Improvement of pulse wave velocity and metabolic cardiovascular risk parameters through egg protein hydrolysate intake: A randomized trial in overweight or obese subjects with impaired glucose tolerance or type 2 diabetes

Long-term effects of an egg-protein hydrolysate on cognitive performance and brain vascular function: a double-blind randomized controlled trial in adults with elevated subjective cognitive failures

PURPOSE

Short-term intake of the egg-protein hydrolysate Newtricious (NWT)-03 improved executive function, but underlying mechanisms and long-term effects, including other cognitive domains, are unknown.

METHODS

A 36-week randomized controlled trial involving 44 overweight/obese individuals experiencing elevated Subjective Cognitive Failures (SCF; aged 60-75 years) assessed the impact of daily consumption of 5.7 g of NWT-03 or placebo powders on cognitive performance (psychomotor speed, executive function, memory) and Cerebral Blood Flow (CBF), a marker of brain vascular function. Cognitive performance was evaluated using a neurophysiological test battery (CANTAB) and CBF was measured using magnetic resonance imaging perfusion method Arterial Spin Labeling (ASL). Serum samples were collected to determine brain-derived neurotrophic factor (BDNF) concentrations.

RESULTS

Anthropometrics, and energy and nutrient intakes remained stable throughout the trial. NWT-03 was well tolerated, and compliance was excellent (median: 99%; range: 87-103%). No overall intervention effects were observed on cognitive performance or CBF, but post-hoc analyses revealed significant improvements on executive function in women, but not men. Specifically, a reduction of 74 ms in reaction latency on the multitasking task (95% CI: -134 to -15; p = 0.02), a reduction of 9 between errors (95%CI: -14 to -3; p < 0.001), and a reduction of 9 total errors (95%CI: -15 to -3; p < 0.001) on the spatial working memory task were found in women. No intervention effects were observed on serum BDNF concentrations (p = 0.31).

CONCLUSION

Long-term consumption of NWT-03 improved multitasking abilities and working memory in women with elevated SCF. Brain vascular function remained unaffected. Sex differences in executive function require additional clarification.

Protein Hydrolysates and Bioactive Peptides as Mediators of Blood Glucose-A Systematic Review and Meta-Analysis of Acute and Long-Term Studies

Type 2 diabetes mellitus (T2DM) is a major public health concern associated with high mortality and reduced life expectancy. Since diabetes is closely linked with lifestyle, not surprisingly, nutritional intervention and increased physical activity could play a vital role in attenuating the problems related to diabetes. Protein hydrolysates (PHs) and their bioactive peptides (BP) have been shown to exert a wide range of biological effects, including antioxidative, antihypertensive, and in particular, hypoglycaemic activities. To better understand the efficacy of such interventions, a systematic review and meta-analysis of randomised controlled trials (RCTs) were performed concerning the influence of protein hydrolysates on glycaemic biomarkers in subjects with and without hyperglycaemia. Five different databases were used to search for RCTs. In total, 37 RCTs were included in the systematic review and 29 RCTs in the meta-analysis. The meta-analysis revealed a significant reduction in postprandial blood glucose response (PPGR) in normoglycaemic (-0.22 mmol/L; 95% CI -0.43, -0.01; p ≤ 0.05) and in hyperglycaemic adults (-0.88 mmol/L; 95% CI -1.37, -0.39; p ≤ 0.001) compared with the respective control groups. A meta-regression analysis revealed a dose-dependent response for PPGR following PH consumption in normoglycaemic adults, specifically for doses ≤ 30 g. The postprandial blood insulin responses (PPIR) were significantly higher after the ingestion of PHs in both the group with and the group without hyperglycaemia, respectively (23.05 mIU/L; 95% CI 7.53, 38.57; p ≤ 0.01 and 12.57 mIU/L; 95% CI 2.72, 22.41; p ≤ 0.01), compared with controls. In terms of long-term responses, there was a small but significant reduction in both fasting blood glucose (FBG) and fasting glycated haemoglobin (HbA1c) in response to PH compared with the control group (p < 0.05). The PHs significantly improved the parameters of glycaemia in adults and, hence, it may contribute to the management and regulation of the future risk of developing T2DM.

Effects of the egg protein hydrolysate NWT-03 on cognitive function in men and women with the metabolic syndrome: a randomized, double-blind, placebo-controlled study

Objectives: The metabolic syndrome is associated with cardiovascular diseases and cognitive decline. The egg protein hydrolysate NWT-03 has shown to improve cardiovascular risk factors in humans. This study investigated whether NWT-03 also has an effect on cognitive function.Methods: Men and women with the metabolic syndrome (n = 76) with a mean age of 60 ± 10 years participated in this randomized, double-blind, placebo-controlled, cross-over trial with an intervention (5 g/day NWT-03) and control period (5 g/day maltodextrin) of 4 weeks separated by a wash-out period of 2-8 weeks. Cognitive function was assessed with the anti-cue reaction time test (impulse control) and psychomotor vigilance test (sustained attention) at day 0, 2, and 27 of both periods. Serum brain-derived neurotrophic factor (BDNF) concentrations were measured at the start and end of both periods.Results: NWT-03 consumption significantly improved the change (day 27 - day 0) in response times of the anti-cue reaction time test compared with the control period (P < 0.001), but not of the psychomotor vigilance test (P = 0.487). Serum BDNF concentrations of all subjects did not significantly change (P = 0.241).Conclusion: NWT-03 has the ability to improve cognitive function within the executive function domain. The underlying mechanism warrants further research and could either be indirect via inhibition of dipeptidyl peptidase 4 (DPP4) or direct via passage of small peptides over the blood-brain barrier inducing local effects.Trial registration: ClinicalTrials.gov identifier: NCT02561663.

Protein-based nutritional strategies to manage the development of diabetes: evidence and challenges in human studies

Type 2 diabetes mellitus (T2DM) is one of the most prevalent diseases in modern society, governed by both genetic and environmental factors, such as nutritional habits. This metabolic disorder is characterized by insulin resistance, which is related to high blood glucose levels, implying negative health effects in humans, hindering the healthy ageing of people. The relationship between food and health is clear, and the ingestion of specific nutrients modulates some physiological processes, potentially implying biologically relevant changes, which can translate into a health benefit. This review aims to summarize human studies published in which the purpose was to investigate the effect of protein ingestion (in native state or as hydrolysates) on human metabolism. Overall, several studies showed how protein ingestion might induce a decrease of glucose concentration in the postprandial state (area under the curve), although it is highly dependent on the source and the dose. Other studies showed no biological effects upon protein consumption, mostly with fish-derived products. In addition, the major challenges and perspectives in this research field are highlighted, suggesting the future directions, towards which scientists should focus on. The dietary intake of proteins has been proven to likely exert a beneficial effect on diabetes-related parameters, which can have a biological relevance in the prevention and pre-treatment of diabetes. However, the number of well-designed human studies carried out to date to demonstrate the effects of specific proteins or protein hydrolysates in vivo is still scarce.

Longer-term effects of the egg-protein hydrolysate NWT-03 on arterial stiffness and cardiometabolic risk markers in adults with metabolic syndrome: a randomized, double-blind, placebo-controlled, crossover trial

BACKGROUND

Short-term intake of egg-derived protein hydrolysates, such as NWT-03, suggest improvements in arterial stiffness and metabolic profiles, but longer-term trials are lacking. This study therefore examined the longer-term effects of NWT-03 on arterial stiffness and cardiometabolic markers in men and women with metabolic syndrome.

METHODS

Seventy-six adults with metabolic syndrome (age 61 ± 10 years; BMI 31.7 ± 4.0 kg/m2) participated in a randomized, controlled, double-blind, cross-over trial with a 27-day intervention (5 g/day NWT-03) or placebo period, separated by two-to-eight weeks of washout. At the start and end of both periods, measurements were performed in the fasting state and 2 h following acute NWT-03 intake. Arterial stiffness was assessed by carotid-to-radial (PWVc-r), carotid-to-femoral pulse wave velocity (PWVc-f), and central augmentation index (CAIxHR75). Moreover, cardiometabolic markers were assessed.

RESULTS

Compared with control, longer-term NWT-03 supplementation did not affect fasting PWVc-r (0.1 m/s; -0.2 to 0.3; P = 0.715) or PWVc-f (-0.2 m/s; -0.5 to 0.1; P = 0.216). Fasting pulse pressure (PP) was however reduced by 2 mmHg (95% CI: -4 to 0; P = 0.043), but other fasting cardiometabolic markers were not affected. No effects were observed following acute NWT-03 intake at baseline. However, acute intake of NWT-03 after the intervention significantly lowered CAIxHR75 (-1.3%-point; -2.6 to -0.1; P = 0.037) and diastolic BP (-2 mmHg; -3 to 0; P = 0.036), but other cardiometabolic markers did not change.

CONCLUSION

Longer-term NWT-03 supplementation did not affect arterial stiffness, but modestly improved fasting PP in adults with metabolic syndrome. Acute intake of NWT-03 after the intervention also improved CAIxHR75 and diastolic BP.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov as NCT02561663.

Food protein-derived bioactive peptides for the management of nutrition related chronic diseases

Dietary intervention via modifications of dietary pattern or supplementations of naturally derived bioactive compounds has been considered as an efficient approach in management of nutrition related chronic diseases. Food protein-derived bioactive peptide is representative of natural compounds which show the potential to prevent or mitigate nutrition related chronic diseases. In the past decades, substantial research has been conducted concentrating on the characterization, bioavailability, and activity assessment of bioactive peptides. Although various activities of bioactive peptides have been reported, the activity testes of most peptides were only conducted in cells and animal models. Some clinical trials of bioactive peptides were also reported but only limited to antihypertensive peptides, antidiabetic peptides and peptides modulating blood lipid profile. Hereby, clinical evidence of bioactive peptides in management of nutrition-related chronic diseases is summarized in this chapter, which aims at providing implications for the clinical studies of bioactive peptides in the future.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Egg consumption and health effects: A narrative review

This study was planned and conducted to investigate the effects of egg consumption on metabolic syndrome components and potential mechanisms of action on humans. Egg, an important source of animal protein, is defined as a functional food containing various bioactive compounds that can affect the proinflammatory and anti-inflammatory pathways. As a matter of fact, the egg can show immunomodulatory, anti-inflammatory, antioxidant, anticancer, or antihypertensive effects with its bioactive components. It is claimed that egg consumption may protect individuals against metabolic syndrome by increasing HDL-C levels and reducing inflammation. The increase in egg consumption creates the perception that it may lead to cardiovascular diseases due to its cholesterol content. However, there is insufficient evidence as to whether dietary cholesterol-lowers LDL-C. The possible potential mechanisms of egg impact on human health, MEDLINE, Embase, the Cochrane Central, www.ClinicalTrials.gov, PubMed, Science Direct, Google Scholar, and selected websites including) and databases were examined in this regard. With a view to delving into the rather mysterious relationship between egg cholesterol and blood cholesterol, it is necessary to understand the absorption of cholesterol from the egg and to know the functioning of the intestinal microbiota. Studies conducted to date have generally yielded inconsistent results regarding egg consumption and risks of CVD, diabetes, and metabolic syndrome.

Bioactive Peptides and Hydrolysates from Egg Proteins as a New Tool for Protection Against Cardiovascular Problems

The aim of the present work is to review the potential beneficial effects of dietary supplementation with bioactive egg protein hydrolysates or peptides on cardiometabolic changes associated with oxidative stress. The development of nutritionally improved food products designed to address specific health concerns is of particular interest because many bioactive food compounds can be potentially useful in various physiological functions such as for reducing oxidative stress. The results presented suggest that egg hydrolysates or derived peptides could be included in the diet to prevent and/or reduce some cardiometabolic complications associated with oxidative stress-related diseases.

Antidiabetic Food-Derived Peptides for Functional Feeding: Production, Functionality and In Vivo Evidences

Bioactive peptides released from the enzymatic hydrolysis of food proteins are currently a trending topic in the scientific community. Their potential as antidiabetic agents, by regulating the glycemic index, and thus to be employed in food formulation, is one of the most important functions of these peptides. In this review, we aimed to summarize the whole process that must be considered when talking about including these molecules as a bioactive ingredient. In this regard, at first, the production, purification and identification of bioactive peptides is summed up. The detailed metabolic pathways described included carbohydrate hydrolases (glucosidase and amylase) and dipeptidyl-peptidase IV inhibition, due to their importance in the food-derived peptides research field. Then, their characterization, concerning bioavailability in vitro and in situ, stability and functionality in food matrices, and ultimately, the in vivo evidence (from invertebrate animals to humans), was described. The future applicability that these molecules have due to their biological potential as functional ingredients makes them an important field of research, which could help the world population avoid suffering from several diseases, such as diabetes.