Effects of high-protein diet containing isolated whey protein in rats submitted to resistance training of aquatic jumps

High-protein diet associated with resistance training reduces cardiac TNF-α levels and up-regulates MMP-2 activity in rats

The consumption of high-protein diets (HPD) is associated with resistance training (RT) due to effects on metabolism. However, little is known about these effects on cardiac tissue. This study aimed to investigate effects of HPD and RT on cardiac biomarkers. 18 rats were divided into normo-protein (NPD), and HPD groups: NPD-Control, NPD-RT, HPD-Control, and HPD-RT. Interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-a), nitric oxide (NO), activity of metalloproteinase-2 (MMP-2), and vascular factor (VEGF) were analysed. RT was effective in regulating body weight, increasing strength, and reducing food consumption (p < .05). HPD induces higher levels of interleukin 6 (p = .0169), and lowers NO (p < .0001). When associated with RT, the HPD decreases levels of tumour necrosis factor alpha, while enhances NO, and MMP activity (p < .05). The association of RT with HDP decreases inflammatory parameters and indicates an enhancement in the molecular parameters of cardiac tissue.

High animal protein diet and gut microbiota in human health

The role of the intestinal flora in health and disease has become a research hotspot. Compared with carbohydrates and fats, proteins are metabolized primarily by microbial fermentation in the intestine. The production of protein fermentation products and metabolites depends on the composition, diversity, and metabolism of the gut microbiota. Several protein fermentation products, including indoles, phenols, polyamines, hydrogen sulfide (H₂S), amines, and carnitine, are toxic. This study analyzes the relationship between high-protein diets (HPDs), the intestinal microbiota, and human health and disease. Long-term HPDs increase the risk of intestinal diseases, type 2 diabetes (T2DM), obesity, central nervous system (CNS) diseases, and cardiovascular diseases (CVD) by producing toxic metabolites in the colon, including amines, H₂S, and ammonia. Short-term HPDs have little effect on the metabolism of healthy individuals under 65 years old. However, meeting the protein requirements of individuals over 65 years old using HPDs is more challenging. The adverse effects of HPDs on athletes are minimal. Natural compounds (plant extracts, whose main constituents are polysaccharides and polyphenols), prebiotics, probiotics, and regular physical exercise improve gut dysbiosis and reduce disease risk.

Effects of Consumption of Coconut and Cow's Milk on the Metabolic Profile of Wistar Rats Fed a Hyperprotein Diet

The intake of milk has decreased over the past few decades in Western populations and has been replaced by drinks of plant origin. Substitution of cow's milk by vegetable drinks occurs for some reasons, such as the presence of lactose intolerance, reduced calorie intake, prevention of obesity, vegan diets, and concern about the use of hormone therapy and its possible residues in bovine milk. For these reasons, the objective of this study was to evaluate the biochemical and anthropometric profile of animals subjected to a diet supplemented with coconut milk. Animals were divided into six groups (G1-G6), treated, respectively, regular diet and coconut milk or cow's milk, and with a high-protein content diet and coconut milk or cow's milk. Our results showed that the animals treated with coconut milk reduced body weight and visceral fat, and also showed that the use of a high-protein diet in association with coconut milk is a good combination in reducing visceral fat, percentage of weight gain, food intake, cholesterol, and triglycerides. Our results do not show substantial metabolic changes when comparing the use of coconut milk with the use of cow's milk (we cannot say that the coconut milk itself can be better than cow's milk in the evaluated metabolic parameters).

Whey protein boosts the antioxidant profile of rats by enhancing the activities of crucial antioxidant enzymes in a tissue-specific manner

Whey protein, a by-product of cheese industry, is harmful for the environment (i.e., surface and subterranean waters, soil) and, therefore, for humans due to its high polluting burden. Concomitantly, it has been reported that it is a mixture with potent antioxidant action since it is rich in cysteine residues, which are necessary for glutathione synthesis in vivo. On this basis, this study intended to examine the role of whey protein on the intensification of tissue antioxidant arsenal. To this end, a dose of sheep/goat whey protein equal to 1 g/kg of body weight/day dissolved in drinking water was administered to rats for 28 consecutive days. According to our findings, whey protein improved the antioxidant profile of liver, small intestine, lung and muscle whereas it did not affect the redox state of kidney. Our results were based on the alterations found in the protein expression of glutamate cysteine ligase, catalase and superoxide dismutase-1 measured in all tissues and the activity of glutathione S-transferase evaluated in muscle. Although tissue-specific, it is obvious that the action of whey protein is biologically beneficial and could serve as a biofunctional constituent for foods able to improve redox profile when administered against redox-related diseases.

Effect of whey protein on blood pressure in pre- and mildly hypertensive adults: A randomized controlled study

In China, the frequency of mild hypertension cases remains prevalently high. Meanwhile, diets containing functional ingredients that control blood pressure have received considerable attention. In this randomized, controlled intervention study, 65 participants were randomly assigned to consume 30 g of whey protein or maltodextrin daily for 12 weeks. Blood pressure, body composition, biochemical analysis in plasma, and flow-mediated dilation (FMD), an index for evaluating endothelial function, were measured. Finally, 54 participants (27 participants in each group) completed the study. At the end of the intervention, the average systolic blood pressure (SBP) was 129.5 ± 7.7 mmHg in the control group and 128.2 ± 6.9 mmHg in the whey protein group (p = 0.052). In the overweight and obese participants, the SBP was significantly lower in the whey protein group than in the control group (126.5 ± 6.9 mmHg vs. 128.8 ± 7.4 mmHg, p = 0.033), and body fat, fat percentage, and waist circumference significantly decreased in the whey protein group (p = 0.010, 0.016, 0.019, respectively). No difference was observed between the control and whey protein groups with regard to the changes in plasma lipids, inflammatory cytokines, antioxidative indexes, endothelium-1, nitric oxide, angiotensin II, and angiotensin-converting enzyme. The increase in FMD was significantly higher in the whey protein group than in the control group (5.2% vs. 0.3%, p = 0.040). In conclusion, whey protein significantly decreased SBP in pre- and mildly hypertensive adults, who are also overweight and obese. Whey protein also improved endothelial function. The lowering effect of blood pressure was probably related to body fat loss in these participants.