유청단백 (WPI)

This study investigated the acute effects of different protein sources consumed at sahur on anaerobic power and strength performances in trained male combat sport athletes during Ramadan fasting. Using a single blind, randomized, placebo-controlled, counterbalanced crossover study design, 24 male combat sports' athletes (mean age: 27.3 ± 3.8 years, Tier 3 national level) completed four experimental conditions: (1) non-fasting control, (2) fasting + placebo (maltodextrin), (3) fasting + whey protein isolate (WPI), and (4) fasting + micellar casein (MC). In each condition, a standardized sahur meal (6.3-7.7 kcal/kg body weight) and supplementation (0.4 g/kg for WPI/MC and 0.4 g/kg for Placebo) were administered. Physical Performances was assessed 11-13 hours post-sahur (or 3-5 hours post-lunch for control) including the Wingate anaerobic test, bench press, leg press, and countermovement jump (CMJ), and handgrip strength tests. Ramadan fasting significantly lowered Wingate peak power, mean power, and bench press strength compared to the non-fasting control. MC supplementation reduced these declines, outperforming WPI and the placebo in peak power and mean power, and surpassing the placebo in bench press strength, although not WPI. Leg press, countermovement jump, and handgrip strength showed no significant differences across conditions. MC supplementation at sahur provides partial protection against fasting-induced declines in anaerobic power and upper body endurance, but does not fully restore performance to non-fasting levels. These findings emphasize the importance of protein timing and selection in mitigating performance decrements during Ramadan fasting, highlighting the need for further research on optimal nutritional strategies for athletes training and competing under fasting conditions. Copyright: © 2026 Demirli et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

BACKGROUND: β-lactoglobulin (BLG) is a protein found within whey protein (WP) that is rich in essential amino acids, most notably, leucine (LEU). LEU is considered the most potent EAA in the postprandial stimulation of muscle protein synthesis (MPS), such that suboptimal protein/essential amino acid (EAA) doses containing higher LEU content elicit muscle anabolism comparable to larger protein doses. Our objective was to test the effects of naturally LEU-rich BLG (~10 g protein) versus isonitrogenous whey protein isolate (WPI, ~10 g) on MPS. METHODS: Ten healthy young men (26 ± 2 y; 179 ± 2 cm; 81 ± 3 kg) received BLG (1.57 g LEU) or WPI (1.02 g LEU) in a randomised double-blind cross-over fashion. A primed constant intravenous infusion of [1,2 13C2] LEU was used to determine MPS (isotope ratio mass spectrometry) at baseline and in response to feeding (FED) and feeding-plus-exercise (FED-EX; 6 × 8 unilateral leg extensions; 75% 1-RM). Plasma insulin and EAA's were quantified. RESULTS: Plasma EAA, branched-chain amino acid (BCAA), and LEU concentrations increased rapidly following both protein supplements but exhibited a significantly greater EAA/BCAA/leucinemia following BLG (p < 0.05 for all). MPS increased significantly in both FED (~52%) and FED-EX (~58%) states, with no significant differences between supplements. CONCLUSIONS: Both BLG and WPI effectively stimulated MPS doses in young healthy males, with BLG offering an advantage in EAA/BCAA/LEU bioavailability. It follows that future research should explore the potential of BLG in populations exhibiting anabolic resistance and exercise anabolism deficiency, such as older adults as well as frail and clinical populations, to assess its utility in preserving muscle mass under conditions of suboptimal protein intake.

Background: Circadian rhythm disruption caused by shift work alters metabolic and hormonal pathways, which accelerates chronic disease onset, leading to decreased quality and quantity of life. This study aimed to determine whether a practical lifestyle intervention emphasizing nutrition timing and recovery habits could mitigate the metabolic and psychological effects of night-shift work. We conducted a randomized, open-label, crossover trial with two 8-week periods. Methods: Female healthcare workers (n = 13) aged 18-50 years with a body mass index (BMI) between 27 and 40 kg/m2 and working predominantly night shifts (≥30 h/week for ≥6 months) were randomized. During the 8-week intervention phase, participants received daily text messages with guidance on food, sleep/rest, and physical activity and were provided with whey protein isolate powder and grain-based snack bars to consume during work shifts. The program targeted improved nutrient timing, adequate protein intake, and structured rest without formal exercise training, allowing evaluation of dietary and behavioral effects feasible for this population. Total caloric (~30 kcal/kg lean mass) and protein (2 g/kg lean mass) needs were measured, along with sleep/rest goals of 6-8 h/24 h. Primary outcome measures were change in visceral fat percentage (VF%) by DXA and mental/physical quality of life (RAND SF-12). Secondary outcomes included fasting triglycerides, ALT, blood glucose, LDL, actigraphy, and fecal microbiome. Mixed-design two-way ANOVA was conducted to assess the effects of group (immediate [IG] and delayed [DG]), time (baseline, 8-week crossover, and week 16), and Group × Time (GxT) interactions, and Bonferroni correction was applied to post hoc t-tests. Results: Eleven participants completed the study. Both groups increased dietary protein intake (p < 0.001), and a GxT interaction for VF% (p = 0.039) indicated DG reduced VF% to a greater extent (-0.335 ± 0.114% (p = 0.003) vs. 0.279 ± 0.543% (p = 0.158)). Mental and physical QOL, objectively measured physical activity and sleep, serum lipids and inflammatory markers, and fecal microbiota remained unchanged (p > 0.05 for all GxT). Conclusions: The fin

Canola protein is a rapeseed-derived protein that contains all essential amino acids in proportions that meet the WHO amino acid scoring requirements, making it an interesting protein for human food applications. It is currently unknown whether canola protein processing modulates postprandial plasma amino acid bioavailability in vivo in humans. This study compared postprandial plasma amino acid profiles following the ingestion of unprocessed (native) canola, processed canola, and whey protein isolate in healthy, young, females. In a randomized, clinical, cross-over design, 15 healthy young females (25 ± 3 y) participated in four test days on which they consumed 20 g protein as either native canola, enzyme processed or heat processed canola protein, or 20 g whey protein. Blood samples were collected for 5 h following protein ingestion to assess plasma amino acid concentrations. Ingestion of native canola protein resulted in lower increases in plasma total amino acid (TAA) concentrations compared to whey protein (3191 ± 794 vs. 4429 ± 84 µmol∙L- 1, P < 0.001). Canola protein processing resulted in greater peak plasma total amino acids concentrations, reaching statistical significance for enzyme (3599 ± 687 µmol∙L- 1, P = 0.045) but not heat (3565 ± 722 µmol∙L- 1, P = 0.166) treated compared to native canola protein. Plasma total amino acid availability, expressed as incremental area under the curve over a 5 h postprandial period, did not differ between treatments and averaged 163 ± 81, 171 ± 76, 194 ± 82, and 207 ± 85 mmol∙300 min∙L- 1 following ingestion of native, enzyme- and heat processed canola, and whey protein, respectively (P > 0.05). Ingestion of whey protein allows for a more rapid postprandial rise in circulating essential and non-essential amino acids and greater postprandial plasma total amino acid availability when compared to the ingestion of native canola protein. Ingestion of enzyme- or heat processed canola protein accelerates the postprandial rise in circulating amino acids but does not further augment overall plasma amino acid availability throughout a 5 h postprandial period when compared to the ingestion of native canola protein. © 2025. The

BACKGROUND: Protein ingestion during recovery from exercise can further increase muscle protein synthesis rates. Plant-derived proteins are generally believed to have lesser anabolic properties than animal-derived proteins. To our knowledge, no studies have compared the impact of plant-derived with that of animal-derived protein ingestion on postexercise muscle protein synthesis rates in healthy, young females. OBJECTIVES: This study compared muscle protein synthesis rates following the ingestion of 20 g native canola protein, 20 g whey protein, or a noncaloric placebo during recovery from a single bout of resistance exercise in healthy, young females. METHODS: In this randomly assigned, parallel group, double-blind placebo-controlled design, 36 healthy young (age, 23 ± 4 y; BMI, 22.7 ± 2.2 kg/m2) females performed 8 sets of lower-body resistance exercise at 80% of their predetermined 1-repetition maximum after which they ingested 20 g native canola protein isolate, 20 g whey protein isolate, or a noncaloric placebo. Primed continuous L-[ring-13C6]-phenylalanine infusions were applied with frequent sampling of blood and muscle tissue to assess postprandial plasma amino acid profiles and 5-h postexercise muscle protein synthesis rates. Data are presented as mean ± SD. RESULTS: Plasma essential amino acid concentrations strongly increased following ingestion of both whey and canola protein when compared with the placebo treatment (peak: 2113 ± 354, 1249 ± 173, and 780 ± 60 μmol/L, respectively; P < 0.001) with greater postprandial plasma essential amino acid availability following whey than after canola protein ingestion (incremental AUC, 158 ± 50 and 90 ± 23 mmol/L × 5 h; P < 0.001). No significant differences in postexercise muscle protein synthesis rates were observed following the ingestion of whey protein isolate, canola protein isolate, and placebo (0.071 ± 0.015, 0.069 ± 0.016, and 0.061 ± 0.013%/h, respectively; treatment; P = 0.200). CONCLUSIONS: A single session of resistance exercise strongly increases muscle protein synthesis rates in young females. Ingestion of 20 g whey or native canola protein does not further augment muscle protein synthesis rates

BACKGROUND: The milk fat globule membrane (MFGM) is a structural membrane that covers the globules of triglycerides dispersed in an emulsion of milk. In previous human studies, MFGM ingestion combined with light aerobic exercise training improved agility in elderly individuals. The purpose of this study was to examine whether 4 weeks of daily ingestion of MFGM combined with power training improves instantaneous physical strength - muscle strength, agility, and muscle power compared with placebo (whey protein isolate) in healthy young adults. METHOD: The study was designed as a randomized, double-blind, and placebo-controlled trial. Ninety-eight healthy young adults aged 20-49 completed the study intervention, and they received either an MFGM powder containing 1.7 g of fat and 160 mg of sphingomyelin or an isocaloric placebo powder daily throughout 4 weeks (3 times/week) of power training. Physical strength tests and body composition measurements were conducted before and after the four-week intervention. An analysis of covariance (ANCOVA) model with baseline values as a covariate was carried out to test differences in post intervention values between groups. RESULTS: Ingestion of MFGM significantly improved peak torque (p = 0.003) and average power (p = 0.019) of isokinetic knee extensors, leg press 1 repetition maximum (RM) (p = 0.004) and sit-ups reps (p = 0.030), but not indicators of agility, compared with placebo after the 4-week intervention. There were no significant changes in lean body mass during the intervention period in either group and no significant differences between groups. CONCLUSIONS: We conclude that daily MFGM supplementation combined with power training are effective to improve instantaneous physical strength, such as muscle strength and power, compared with placebo in healthy young adults.

BACKGROUND: Small nutritional preloads can reduce postprandial glucose excursions in individuals with and without metabolic syndrome or type 2 diabetes (T2D). However, most studies have focused on preloads administered before single meals and have predominantly used protein-based preloads. OBJECTIVES: To investigate the effects of sequential consumption of medium-chain triglycerides (MCT) and whey protein isolate (WPI) preloads before breakfast, lunch, and dinner on postprandial, diurnal, and 24-h glycaemia in individuals with T2D. METHODS: Participants with T2D were studied over 3 randomized 24-h periods. They consumed either water before standardized breakfast, lunch, and dinner (CONTROL), 15 g MCT before breakfast and water before lunch and dinner (MCT), or 15 g MCT before breakfast and 10 g WPI before lunch and dinner (MCT + WPI). Diurnal (08:00-23:00 h) and 24 h (08:00-08:00 h) glycaemia (incremental AUC [iAUC]) and glycaemic variability (%coefficient of variation [%CV]) were evaluated by continuous glucose monitoring. Postprandial glycaemia (PPG) after breakfast and lunch was assessed by arterialized blood glucose iAUC. RESULTS: In 21 enrolled patients (8 males/13 females, mean ± standard deviation age 55.1 ± 8.5 y, body mass index 31.7 ± 4.3 kg·m-2, glycated hemoglobin 59 ± 12 mmol·mol-1) diurnal and 24-h iAUC were similar across interventions, whereas 24-h %CV was lower in MCT (16.8 ± 0.8%, P = 0.033) and MCT + WPI (16.1 ± 0.9%, P = 0.0004) than CONTROL (18.7 ± 0.9%). PPG iAUC was ∼17% lower after breakfast in MCT and MCT + WPI compared with CONTROL, but only the MCT + WPI lowered glucose by 20% (P = 0.002) over the entire day (08:30-17:30 h). Gastric inhibitory polypeptide (GIP) (P = 0.00004), peptide YY (PYY) (P = 0.01), and β-hydroxybutyrate (P = 0.0001) were higher in MCT and MCT + WPI than CONTROL. Subjective appetite ratings were lower after breakfast and lunch in MCT + WPI (P = 0.001). CONCLUSIONS: Sequential consumption of MCT and WPI preloads did not affect diurnal or 24-h glycaemia but lowered PPG and 24-h glycaemic variability in individuals with T2D. These effects were associated with increased circulating β-hydroxybutyrate, PYY, and GIP, and

Marine-derived proteins, such as blue whiting-derived protein hydrolysates (BWPH), represent high-quality sources of dietary protein, but their ability to support postexercise anabolism is not established. The impact of BWPH on whole-body anabolism was compared with an isonitrogenous whey protein isolate (WPI) and nonessential amino acid (NEAA) control in 10 trained young males (31 ± 4 years) who, on three separate visits, performed a session of whole-body resistance exercise and then consumed, in randomized crossover fashion, BWPH, WPI, or NEAA (0.33 g/kg; 19, 33, and 0 mg/kg leucine, respectively) with L-[1-13C]leucine. Breath, blood, and urine samples were collected for 6-hr postprandial to assess dietary leucine oxidation, amino acid (AA) concentrations, and 3-methylhistidine: creatinine ratio. Peak and area under the curve concentrations for leucine, branched-chain amino acids, and essential amino acids were greater in WPI compared with BWPH (all p < .05) but with no differences in time to peak concentration. Total oxidation reflected leucine intake (WPI > BWPH > NEAA; p < .01), whereas relative oxidation was greater (p < .01) in WPI (28.6 ± 3.6%) compared with NEAA (21.3 ± 4.2%), but not BWPH (28.6 ± 8.8%). Leucine retention, a proxy for whole-body protein synthesis, was greater in WPI (185.6 ± 9.5 μmol/kg) compared with BWPH (109.3 ± 14.1 μmol/kg) and NEAA (5.74 ± 0.30 μmol/kg; both p < .01), with BWPH being greater than NEAA (p < .01). Urinary 3-methylhistidine: creatinine ratio did not differ between conditions. Both WPI and BWPH produced essential aminoacidemia and supported whole-body anabolism after resistance exercise, but a higher intake of BWPH to better approximate the leucine and EAA content of WPI may be needed to produce an equivalent anabolic response.

BACKGROUND & AIM: Patients with an ileostomy are at increased risk of dehydration and sodium depletion. Treatments recommended may include oral rehydration solutions (ORS). We aimed to investigate if protein type or protein hydrolysation affects absorption from iso-osmolar ORS in patients with an ileostomy. METHODS: This was a randomised, double-blinded, active comparator-controlled 3 × 3 crossover intervention study. We developed three protein-based ORS with whey protein isolate, caseinate or whey protein hydrolysate. The solutions contained 40-48 g protein/L, 34-45 mmol sodium/L and had an osmolality of 248-270 mOsm/kg. The patients ingested 500 mL/d. The study consisted of three 4-week periods with a >2-week washout between each intervention. The primary outcome was wet-weight ileostomy output. Ileostomy output and urine were collected for a 24-h period before and after each intervention. Additionally, blood sampling, dietary records, muscle-strength tests, bioimpedance analyses, questionnaires and psychometric tests were conducted. RESULTS: We included 14 patients, of whom 13 completed at least one intervention. Ten patients completed all three interventions. Wet-weight ileostomy output did not change following either of the three interventions and did not differ between interventions (p = 0.38). A cluster of statistically significant improvements related to absorption was observed following the intake of whey protein isolate ORS, including decreased faecal losses of energy (-365 kJ/d, 95% confidence interval (CI), -643 to -87, p = 0.012), potassium (-7.8 mmol/L, 95%CI, -12.0 to -3.6, p = 0.001), magnesium (-4.0 mmol/L, 95%CI, -7.4 to -0.7, p = 0.020), improved plasma aldosterone (-4674 pmol/L 95%CI, -8536 to -812, p = 0.019), estimated glomerular filtration rate (eGFR) (2.8 mL/min/1.73 m2, 95%CI, 0.3 to 5.4, p = 0.03) and CO2 (1.7 mmol/L 95%CI, 0.1 to 3.3, p = 0.04). CONCLUSION: Ingestion of 500 mL/d of iso-osmolar solutions containing either whey protein isolate, caseinate or whey protein hydrolysate for four weeks resulted in unchanged and comparable ileostomy outputs in patients with an ileostomy. Following whey protein isolate ORS, we observed discrete

PURPOSE: Ageing is associated with cognitive decline. This study investigated the individual and combined effects of resistance exercise (RE) and whey protein supplementation (PRO) on cognitive function in older men. METHODS: In a pooled-groups analysis, 36 older men (age: 67 ± 4 years) were randomised to either RE (2 x/week; n = 18) or no exercise (NE; n = 18), and either PRO (2 × 25 g/d whey protein isolate; n = 18) or control (CON, 2 × 23.75 g maltodextrin/d; n = 18). A sub-analysis was also conducted between RE + CON (n = 9) and RE + PRO (n = 9). At baseline and 12 weeks, participants completed a battery of neuropsychological tests (CANTAB; Cambridge Cognition, UK) and neurobiological, inflammatory, salivary cortisol and insulin sensitivity biomarkers were quantified. RESULTS: PRO improved executive function z-score (+0.31 ± 0.08) greater than CON (+0.06 ± 0.08, P = 0.03) and there was a trend towards improved global cognitive function (P = 0.053). RE and RE + PRO did not improve any cognitive function domains (p ≥ 0.07). RE decreased tumor necrosis factor-alpha (P = 0.02) and interleukin-6 (P = 0.048) concentrations compared to NE, but changes in biomarkers did not correlate with changes in cognitive domains. Muscle strength (r = 0.34, P = 0.045) and physical function (ρ = 0.35-0.51, P < 0.05) outcomes positively correlated with cognitive function domains at baseline, but only Δskeletal muscle index correlated with Δepisodic memory (r = 0.34, P = 0.046) following the intervention. CONCLUSION: In older men, PRO improved cognitive function, most notably executive functioning. RE did not improve any cognitive function domains but did decrease biomarkers of systemic inflammation. No synergistic effects were observed.

The effect of the administration of a whey protein isolate (WPI) and collagen hydrolysates on ethanol-induced ulcerative lesions was studied in rats. WPI and bovine or porcine collagen hydrolysate (BCH and PCH, respectively) were given to rats by gavage. In acute experiments, (single-dose) physiological saline (10 mL/kg of body weight) was used as the negative control, and carbenoxolone (200 mg/kg of body weight) was used as a positive control. Ethanol (1 mL per 250-g rat) was also given by gavage. These treatments reduced the ulcerative lesion index (ULI) in a range of 40-77%, depending on the dosage. Some mixtures of WPI with either PCH or BCH provided results that suggested synergisms between WPI and the collagen hydrolysates. For example, WPI/BCH (in the proportion of 375:375 mg/kg of body weight) decreased ULI by 64%. The mechanism for mucosal protection involved a decrease in plasma gastrin (approximately 40%), a significant increase (50-267%) in mucus production, and a reduction in ULI (percentage) when intragastric administrations were performed after in vivo alkylation by N-ethylmaleimide. Results suggest that gastrin, sulfhydryl substances, and some mechanisms related to mucus production are all involved in gastric ulcer protection against ethanol. The collagen hydrolysates (both PCH and BCH) presented a stronger effect on mucus production; on the other hand, the effect of WPI was also dependent on sulfhydryl compounds, resulting in a more protective effect when the two proteins were administered together.

BACKGROUND: A number of clinical trials have successfully been performed using whey and/or soy proteins in the treatment of many diseases. They both have antioxidant properties, which appears to be a factor in aerobic physical performance as well. In addition, these are the most often used supplements that sportsmen take to increase their performance. AIM OF THE STUDY: To investigate the effect of whey and soy protein supplementation on redox parameters in the muscle, on body weight, and body composition in swimming-trained and non-trained animals. METHODS: The effect of whey and soy protein-isolate supplementation on muscle redox parameters, body weight, and body composition in trained and non-trained mice was investigated after a single exhaustive bout of exercise. Steady state free radical concentration measured using electron spin resonance (ESR) spectroscopy, reduced and oxidized glutathione ratio, thiobarbituric acid-reactive substances (TBARS), and protein carbonyl levels of the red leg muscle were measured. RESULTS: Free radical concentrations and glutathione composition of the tissue indicated that whey protein supplementation of the regular diet was able to prevent oxidative stress regardless of training. Soy protein supplementation decreased TBARS only in the muscle of untrained animals, while training per se lowered protein damage in all investigated groups. A mixture of soy and whey protein supplementation resulted in leaner animals after training, but had no synergistic effect on either of the measured redox parameters. CONCLUSIONS: Athletes consuming these supplements could train with higher exercise intensity. The antioxidant effect of the two proteins is based on different mechanisms of action.

The contribution of thermal and radiative treatments as well as the presence of some excipients, namely glycerol, carboxymethylcellulose (CMC), pectin, and agar, on the formation of protein-protein interactions as well as the formation and loss of protein-water interactions was investigated by means of differential scanning calorimetry in an isothermal mode. Protein-water interactions were assessed through measurement of the heat of the wetting parameter. Isothermal calorimetry measurements pointed out that gamma-irradiation does not favor protein-water interactions, as reflected by its endothermic contribution (P < or = 0.05) to the heat of wetting values. Although significant (P < or = 0.05), the effect of the thermal treatment on endothermic responses using isothermal calorimetry was found to be somewhat lower. Among excipients added to biofilm formulations, glycerol generated the most important losses of protein-water interactions, as inferred by its significant (P < or = 0.05) endothermic impact on the heat of wetting values.

To determine the enhancing effect of a whey protein isolate on the cytotoxicity of a potential anticancer drug, baicalein, the human hepatoma cell line Hep G2 was assigned to grow in different media for four days, and cell growth and apoptosis were investigated. The control group was grown in normal medium; the other three groups were grown in whey protein isolate (Immunocal) medium, baicalein medium, and a combination of Immunocal and baicalein. As indicated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, survival rate was significantly lower in cells grown in baicalein + Immunocal than in cells grown in baicalein alone. In contrast, there was no significant difference in survival rate of the cells grown in Immunocal. In the investigation of apoptosis, cells grown in baicalein + Immunocal showed a higher phosphatidylserine exposure, lower mitochondrial transmembrane potential, and nearly 13 times more cells undergoing apoptosis than cells grown in baicalein alone. We also demonstrated that Immunocal reduced glutathione (GSH) in Hep G2 cells by 20-40% and regulated the elevation of GSH, which was in response to baicalein. In conclusion, Immunocal seemed to enhance the cytotoxicity of baicalein by inducing more apoptosis; this increase in apoptotic cells may be associated with the depletion of GSH in Hep G2 cells. This is the first study to demonstrate, in vitro, that Immunocal may function as an adjuvant in cancer treatments.

Proteins, especially plant proteins, may reduce inflammation among adults with chronic kidney disease (CKD). This systematic review and meta-analysis were conducted to evaluate the effect protein types (animal or plant) have on inflammation markers (CRP, IL-6, TNF-α) among adults with varying stages of CKD. The Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) was conducted to identify articles from inception until January 2021, utilizing six databases. Controlled trials that compared the effects of different protein types were analyzed using random-effects meta-analysis. Quality assessment and risk of bias of the included articles were assessed by using Cochrane risk of bias instrument and ROBINS-I. Out of the 10 studies that met the criteria, there was a decreasing trend in CRP levels when consuming plant proteins compared to animal proteins among non-dialysis participants. There was a statistically significant decrease when comparing animal proteins to unspecified proteins in CRP levels among dialysis participants [Hedges' g = 2.11; 95% CI 1.12, 3.11; p ≤ 0.001], favoring unspecified proteins. Furthermore, animal proteins (eggs, red meat) showed increasing trends in CRP levels compared to whey protein isolate. Caution must be considered regarding these results as controlled, non-randomized, trials were included in the analysis, which may have contributed to high risk of bias. Future research should focus on protein types and the impact they have on kidney disease progression and inflammation markers.