Selenium biochemistry and its role for human health

Despite its very low level in humans, selenium plays an important and unique role among the (semi)metal trace essential elements because it is the only one for which incorporation into proteins is genetically encoded, as the constitutive part of the 21st amino acid, selenocysteine. Twenty-five selenoproteins have been identified so far in the human proteome. The biological functions of some of them are still unknown, whereas for others there is evidence for a role in antioxidant defence, redox state regulation and a wide variety of specific metabolic pathways. In relation to these functions, the selenoproteins emerged in recent years as possible biomarkers of several diseases such as diabetes and several forms of cancer. Comprehension of the selenium biochemical pathways under normal physiological conditions is therefore an important requisite to elucidate its preventing/therapeutic effect for human diseases. This review summarizes the most recent findings on the biochemistry of active selenium species in humans, and addresses the latest evidence on the link between selenium intake, selenoproteins functionality and beneficial health effects. Primary emphasis is given to the interpretation of biochemical mechanisms rather than epidemiological/observational data. In this context, the review includes the following sections: (1) brief introduction; (2) general nutritional aspects of selenium; (3) global view of selenium metabolic routes; (4) detailed characterization of all human selenoproteins; (5) detailed discussion of the relation between selenoproteins and a variety of human diseases

Experimental results of the effects of Hungarian climatic conditions to German disease-resistant industrial apple varieties

In the recent years, several disease-resistant apple varieties appeared through the modern breeding technologies. These varieties can be grown with low usage of pesticides, which mean not only environment friendly fruit growing, but the production costs are also lower. In Eastern-Hungary — it is one of the main apple growing regions — a new apple growing structure started to form by the investment of the German Wink Ltd. — several resistant apple varieties were brought from Germany. 'Resistant' refers genetic resistance that usually transferred from the genome of wild apple species. But the fruit of these apple species is not only resistant to diseases, but its quality is poorer, too. In Germany the Re-apples are grown only for the processing industry. Due to climatic circumstances in Eastern Hungary, the first experiences showed better parameters during laboratory measurement, the fruits have more beautiful view, shape and inner characters than usual industrial apples. In our paper we discuss the results of sensory (consumer) tests, carried out in Eastern Hungary and in the Budapest-region the data analysis of systematic storing experiments (refraction, flesh firmness, weight loss, etc.) and profile analysis of fresh and stored Re-apples. (In the profile analysis the ProfiSens software [4,5] has been used.

No Effects of Organic and Conventional Diets on Intake and Absorption of Zinc and Copper in Men – Evidence from Two Cross-over Trials Using Stable Enriched Isotopes

Organic foods have been repeatedly claimed to have a superior nutrient content. However, effects of production method on absorption of nutrients in vivo remains understood. Our aim was to investigate the effects of organic and conventional diets on intake and absorption of zinc and copper in humans. A double-blind, cross-over, intervention trial (3 dietary periods of 12 days, separated with 2-week-long wash-out periods) was performed in 2008 (n=17) and 2009 (n=16) in young men. The diets were based on 9 crops grown in 2 organic and 1 conventional systems in 2 replications over 2 years. Primary outcomes were intake and apparent absorption of zinc and copper. The absorption was determined by fecal excretion of stable enriched isotopes extrinsically added to the entire menu. Within each year, intake and absorption of zinc (overall mean ± SD 12.35 ± 0.47 mg 10MJ-1 and 44.6% ± 12.1, respectively) and copper (overall mean ± SD 2.12 ± 0.28 mg 10MJ-1 and 41.2% ± 13.2, respectively) were not significantly different between the organic and conventional diets. Growing season had no effect on zinc intake and absorption. However, in 2008 copper intake was higher (P=0.01) and absorption lower (P<0.005) compared with 2009 (mean absorption ± SD; 35.3% ± 13.5 in 2008 and 54.0% ± 10.7 in 2009). Zinc and copper were well absorbed from the investigated diets. The consumption of organic diets did not improve apparent absorption of these trace elements compared with the conventional diets

Consumption of organic diets does not affect intake and absorption of zinc and copper in men–evidence from two cross-over trials

Organic foods have been repeatedly claimed to have a superior nutrient content. However, effects of production method on absorption of nutrients in vivo remains understood. Our aim was to investigate the effects of organic and conventional diets on intake and absorption of zinc and copper in humans. A double-blind, cross-over, intervention trial (3 dietary periods of 12 days, separated with 2-week-long wash-out periods) was performed in 2008 (n=17) and 2009 (n=16) in young men. The diets were based on 9 crops grown in 2 organic and 1 conventional systems in 2 replications over 2 years. Primary outcomes were intake and apparent absorption of zinc and copper. The absorption was determined by fecal excretion of stable enriched isotopes extrinsically added to the entire menu. Within each year, intake and absorption of zinc (overall mean ± SD 12.35 ± 0.47 mg 10MJ-1 and 44.6% ± 12.1, respectively) and copper (overall mean ± SD 2.12 ± 0.28 mg 10MJ-1 and 41.2% ± 13.2, respectively) were not significantly different between the organic and conventional diets. Growing season had no effect on zinc intake and absorption. However, in 2008 copper intake was higher (P=0.01) and absorption lower (P<0.005) compared with 2009 (mean absorption ± SD; 35.3% ± 13.5 in 2008 and 54.0% ± 10.7 in 2009). Zinc and copper were well absorbed from the investigated diets. The consumption of organic diets did not improve apparent absorption of these trace elements compared with the conventional diets