1.
Consumption of calcium-fortified cereal bars to improve dietary calcium intake of healthy women: randomized controlled feasibility study.
Lee, JT, Moore, CE, Radcliffe, JD
PloS one. 2015;10(5):e0125207
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Calcium intake is essential to maintain bone heath and reduce the risk of osteoporosis, however most adult women are not meeting the current daily recommendations. The aim of this trial was to examine the benefits of including a non-dairy source of calcium in the diet of women during a 9-week crossover study. 35 women aged 21-58 were assigned to consume two calcium-fortified cereal bars daily for three weeks, after which diets were switched for another three weeks. Diet diaries were used to monitor intake. This study found that dietary calcium was significantly higher during the intervention period when two calcium-fortified cereal bars were consumed than during the baseline period. This addition did not increase total energy intake or result in weight gain. Further research is warranted to determine the whether consumption of calcium-fortified bars improves calcium bioavailability, and should monitor changes of bone health markers and bone density.
Abstract
UNLABELLED Calcium is an important structural component of the skeletal system. Although an adequate intake of calcium helps to maintain bone health and reduce the risk of osteoporosis, many women do not meet recommended daily intakes of calcium. Previous interventions studies designed to increase dietary intake of women have utilized primarily dairy sources of calcium or supplements. However, lactose intolerance, milk protein allergies, or food preferences may lead many women to exclude important dairy sources of dietary calcium. Therefore, we undertook a 9 week randomized crossover design trial to examine the potential benefit of including a non-dairy source of calcium in the diet of women. Following a 3 week run-in baseline period, 35 healthy women > 18 years were randomized by crossover design into either Group I or Group II. Group I added 2 calcium-fortified cereal bars daily (total of 400 mg calcium/day) (intervention) to their usual diet and Group II continued their usual diet (control). At the end of 3 weeks, diets were switched for another 3 weeks. Intakes of calcium and energy were estimated from 3-day diet and supplemental diaries. Wilcoxon signed-rank tests were used for within group comparisons and Mann Whitney U tests were used for between group comparisons of calcium and energy intake. Dietary calcium was significantly higher during intervention (1071 mg/d) when participants consumed 2 calcium-fortified cereal bars daily than during the baseline (720 mg/d, P <0.0001) or control diets (775 mg/d, P = 0.0001) periods. Furthermore, the addition of 2 calcium-fortified cereal bars daily for the 3 week intervention did not significantly increase total energy intake or result in weight gain. In conclusion, consumption of calcium-fortified cereal bars significantly increased calcium intake of women. Further research examining the potential ability of fortified cereal bars to help maintain and improve bone health of women is warranted. TRIAL REGISTRATION ClinicalTrials.gov NCT01508689.
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Physiologic and behavioral indicators of energy deficiency in female adolescent runners with elevated bone turnover.
Barrack, MT, Van Loan, MD, Rauh, MJ, Nichols, JF
The American journal of clinical nutrition. 2010;92(3):652-9
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Young female runners are more likely to have a low bone mass for their age. It is thought that this might be partly due to them using more energy (calories) than they consume. This study looked at the relationship between nutrition intake and biomarkers of bone turnover in young female runners. Participants were competitive cross-country runners, aged 14-17. The girls ate their usual diet and kept a food diary for a week, to allow the researchers to analyse their nutritional intakes. Runners that had an elevated bone turnover consumed significantly less calories and calcium than the runners with a normal bone turnover. They were also more likely to have a lower body mass, fewer menstrual cycles, lower oestrogen and vitamin D levels, lower BMI and lower bone mass. The authors concluded that nutritional support to increase energy and calcium intake, and vitamin D levels may improve bone growth in young female runners.
Abstract
BACKGROUND Female adolescent runners have an elevated prevalence of low bone mass for agemdashan outcome that may be partially due to inadequate energy intake. OBJECTIVE The objective was to evaluate diet, menstrual history, serum hormone concentrations, and bone mass in female adolescent runners with normal or abnormal bone turnover. DESIGN Thirty-nine cross-country runners (age: 15.7 plusmn 0.2 y) participated in the study, which included a 7-d dietary assessment with the use of a food record and daily 24-h dietary recalls; serum measures of insulin-like growth factor I, estradiol, leptin, parathyroid hormone, progesterone, triiodothyronine, 25-hydroxycholecalciferol, bone-specific alkaline phosphatase (BAP), and cross-linked C-telopeptides of type I collagen (CTX); an evaluation of height, weight, bone mass, and body composition with the use of dual-energy X-ray absorptiometry; and a questionnaire to assess menses and sports participation. Age- and sex-specific BAP and CTX concentrations of at least the 97th percentile and no greater than the third percentile, respectively, were considered abnormal. RESULTS All abnormal BAP and CTX concentrations fell within the elevated ( ge 97%) range. Runners with an elevated bone turnover (EBT) (n = 13) had a lower body mass, fewer menstrual cycles in the past year, lower estradiol and 25-hydroxycholecalciferol concentrations, and a higher prevalence of body mass index lt 10% for age, vitamin D insufficiency, amenorrhea, and low bone mass. Girls with EBT consumed less than the recommended amounts of energy and had a higher prevalence of consuming lt 1300 mg Ca than did those with normal bone turnover. CONCLUSIONS Runners with EBT had a profile consistent with energy deficiency. Nutritional support to increase energy, calcium intake, and 25-hydroxycholecalciferol concentrations may improve bone mineral accrual in young runners with EBT. This trial was registered at clinicaltrials.gov as NCT01059968.
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Gastrointestinal permeability during exercise: effects of aspirin and energy-containing beverages.
Lambert, GP, Broussard, LJ, Mason, BL, Mauermann, WJ, Gisolfi, CV
Journal of applied physiology (Bethesda, Md. : 1985). 2001;90(6):2075-80
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Many athletes use aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) for analgesia. This study of 17 subjects aimed to assess whether the use of aspirin with prolonged exercise could increase gastrointestinal permeability. It also aimed to examine whether consumption of a carbohydrate-containing or a carbohydrate and glutamine-containing beverage could reduce this effect. Authors concluded that acute aspirin consumption before prolonged exercise could increase gastroduodenal and intestinal permeability. They also indicated that gastroduodenal permeability was significantly decreased by the ingestion of carbohydrate-containing beverages and that consumption of carbohydrate containing glutamine beverage provided no additional benefits than the carbohydrate alone beverage.
Abstract
The purpose of this study was to determine whether aspirin (A) ingestion combined with prolonged exercise increases gastrointestinal permeability and whether consumption of a carbohydrate-containing (CHO) or a CHO + glutamine-containing (CHO+G) beverage would reduce this effect. Seventeen subjects completed six experiments. They ingested A (1,300 mg) or placebo (P) pills the evening before and before running 60 min at 70% maximal oxygen uptake. Also, before running they ingested a solution containing 5 g lactulose (L), 5 g sucrose (S), and 2 g rhamnose (R). During each trial, either a 6% CHO beverage, a 6% CHO+G (0.6%; 41 mM) beverage, or a water placebo (WP) was consumed. For 4 h after a run, all urine was collected to measure urinary excretion of L, R, and S. S excretion (percentage of dose ingested; measure of gastroduodenal permeability) was significantly greater (P < 0.05) during the A trial while the subjects drank the WP compared with all other trials. Administration of A also significantly increased L/R (measure of intestinal permeability) for the CHO and WP trials compared with all P trials. Ingestion the CHO or CHO+G beverages significantly reduced S excretion and L excretion when A was administered, but it did not reduce L/R. These results indicate that gastroduodenal and intestinal permeability increase after A ingestion during prolonged running and that ingestion of a CHO beverage attenuates the gastroduodenal effect but not the intestinal effect. Furthermore, addition of G to the CHO beverage provided no additional benefit in reducing gastroduodenal or intestinal permeability.