Antioxidant supplementation and endurance training: Win or loss?

Typically, free radicals are thought of as perpetrators of cell damage, ageing, even cancer, whereas antioxidants are seen as the defence against these threats. Accordingly, antioxidants are among the most common sports supplements used by amateur and professional athletes. However, the sensibility of this practice has recently been challenged in the scientific literature. This article briefly summarizes both positive and negative physiological effects of free radicals and antioxidants, culminating with emphasis on the signalling roles played by free radicals during training adaptations and the ability of superfluous antioxidants to weaken these desired signals, as revealed in several recent publications. The aim of this article is not to explicitly condemn antioxidant supplementation by athletes, but to underscore complexity of the situation and to champion efforts to achieve a deeper understanding of circumstances (e.g. dosage, timing, and setting) that might deem antioxidant supplementation as either largely beneficial or largely detrimental for endurance athletes in training.

Selenium for preventing cancer

Selenium is a trace element essential to humans. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers.

Sudden Increase and Regrowth of Fecal Coliforms and Escherichia Coli in Wastewater Biosolids After High Solids Centrifugation

Treatment plants that operate either thermophilic or mesophilic anaerobic digesters with centrifugal dewatering processes have consistently observed densities of fecal coliform and Escherichia coli, both indicator bacteria, that decrease during digestion but then increase after dewatering and storage. The increases have been characterized as two separate phenomena to explain this observation: 1) “Sudden Increase,” or SI, which is defined as the increase that occurs immediately after dewatering and 2) “regrowth,” which is defined as an increase during storage of cake samples over a period of hours or days. The SI observation appears to be more prevalent with biosolids that are generated with thermophilic processes and dewatered by centrifugation. Both thermophilic and mesophilic digesters with centrifuge dewatering processes have observed the regrowth phenomena. This research hypothesizes that the SI phenomenon is due to the presence of viable nonculturable (VNC) bacteria that are reactivated during dewatering. In other words, the bacteria were always present but were not enumerated by standard culturing methods (SCM). Analysis of the E. coli density in thermally treated solids by SCMs and quantitative real-time polymerase chain reaction (qPCR) indicated that E. coli densities are often underestimated by SCM. When analyzed with qPCR, the E. coli density after digestion can be 4-5 orders of magnitude greater than the non-detect levels identified by SCMs, which supports the non-culturable hypothesis. The VNC state describes a condition where bacteria are alive but unable to sustain the metabolic process needed for cellular division. Supplements added to culturing media were investigated to determine if the resuscitation of VNC bacteria could be enhanced. The autoinducer molecules Nhexanoyl- L-Homoserine lactone (C6-HSL), 3-oxo-N-octanoyl-L-Homoserine lactone (3-oxo- C8-HSL), and norepinephrine were unable to induce the resuscitation of VNC E. coli. Additional sampling was performed to determine if autoinducer molecules, peroxides, or other as of yet unknown inhibitory agents and toxins could be removed from biosolids during SCM. Culture media supplemented with the peroxide degrading compounds catalase, α-ketoglutaric acid, and sodium pyruvate was unable to resuscitate non-culturable E. coli. The additions of bentonite and exponential growth phase E. coli cell-free supernatant to culturing media were also unable to increase the culturability of E. coli. To remove inhibitory agents and toxins, a cell washing technique was employed prior to performing SCM; however, this cell washing technique may have increased cellular stresses that inhibited resuscitation since cell densities decreased. A novel laboratory-scale dewatering process was also investigated to determine if the SI and regrowth phenomena observed in full-scale centrifugal dewatering could be mimicked in the laboratory using a lab shearing device. Fecal coliform and E. coli densities in laboratory prepared cake samples were observed to be an order of magnitude higher than full-scale dewatered cakes. Additionally, the laboratory-scale dewatering process was able to resuscitate fecal coliforms and E. coli in stored sludge such that the density increased by 4-5 orders of magnitude from nondetect values. Lastly, the addition of aluminum sulfate during centrifuge dewatering at a full-scale utility produced an increased regrowth of fecal coliforms and E. coli that was sustained for 5 days.

ESPEN Guidelines on Enteral Nutrition: Geriatrics

Nutritional intake is often compromised in elderly, multimorbid patients. Enteral nutrition (EN) by means of oral nutritional supplements (ONS) and tube feeding (TF) offers the possibility to increase or to insure nutrient intake in case of insufficient oral food intake. The present guideline is intended to give evidence-based recommendations for the use of ONS and TF in geriatric patients. It was developed by an interdisciplinary expert group in accordance with officially accepted standards and is based on all relevant publications since 1985. The guideline was discussed and accepted in a consensus conference. EN by means of ONS is recommended for geriatric patients at nutritional risk, in case of multimorbidity and frailty, and following orthopaedic-surgical procedures. In elderly people at risk of undernutrition ONS improve nutritional status and reduce mortality. After orthopaedic-surgery ONS reduce unfavourable outcome. TF is clearly indicated in patients with neurologic dysphagia. In contrast, TF is not indicated in final disease states, including final dementia, and in order to facilitate patient care. Altogether, it is strongly recommended not to wait until severe undernutrition has developed, but to start EN therapy early, as soon as a nutritional risk becomes apparent.

Alendronate with and without cholecalciferol for osteoporosis: results of a 15-week randomized controlled trial

OBJECTIVE: Many osteoporosis patients have low 25-hydroxyvitamin D (25OHD) and do not take recommended vitamin D amounts. A single tablet containing both cholecalciferol (vitamin D3) and alendronate would improve vitamin D status concurrently, with a drug shown to reduce fracture risk. This study assessed the efficacy, safety, and tolerability of a once-weekly tablet containing alendronate 70 mg and cholecalciferol 70 microg (2800 IU) (ALN + D) versus alendronate 70 mg alone (ALN). METHODS: This 15-week, randomized, double-blind, multi-center, active-controlled study was conducted during a season when 25OHD levels are declining, and patients were required to avoid sunlight and vitamin D supplements for the duration of the study. Men (n = 35) and postmenopausal women (n = 682) with osteoporosis and 25OHD >or= 9 ng/mL were randomized to ALN + D (n = 360) or ALN (n = 357). MAIN OUTCOME MEASURES: Serum 25OHD, parathyroid hormone, bone-specific alkaline phosphatase (BSAP), and urinary N-telopeptide collagen cross-links (NTX). RESULTS: Serum 25OHD declined from 22.2 to 18.6 ng/mL with ALN (adjusted mean change = -3.4; 95% confidence interval [CI]: -4.0 to -2.8), and increased from 22.1 to 23.1 ng/mL with ALN + D (adjusted mean change = 1.2; 95% CI: 0.6 to 1.8). At 15 weeks, adjusted mean 25OHD was 26% higher (p < 0.001, ALN + D versus ALN), the adjusted relative risk (RR) of 25OHD < 15 ng/mL (primary endpoint) was reduced by 64% (incidence 11% vs. 32%; RR = 0.36; 95% CI: 0.27 to 0.48 [p < 0.001]), and the RR of 25OHD < 9 ng/mL (a secondary endpoint) was reduced by 91% (1% vs. 13%; RR = 0.09; 95% CI: 0.03 to 0.23 [p < 0.001]). Antiresorptive efficacy was unaltered, as measured by reduction in bone turnover (BSAP and NTX). CONCLUSION: In osteoporosis patients who avoided sunlight and vitamin D supplements, this once-weekly tablet containing alendronate and cholecalciferol provided equivalent antiresorptive efficacy, reduced the risk of low serum 25OHD, improved vitamin D status over 15 weeks, and was not associated with hypercalcemia, hypercalciuria or other adverse findings, versus alendronate alone.

Dietary supplementation with the tribomechanically activated zeolite clinoptilolite in immunodeficiency: effects on the immune system

Natural zeolites are crystalline aluminosilicates with unique adsorption, cation-exchange, and catalytic properties that have multiple uses in industry and agriculture. TMAZ, a natural zeolite clinoptilolite with enhanced physicochemical properties, is the basis of the dietary supplements Megamin and Lycopenomin, which have demonstrated antioxidant activity in humans. The aim of this prospective, open, and controlled parallel-group study was to investigate the effects of supplementation with TMAZ on the cellular immune system in patients undergoing treatment for immunodeficiency disorder. A total of 61 patients were administered daily TMAZ doses of 1.2 g (Lycopenomin) and 3.6 g (Megamin) for 6 to 8 weeks, during which the patients' primary medical therapy was continued unchanged. Blood and lymphocyte counts were performed at baseline and at the end of the study. Blood count parameters were not relevantly affected in either of the two treatment groups. Megamin administration resulted in significantly increased CD4+, CD19+, and HLA-DR+ lymphocyte counts and a significantly decreased CD56+ cell count. Lycopenomin was associated with an increased CD3+ cell count and a decreased CD56+ lymphocyte count. No adverse reactions to the treatments were observed.

gamma-tocopherol, the major form of vitamin E in the US diet, deserves more attention

gamma-tocopherol is the major form of vitamin E in many plant seeds and in the US diet, but has drawn little attention compared with alpha-tocopherol, the predominant form of vitamin E in tissues and the primary form in supplements. However, recent studies indicate that gamma-tocopherol may be important to human health and that it possesses unique features that distinguish it from alpha-tocopherol. gamma-Tocopherol appears to be a more effective trap for lipophilic electrophiles than is alpha-tocopherol. gamma-Tocopherol is well absorbed and accumulates to a significant degree in some human tissues; it is metabolized, however, largely to 2,7,8-trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman (gamma-CEHC), which is mainly excreted in the urine. gamma-CEHC, but not the corresponding metabolite derived from alpha-tocopherol, has natriuretic activity that may be of physiologic importance. Both gamma-tocopherol and gamma-CEHC, but not alpha-tocopherol, inhibit cyclooxygenase activity and, thus, possess antiinflammatory properties. Some human and animal studies indicate that plasma concentrations of gamma-tocopherol are inversely associated with the incidence of cardiovascular disease and prostate cancer. These distinguishing features of gamma-tocopherol and its metabolite suggest that gamma-tocopherol may contribute significantly to human health in ways not recognized previously. This possibility should be further evaluated, especially considering that high doses of alpha-tocopherol deplete plasma and tissue gamma-tocopherol, in contrast with supplementation with gamma-tocopherol, which increases both. We review current information on the bioavailability, metabolism, chemistry, and nonantioxidant activities of gamma-tocopherol and epidemiologic data concerning the relation between gamma-tocopherol and cardiovascular disease and cancer.

gamma-tocopherol traps mutagenic electrophiles such as NO(X) and complements alpha-tocopherol: physiological implications

Peroxynitrite, a powerful mutagenic oxidant and nitrating species, is formed by the near diffusion-limited reaction of .NO and O2.- during activation of phagocytes. Chronic inflammation induced by phagocytes is a major contributor to cancer and other degenerative diseases. We examined how gamma-tocopherol (gammaT), the principal form of vitamin E in the United States diet, and alpha-tocopherol (alphaT), the major form in supplements, protect against peroxynitrite-induced lipid oxidation. Lipid hydroperoxide formation in liposomes (but not isolated low-density lipoprotein) exposed to peroxynitrite or the .NO and O2.- generator SIN-1 (3-morpholinosydnonimine) was inhibited more effectively by gammaT than alphaT. More importantly, nitration of gammaT at the nucleophilic 5-position, which proceeded in both liposomes and human low density lipoprotein at yields of approximately 50% and approximately 75%, respectively, was not affected by the presence of alphaT. These results suggest that despite alphaT's action as an antioxidant gammaT is required to effectively remove the peroxynitrite-derived nitrating species. We postulate that gammaT acts in vivo as a trap for membrane-soluble electrophilic nitrogen oxides and other electrophilic mutagens, forming stable carbon-centered adducts through the nucleophilic 5-position, which is blocked in alphaT. Because large doses of dietary alphaT displace gammaT in plasma and other tissues, the current wisdom of vitamin E supplementation with primarily alphaT should be reconsidered.