Effects Of Whey Protein Supplementation Research Articles

Effects of Whey Protein Supplementation Pre- or Post-Resistance Training on Muscle Mass, Muscular Strength, and Functional Capacity in Pre-Conditioned Older Women: A Randomized Clinical Trial.

Aging is associated with sarcopenia and dynapenia, with both processes contributing to functional dependence and mortality in older adults. Resistance training (RT) and increased protein intake are strategies that may contribute to health improvements in older adults. Therefore, the aim was to investigate the effects of whey protein (WP) supplementation consumed either immediately pre- or post-RT on skeletal muscle mass (SMM), muscular strength, and functional capacity in pre-conditioned older women. Seventy older women participated in this investigation and were randomly assigned to one of three groups: whey protein pre-RT and placebo post-RT (WP-PLA, n = 24), placebo pre-RT and whey protein post-RT (PLA-WP, n = 23), and placebo pre- and post-RT (PLA-PLA, n = 23). Each group ingested 35 g of WP or PLA. The RT program was carried out over 12 weeks (three times per week; 3 × 8–12 repetition maximum). Body composition, muscular strength, functional capacity, and dietary intake were assessed pre- and post-intervention. Two-way analysis of covariance (ANCOVA) for repeated measures, with baseline scores as covariates were used for data analysis. A time vs. group interaction (p < 0.05) was observed with WP-PLA and PLA-WP presenting greater increases compared with PLA-PLA for SMM (WP-PLA = 3.4%; PLA-WP = 4.2%; PLA-PLA = 2.0%), strength (WP-PLA = 8.1%; PLA-WP = 8.3%; PLA-PLA = 7.0%), and the 10-m walk test (WP-PLA = −10.8%; PLA-WP = −11.8%; PLA-PLA = −4.3%). Whey protein supplementation was effective in promoting increases in SMM, muscular strength, and functional capacity in pre-conditioned older women, regardless of supplementation timing. This trial was registered at ClinicalTrials.gov: NCT03247192.

The Effect of Whey Protein Supplementation on the Recovery of Contractile Function following Resistance Training

The Effect of Whey Protein Supplementation on the Recovery of Contractile Function following Resistance Training

Effect of whey protein supplementation on body composition changes in women: a systematic review and meta-analysis.

A preponderance of evidence supports the beneficial effects of whey protein (WP) supplementation on body composition in men; however, there is currently insufficient evidence to make an equivalent claim in women. This systematic review and meta-analysis assessed the effects of WP supplementation with or without energy restriction (ER) and resistance training (RT) on changes in body mass, lean mass, and fat mass in women. Pubmed, Scopus, Cochrane, and CINAHL were searched using the keywords "whey protein," "body composition," and "lean mass." Two researchers independently screened 1845 abstracts and extracted 276 articles. Thirteen randomized controlled trials with 28 groups met the inclusion criteria. Globally, WP supplementation increased lean mass (WMD, 0.37 kg; 95% confidence interval [CI], 0.06 to 0.67) while not influencing changes in fat mass (-0.20 kg; 95%CI, -0.67 to 0.27) relative to non-WP control. The beneficial effect of WP on lean mass was lost when only studies with RT were included in the analysis (n = 7 comparisons; 0.23 kg; 95%CI, -0.17 to 0.63). The beneficial effect of WP on lean mass was more robust when only studies with an ER component were included (n = 6 comparisons; 0.90 kg; 95%CI, 0.31 to 1.49). There was no effect of WP on lean mass in studies without ER (n = 9 comparisons; 0.22 kg; 95%CI, -0.12 to 0.57). Whey protein supplementation improves body composition by modestly increasing lean mass without influencing changes in fat mass. Body composition improvements from WP are more robust when combined with ER .

Whey Protein Supplementation Improves Nutritional Status, Glutathione Levels, and Immune Function in Cancer Patients: A Randomized, Double-Blind Controlled Trial.

Clinical side effects from medical therapy play an important role in causing malnutrition among cancer patients. Whey protein isolates (WPIs) have the potential to improve the nutritional status of cancer patients. The present study determined the effects of whey protein supplementation on nutritional status, glutathione (GSH) levels, immunity, and inflammatory markers in cancer patients in Thailand. A total of 42 cancer patients (41-63 years old) who received intravenous chemotherapy were randomized in a double-blind controlled trial at the National Cancer Institute in Thailand. Patients received 40 g of WPI plus zinc and selenium (intervention group, n = 23) or a maltodextrin oral snack (control group, n = 19) every day during the daytime for 12 weeks. Nutritional status, GSH levels, immunity, and inflammatory markers were assessed at baseline, 6, and 12 weeks. Whey protein supplementation significantly increased albumin (2.9%) and immunoglobulin G (4.8%) levels compared to the control group at week 12. Controls showed a significantly lower percent change in GSH levels (6.0%), whereas there was a significant time-dependent increase in the intervention group (11.7%). Whey protein supplementation improved nutrition status scores in the intervention group compared to the control. These data indicate that whey protein supplementation can increase GSH levels and improve nutritional status and immunity in cancer patients undergoing chemotherapy. These results will facilitate implementation of malnutrition risk prevention strategies and improve protein status, including immune function, during chemotherapy.

The Effect of Whey Protein Supplementation on the Temporal Recovery of Muscle Function Following Resistance Training: A Systematic Review and Meta-Analysis.

Whey protein (WP) is a widely consumed nutritional supplement, known to enhance strength and muscle mass during resistance training (RT) regimens. Muscle protein anabolism is acutely elevated following RT, which is further enhanced by WP. As a result, there is reason to suggest that WP supplementation may be an effective nutritional strategy for restoring the acute loss of contractile function that occurs following strenuous RT. This systematic review and meta-analysis provides a synthesis of the literature to date, investigating the effect of WP supplementation on the recovery of contractile function in young, healthy adults. Eight studies, containing 13 randomised control trials (RCTs) were included in this review and meta-analysis, from which individual standardised effect sizes (ESs) were calculated, and a temporal overall ES was determined using a random-effects model. Whilst only half of the individual studies reported beneficial effects for WP, the high-quality evidence taken from the 13 RCTs was meta-analysed, yielding overall positive small to medium effects for WP from < 24 to 96 h (ES range = 0.4 to 0.7), for the temporal restoration of contractile function compared to the control treatment. Whilst the effects for WP were shown to be consistent over time, these results are limited to 13 RCTs, principally supporting the requirement for further comprehensive research in this area.

Effects of Whey Protein Supplementation Associated With Resistance Training on Muscular Strength, Hypertrophy, and Muscle Quality in Preconditioned Older Women.

The purpose of this study was to investigate the effect of whey protein (WP) supplementation on muscular strength, hypertrophy, and muscular quality in older women preconditioned to resistance training (RT). In a randomized, double-blind, and placebo (PLA)-controlled design, 31 older women (67.4 ± 4.0 years, 62.0 ± 6.9kg, 155.9 ± 5.7cm, and 25.5 ± 2.4kg/m2) received either 35g of WP (n = 15) or 35g of PLA (n = 16) over a 12-week study period while performing an RT program three times a week. Dietary intake, one-repetition maximum test, and skeletal muscle mass by dual-energy X-ray absorptiometry were assessed before and after the intervention period. Both groups showed significant (p < .05) improvements in skeletal muscle mass and total strength, and the WP group realized greater increases (p < .05) in these measures compared with PLA (skeletal muscle mass: WP = +4.8% vs. PLA = +2.3%; strength: WP = +8.7% vs. PLA = +4.9%). Muscular quality increased (p < .05) in both groups (WP = +2.9% vs. PLA = +1.5%) without statistical differences (p > .05) noted between conditions. We conclude that WP supplementation in combination with RT induces higher increases in both strength and hypertrophy in older women preconditioned to RT.

Effect of whey protein supplementation on levels of endocannabinoids and some of metabolic risk factors in obese women on a weight-loss diet: a study protocol for a randomized controlled trial

BackgroundBesides the effects of dietary long chain PUFA on circulating endocannabinoids concentrations, the impact of other nutrients on these system is not known and, whether changes in plasma endocannabinoids levels correlated with changes in body composition and biochemical metabolic risk factors in obese individuals, however, still remains to be characterized.MethodsWe will conduct a 2 months’ open label, parallel-group, randomized controlled trial to determine the effect of whey protein supplementation on levels of endocannabinoids, glycemic and lipid profile, inflammatory factors, adipocytokines and body composition in 60 premenopausal obese women on a weight-loss diet.ConclusionDue to strong relationship between endocannabinoids level and insulin resistance and obesity, in this trial, we will illustrate the other benefits of weight loss diet on health and metabolic risk factors. Also for the first, the effects of simultaneous weight loss diet and whey protein supplementation on these variables will be determined.Trial registrationIranian Registry of Clinical Trials IRCT2017021410181N8.

Whey protein supplementation in association with resistance training on additional muscle strength gain in older adults: A meta-analysis

Summary Objective To examine the effects of whey protein supplementation in association with resistance training on additional muscle strength gain in older adults. News Data concerning the effect of dietary interventions are emerging in the literature as a promising co-adjuvant intervention to potentiate muscle mass and strength gains. Whey protein concentrate may represent an ideal protein source to promote muscle anabolism in older individuals undergoing resistance exercise However, randomized controlled trials (RCTs) show contradictory results. Systematic review or meta-analysis has never been performed to investigate the effects of whey protein supplementation in additional muscle strength gain in elderly engaged in resistance exercise training. Prospects and projects Future investigations in effects of whey protein supplementation on muscle strength in older adults are needed to support the findings presented in the current review. Conclusions Whey protein supplementation in association with resistance exercise training did not contribute to additional gain of muscle strength in the older adults.

Effect of whey protein supplementation on long and short term appetite: A meta-analysis of randomized controlled trials

Specific components of dairy, such as whey proteins may have beneficial effects on body composition by suppressing appetite, although the findings of existing studies have been inconsistent. Therefore, a meta-analysis of randomized controlled trials was performed to investigate effect of whey protein supplementation on long and short term appetite. A systematic search was conducted to identify eligible publications. Means and SDs for hunger, fullness, satiety, desire to eat and prospective consumption of food, before and after intervention, were extracted and then composite appetite score (CAS) calculated. To pool data, either a fixed-effects model or a random-effects model and for assessing heterogeneity, Cochran's Q and I2 tests were used. Eight publications met inclusion criteria that 5 records were on short term and 3 records on long term appetite. The meta-analysis showed a significant reduction in long term appetite by 4.13 mm in combined appetite score (CAS) (95% Confidence interval (CI): −6.57, −1.96; p = 0.001). No significant reduction in short term appetite was also seen (Mean difference (MD) = −0.39 95% CI = −2.07, 1.30; p = 0.653). Subgroup analyses by time showed that compared with carbohydrate, the reduction in appetite following consumption of whey consumption was not significant (MD = −0.39, 95% CI = −2.07, 1.3, p = 0.65, I2 = 0.0%.)A significant reduction in prospective food consumption was seen (MD = −2.17, 95% CI = −3.86, −0.48). The results of our meta-analysis showed that whey protein may reduce the long and short term appetite, but our finding did not show any significant difference in appetite reduction between whey protein and carbohydrate in short duration.

Whey Protein Supplementation Enhances Body Fat and Weight Loss in Women Long After Bariatric Surgery: a Randomized Controlled Trial.

The ideal nutritional approach for weight regain after bariatric surgery remains unclear. The objective of this study is to assess the effect of whey protein supplementation on weight loss and body composition of women who regained weight 24 or more months after bariatric surgery. This is a 16-week open-label, parallel-group, randomized controlled trial of women who regained at least 5% of their lowest postoperative weight after a Roux-en-Y gastric bypass (RYGB). A total of 34 participants were treated with hypocaloric diet and randomized (1:1) to receive or not supplementation with whey protein, 0.5g/kg of the ideal body weight. The primary outcomes were changes in body weight, fat free mass (FFM), and fat mass (FM), evaluated by tetrapolar bioelectrical impedance analysis (BIA). Secondary outcomes included resting energy expenditure, blood glucose, lipids, adiponectin, interleukin 6 (IL-6), and cholecystokinin levels. Statistical analyses included generalized estimating equations adjusted for age and physical activity. Fifteen patients in each group were evaluated: mean age was 45±11years, body mass index (BMI) was 35.7±5.2kg/m2, and time since surgery was 69±23months. Protein intake during follow-up increased by approximately 75% in the intervention group (p=0.01). The intervention group presented more body weight loss (1.86kg, p=0.017), accounted for FM loss (2.78, p=0.021) and no change in FFM, as compared to controls (gain of 0.42kg of body weight and 0.6kg of FM). No differences in secondary outcomes were observed between groups. Whey protein supplementation promoted body weight and FM loss in women with long-term weight regain following RYGB.

Effects of whey protein supplement in the elderly submitted to resistance training: systematic review and meta-analysis

Aim: We performed a systematic review to map the evidence and analyze the effect of whey protein supplementation in the elderly submitted to resistance training.Methods: A comprehensive search on Medline, LILACS, EMBASE, and the Cochrane Library for relevant publications was conducted until August 2015. The terms used in the search were: “Resistance training”; “Whey protein”; “Elderly”.Results: A total of 632 studies were screened. Five studies were included composing a sample of 391 patients. The supplement whey protein was associated with higher total protein ingestion 9.40 (95% CI: 4.03–14.78), and with an average change in plasma leucine concentration. The supplementation was also associated with increased mixed muscle protein synthesis 1.26 (95% CI: 0.46–2.07) compared to the control group.Conclusion: We observed an increase in total protein intake, resulting in increased concentration of leucine and mixed muscle protein fractional synthesis rate.

Biochemical and clinical effects of Whey protein supplementation in Parkinson's disease: A pilot study

BackgroundParkinson's disease (PD) is an oxidative stress-mediated degenerative disorder. Elevated plasma homocysteine (Hcy) is frequently found in the levodopa-treated PD patients, is associated with disease progression and is a marker of oxidative stress. Whey protein is a rich source of cysteine, and branched-chain amino acids (BCAA). It has been shown that supplementation with Whey protein increases glutathione synthesis and muscle strength. Objectives and methodsIn this study, we conducted a placebo-controlled, double-blind study (NCT01662414) to investigate the effects of undenatured Whey protein isolate supplementation for 6months on plasma glutathione, plasma amino acids, and plasma Hcy in PD patients. Clinical outcome assessments included the unified Parkinson's disease rating scale (UPDRS) and striatal L-3,4-dihydroxy-6-(18)F-fluorophenylalanine (FDOPA) uptake were determined before and after supplementation. 15 patients received Whey protein, and 17 received Soy protein, served as a control group. ResultsSignificant increases in plasma concentration of reduced glutathione and the ratio of reduced to oxidized glutathione were found in the Whey-supplemented patients but not in a control group. This was associated with a significant decrease of plasma levels of Hcy. The plasma levels of total glutathione were not significantly changed in either group. Plasma BCAA and essential amino acids (EAA) were significantly increased in the Whey-supplemented group only. The UPDRS and striatal FDOPA uptake in PD patients were not significantly ameliorated in either group. However, significant negative correlation was observed between the UPDRS and plasma BCAA and EAA in the pre-supplemented PD patients. ConclusionThis study is the first to report that Whey protein supplementation significantly increases plasma reduced glutathione, the reduced to oxidized glutathione ratio, BCAAs and EAAs in patients with PD, together with a concomitant significant reduction of plasma Hcy. However, there were no significant changes in clinical outcomes. Long-term, large randomized clinical studies are needed to explore the benefits of Whey protein supplementation in the management of PD patients.

Effect of whey protein on blood lipid profiles: a meta-analysis of randomized controlled trials.

Previous studies have suggested that whey supplementation may have beneficial effects on lipid profiles, although results were inconsistent. A literature search was performed in March 2015 for randomized controlled trials observing the effects of whey protein and its derivatives on circulating levels of triacylglycerol (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). A meta-analysis was subsequently conducted. The meta-analysis results of 13 trials showed that whey supplementation significantly reduced the circulating TG level by 0.11 mmol/l (95% CI: -0.21, 0 mmol/l), whereas the whey protein had no effects on circulating TC (-0.11 mmol/l, 95% CI: -0.27, 0.05 mmol/l), LDL-C (-0.08 mmol/l, 95% CI: -0.23, 0.07 mmol/l) and HDL-C (0.01 mmol/l, 95% CI: -0.04, 0.05 mmol/l). Subgroup analysis showed that significant TG reduction disappeared in participants with low body mass index, low supplemental whey dose or under exercise training/energy restriction during the trial. No evidence of heterogeneity across studies and publication bias was observed. In conclusion, our findings demonstrated that the effects of whey protein supplementation were modest, with an overall lowering effect on TG but no effect on TC, LDL-C and HDL-C.

Two-Year Whey Protein Supplementation Did Not Enhance Muscle Mass and Physical Function in Well-Nourished Healthy Older Postmenopausal Women1–3

Background: Protein may play a role in preventing muscle loss with aging. To our knowledge, there have been no long-term randomized controlled trials to examine the effects of increased dietary protein intake on muscle health in community-dwelling older women.Objective: In this study, we evaluated the effects of whey protein supplementation on muscle mass and physical function in community-dwelling older Australian women.Methods: In this 2 y randomized, double-blind, placebo-controlled trial, women aged 70–80 y (mean 74.3 ± 2.7 y) were randomly assigned to either a high protein drink containing 30 g of whey protein (n = 109) or a placebo drink containing 2.1 g protein (n = 110) daily. Dual-energy X-ray absorptiometry appendicular skeletal muscle mass, upper arm and calf (38% tibia) muscle cross-sectional area, physical function including hand grip strength, lower limb muscle strength and Timed Up and Go test, and 24 h urinary nitrogen were measured at baseline, 1 y, and 2 y.Results: A total of 196 women with at least one follow-up measurement were included in this analysis. Baseline mean BMI was 26.7 ± 3.9 kg/m2 and protein intake was 76 ± 17 g/d (1.1 ± 0.3 g · kg body weight−1 · d−1). A mean increase in protein intake of ∼20 g/d in the protein group was confirmed by the estimates from 24 h urinary nitrogen. Over the 2 y in both groups there was a significant decrease in the upper arm (mean ± SE: −5.59 ± 0.75 cm2) and calf (−0.77 ± 0.11 cm2) muscle area, as well as hand grip strength (−1.30 ± 0.3 kg) (all P < 0.05), but appendicular skeletal muscle mass did not change significantly. There were no significant effects of the protein intervention on any of the muscle mass or physical function measures (all P > 0.05) at 1 and 2 y.Conclusion: This study showed that in protein-replete, healthy, ambulant, postmenopausal older women, 30 g/d of extra protein did not improve the maintenance of muscle mass or physical function despite evidence of deterioration in muscle measurements in the upper limb. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN012607000163404.

Whey protein and high-volume resistance training in postmenopausal women.

To examine the combined effects of whey protein supplementation and low intensity, high-volume resistance training in healthy postmenopausal women. Postmenopausal women (n=12; age: 57 ± 4.7 years, weight: 75 ± 17.4 kg, height: 163 ± 5.5 cm, body mass index: 28.3 ± 7.0) consumed whey protein (4 x 10 gram aliquots) or placebo (maltodextrin) during unilateral resistance training sessions 2 days per week (Monday, Thursday) and consumed the opposite beverage during training the other side of the body on alternating days (Tuesday, Friday) for 10 weeks. Participants performed 3 sets at 30% baseline 1-repetition maximum (1RM) to volitional muscle fatigue for 4 exercises (leg curl, biceps curl, leg extension, triceps extension). Prior to and following training, assessments were made for upper and lower limb lean tissue mass (dual energy x-ray absorptiometry), muscle thickness of the elbow and knee flexors and extensors (ultrasound) and muscle strength (1RM leg curl, biceps curl, leg extension, triceps extension). There was a significant increase over time for muscle strength (biceps curl, leg extension, triceps extension; P = 0.006) and muscle thickness (elbow flexors and extensors; P = 0.022) with no differences between whey protein and placebo. High volume resistance training is effective for improving some indices of muscle mass and strength in postmenopausal women, but the strategic ingestion of whey protein during training sessions does not augment this response.

The effects of whey protein supplementation on body composition and physical performance tests in men (381.2)

The purpose of this study was to determine the effects of whey protein supplements on total and regional body compositions and physical performance tests in response to 10 weeks of resistance training. Twenty‐four men aged 18‐32 years, mean age 23 ± 3.4 years, were randomly divided into Protein (P) group, with whey protein supplementation (70 g/day on training days and 35 g/day on non‐training days) or Control (C) group, without supplementation. Daily mean total protein intakes of P and C groups were 118.2 ± 27.3 g (2.25 ± 0.26 g / kg BW) and 66.3 ± 15.0 g (1.16 ± 0.26g /kg BW), respectively (p &lt; 0.001). All subjects trained 3 days/week for 10 weeks. At 0 and 10th weeks, subjects underwent bioelectrical impedance for total and regional body composition measurements and physical performance tests; i.e., one repetition maximum (1RM) strength, hand grip, and wall sit time tests. Data were analyzed using repeated measures ANOVA and presented as mean ±SD changes from baseline. No significant group x time interaction effects were observed among groups in changes in any variable. A significant time effect was observed for lean mass (P:2.3 ± 3.6 kg; C:0.8 ± 0.9 kg), mid‐upper arm area (P:8.0 ± 5.5 cm2; C:0.9 ± 2.5 cm2), bench press 1RM (P:18.5 ± 7.5 kg; C:11.4 ± 6.7 kg), wall sit time test (P:5.9 ± 18.4 sec; C:20.5 ± 31.2 sec), and handgrip test (P:4.9 ± 3.8; C:2.5 ± 2.2,) (all, p &lt; 0.001). During resistance training, daily supplementation with whey protein was effective for promoting gains in lean mass and muscle strength.Grant Funding Source: Supported by Hacettepe University Scientific Research Projects Coordination Unit

Effect of resistance exercise contraction mode and protein supplementation on members of the STARS signalling pathway

The striated muscle activator of Rho signalling (STARS) pathway is suggested to provide a link between external stress responses and transcriptional regulation in muscle. However, the sensitivity of STARS signalling to different mechanical stresses has not been investigated. In a comparative study, we examined the regulation of the STARS signalling pathway in response to unilateral resistance exercise performed as either eccentric (ECC) or concentric (CONC) contractions as well as prolonged training; with and without whey protein supplementation. Skeletal muscle STARS, myocardian-related transcription factor-A (MRTF-A) and serum response factor (SRF) mRNA and protein, as well as muscle cross-sectional area and maximal voluntary contraction, were measured. A single-bout of exercise produced increases in STARS and SRF mRNA and decreases in MRTF-A mRNA with both ECC and CONC exercise, but with an enhanced response occurring following ECC exercise. A 31% increase in STARS protein was observed exclusively after CONC exercise (P < 0.001), while pSRF protein levels increased similarly by 48% with both CONC and ECC exercise (P < 0.001). Prolonged ECC and CONC training equally stimulated muscle hypertrophy and produced increases in MRTF-A protein of 125% and 99%, respectively (P < 0.001). No changes occurred for total SRF protein. There was no effect of whey protein supplementation. These results show that resistance exercise provides an acute stimulation of the STARS pathway that is contraction mode dependent. The responses to acute exercise were more pronounced than responses to accumulated training, suggesting that STARS signalling is primarily involved in the initial phase of exercise-induced muscle adaptations.

Effects of whey protein supplementation on dietary compensation and muscle energetics in elderly adults

PurposeThis study assessed the effects of whey protein (WPro) supplementation on dietary compensation (DC) and skeletal muscle gross mechanical efficiency (GME), an index of muscle energetics, in elderly people.MethodsUsing a randomized, crossover design, 12 adults (7 F, 5 M), aged 82 ± 7 y (mean ± SD) completed two 6‐day periods of consuming fruit‐smoothie beverages twice daily (with breakfast and lunch) containing 230 kcal and 25 g WPro or 25 g corn‐derived glucose polymer (CHO) (total 460 kcal/d and 50 g/day WPro or CHO). On day 7 of each period, GME was measured while the subjects were fasting and exercising on a stationary cycle at 1, 10, and 20 watts.ResultsCompared with baseline, total energy intake was ~286 kcal/d higher during WPro and CHO, consistent with incomplete DC to the supplements (~36–40% DC). Total protein intake was 46 ± 13 g/d higher with WPro vs. CHO. During exercise, GME was progressively higher from 1 to 10 to 20 watts. Compared to baseline, GME was not different for WPro or CHO. Among all subjects, the magnitude of DC did not influence the change in GME at 1, 10, or 20 watts.ConclusionFor elderly adults, short‐term use of supplements with whey protein or glucose polymer effectively increase total energy intake due to incomplete dietary compensation. These dietary changes did not influence muscle energetics during low‐level physical activity.Support: NIH CTSI Grant #TR000006

Changes in antioxidant status and cardiovascular risk factors of overweight young men after six weeks supplementation of whey protein isolate and resistance training

The study’s purpose was to examine the effects of whey protein supplementation and resistance training on antioxidant status and cardiovascular risk factors in overweight young men. Thirty healthy male subjects (age, 23.4±3.6years; body mass index, 25–30kg/m2) were randomly divided into three groups of 10 persons including; Experimental group 1: resistance training+whey supplement (RW); Experimental group 2: resistance training+placebo (RP), and Control group (C). Subjects in intervention groups underwent 3 resistance training sessions per week, each session with 60–70% 1RM, for 6weeks. No significant changes in fibrinogen level, fasting blood glucose, resting systolic and diastolic blood pressures, waist to hip ratio (WHR), and body mass index were observed in any of the groups. Total antioxidant capacity (TAC), cholesterol and HDL varied significantly in the RW group compared with the pre-test. We found significant changes in both RW and RP groups for glutathione, vitamin C, LDL, and triglyceride levels. In addition, in the post-test, TAC, glutathione, and HDL levels were higher in the RW in comparison to C group. Research findings showed that although exercise can lead to antioxidant system improvement and reduce some cardiovascular risk factors among overweight subjects, the combination of resistance training and whey consumption is more effective.

Effects of whey protein supplements on metabolism

Epidemiological studies indicate that the consumption of milk and dairy products is inversely associated with a lower risk of metabolic disorders and cardiovascular diseases. In particular, whey protein seems to induce these effects because of bioactive compounds such as lactoferrin, immunoglobulins, glutamine and lactalbumin. In addition, it is an excellent source of branch chained amino acids. This review summarizes recent findings on the effects of whey protein on metabolic disorders and the musculoskeletal system. We identified 25 recently published intervention trials examining chronic and/or acute effects of whey protein supplementation on lipid and glucose metabolism, blood pressure, vascular function and on the musculoskeletal system. Whey protein appears to have a blood glucose and/or insulin lowering effect partly mediated by incretins. In addition, whey protein may increase muscle protein synthesis. In contrast there are no clear-cut effects shown on blood lipids and lipoproteins, blood pressure and vascular function. For bone metabolism the data are scarce. In summary, whey protein may affect glucose metabolism and muscle protein synthesis. However, the evidence for a clinical efficacy is not strong enough to make final recommendations with respect to a specific dose and the duration of supplementation.