A case study evaluation of competitors undertaking an antarctic ultra-endurance event: nutrition, hydration and body composition variables

Background: The nutritional demands of ultra-endurance racing are well documented. However, the relationship between nutritional consumption and performance measures are less obvious for athletes competing in Polar conditions. Therefore, the aim of this study was to evaluate dietary intake, hydration status, body composition and performance times throughout an 800-km Antarctic race. Methods: The event organisers declared that 17 competitors would participate in the South Pole race. Of the 17 competitors, pre-race data were collected from 13 participants (12 males and 1 female (M±SD): age: 40.1±8.9 years; weight 83.9±10.3kg; and body fat percentage: 21.9±3.8%). Dietary recall, body composition and urinary osmolarity were assessed pre-race, midway checkpoint and end race. Data were compared on the basis of fast finishers (the Norwegian team (n=3) who won in a record of 14 day) and slower finishers (the remaining teams (n=10) reaching the South Pole between 22 and 28 days). Results: The percentage contribution of macronutrients to daily energy intake for all participants was as follows: carbohydrate (CHO) - 23.7% (221±82 g.day-1), fat = 60.6% (251±127g.day-1) and protein = 15.7% (117±52g.day-1). Energy demands were closer met by faster finishers compared to slower finishers (5,332±469 vs. 3,048±1,140kcal.day-1, p=0.02). Average reduction in body mass throughout the race was 8.3±5.5kg, with an average loss of lean mass of 2.0±4.1kg. There as a significant negative correlation between changes in lean mass and protein intake (p=0.03), and lean mass and energy intake (p=0.03). End-race urinary osmolarity was significantly elevated for faster finishers compared to slower finishers and control volunteers (faster finishers: 933±157mOsmol.L-1; slower finishers: 543±92mOsmol.L-1; control: 515±165mOsmol.L-1, p+0.04). Conclusions: Throughout the race, both groups were subjected to a negative change in energy balance which partly explained reduced body mass. Carbohydrate availability was limited inferring a greater reliance on fat and protein metabolism. Consequently, loss in fat-free mass was more prevalent with insufficient protein and caloric intake, which may relate to performance

Legumes as food ingredient: characterization, processing, and applications

Editores: Jiménez-López, José Carlos (CSIC); Clemente, Alfonso (CSIC

Prostatic and Peripheral Blood Selenium Levels After Oral Supplementation

Purpose: The dietary trace element selenium has been proposed to be a potential chemopreventive agent for prostate cancer. Epidemiological studies have suggested an inverse association between blood selenium and prostate cancer incidence. However, to our knowledge no study to date has examined selenium absorption by the prostate. Therefore, we determine whether oral selenium supplementation alters selenium levels within the prostate and/or peripheral blood. Materials and Methods: In this prospective trial 51 men undergoing transurethral resection of the prostate for benign prostatic hyperplasia were randomly assigned to serve as controls or receive 200 μg selenium daily orally for 1 month. Sample size was calculated to detect a difference of 30 ng/gm in prostate tissue with a power of 80%. Peripheral blood was obtained at enrollment and subsequently at surgery, when prostate tissue was also sampled. Selenium levels were determined using inductively coupled plasma mass spectrometry. Results: Baseline erythrocyte selenium was within the standard reference range. Supplementation increased erythrocyte (initial median 173 and final median 209 ng/ml, p = 0.008) and prostate (supplement median 241 and control median 196 ng/gm, p = 0.016) levels. Erythrocyte levels at surgery correlated poorly with prostate levels in the control (r = 0.18) and supplement (r = 0.07) groups. Conclusions: Oral selenium supplementation increases prostatic and peripheral blood levels in men in a nonselenium deficient population. Blood and prostate levels correlated poorly, suggesting that peripheral blood measurements are a poor indicator of prostatic selenium content

Micronutrient intakes in enterally and orally fed children with severe cerebral palsy

Background & aims: This study aims to investigate micronutrient balance in children with Cerebral Palsy (CP), due to a paucity of this literature and their well documented issues with undernutrition. Methods: Twenty-one children aged 4-12 years with marked CP fed orally (O, n = 12) or enterally (PEG, n = 9) were recruited, including age matched typically developing children (C, n = 16). Parents collected three consecutive days food replica of their child's actual intake and the contents directly analysed. Values were calculated as percentage (%) of Estimated Average Requirement (EAR) or Adequate Intake (AI) where applicable. Results: Micronutrient intakes varied widely. Significant differences were found for Zinc: mean(±SD%) between PEG = 379(153) versus both O = 185(67) and C = 171(54) p < 0.001 and Iron: PEG = 311(93) versus O = 110(54) and C = 179(108), p = 0.001 and Copper: PEG = 162(±70); O = 44(±30); C = 78(±23) p < 0.001. Many O and C consumed insufficient iodine or calcium, including less than AI in potassium and manganese. Sodium intakes in 6/16 C were in excess of upper safety limits and 4/9 PEG consumed excessive Zinc. Conclusions: Micronutrients have the potential to competitively inhibit one another in excess or deficiency through limiting their metabolism. In light of this, further investigations should assess the physiological impact of dietary imbalances, particularly in populations with limitations in their food consumption. © 2011 European Society for Clinical Nutrition and Metabolism