Effectiveness of a Per-Meal Protein Prescription and Nutrition Education with versus without Diet Coaching on Dietary Protein Intake and Muscle Health in Middle-Aged Women.

Sufficient dietary protein intake is vital to maintaining muscle health with aging. Yet protein intake among adults is often inadequate. This study's main objective was to examine the impact of nutrition education (NE) and a per-meal protein prescription (PRx) with versus without diet coaching on protein intake. A secondary objective examined its effects on muscle health. Participants included 53 women, age 45-64 years. All participants received NE and PRx; those randomized to coached-group received 10-weeks of diet coaching. Assessments included: protein intake at baseline, weeks 4 and 12 and muscle health (muscle mass, grip strength, five-chair rise test, 4 mgait speed test). The Chi-square test examined percentages of participants meeting PRx between groups. Repeated measures analysis of variance assessed within group and intervention effects on protein intake and muscle health parameters. Protein intake (g/kg body weight) increased (p < 0.001): not-coached (n = 28) 0.8 ± 0.2 to 1.2 ± 0.3 and coached (n = 25) 1.0 ± 0.2 to 1.4 ± 0.3 with no significant difference between groups. A greater percentage of coached-group participants met (p = 0.04) breakfast (72%) and met (p < 0.001) three-meal (76%) PRx versus not-coached participants (25% and 53%, respectively). Participants in both groups exhibited significantly (p < 0.001) improved times for the five-chair rise test and 4 mgait speed test. Diet coaching in conjunction with a PRx and NE should be considered to assist individuals in improving protein intake through self-selection of protein-rich foods.

Iron status of female collegiate athletes involved in different sports.

Iron status was assessed in 70 female athletes aged 18-25 yr participating in collegiate cross-country track, tennis, softball, swimming, soccer, basketball, and gymnastics. No significant differences in mean hemoglobin, hematocrit, serum iron, total iron-binding capacity, transferrin saturation, and ferritin were found among teams. The mean concentrations of each parameter for each of the teams were within the normal ranges. However, several athletes from different sports had suboptimal iron status indexes. Of 17 athletes with a serum ferritin concentration < or = 15 microg/L, 8 (4 freshmen, 2 sophomores, 2 unknown) also exhibited low serum iron concentrations (< 60 microg/dL) and low transferrin saturation (< 16%). Thirteen (6 freshmen, 3 sophomores, 2 juniors, 2 seniors) of 51 (25%) athletes failed to consume two-thirds of the Recommended Dietary Allowance for iron and exhibited suboptimal serum concentrations of ferritin, iron, and/or transferrin saturation. Of nine athletes taking iron supplements, one exhibited suboptimal iron status. In summary, nonanemic iron depletion was present among female collegiate athletes involved in many different sports and in all years of participation (freshmen, sophomore, junior, and senior athletes). Female athletes should continue to be individually and routinely evaluated for nutritional deficiencies throughout their collegiate athletic careers.

Copper status of collegiate female athletes involved in different sports.

Copper status was assessed in 70 female collegiate athletes aged 18 to 25 years participating in cross country track, tennis, softball, swimming, soccer, basketball, and gymnastics during the 2000-2001 season. A group of 8 college-aged females, 20 to 23 years of age, who were not collegiate athletes, served as controls. Mean copper intakes including supplements did not differ significantly among the controls and athletic teams. Mean copper intakes including supplements as micrograms/day and percent recommended dietary allowance (RDA) were as follows: controls 1071 +/- 772 microg (119 +/- 86%), cross country track 1468 +/- 851 microg (163 +/- 95%), tennis 1099 +/- 856 microg (122 +/- 95%), softball 654 +/- 420 microg (73 +/- 47%), swimming 1351 +/- 1060 g (150 +/- 118%), soccer 695 +/- 368 microg (77 +/- 41%), and gymnastics 940 +/- 863 microg (104 +/- 96%). Forty-one percent of athletes and 29% of controls failed to consume two thirds of the RDA for copper. Mean serum copper and ceruloplasmin concentrations were within the normal range and did not differ significantly among the controls (117 +/- 22 microg/dl, 445 +/- 122 mg/L) and cross country track (98 +/- 17 microg/dl, 312 +/- 59 mg/L), tennis (140 +/- 84 microg/dl, 424 +/- 244 mg/L), softball (95 +/- 30 microg/dl, 310 +/- 77 mg/L), swimming (98 +/- 25 microg/dl, 312 +/- 40 mg/L), soccer (93 +/- 15 microg/dl, 324 +/- 54 mg/ L), basketball (85 +/- 10 microg/dl, 280 +/- 62 mg/L), and gymnastics (96 +/- 21 microg/dl, 315 +/- 68 mg/L) teams. Copper status of female collegiate athletes appears to be adequate in this cross-sectional assessment.

Beta-carotene supplementation decreases leukocyte superoxide dismutase activity and serum glutathione peroxidase concentration in humans.

The effects of a 30 mg/day beta-carotene supplement for 60 days on blood cell and serum antioxidant enzymes and selenium concentrations were examined in healthy adults. Serum beta-carotene concentrations increased significantly (P < 0.05) in response to supplementation. Forty percent of subjects exhibited hypercarotenemia of the skin after 30 days. There were no changes in the activity of red blood cell or leukocyte catalase activity, red blood cell copper,zinc-dependent superoxide dismutase activity or serum myeloperoxidase concentration in response to beta-carotene supplementation. Leukocyte superoxide dismutase activity decreased significantly (P < 0.05) at 30 and 60 days compared to baseline. Serum glutathione peroxidase concentration decreased significantly (P < 0.05) between baseline and days 45 and 60 of supplementation. Serum selenium and blood hemoglobin concentrations did not change during the study. Supplemental beta-carotene may alter the antioxidant capacity of plasma and/or blood cells in vivo.

Non-anemic iron deficiency, oral iron supplementation, and oxidative damage in college-aged females.

Oxidative damage, as indicated by protein carbonyl and lipid hydroperoxide concentrations, was assessed in the plasma of college-aged females with adequate iron status and with non-anemic iron deficiency before and after eight weeks of iron supplementation. At baseline, the mean serum ferritin, iron, transferrin saturation, and total iron binding capacity of the iron deficient group (n = 13) was significantly different from the iron adequate controls (n = 24). Mean plasma lipid hydroperoxide and protein carbonyl concentrations did not differ between groups at baseline. Following eight weeks of iron supplementation, the mean serum ferritin, iron, and transferrin saturation significantly increased and the total iron binding capacity significantly decreased in the iron deficient group. No significant differences in plasma lipid hydroperoxide or protein carbonyl concentrations were found between groups at the end of the study period. When plasma lipid hydroperoxide and protein carbonyl concentrations of subjects within groups were compared at the start versus at the end of the study, no significant differences were found for either group. Neither non-anemic iron deficiency nor its treatment with oral iron supplements is associated with oxidative damage in the plasma of college-aged females.

Iron depletion without anemia is not associated with impaired selenium status in college-aged women.

Iron-deficiency anemia has been shown to alter body mineral concentrations and activities of iron- and non-iron-containing enzymes, especially those with antioxidant functions. These effects, however, have been less studied in nonanemic iron-depleted individuals. Thus, this study assessed indices of selenium status in 12 college-aged females with adequate iron stores and 15 college-aged females with low iron stores before and after iron therapy. Blood samples were drawn at baseline for both groups and following iron supplementation in the low-iron-stores group. Hematocrit, hemoglobin, and serum ferritin concentrations of the low iron- stores group were significantly lower than those of the control group. The serum transferrin receptor-to-serum ferritin ratio in the low-iron stores group was significantly greater than that of the control group. Serum selenium and glutathione peroxidase concentrations of the low-iron-stores group were not significantly different from those of the controls. Iron supplementation significantly increased hemoglobin, hematocrit, and serum ferritin concentrations and significantly decreased the serum transferrin receptor concentration and serum transferrin receptor:serum ferritin ratio in the low-iron-stores group posttreatment compared to pretreatment. Serum selenium and glutathione peroxidase concentrations did not differ significantly from pretreatment to posttreatment in the low-iron-stores group. Results of this study indicate that low iron stores without anemia are not associated with impaired selenium status in college-aged females.

Non-anemic iron depletion, oral iron supplementation and indices of copper status in college-aged females.

OBJECTIVES: Indices of copper status, specifically serum copper and ceruloplasmin concentrations and erythrocyte superoxide dismutase activity, and iron status, including serum ferritin, transferrin receptors, hemoglobin and hematocrit, were studied in 27 college-aged females with adequate iron versus low iron stores. METHODS: Serum copper and ceruloplasmin concentrations, erythrocyte superoxide dismutase activity, serum ferritin, transferrin receptors, hemoglobin and hematocrit were studied in 15 females with non-anemic iron depletion before and after five weeks of iron supplementation and in 12 healthy iron-adequate females aged 19 to 28 years. RESULTS: Mean hemoglobin, hematocrit and ferritin concentrations of the control group (144 +/- 11 g/L, 43 +/- 3% and 38 +/- 15 micro g/L, respectively) were significantly higher than those of the iron depleted group prior to supplementation (134 +/- 9 g/L, 39 +/- 2% and 11 +/- 6 micro g/L, respectively). The serum transferrin receptor to serum ferritin ratio was significantly greater for the iron depleted group prior to supplementation (890 +/- 753) versus the control group (151 +/- 61). Mean serum copper and ceruloplasmin concentrations and erythrocyte superoxide dismutase activity of the iron-adequate control group (20.0 +/- 5.7 micro mol/L, 463 +/- 142 mg/L and 527 +/- 124 U/mL, respectively) were significantly higher than those of the iron depleted group (12.4 +/- 3.8 micro mol/L, 350 +/- 108 mg/L and 353 +/- 186 U/mL, respectively) prior to supplementation. Following iron supplementation, hematocrit and ferritin concentrations of the iron depleted group significantly increased to 42 +/- 3% and 26 +/- 8 micro g/L, respectively. Mean serum transferrin receptor concentrations and the serum transferrin receptor to ferritin ratios significantly decreased in the iron depleted group following supplementation (6.1 +/- 1.6 mg/L to 4.6 +/- 1.5 mg/L and 890 +/- 753 to 198 +/- 114, respectively). Iron supplementation also significantly increased the mean serum copper concentration to 14.2 +/- 5.4 micro mol/L and, in subjects with serum ferritin concentrations