Journal of the American College of Nutrition最新文献

Objective: Adolescents may be vulnerable to misleading nutritional information and adopt unhealthy food habits. In addition, specific features related to physical training, either aimed to improve fitness or to comply with sport demands, may influence food habits of the youth. This cross-sectional study was aimed to compare nutrition knowledge, food habits and adherence to Mediterranean diet in youth engaged in fitness training, competitive sports or inactive.

Methods: Three questionnaires, the General and Sport Nutrition Knowledge (GeSNK) questionnaire, a food habit questionnaire and the KIDMED were administered to gym members, athletes engaged in volleyball, long-distance swimming, and gymnastics, and inactive adolescents.

Results: The total sample included 211 youth (age 16.8 ± 1.7 years). Gym members, like the inactive youth, had lower general and sport-related nutrition knowledge compared to athletes (p = 0.001). In the whole sample, general nutrition knowledge was positively associated with healthy food habits (p < 0.01) and adherence to the Mediterranean diet pattern (p < 0.02).

Conclusions: Gym members had a level of nutrition knowledge lower than young athletes and similar to inactive youth. Healthy food habits were related with nutrition knowledge among adolescents. Specific nutritional education programs are needed to address food habits in fitness settings.

Background: Patients with systemic lupus erythematosus (SLE) have elevated cardiovascular risk. Hyperhomocysteinemia may be one of the contributing factors to this phenomenon. This study therefore aimed to compare the serum homocysteine levels and the levels of folate and vitamin B12, cofactors for homocysteine metabolism, between individuals with and without SLE.

Methods: A literature search was performed in PubMed, Embase, and the Cochrane library (from inception to March 31, 2019). Studies comparing serum homocysteine, folate or vitamin B₁₂ levels between individuals with and without SLE were selected. Of the 1040 screened studies, 50 studies met the inclusion criteria.

Results: A total of 50 studies involving 4396 patients with SLE were included. Patients with SLE had a significantly higher serum level of homocysteine (standardized mean difference [SMD], 1.134; 95% CI, 0.795-1.474) and lower level of vitamin B₁₂ (SMD, -0.359; 95% CI, -0.638 to -0.080) than controls. The folate level didn't differ markedly between SLE patients and the control group (SMD, -0.276; 95% CI, -0.674-0.123). Subgroup analysis showed consistent results in adult SLE patients. A random effects meta-regression analysis revealed a significantly inverse correlation between the SMD of homocysteine levels and C3 levels (coefficient, -0.0356, 95% CI, -0.054 to -0.0171; P < .001) and C4 levels (coefficient, -0.0876, 95% CI, -0.1407 to -0.0345; P = .0012).

Conclusions: Serum homocysteine levels were higher and vitamin B₁₂ levels were lower among individuals with SLE than those without SLE. Physicians are encouraged to monitor these parameters and offer timely interventions for patients with SLE.

Background: Skeletal abnormalities such as bone loss occur when there is an imbalance in bone matrix synthesis and bone resorption. This imbalance is also caused by hormonal changes and inflammation. Chia (Salvia hispanica L.) has a high nutritional value and is an excellent source of calcium. Evaluate the bioavailability of calcium from chia, and its effect on bone metabolism when consumed as part of a standard or high fat diet (HFD) in ovariectomized rats.

Methods: The study was conducted with 80 female Wistar rats that received standard diet or HFD. 40 female mice were ovariectomized (OVX) and 40 were sham-operated (SHAM). After recovery from surgery the animals received chia as a source of 20% of the calcium recommendation, calcium bioavailability was measured using the calcium balance technique. Bone strength and bone morphometry were evaluated by weight, length and microtomography measurements.

Results: HFD increased serum calcium and decreased calcium retention. The addition of chia to HFD did not alter bone morphology. Ovariectomy led to lower percentage of bone volume, smaller trabecular thickness, higher trabecular separation and higher porosity, when ovariectomy was associated with HFD, the final weight, waist circumference, body mass index and adiposity were increased.

Conclusions: Chia maintained bone health when offered as a source of 20% calcium, in a diet that met 100% of the mineral recommendation, regardless of the type of diet, in animals non-ovariectomized adults.

Purpose: Curcumin is a polyphenolic compound that is suggested to dysregulate the ubiquitin-proteasome system (UPS). This study investigated the effects of curcumin supplementation on markers of UPS activity in response to muscle damage.

Methods: Twenty-three recreationally active male and females between the ages of 18-30 were randomized into a curcumin (CUR) or placebo (PLA) group. Both groups ingested 2 g of their respective supplement and 20 mg of piperine for 11 consecutive days. Following 8 consecutive days of supplementation, participants performed a 45-minute eccentrically-biased treadmill protocol at 60% VO2max. Muscle biopsies and delayed onset muscle soreness (DOMS) assessments were performed 30 minutes prior and 3, 24, 48, and 72 hours following exercise. Skeletal muscle ubiquitin, MAFbx/Atrogin-1, ubiquitin specific peptidase 19 (USP19), and chymotrypsin-like protease concentrations were measured using ELISA. A 3-way repeated measures ANOVA with pairwise comparisons was conducted with significance set at p ≤ 0.05.

Results: Compared to baseline, DOMS for both groups was significantly increased (p < 0.05) at all time points except 72 hours following exercise. No significant differences were found for USP19 between groups. Ubiquitin (p=.016) and MAFbx/Atrogin-1 (p=.006) were significantly lower for CUR compared to PLA. Additionally, MAFbx/Atrogin-1 was significantly greater for females (p=.013) compared to males. In males, curcumin resulted in significant reductions (p = .049) in chymotrypsin-like protease (p = .049).

Conclusion: While elevations in UPS activity were not observed in response to muscle damage, curcumin supplementation in humans does appear to dysregulate basal UPS activity in the presence of exercise-induced muscle damage.

Objective: Determining the available energy (caloric value) of dietary non-digestible fibers that are fermented to varying degrees by intestinal microbes and metabolized to short chain fatty acids is important for provision of accurate information to food and beverage manufacturers for reformulation and labeling purposes. The objective of this human study was to determine the available energy of soluble fiber products by measuring post consumption breath hydrogen, with inulin as a control.

Methods: PROMITOR^® Soluble Corn Fiber 70 (SCF70) and PROMITOR^® Soluble Corn Fiber 85B (SCF85B) are Tate & Lyle dietary fiber products with 70% and 85% fiber, respectively. The fiber portion of these products is structurally representative of the fiber portion of all PROMITOR^® SCF products. The study conducted was a randomized, double-blind, crossover design. Breath hydrogen was quantified following consumption of beverages consisting of 8 oz. of water and: inulin (control), SCF70, or SCF85B at 5, 10, or 15 g (total ingredient weight, "as is"). Subjects were generally healthy men and women (N = 19), age 18 to 34 years, with body mass index (BMI) 19.3 to 24.8 kg/m². The primary outcome was incremental area under the curve over 10 h (iAUC0-10 h) for inulin, SCF70, and SCF85B at each dose. The available energy (kcal/g ingredient and kcal/g fiber) from SCF70 and SCF85B at each dose was then calculated using inulin as the reference.

Results: Results demonstrated that breath hydrogen production was significantly lower following consumption of SCF70 and SCF85B compared to inulin at all consumption amounts. There were no significant differences in breath hydrogen production following consumption of SCF70 compared to SCF85B.

Conclusion: The available energy per gram of fiber was not significantly different between the SCF70 and SCF85B PROMITOR^® products. The available energy of the fiber portion of PROMITOR^® SCF products was determined to be 0.2 kcal/gram.

Aim: Analyze the effects of green banana biomass (Musa spp.) on the biochemical parameters in Wistar male rats under standard and hyperlipidic diet.

Methods: Ethical approval for this study was obtained from Ethics Committee on the Use of Animals CEUA - PUC-GO and consisted in the division of 32 rats in 4 differentiated groups according to their diet (standard - CT; standard with green banana biomass - CTBM; hyperlipidic - HL and hyperlipidic with green banana biomass - HLBM). Through 8 weeks animals were weighted and their glycemia were measured. After this period, they were euthanized and biological material was collected to evaluate the biochemical parameters, which analysis used the ANOVA test.

Results: The weekly evaluation confirmed that the efficacy of the hyperlipidic model since the final weight was bigger in the HL group in comparison with the CT group, from the sixth to the eighth week. It was also possible to observe that the CTBM group had a smaller weight compared to the CT group. Besides, the measurement of glycemia, high-density lipoprotein, triglycerides, alanine aminotransferase, aspartate aminotransferase, serum total bilirubin, direct bilirubin, alkaline phosphatase, urea, serum creatine, uric acid, calcium, phosphor, magnesium and the hematological parameters from the 8 animal of each group were compared by the ANOVA test without any significative difference (p < 0.05) in the comparisons.

Conclusions: This study it did not demonstrate significative changes of the green banana biomass on the observed laboratory parameters during the 8 weeks in comparison to the standard group, indicating an absence of interference of the probiotics in the laboratory parameters on the hyperlipidic model during the analyzed period. Therefore, it is necessary an evaluation of its efficacy in obesity treatment in longer studies with molecular parameters.

Objective: We investigated the effects of acute ingestion of Maytenus ilicifolia extract on metabolic and cardiopulmonary responses during a high-intensity interval exercise (HIIE), and its consequence on neuromuscular fatigue.

Methods: Ten healthy men underwent a HIIE (4 x 4 min, 3 min recovery) one hour after ingesting 400 mg of Maytenus ilicifolia extract (MIE) or placebo. Oxygen uptake ($\dot{V}$O₂), dioxide carbon production ($\dot{V}$CO₂), ventilation ($\dot{V}$E) and heart rate (HR) were measured throughout the HIIE. Maximal voluntary contraction (MVC), voluntary activation (VA), and evoked 1, 10 and 100 Hz force twitch were measured before supplementation (baseline), and before (pre-HIIE) and after the HIIE (post-HIIE).

Results: The $\dot{V}$O₂, $\dot{V}$E, $\dot{V}$E/$\dot{V}$O₂ ratio and HR increased progressively throughout the HIIE under both conditions (p < 0.05). MIE increased HR, however, at bouts 1 and 2 and mean $\dot{V}$O₂ during HIIE. The mean respiratory exchange ratio during recovery was also reduced with MIE (p < 0.05). MVC and evoked force at 1, 10 and 100 Hz declined similarly after HIIE, regardless of the condition (MIE: -18 ± 17%, -50 ± 15%, -61 ± 13% and -34 ± 10% vs. placebo: -19 ± 15%, -48 ± 16%, -58 ± 12 and -29 ± 11%, respectively, p < 0.05). There was no effect of exercise or MIE on VA (p > 0.05).

Conclusion: MIE increases heart rate in the first bouts and mean oxygen uptake during HIIE without changes in neuromuscular fatigue development.

Objective: The study's purpose was to examine a free-living, ketogenic diet (WFKD) on feasibility, satiety, body composition, and metabolic health in women.

Methods: Twenty-two women (age (yr.) 42.2 ± 8.1, Ht. (cm) 164.2 ± 5.9, BMI 27.3 ± 6.0) participated in a 21-day, free-living dietary intervention. Daily ketone measurements and satiety/craving surveys, weekly diet records, and PRE and POST assessments of anthropometrics, body composition, blood pressure, and fasted capillary-blood glucose (BG) and cholesterol panels were collected.

Results: Women maintained calories (PRE: 1938 kcal vs POST: 1836 kcal) and protein (PRE: 17% vs POST: 20%) but decreased carbohydrate (PRE: 36% vs POST: 13%) and increased fat (PRE: 45% vs POST: 65%) PRE to POST (p ≤ 0.05). Daily self-reports suggested no changes in satiety or food cravings between PRE, WK 1, WK 2, and WK 3. Ketones increased (PRE 0.3 ± 0.2 mmol vs POST 0.8 ± 0.6 mmol) PRE to POST with significant differences between PRE and all other time points (p ≤ 0.05). Bodyweight (PRE: 73.9 kg vs POST: 72.3 kg) and body fat (PRE: 28.9 ± 13.4 kg vs POST 27. 4 ± 13.5 kg) decreased but there were no differences in fat-free mass PRE to POST (p ≤ 0.05). Systolic blood pressure decreased (PRE: 119.2 ± 8.9 mmHg vs POST: 109.5 ± 10.9 mmHg), diastolic blood pressure increased (PRE: 74.1 ± 7.5 mmHg vs POST: 78.8 ± 7.4 mmHg), and BG improved (94.0 ± 8.3 mg/dL vs POST 89.9 ± 9.0 mg/dL) PRE to POST (p ≤ 0.05). No differences were observed in total cholesterol (TC), high-density lipoprotein (HDL), and triglycerides (TG) but TC/HDL decreased and low-density lipoprotein increased PRE to POST (p ≤ 0.05).

Conclusion: Women were able to maintain calories, improve body composition, blood pressure, and BG, increase ketones, and improve some but not all cholesterol markers after 21 days on a free-living WFKD.