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

Impact of Quantity and Type of Dietary Protein on Cardiovascular Disease Risk Factors Using Standard and Network Meta-analyses of Randomized Controlled Trials

CONTEXT

Higher protein diets (HPDs) have shown favorable outcomes on weight maintenance and body-composition management; however, their protective effects against cardiovascular diseases (CVDs) remain uncertain and contentious. Furthermore, it is important to consider the influence of other macronutrients in the diet and type of dietary protein when studying HPDs, because this aspect has been overlooked in previous studies.

OBJECTIVE

We assessed the impacts of quantity and type of dietary protein on CVD risk factors.

DATA SOURCES

A database search was conducted in PubMed, Embase, CINAHL, Web of Science, and Cochrane Library and a total of 100 articles met the eligibility criteria.

DATA EXTRACTION

Extracted data from 100 articles were analyzed using standard meta-analysis, and 41 articles were also analyzed using network meta-analysis.

DATA ANALYSIS

In the standard meta-analysis, an HPD had significant favorable effects on systolic blood pressure (SBP) (mean difference [MD] = -1.51 mmHg; 95% CI: -2.77, -0.25), diastolic blood pressure (DBP) (MD = -1.08 mmHg; 95% CI: -1.81, -0.35), and flow-mediated dilation (MD = 0.78%; 95% CI: 0.09, 1.47) compared with lower protein diets. The further network meta-analysis supported that the high-protein, high-carbohydrate, low-fat diet was the most recommended diet to ensure a maximum decrease in SBP, DBP, total cholesterol (TC), and low-density-lipoprotein cholesterol (LDL-C). In comparison to animal-protein-rich diets, plant-protein-rich diets (PPRs) exhibited a significant favorable effects on improving TC (MD = -0.12 mmol/L; 95% CI: -0.19, -0.05), triglyceride (MD = -0.05 mmol/L; 95% CI: -0.09, -0.01), LDL-C (MD = -0.11 mmol/L; 95% CI: -0.18, -0.04), and high-density-lipoprotein cholesterol (MD = 0.03 mmol/L; 95% CI: 0.02, 0.04) levels.

CONCLUSION

Consumption of HPDs and PPRs supports improvements in vascular health and lipid-lipoprotein profiles, respectively. Furthermore, macronutrient composition should be carefully designed in the dietary approach to maximize the effectiveness of HPDs in improving CVD risk factors.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022369931.

Whey proteins as a functional food: Health effects, functional properties, and applications in food

Functional foods are defined as foods and ingredients that exhibit health benefits beyond their nutritional value. Research on functional foods is increasing rapidly as they may help prevent and manage some non-communicable diseases. Whey proteins are recognized as a high-quality nutrient source and known to contain some bioactive components. They are rich in essential amino acids such as cysteine, branched-chain amino acids such as leucine, valine, and isoleucine, and bioactive peptides. Whey proteins look promising as a potential functional food, given its antioxidant, anti-inflammatory, blood pressure lowering, anti-obesity, and appetite suppressing effects that is discussed in the literature. Whey proteins also show functional properties that play an essential role in food processing as an emulsifier, fat-replacer, gelling and encapsulating agent and are known to improve sensory and textural characteristics of food. This review focuses on the functional food aspects of whey proteins, associated health effects, and current food applications.

Effects of supplementation with milk protein on glycemic parameters: a GRADE-assessed systematic review and dose-response meta-analysis

BACKGROUND

It is suggested that supplementation with milk protein (MP) has the potential to ameliorate the glycemic profile; however, the exact impact and certainty of the findings have yet to be evaluated. This systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) assessed the impact of MP supplementation on the glycemic parameters in adults.

METHODS

A systematic search was carried out among online databases to determine eligible RCTs published up to November 2022. A random-effects model was performed for the meta-analysis.

RESULTS

A total of 36 RCTs with 1851 participants were included in the pooled analysis. It was displayed that supplementation with MP effectively reduced levels of fasting blood glucose (FBG) (weighted mean difference (WMD): -1.83 mg/dL, 95% CI: -3.28, -0.38; P = 0.013), fasting insulin (WMD: -1.06 uU/mL, 95% CI: -1.76, -0.36; P = 0.003), and homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -0.27, 95% CI: -0.40, -0.14; P < 0.001) while making no remarkable changes in serum hemoglobin A1c (HbA1c) values (WMD: 0.01%, 95% CI: -0.14, 0.16; P = 0.891). However, there was a significant decline in serum levels of HbA1c among participants with normal baseline body mass index (BMI) based on sub-group analyses. In addition, HOMA-IR values were significantly lower in the MP supplement-treated group than their untreated counterparts in short- and long-term supplementation (≤ 8 and > 8 weeks) with high or moderate doses (≥ 60 or 30-60 g/d) of MP or whey protein (WP). Serum FBG levels were considerably reduced upon short-term administration of a low daily dose of WP (< 30 g). Furthermore, the levels of serum fasting insulin were remarkably decreased during long-term supplementation with high or moderate daily doses of WP.

CONCLUSION

The findings of this study suggest that supplementation with MP may improve glycemic control in adults by reducing the values of fasting insulin, FBG, and HOMA-IR. Additional trials with longer durations are required to confirm these findings.

The effects of whey protein on blood pressure: A systematic review and dose-response meta-analysis of randomized controlled trials

AIMS

This systematic review and dose-response meta-analysis was conducted to summarize data from available clinical trials on the effects of whey protein (WP) supplementation on blood pressure (BP) in adults.

DATA SYNTHESIS

A comprehensive literature search was conducted in the electronic databases PubMed, Web of Science, ProQuest, Embase, and SCOPUS from inception to October 2022. Weighted mean differences (WMD) and 95% confidence intervals (CI) were calculated to assess pooled effect sizes. Heterogeneity between studies was assessed using the Cochran's Q test and I2. Subgroup analysis was performed to assess potential sources of heterogeneity. The dose-response relationship was assessed using fractional polynomial modeling. Of the 2,840 records, 18 studies with 1,177 subjects were included. Pooled analysis showed that whey protein supplementation resulted in a significant reduction in systolic blood pressure (WMD: -1.54 mmHg; 95% CI: -2.85 to -0.23, p = 0.021), with significant heterogeneity between studies (I2 = 64.2%, p < 0.001), but not for diastolic blood pressure (DBP) (WMD: -0.27 mmHg; 95% CI: -1.14, 0.59, p = 0.534) with high heterogeneity between studies (I2 = 64.8%, p < 0.001). However, WP supplementation significantly reduced DBP at a dose of ˃30 g/day, in RCTs that used WP isolate powder for their intervention, in sample sizes ≤100, in studies with an intervention duration of ≤10 weeks, and in those studies that were conducted in patients with hypertension and had participants with a BMI of 25-30 kg/m2.

CONCLUSION

This meta-analysis demonstrated that WP intake significantly reduced SBP levels. Further large-scale studies are needed to specify the exact mechanism, and optimal dosage of WP supplementation to obtain a beneficial effect on BP.

Bioactive milk peptides: an updated comprehensive overview and database

Partial digestion of milk proteins leads to the formation of numerous bioactive peptides. Previously, our research team thoroughly examined the decades of existing literature on milk bioactive peptides across species to construct the milk bioactive peptide database (MBPDB). Herein, we provide a comprehensive update to the data within the MBPDB and a review of the current state of research for each functional category from in vitro to animal and clinical studies, including angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, antioxidant, dipeptidyl peptidase (DPP)-IV inhibitory, opioid, anti-inflammatory, immunomodulatory, calcium absorption and bone health and anticancer activity. This information will help drive future research on the bioactivities of milk peptides.

Benefits of Whey Proteins on Type 2 Diabetes Mellitus Parameters and Prevention of Cardiovascular Diseases

Type 2 diabetes mellitus (T2DM) is a major cause of morbidity and mortality, and it is a major risk factor for the early onset of cardiovascular diseases (CVDs). More than genetics, food, physical activity, walkability, and air pollution are lifestyle factors, which have the greatest impact on T2DM. Certain diets have been shown to be associated with lower T2DM and cardiovascular risk. Diminishing added sugar and processed fats and increasing antioxidant-rich vegetable and fruit intake has often been highlighted, as in the Mediterranean diet. However, less is known about the interest of proteins in low-fat dairy and whey in particular, which have great potential to improve T2DM and could be used safely as a part of a multi-target strategy. This review discusses all the biochemical and clinical aspects of the benefits of high-quality whey, which is now considered a functional food, for prevention and improvement of T2DM and CVDs by insulin- and non-insulin-dependent mechanisms.

Donkey whey protein and peptides regulate gut microbiota community and physiological functions of D-galactose-induced aging mice

The prolongation of life span has attracted more and more attention in the current world. Gut microbiota is considered one of the most critical elements and is essential in regulating life span and quality. The effects of donkey whey protein (DWP) and donkey whey hydrolysate (DWPP) on physiological functions and gut microbiota of D-galactose-induced aging mice were investigated to find new strategies for resisting aging. Our results showed that DWP and DWPP could increase the body weight gain velocity, superoxide dismutase (SOD) activity, and thymus index, whereas decrease the level of reactive oxygen species (ROS) and malondialdehyde (MDA), and improve the aging of the body in the liver congestion, oozy draw focal sclerosis of chronic inflammation. The effects of medium and high concentrations of DWP and low and medium concentrations of DWPP were the same as the vitamin C (Vc)-positive control group. It was found that both DWP and DWPP could change α-diversity; the relative abundance of Lactobacillus increased, whereas the relative abundance of Helicobacter and Stenotrophomonas decreased after being treated with DWP and DWPP. The correlation between intestinal microflora and physiological indexes showed that chao1, ACE, and observed species indexes in the α index were positively correlated with weight gain velocity, SOD activity, and thymus index. The relative abundance of Lactobacillus was positively correlated with SOD and thymus index but negatively correlated with MDA. The relative abundance of Stenotrophomonas was opposite to that of Lactobacillus. The Anaerobiospirillum, Fusobacterium, and Dubosiella had a significant positive correlation with the weight gain velocity. The study provided a deeper more profound understanding of the potential use of DWP and DWPP in senescence delays.

Transepithelial transport and cellular mechanisms of food-derived antioxidant peptides

Considering the involvement of oxidative stress in the etiology of many non-communicable diseases, food-derived antioxidant peptides (FDAPs) are strong candidates for nutraceutical development for disease prevention and management. This paper reviews current evidence on the transepithelial transport and cellular mechanisms of antioxidant activities of FDAPs. Several FDAPs have multiple health benefits such as anti-inflammatory and anti-photoaging activities, in addition to antioxidant properties through which they protect cellular components from oxidative damage. Some FDAPs have been shown to permeate the intestinal epithelium, which could facilitate their bioavailability and physiological bioactivities. Molecular mechanisms of FDAPs include suppression of oxidative stress as evidenced by reduction in intracellular reactive oxygen species production, lipid peroxidation and apoptotic protein activation as well as increase in antioxidant defense mechanisms (enzymatic and non-enzymatic). Since many FDAPs have demonstrated promising antioxidant activity, future investigation should focus on further elucidation of molecular mechanisms and human studies to explore their practical application for the prevention and management of oxidative stress-related diseases.

Resistance training effectiveness on body composition and body weight outcomes in individuals with overweight and obesity across the lifespan: A systematic review and meta-analysis

To systematically review and analyze the effects of resistance-based exercise programs on body composition, regional adiposity, and body weight in individuals with overweight/obesity across the lifespan. Using PRISMA guidelines, randomized controlled trials were searched in nine electronic databases up to December 2020. Meta-analyses were performed using random-effects model. One-hundred sixteen articles describing 114 trials (n = 4184 participants) were included. Interventions involving resistance training and caloric restriction were the most effective for reducing body fat percentage (ES = -3.8%, 95% CI: -4.7 to -2.9%, p < 0.001) and whole-body fat mass (ES = -5.3 kg, 95% CI: -7.2 to -3.5 kg, p < 0.001) compared with groups without intervention. Significant results were also observed following combined resistance and aerobic exercise (ES = -2.3% and -1.4 kg, p < 0.001) and resistance training alone (ES = -1.6% and -1.0 kg, p < 0.001) compared with no training controls. Resistance training alone was the most effective for increasing lean mass compared with no training controls (ES = 0.8 kg, 95% CI: 0.6 to 1.0 kg, p < 0.001), whereas lean mass was maintained following interventions involving resistance training and caloric restriction (ES = ~ - 0.3 kg, p = 0.550-0.727). Results were consistently observed across age and sex groups (p = 0.001-0.011). Reductions in regional adiposity and body weight measures were also observed following combined resistance and aerobic exercise and programs including caloric restriction (p < 0.001). In conclusion, this study provides evidence that resistance-based exercise programs are effective and should be considered within any multicomponent therapy program when caloric restriction is utilized in individuals with overweight or obesity.

Effect of high-intensity resistance exercise on cardiometabolic health in older men with osteosarcopenia: the randomised controlled Franconian Osteopenia and Sarcopenia Trial (FrOST)

OBJECTIVES

Sarcopenia is related to the metabolic syndrome (MetS), a cluster of cardiometabolic risk-factors (CRF). Most exercise trials apply aerobic rather than resistance exercise to address CRF, while the strategy for maintaining muscle and bone is the opposite. However, there is considerable evidence that resistance exercise positively affects CRF. In the present study, we determined the effect of high-intensity resistance exercise training (HIT-RT) on CRF represented by the MetS in older men.

METHODS

Forty-three osteosarcopenic and predominately obese older men (>72 years) living independently in Erlangen-Nürnberg, Germany were randomly assigned to two study arms. The HIT-RT group (n=21) conducted a periodised high intensity/effort protocol dedicated to muscle and bone mass and function two times per week, while the control group (CG: n=22) maintained their habitual physical activities. Both groups were supplemented with protein, cholecalciferol and calcium. Study outcomes presented here were the MetS-Z (MetSZ) score and its underlying risk-factors.

RESULTS

After 18 months of intervention, we observed significant effects for the MetSZ score (p<0.001), with significant improvements in the HIT-RT and significant worsening in the CG. In detail, all parameters constituting the MetS contributed to this result, however, only waist-circumference, HDL-cholesterol and mean arterial blood pressure revealed significant effects. No adverse events were reported and high adherence was determined for the HIT-RT-protocol.

CONCLUSION

Continuously supervised HIT-RT is an effective, attractive, feasible and safe method to address cardiometabolic risk factors in community-dwelling men aged 72 years and older. Further, considering the proven effects on musculoskeletal risk factors, the present results indicate a more prominent role for HIT-RT within non-pharmacological prevention strategies of older adults.

TRIAL REGISTRATION NUMBER

NCT03453463.

Effects of whey protein on glycemic control and serum lipoproteins in patients with metabolic syndrome and related conditions: a systematic review and meta-analysis of randomized controlled clinical trials

Background

This systematic review and meta-analysis aimed to assess the effects of whey protein on serum lipoproteins and glycemic status in patients with metabolic syndrome (MetS) and related disorders.

Methods

Online databases, such as Web of Science, Cochrane Library, PubMed and Scopus were systematically searched by two independent authors from inception until 30th April 2020 for English randomized clinical trials investigating the efficacy of whey protein administration in subjects with Mets or related conditions on the parameters of glycemic and lipid control compared to certain control. In order to evaluate the included studies’ methodological quality, Cochrane Collaboration risk of bias tool was applied. Using Cochrane’s Q test and I-square (I²) statistic, the included trials’ heterogeneity was also examined. Using a random-effects model, data were pooled, and weighted mean difference (WMD) was considered as the overall effect size.

Results

Twenty-two studies were selected to be included in this meta-analysis. Consumption of whey protein resulted in significant reduction of HbA1c (WMD: -0.15; 95% CI: − 0.29, − 0.01) insulin (WMD: -0.94; 95% CI: − 1.68, − 0.21) and homeostasis model assessment-estimated insulin resistance (HOMA-IR) (WMD: -0.20; 95% CI: − 0.36, − 0.05). A significant reduction in triglycerides levels (WMD: -17.12; 95% CI: − 26.52, − 7.72), total cholesterol (WMD: -10.88; 95% CI -18.60, − 3.17), LDL-cholesterol levels (WMD: -8.47 95% CI: − 16.59, − 0.36) and total cholesterol/HDL-cholesterol ratio (WMD: -0.26; 95% CI: − 0.41, − 0.10) was found as well.

Conclusions

This meta-analysis suggests that supplementation with whey protein had beneficial effect on several indicators of glycemic control and lipid parameters in patients with MetS and related conditions.

Applications of Ma'aljobon, a natural remedy from traditional Persian medicine, in dermatology: A journey from past to modernity

Ma'aljobon, a handmade substance, is the liquid portion of coagulated milk after adding vinegar to the heated milk. In traditional Persian medicine (TPM) it has been known as a useful remedy for the treatment of some skin disorders. The aim of this study was to review the applications of Ma'aljobon for skin diseases according to the sages of TPM and modern medicine. Main TPM sources were reviewed with the keyword of "Ma'aljobon." Furthermore, electronic databases including Scopus, PubMed, SID, and Google Scholar were searched with the keyword "Whey protein" during 2000 to 2018. According to TPM sources, Ma'aljobon was used by Iranian sages as a safe and effective remedy to treat a wide range of skin diseases, such as pimples, and ulcers. Meantime, recent evidence has also shown the effectiveness of whey protein in treating some skin disorders such as atopic dermatitis. Gastrointestinal discomfort was the most adverse effect of Ma'aljobon mentioned in TPM sources. In conclusion, there were several applications for Ma'aljobon in treatment of dermatologic disease according to TPM, as well as modern medicine. These finding could be the basis of future clinical trials on the effects of Ma'aljobon in the treatment of skin problems.

Effect of Whey Protein Supplementation on Inflammatory and Antioxidant Markers, and Clinical Prognosis in Acute Ischemic Stroke (TNS Trial): A Randomized, Double Blind, Controlled, Clinical Trial

Purpose: Malnutrition is extensively prevalent amongst critically ill patients afflicted by ischemic stroke (IS). This study purpose was to evaluate the protein whey effect on inflammatory and antioxidant markers and functional prognosis in acute IS patients.

Methods: out of 42 patients with acute IS who were referred to Imam Reza Educational Hospital, Tabriz, Iran, 40 patients participated in the study. Twenty-one patients as control group received the hospital routine formula, and 19 patients as intervention group received 20 g/daily of whey protein through oral gavage. Inflammation and oxidative stress indicators (e.g., albumin, malondialdehyde (MDA), total antioxidant capacity (TAC), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and high sensitivity C reactive protein (hs-CRP)and clinical variables included in were evaluated using National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) during admission and also 3 weeks after intervention.

Results: Whey protein supplementation significantly decreased the NIHSS and mRS scores, TNF-α, IL-6, and hs-CRP by passing 3 weeks from intervention (P<0.05). However, whey formula had no significant effect on other markers including albumin, and MDA. The hs-CRP (P = 0.02) reduction was significantly higher in whey protein group in comparison with control group.

Conclusion: Whey protein supplementation reduced inflammation markers in those patients with IS. However, these changes should be studied in larger-scale trials.

The effect of whey protein on the components of metabolic syndrome in overweight and obese individuals; a systematic review and meta-analysis

BACKGROUND

The risk of developing chronic diseases such as diabetes, cardiovascular disease, dyslipidemia, and stroke is increased following an outbreak of metabolic syndrome. Whey protein can play a major role in preventing metabolic syndrome.

OBJECTIVE

This study was conducted to systematically evaluate the effect of whey protein on the components of metabolic syndrome in overweight and obesity patients.

METHODS

This systematic review and meta-analysis was conducted on RCTs (PROSPERO registration number: CDR42019114794). Published articles of controlled trials between 1 January 2000 to 30 May 2019 indexed in PubMed, Scopus, Web of Science and Cochrane Library were reviewed. Keywords were Whey Protein, Metabolic Syndrome, HDL Lipoprotein, Blood Pressure, Triglyceride, Fasting Blood Glucose, Waist Circumference, Overweight and Obesity or a combination of them in the title/abstracts. The mean difference was extracted for each study. All analyses performed using STATA version 11.

RESULTS

There were 2344 individuals reviewed in this systematic review of 37 published articles.

CONCLUSION

According to the results, whey supplementation significantly reduced the SBP, DBP, HDL, waist circumference, TG and FBS in intervention groups in comparing to control groups.

Whey proteins: targets of oxidation, or mediators of redox protection

Bovine whey proteins are highly valued dairy ingredients. This is primarily due to their amino acid content, digestibility, bioactivities and their processing characteristics. One of the reported bioactivities of whey proteins is antioxidant activity. Numerous dietary intervention trials with humans and animals indicate that consumption of whey products can modulate redox biomarkers to reduce oxidative stress. This bioactivity has in part been assigned to whey peptides using a range of biochemical or cellular assays in vitro. Superimposing whey peptide sequences from gastrointestinal samples, with whey peptides proven to be antioxidant in vitro, allows us to propose peptides from whey likely to exhibit antioxidant activity in the diet. However, whey proteins themselves are targets of oxidation during processing particularly when exposed to high thermal loads and/or extensive processing (e.g. infant formula manufacture). Oxidative damage of whey proteins can be selective with regard to the residues that are modified and are associated with the degree of protein unfolding, with α-Lactalbumin more susceptible than β-Lactoglobulin. Such oxidative damage may have adverse effects on human health. This review summarises how whey proteins can modulate cellular redox pathways and conversely how whey proteins can be oxidised during processing. Given the extensive processing steps that whey proteins are often subjected to, we conclude that oxidation during processing is likely to compromise the positive health attributes associated with whey proteins.

RESISTANCE EXERCISE PROTOCOL DOES NOT CAUSE ACUTE GENOTOXIC EFFECTS IN TRAINED INDIVIDUALS

ABSTRACT Introduction: Resistance exercise, particularly strength training, has been progressively gaining more and more followers worldwide. Despite a considerable increase in the amount of research and literature available on this topic, resistance training is undergoing important developments. Anaerobic metabolism, which characterizes resistance training, enhances the ischemic process and blood reperfusion, thereby generating reactive oxygen species (ROS). The imbalance between the production of free radicals and antioxidant defenses may induce oxidative stress with subsequent protein oxidation, lipid peroxidation, DNA damage in several cells, and other effects. This process may be intensified at rest because the O2 deficit is counteracted by a process known as excess post-exercise oxygen consumption. Objective: To analyze the effects of ROS in strength training on the DNA of human lymphocyte, biomarkers of lipid damage (TBARS) and metabolism (triglycerides, protein, glycose, albumin and urea). Methods: Comet assay involving a count of 100 cells, which were divided into five classes of damage (no damage = 0, maximum damage = 4), thereby constituting an indication of DNA damage, and the micronucleus test, where the cell samples were centrifuged at 1000-1500 RPM for ten minutes at room temperature for the micronuclei analysis. Results: An elevation in triglyceride concentrations was observed 5h post-exercise (p=0.018), probably due to nutrition. There were no significant differences in the other biochemical parameters. In terms of the DNA damage measured by the Comet assay and micronucleus test, no statistical differences were observed until 5h post-exercise. Conclusion: The proposed training session did not cause oxidative or genotoxic damage in trained individuals under the proposed conditions. Level of Evidence II; Prognostic studies-Investigation of the effect of patient characteristics on the disease outcome.

High-fat diet leads to adiposity and adipose tissue inflammation: the effect of whey protein supplementation and aerobic exercise training

There is little understanding about dietary proteins and their potential contribution to obesity-induced inflammation. This study investigates the effect of 10 weeks of aerobic training and whey protein (WP) supplementation on visceral adipose tissue inflammation in rats fed a high-fat diet (HFD). In the first phase, which lasted 9 weeks, 40 male Wistar rats were randomly divided into 2 groups: (1) normal diet (n = 8), and (2) HFD (n = 32). In the second phase, rats fed an HFD were randomly assigned into 4 groups (n = 8/group): (1) sedentary, (2) WP, (3) aerobic training, and (4) WP + aerobic training. The aerobic training was performed for 10 weeks, 5 days/week at 21 m/min, 15% incline, for 60 min/day. HFD significantly increased body weight, adiposity index, fat pads weight, glucose levels, and insulin resistance index compared with the normal diet. Also, levels of tumor necrosis factor alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), hypoxia inducible factor 1 alpha (HIF-1α), and vascular endothelial growth factor A (VEGF-A) in adipose tissue and serum levels of TNF-α were increased in the HFD group. Glucose levels, insulin resistance index, and triglycerides were reduced only by WP, independently of aerobic training. Both the aerobic training and WP reduced the fat pads weight and levels of TNF-α, HIF-1α, and VEGF-A in adipose tissue. Nevertheless, the levels of MCP-1 in adipose tissue and serum levels of TNF-α and MCP-1 were not reduced significantly by WP or aerobic training. These findings suggest that both aerobic training and WP supplementation lead to a reduction in adiposity and ameliorate obesity-induced inflammation in visceral adipose tissue.

Invited review: Whey proteins as antioxidants and promoters of cellular antioxidant pathways

Oxidative stress contributes to cell injury and aggravates several chronic diseases. Dietary antioxidants help the body to fight against free radicals and, therefore, avoid or reduce oxidative stress. Recently, proteins from milk whey liquid have been described as antioxidants. This review summarizes the evidence that whey products exhibit radical scavenging activity and reducing power. It examines the processing and treatment attempts to increase the antioxidant bioactivity and identifies 1 enzyme, subtilisin, which consistently produces the most potent whey fractions. The review compares whey from different milk sources and puts whey proteins in the context of other known food antioxidants. However, for efficacy, the antioxidant activity of whey proteins must not only survive processing, but also upper gut transit and arrival in the bloodstream, if whey products are to promote antioxidant levels in target organs. Studies reveal that direct cell exposure to whey samples increases intracellular antioxidants such as glutathione. However, the physiological relevance of these in vitro assays is questionable, and evidence is conflicting from dietary intervention trials, with both rats and humans, that whey products can boost cellular antioxidant biomarkers.

The combination of exercise training and Zataria multiflora supplementation increase serum irisin levels in postmenopausal women

Background

We examined the effect of antioxidant supplementation and exercise on irisin within postmenopausal women.

Methods

Forty-eight participants (age: 55.7 ± 4.9 years; weight: 68.0 ± 6.3 kg; BMI 27.0 ± 2.7; mean ± SD) were randomized into four groups for the eight week intervention: control group (CG; n = 12), resistance training group (RTG; n = 12), supplementation with Zataria multiflora group (ZG; n = 12), or supplementation with Z. multiflora and resistance training group (ZRTG; n = 12). RTG and ZRTG performed circuit resistance training, and both ZG and ZRTG consumed 500 mg of Z. multiflora every day during the intervention. Blood samples were taken 48 hours before and after the intervention.

Results

There was a significant difference in irisin at post-training, with greater levels in ZRTG compared to CG. A significant increase was noted for irisin at post-training compared to pre-training for ZG, RTG, and ZRTG. Moreover, we identified a significant decrease in malondialdehyde in the RTG and ZRTG groups and increase in glutathione in the ZG, RTG, and ZRTG groups when compared to CG.

Conclusion

These findings showed that exercise, Z. multiflora supplementation or their combination led to an increase in irisin.

Antimicrobial activity and mechanism of the human milk-sourced peptide Casein201

INTRODUCTION

Casein201 is one of the human milk sourced peptides that differed significantly in preterm and full-term mothers. This study is designed to demonstrate the biological characteristics, antibacterial activity and mechanisms of Casein201 against common pathogens in neonatal infection.

METHODOLOGY

The analysis of biological characteristics was done by bioinformatics. Disk diffusion method and flow cytometry were used to detect the antimicrobial activity of Casein201. Killing kinetics of Casein201 was measured using microplate reader. The antimicrobial mechanism of Casein201 was studied by electron microscopy and electrophoresis.

RESULTS

Bioinformatics analysis indicates that Casein201 derived from β-casein and showed significant sequence overlap. Antibacterial assays showed Casein201 inhibited the growth of S taphylococcus aureus and Y ersinia enterocolitica. Ultrastructural analyses revealed that the antibacterial activity of Casein201 is through cytoplasmic structures disintegration and bacterial cell envelope alterations but not combination with DNA.

CONCLUSION

We conclude the antimicrobial activity and mechanism of Casein201. Our data demonstrate that Casein201 has potential therapeutic value for the prevention and treatment of pathogens in neonatal infection.

Effects of milk proteins on blood pressure: a meta-analysis of randomized control trials

Certain foods or their components are widely used in the prevention and/or management of cardiovascular disease. Milk proteins have been suggested to have hypotensive properties. A number of clinical trials have been carried out to evaluate the effect of milk proteins from whole foods and supplements on blood pressure (BP). However, the effect of milk proteins on BP is not well understood. Therefore, we conducted a meta-analysis of randomized control trials to provide insight into and robust evidence concerning the overall impact of milk proteins on BP. The PubMed and Cochrane databases were searched for literature concerning the effects of milk proteins on BP up to May 2016. A random effects model was used to calculate the pooled estimates and 95% confidence intervals of effect sizes. The final analysis included seven randomized control trials involving 412 participants. Overall, milk protein interventions significantly lowered systolic BP by -3.33 mm Hg (95% confidence interval -5.62, -1.03) and diastolic BP by -1.08 mm Hg (95% confidence interval -3.38, -0.22). There was no statistical evidence of publication bias across the studies. In conclusion, this meta-analysis provides further evidence that milk proteins slightly but significantly lower both systolic and diastolic BP.

Dynamic Resistance Training as Stand-Alone Antihypertensive Lifestyle Therapy: A Meta-Analysis

Background

Aerobic exercise (AE) is recommended as first‐line antihypertensive lifestyle therapy based on strong evidence showing that it lowers blood pressure (BP) 5 to 7 mm Hg among adults with hypertension. Because of weaker evidence showing that dynamic resistance training (RT) reduces BP 2 to 3 mm Hg among adults with hypertension, it is recommended as adjuvant lifestyle therapy to AE training. Yet, existing evidence suggests that dynamic RT can lower BP as much or more than AE.

Methods and Results

We meta‐analyzed 64 controlled studies (71 interventions) to determine the efficacy of dynamic RT as stand‐alone antihypertensive therapy. Participants (N=2344) were white (57%), middle‐aged (47.2±19.0 years), and overweight (26.8±3.4 kg/m²) adults with prehypertension (126.7±10.3/76.8±8.7 mm Hg); 15% were on antihypertensive medication. Overall, moderate‐intensity dynamic RT was performed 2.8±0.6 days/week for 14.4±7.9 weeks and elicited small‐to‐moderate reductions in systolic BP (SBP; d₊=−0.31; 95% CIs, −0.43, −0.19; −3.0 mm Hg) and diastolic BP (DBP; d₊=−0.30; 95% CIs, −0.38, −0.18; −2.1 mm Hg) compared to controls (Ps<0.001). Greater BP reductions occurred among samples with higher resting SBP/DBP: ≈6/5 mm Hg for hypertension, ≈3/3 mm Hg for prehypertension, and ≈0/1 mm Hg for normal BP (Ps<0.023). Furthermore, nonwhite samples with hypertension experienced BP reductions that were approximately twice the magnitude of those previously reported following AE training (−14.3 mm Hg [95% CIs, −19.0, −9.4]/−10.3 mm Hg [95% CIs, −14.5, −6.2]).

Conclusions

Our results indicate that for nonwhite adult samples with hypertension, dynamic RT may elicit BP reductions that are comparable to or greater than those reportedly achieved with AE training. Dynamic RT should be further investigated as a viable stand‐alone therapeutic exercise option for adult populations with high BP.

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.

High Intensity Resistance Training Methods with and without Protein Supplementation to Fight Cardiometabolic Risk in Middle-Aged Males: A Randomized Controlled Trial

Time-effective protocols may potentially increase people's compliance with exercise. The purpose of this paper was to compare the relative effects of 16 weeks of high intensity (resistance) training (HIT) with and without protein supplementation (HIT&P) and HVHIT (high volume/high intensity training) versus a nontraining control group on cardiometabolic risk factors. One hundred and twenty untrained males 30–50 years old were randomly assigned to 3 subgroups: (a) a HIT group; (b) a HIT&P group, and (c) a waiting-control group (phase I) that crossed over to (d) high volume/high intensity training (HVHIT) during the second study phase. HIT was defined as “single set to failure protocol” while HVHIT consistently applied two sets. Protein supplementation provided an overall intake of 1.5 g/kg/body mass. Primary study endpoint was the metabolic syndrome Z-Score (MetS-Z-Score). MetS-Z-Score significantly improved in all exercise groups (p ≤ 0.001) with no significant difference between HIT, HIT&P, and HVHIT (p ≥ 0.829). However, all the exercise groups differed significantly from the CG (p < 0.001) which deteriorated significantly (p = 0.039). In conclusion, all exercise protocols were similarly effective in improving cardiometabolic risk factors. Thus, HIT may be the best choice for people with low time budgets looking to improve their cardiometabolic health.

Bioactive properties of milk proteins in humans: A review

Many studies have demonstrated that milk protein consumption has benefits in terms of promoting human health. This review assesses the intervention studies which have evaluated potential health enhancing effects in humans following the ingestion of milk proteins. The impact of milk protein ingestion has been studied to asses their satiating, hypotensive, antimicrobial, anti-inflammatory, anticancer, antioxidant and insulinotropic properties as well as their impact on morphological modifications (e.g., muscle and fat mass) in humans. Consistent health promoting effects appear to have been observed in certain instances (i.e., muscle protein synthesis, insulinotropic and hypotensive activity). However, controversial outcomes have also been reported (i.e., antimicrobial, anti-inflammatory, anticancer and antioxidant properties). Several factors including interindividual differences, the timing of protein ingestion as well as the potency of the active components may explain these differences. In addition, processing conditions have been reported, in certain instances, to affect milk protein structure and therefore modify their bioactive potential. It is thought that the health promoting properties of milk proteins are linked to the release of bioactive peptides (BAPs) during gastrointestinal digestion. There is a need for further research to develop a more in-depth understanding on the possible mechanisms involved in the observed physiological effects. In addition, more carefully controlled and appropriately powered human intervention studies are required to demonstrate the health enhancing properties of milk proteins in humans.

Emerging trends in nutraceutical applications of whey protein and its derivatives

The looming food insecurity demands the utilization of nutrient-rich residues from food industries as value-added products. Whey, a dairy industry waste has been characterized to be excellent nourishment with an array of bioactive components. Whey protein comprises 20 % of total milk protein and it is rich in branched and essential amino acids, functional peptides, antioxidants and immunoglobulins. It confers benefits against a wide range of metabolic diseases such as cardiovascular complications, hypertension, obesity, diabetes, cancer and phenylketonuria. The protein has been validated to boost recovery from resistance exercise-injuries, stimulate gut physiology and protect skin against detrimental radiations. Apart from health invigoration, whey protein has proved its suitability as fat replacer and emulsifier. Further, its edible and antimicrobial packaging potential renders its highly desirable in food as well as pharmaceutical sectors. Considering the enormous nutraceutical worth of whey protein, this review emphasizes on its established and emerging biological roles. Present and future scopes in food processing and dietary supplement formulation are discussed. Associated hurdles are identified and how technical advancement might augment its applications are explored. This review is expected to provide valuable insight on whey protein-fortified functional foods, associated technical hurdles and scopes of improvement.

Comparing serum responses to acute feedings of an extensively hydrolyzed whey protein concentrate versus a native whey protein concentrate in rats: a metabolomics approach

We examined how gavage feeding extensively hydrolyzed whey protein (WPH) versus a native whey protein concentrate (WPC) transiently affected serum biochemical profiles in rodents. Male Wistar rats (250-300 g) were 8 h fasted and subsequently fed isonitrogenous amounts of WPH or WPC, or remained unfed (control). Animals were sacrificed 15 min, 30 min, and 60 min post-gavage for serum extraction, and serum was analyzed using untargeted global metabolic profiling via gas chromatography/mass spectrometry (MS) and liquid chromatography/MS/MS platforms. We detected 333 serum metabolites amongst the experimental and control groups. Both WPH and WPC generally increased amino acids (1.2-2.8-fold), branched-chain amino acids (1.2-1.7-fold), and serum di- and oligo-peptides (1.1-2.7-fold) over the 60 min time course compared with control (q < 0.05). However, WPH increased lysine (false discovery rate using a q-value <0.05) and tended to increase isoleucine and valine 15 min post-feeding (q < 0.10) as well as aspartylleucine 30 min post-feeding compared with WPC (q < 0.05). While both protein sources led to a dramatic increase in free fatty acids compared with control (up to 6-fold increases, q < 0.05), WPH also uniquely resulted in a 30 min post-feeding elevation in free fatty acids compared with WPC (q < 0.05), an effect which may be due to the robust 30 min postprandial increase in epinephrine in the WPH cohort. These data provide a unique postprandial time-course perspective on how WPH versus WPC feedings affect circulating biochemicals and will guide future research comparing these 2 protein sources.

Milk protein for improved metabolic health: a review of the evidence

Epidemiological evidence shows that consumption of dairy products is associated with decreased prevalence of metabolic related disorders, whilst evidence from experimental studies points towards dairy protein as a dietary component which may aid prevention of type 2 diabetes (T2DM). Poor metabolic health is a common characteristic of overweight, obesity and aging, and is the forerunner of T2DM and cardiovascular disease (CVD), and an ever increasing global health issue. Progressive loss of metabolic control is evident from a blunting of carbohydrate, fat and protein metabolism, which is commonly manifested through decreased insulin sensitivity, inadequate glucose and lipid control, accompanied by a pro-inflammatory environment and hypertension. Adverse physiological changes such as excess visceral adipose tissue deposition and expansion, lipid overspill and infiltration into liver, muscle and other organs, and sarcopaenia or degenerative loss of skeletal muscle mass and function all underpin this adverse profile. ‘Sarcobesity’ and sarcopaenic diabetes are rapidly growing health issues. As well as through direct mechanisms, dairy protein may indirectly improve metabolic health by aiding loss of body weight and fat mass through enhanced satiety, whilst promoting skeletal muscle growth and function through anabolic effects of dairy protein-derived branch chain amino acids (BCAAs). BCAAs enhance muscle protein synthesis, lean body mass and skeletal muscle metabolic function. The composition and processing of dairy protein has an impact on digestion, absorption, BCAA kinetics and function, hence the optimisation of dairy protein composition through selection and combination of specific protein components in milk may provide a way to maximize benefits for metabolic health.