complex relationship between free radicals and antioxidants after a single bout of ultra endurance exercise. Therefore, the blood samples of the well trained triathletes of 5 different time points (prerace, 20minutes postrace, 1d, 5d, 19d postrace) were analysed. The ORAC assay provides a good linear relationship between concentration and fluorescence. Concerning the study collective the ORAC values increased significantly immediately postrace and remained higher until 1d postrace. After five days, ORAC values returned to prerace concentrations. The applied method offers a good index of antioxidant capacity in biological fluids within the technological equipment of every laboratory. Moreover it is inexpensive, reagents are simple to prepare and the procedure is fast. The data of the current work demonstrates that there is no persistent oxidative stress in well trained athletes after an Ironman triathlon, probably due to training and exercise induced adaptions of the antioxidant defense system

Factors affecting fruit and vegetable consumption and purchase behavior of adults in sub-Saharan Africa:A rapid review

In order to achieve the Sustainable Development Goals, considerable dietary shifts, including an increase in the consumption of fruit and vegetables (FV) will be required. However, worldwide consumption of FV is far below international recommendations, including in many low- and middle-income countries (LMICs), particularly in Africa. Understanding what, where, when, and how people choose to eat requires an understanding of how individuals are influenced by factors in their social, physical, and macro-level environments. In order to develop effective interventions to increase fruit and vegetable consumption, the factors influencing consumer behavior need to be better understood. We conducted a rapid review to assess and synthesize data on individual, social, physical, and macro-level factors that enable or constrain fruit and vegetable consumption and purchase among adults living in sub-Saharan Africa. Our conceptual framework is based on a socio-ecological model which has been adapted to settings in LMICs and Africa. We systematically searched four electronic databases including Scopus, Medline (PubMed), PsycInfo, and African Index Medicus, and screened Google Scholar for gray literature. We included a total of 52 studies and narratively summarized the existing evidence for each identified factor across the different levels. We found that most studies assessed demographic factors at the individual level including household or family income, socio-economic status and education. Furthermore we identified a variety of important factors that influence FV consumption, in the social, physical, and macro environment. These include women's empowerment and gender inequalities, the influence of neighborhood and retail food environment such as distance to market and price of FV as well as the importance of natural landscapes including forest areas for FV consumption. This review identified the need to develop and improve indicators both for exposure and outcome variables but also to diversify research approaches

Importance of cattle biodiversity and its influence on the nutrient composition of beef

Livestock make a substantial contribution to achieving food and nutrition security due to various factors including the high nutritional quality of animal-source foods. Conservation and sustainable use of cattle genetic resources are important due to the multiple benefits provided by local breeds. These benefits include multiple direct uses, additional market value provided by specialty products, social and cultural roles, and adaptations that local breeds have to climate and diseases in harsh environments. Meat composition varies across cattle breeds. Whereas genetics play a role in this variation, management practices, such as diet, and other environmental factors also affect nutrient composition. Compositional data for cattle breeds have been added to the FAO/INFOODS Food Composition Database for Biodiversity. The database is publicly available and has value for use by researchers, nutritionists, producers, the general public and other stakeholders. More compositional data, including amino acids, minerals, and vitamins, are needed from local breeds in order to understand better the nutritional benefits of sustainably managing animal genetic resources

Determining appropriate interventions to mainstream nutritious orphan crops into African food systems

Nutritious ‘orphan’ crops could (re)diversify African food systems, but appropriate means to bring this about are required. A review of the literature on crop intervention options suggested success and failure factors in promotion, but indicated little about the relative importance of production-versus consumption-based measures and how these interact. An analysis of secondary crop production data indicated that addressing food policies could be valuable for orphan crop mainstreaming, but, as with literature review, did not provide clear guidance on the importance of different interventions. A survey of experts suggested that cross-disciplinary teams are important for developing mainstreaming strategies, but revealed no clear consensus on the importance of particular measures for specific orphan crops. We discuss the implications of these findings

Antioxidant responses to an acute ultra-endurance exercise: Impact on DNA stability and indications for an increased need for nutritive antioxidants in the early recovery phase

Antioxidant requirements have neither been defined for endurance nor been defined for ultra-endurance athletes. To verify whether an acute bout of ultra-endurance exercise modifies the need for nutritive antioxidants, we aimed (1) to investigate the changes of endogenous and exogenous antioxidants in response to an Ironman triathlon; (2) to particularise the relevance of antioxidant responses to the indices of oxidatively damaged blood lipids, blood cell compounds and lymphocyte DNA and (3) to examine whether potential time-points of increased susceptibility to oxidative damage are associated with alterations in the antioxidant status. Blood that was collected from forty-two well-trained male athletes 2 d pre-race, immediately post-race, and 1, 5 and 19 d later was sampled. The key findings of the present study are as follows: (1) Immediately post-race, vitamin C, alpha-tocopherol, and levels of the Trolox equivalent antioxidant capacity, the ferric reducing ability of plasma and the oxygen radical absorbance capacity (ORAC) assays increased significantly. Exercise-induced changes in the plasma antioxidant capacity were associated with changes in uric acid, bilirubin and vitamin C. (2) Significant inverse correlations between ORAC levels and indices of oxidatively damaged DNA immediately and 1 d post-race suggest a protective role of the acute antioxidant responses in DNA stability. (3) Significant decreases in carotenoids and gamma-tocopherol 1 d post-race indicate that the antioxidant intake during the first 24 h of recovery following an acute ultra-endurance exercise requires specific attention. Furthermore, the present study illustrates the importance of a diversified and well-balanced diet to maintain a physiological antioxidant status in ultra-endurance athletes in reference to recommendations

DNA damage in response to an Ironman triathlon

The major aims of this study were to investigate the effect of an Ironman triathlon on DNA migration in the single cell gel electrophoresis assay, apoptosis and necrosis in the cytokinesis-block micronucleus cytome assay with lymphocytes and on changes of total antioxidant capacity in plasma. Blood samples were taken 2 days (d) before, within 20 min, 1 d, 5 d and 19 d post-race. The level of strand breaks decreased (p<0.05) immediately after the race, then increased (p<0.01) 1 d post-race and declined (p<0.01) until 19 d post-race. Apoptotic and necrotic cells decreased (p<0.01) and the total antioxidant status increased (p<0.01) immediately after the race. The results indicate that ultra-endurance exercise does not cause prolonged DNA damage in well-trained male athletes

Importance of cattle biodiversity and its influence on the nutrient composition of beef

Livestock make a substantial contribution to achieving food and nutrition security due to various factors including the high nutritional quality of animal-source foods. Conservation and sustainable use of cattle genetic resources are important due to the multiple benefits provided by local breeds. These benefits include multiple direct uses, additional market value provided by specialty products, social and cultural roles, and adaptations that local breeds have to climate and diseases in harsh environments. Meat composition varies across cattle breeds. Whereas genetics play a role in this variation, management practices, such as diet, and other environmental factors also affect nutrient composition. Compositional data for cattle breeds have been added to the FAO/INFOODS Food Composition Database for Biodiversity. The database is publicly available and has value for use by researchers, nutritionists, producers, the general public and other stakeholders. More compositional data, including amino acids, minerals, and vitamins, are needed from local breeds in order to understand better the nutritional benefits of sustainably managing animal genetic resources. This article is from Animal Frontiers 2 (2012): 54–60, doi:10.2527/af.2012-0062.</p

2. Understanding the Roles of Forests and Tree-based Systems in Food Provision

Forests and other tree-based systems such as agroforestry contribute to food and nutritional security in myriad ways. Directly, trees provide a variety of healthy foods including fruits, leafy vegetables, nuts, seeds and edible oils that can diversify diets and address seasonal food and nutritional gaps. Forests are also sources of a wider range of edible plants and fungi, as well as bushmeat, fish and insects. Tree-based systems also support the provision of fodder for meat and dairy animals..

Forests and Food

As population estimates for 2050 reach over 9 billion, issues of food security and nutrition have been dominating academic and policy debates. A total of 805 million people are undernourished worldwide and malnutrition affects nearly every country on the planet. Despite impressive productivity increases, there is growing evidence that conventional agricultural strategies fall short of eliminating global hunger, as well as having long-term ecological consequences. Forests can play an important role in complementing agricultural production to address the Sustainable Development Goals on zero hunger. Forests and trees can be managed to provide better and more nutritionally-balanced diets, greater control over food inputs–particularly during lean seasons and periods of vulnerability (especially for marginalised groups)–and deliver ecosystem services for crop production. However forests are undergoing a rapid process of degradation, a complex process that governments are struggling to reverse. Forests have huge potential to reduce global hunger and malnutrition. Forests and Food provides the evidence and insights necessary for harnessing that power. This timely volume is essential reading for researchers, students, NGOs and governments around the globe