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Critical Reviews in Food Science and... 2021Dietary proteins and phenolic compounds are commonly co-existing components that readily interact with each other to yield complexes in a wide range of food systems. The... (Review)
Review
Dietary proteins and phenolic compounds are commonly co-existing components that readily interact with each other to yield complexes in a wide range of food systems. The formed complexes play a critical role in the physiochemical characteristics of both reacting molecules, thereby impacting nutritional and quality profiles of related products. In this review, we provided the most updated knowledge on dietary protein-phenolic interactions related with food science and human nutrition, including their mechanisms of complexation, analytical technologies, and alterations in the functionality and nutraceutical properties of both reacting partners. Their potential applications in the industries regarding stability during food processing and storage, impacts on product quality, and fabrication of novel delivery systems for liable bioactives were also discussed. The interactions between dietary proteins and phenolics, either via non-covalent or covalent processes, are ubiquitous in food systems and are closely associated with chemical structures of both compounds and the surrounding conditions, mainly temperature, pH, and the presence of phenolic oxidases. Albeit in different ways, such intermolecular associations induced changes in protein conformational structures, which subsequently impacted their techno-functional properties, digestibility, and allergenic potentials; in turn, the bioaccessibility/bioavailability and health-protecting features of interacted phenolics were modified to various extents, as noticed by in vitro and in vivo evidence. Largely depending on the interaction molecules and preparation steps, those influences can be either favorable or unfavorable in different systems and therefore can be tailored to develop food products and nutraceuticals with maximized functionality and quality attributes.
Topics: Antioxidants; Dietary Proteins; Dietary Supplements; Food Handling; Humans; Phenols
PubMed: 32814438
DOI: 10.1080/10408398.2020.1803199 -
Current Opinion in Clinical Nutrition... Jan 2021In this review, the latest evidence on the influence of dietary protein and plasma amino acids in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is... (Review)
Review
PURPOSE OF REVIEW
In this review, the latest evidence on the influence of dietary protein and plasma amino acids in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) is discussed.
RECENT FINDINGS
Increasing protein consumption during weight loss and maintenance may help reduce liver fat content. Conversely, high protein intake characteristic of the unhealthy Western diet is associated with increased NAFLD prevalence and severity. Plasma concentration of several amino acids, including branched-chain (BCAA) and aromatic amino acids (AAA), is altered in NAFLD. Excess amino acid availability contributes to intrahepatic fat accumulation and may reflect poor dietary habits and dysregulation of amino acid metabolic processing in both liver and peripheral tissues. Specific amino acid patterns, characterized by increased BCAA, AAA, alanine, glutamate, lysine levels, and decreased glycine and serine levels, may be used for early detection of NAFLD and noninvasive assessment of its histological severity.
SUMMARY
Mechanistic studies in NAFLD have been mostly focused on carbohydrate and fat metabolism, while little is known about the influence of protein and amino acids. Moreover, intervention and observational studies on the relation between protein intake and NAFLD yielded conflicting results. Filling the current knowledge gaps would help define the optimal diet composition for NAFLD prevention and management. Furthermore, metabolomics studies may provide insight into the pathogenesis of NAFLD, identify useful diagnostic and prognostic biomarkers, and unravel novel pharmacological targets and treatment options.
Topics: Amino Acids; Dietary Proteins; Humans; Lipid Metabolism; Liver; Non-alcoholic Fatty Liver Disease
PubMed: 33060460
DOI: 10.1097/MCO.0000000000000706 -
International Journal For Vitamin and... Jun 2023Our objective was to study the effect of differing dietary crude protein and vitamin A on retinoid metabolism in a periparturient rat model. Sixty female rats,...
Our objective was to study the effect of differing dietary crude protein and vitamin A on retinoid metabolism in a periparturient rat model. Sixty female rats, approximately 21 d before parturition, were fed rations containing either low protein (13%; LP) or high protein (22%; HP) crude protein and either low vitamin A (3 IU/g; LA) or high vitamin A (5 IU/g; HA), yielding treatments HPHA, HPLA, LPHA, and LPLA. Samples were collected at d -14, d +3, and +10 relative to parturition and analyzed for retinoid acid (RA), RA, and retinol. At d -14, serum RA concentrations decreased compared to baseline. At both d +3 and d +10, serum retinol increased and liver RA decreased. In the small intestine, 13-cis RA was higher in HPHA than HPLA pre-partum (0.93±0.12 vs. 0.40±0.12 ng/ml, =0.04). Post-partum, RA was lower in high vitamin HPHA and LPHA groups (0.35±0.06 and 0.38±0.06 ng/ml) than in low vitamin A HPLA and LPLA treatments (0.50±0.06 and 1.32±0.06 ng/ml, <0.01). In rats fed LA diets, TNF-alpha expression tended to be lower in HPLA than LPLA groups on day +3 (0.69±0.34 vs 1.00±0.52, =0.08), but not day +10 (0.56±0.25 vs. 1.00±0.49 fold change, >0.10). Retinoids accumulated during pregnancy and were mobilized during lactation. The sequestration of retinoids was increased when dietary protein content was low. Further studies are needed to investigate how retinoid metabolism could be manipulated to improve vitamin A delivery to milk.
Topics: Pregnancy; Rats; Female; Animals; Vitamin A; Milk; Retinoids; Diet; Lactation; Dietary Proteins
PubMed: 34013777
DOI: 10.1024/0300-9831/a000712 -
Nutrients Oct 2020Recent interest in protein intake per meal is observed in studies that have reported the protein intake patterns in different countries; however, comparisons of these... (Comparative Study)
Comparative Study
Recent interest in protein intake per meal is observed in studies that have reported the protein intake patterns in different countries; however, comparisons of these data are lacking. We aimed to compare protein intake patterns and the percentage of inadequate protein intake (IPI) per day and meal in older adults from different countries. We acquired data of protein intake in older adults from four countries (Mexico, United States of America, Germany, and United Kingdom). We compared protein intake (per day and meal), IPI per day and meal, and the number of meals with an adequate protein content among countries. The IPI per day significantly differed among countries for <0.8 and <1.0 (both < 0.001), but not for <1.2 g/kg/d ( = 0.135). IPI per meal (<30 g/meal) did not differ among countries at breakfast ( = 0.287) and lunch ( = 0.076) but did differ at dinner ( < 0.001). Conversely, IPI per meal (<0.4 g/kg/meal) significantly differed among countries at breakfast, lunch, and dinner (all < 0.001). The percentage of participants that ate ≥30 g/meal or ≥0.4 g/kg/meal at zero, one, and two or three meals per day significantly differed among countries (all < 0.05). IPI at breakfast and lunch (<30 g/meal) was a common trait in the analyzed samples and might represent an opportunity for nutritional interventions in older adults in different countries.
Topics: Age Factors; Aged; Dietary Proteins; Elder Nutritional Physiological Phenomena; Female; Frailty; Germany; Humans; Male; Meals; Mexico; Nutritional Requirements; Recommended Dietary Allowances; Sarcopenia; United Kingdom; United States
PubMed: 33081081
DOI: 10.3390/nu12103156 -
European Journal of Nutrition Sep 2020This systematic review aimed to synthesize the available evidence on the effects of a high-protein diet on appetite sensations in individuals with overweight and obesity.
PURPOSE
This systematic review aimed to synthesize the available evidence on the effects of a high-protein diet on appetite sensations in individuals with overweight and obesity.
METHODS
Two authors independently conducted literature searches, study selection, design of the method, and quality appraisal. The main inclusion criteria were studies involving protocols that present a protein intake greater than 1.2 g/kg/day or 25% of the total daily energy content compared to a normal protein diet, i.e., 0.8-1.2 g/kg/day or 15%-20% of the total energy content. Studies that evaluated test meals or diet within a period of less than 7 days and participants with diabetes, cancer, or other specific conditions were excluded from this review. The literature search was updated until November 2019 using the main databases available.
RESULTS
Of a total of 4191 records, ten articles met the inclusion criteria and included a total of 1079 subjects. In six studies, participants experienced enhanced fullness or satiety in response to a high-dietary protein intake, of which four studies had an intervention period of 10-12 weeks.
CONCLUSION
Our results suggest that among individuals with overweight or obesity, higher dietary protein intake may influence appetite sensations by enhancing fullness or satiety. The low level of evidence, due to the heterogeneity of the protocols and the high risk of bias, highlights the need for further studies to confirm these results.
Topics: Appetite; Dietary Proteins; Humans; Obesity; Overweight; Sensation
PubMed: 32648023
DOI: 10.1007/s00394-020-02321-1 -
Nutrients Nov 2021Feeding behavior is guided by multiple competing physiological needs, as animals must sense their internal nutritional state and then identify and consume foods that... (Review)
Review
Feeding behavior is guided by multiple competing physiological needs, as animals must sense their internal nutritional state and then identify and consume foods that meet nutritional needs. Dietary protein intake is necessary to provide essential amino acids and represents a specific, distinct nutritional need. Consistent with this importance, there is a relatively strong body of literature indicating that protein intake is defended, such that animals sense the restriction of protein and adaptively alter feeding behavior to increase protein intake. Here, we argue that this matching of food consumption with physiological need requires at least two concurrent mechanisms: the first being the detection of internal nutritional need (a protein need state) and the second being the discrimination between foods with differing nutritional compositions. In this review, we outline various mechanisms that could mediate the sensing of need state and the discrimination between protein-rich and protein-poor foods. Finally, we briefly describe how the interaction of these mechanisms might allow an animal to self-select between a complex array of foods to meet nutritional needs and adaptively respond to changes in either the external environment or internal physiological state.
Topics: Adaptation, Psychological; Animal Nutritional Physiological Phenomena; Animals; Appetite; Dietary Proteins; Eating; Feeding Behavior; Food Preferences; Homeostasis; Nutritional Status
PubMed: 34836357
DOI: 10.3390/nu13114103 -
Bioscience Reports Jan 2020Several papers studied dietary protein intake as a potential influence factor for esophageal cancer, but their findings were inconsistent. Thus, this meta-analysis was... (Meta-Analysis)
Meta-Analysis
Several papers studied dietary protein intake as a potential influence factor for esophageal cancer, but their findings were inconsistent. Thus, this meta-analysis was performed to identify the effect of protein intake on esophageal cancer risk. Potential case-control studies or cohort studies from the databases of Embase, Web of Science and PubMed were searched. The strength of association was quantified by pooling odds ratio (OR) and 95% confidence interval (CI). In total, 11 articles involving 2537 cases and 11432 participants were included in this meta-analysis. As a result, dietary protein intake had non-significant association on esophageal cancer risk overall (pooled OR = 1.11, 95% CI = 0.88-1.40). Meanwhile, we obtained consistent results in the subgroups analyses by study design, protein type, geographic locations and number of cases. Interestingly, dietary protein intake could significantly increase the risk of esophageal squamous cell carcinoma (pooled OR = 1.29, 95% CI = 1.02-1.62), instead of other disease type. To sum up, dietary protein intake had no significant association with esophageal cancer risk in the overall analysis; but, protein intake may be associated with the risk of esophageal squamous cell carcinoma. While some limitations existed in the present paper, more studies with large sample size are warranted to further confirm this result.
Topics: Adult; Aged; Aged, 80 and over; Case-Control Studies; Dietary Proteins; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Female; Humans; Male; Middle Aged; Risk Assessment; Risk Factors
PubMed: 31833539
DOI: 10.1042/BSR20193692 -
The British Journal of Nutrition Mar 2020Dietary protein insufficiency has been linked to excessive TAG storage and non-alcoholic fatty liver disease (NAFLD) in developing countries. Hepatic TAG accumulation... (Review)
Review
Dietary protein insufficiency has been linked to excessive TAG storage and non-alcoholic fatty liver disease (NAFLD) in developing countries. Hepatic TAG accumulation following a low-protein diet may be due to altered peroxisomal, mitochondrial and gut microbiota function. Hepatic peroxisomes and mitochondria normally mediate metabolism of nutrients to provide energy and substrates for lipogenesis. Peroxisome biogenesis and activities can be modulated by odd-chain fatty acids (OCFA) and SCFA that are derived from gut bacteria, for example, propionate and butyrate. Also produced during amino acid metabolism by peroxisomes and mitochondria, propionate and butyrate concentrations correlate inversely with risk of obesity, insulin resistance and NAFLD. In this horizon-scanning review, we have compiled available evidence on the effects of protein malnutrition on OCFA production, arising from loss in mitochondrial, peroxisomal and gut microbiota function, and its association with lipid accumulation in the liver. The methyl donor amino acid composition of dietary protein is an important contributor to liver function and lipid storage; the presence and abundance of dietary branched-chain amino acids can modulate the composition and metabolic activity of the gut microbiome and, on the other hand, can affect protective OCFA and SCFA production in the liver. In preclinical animal models fed with low-protein diets, specific amino acid supplementation can ameliorate fatty liver disease. The association between low dietary protein intake and fatty liver disease is underexplored and merits further investigation, particularly in vulnerable groups with dietary protein restriction in developing countries.
Topics: Dietary Proteins; Fatty Acids; Humans; Liver; Non-alcoholic Fatty Liver Disease; Protein Deficiency
PubMed: 31779730
DOI: 10.1017/S0007114519003064 -
Advances in Experimental Medicine and... 2021Achieving adequate nutrition for exercising humans is especially important for improving both muscle mass and metabolic health. One of the most common misunderstandings... (Review)
Review
Achieving adequate nutrition for exercising humans is especially important for improving both muscle mass and metabolic health. One of the most common misunderstandings in the fitness industry is that the human body has requirements for dietary whole protein and that exercising individuals must consume only whole protein to meet their physiological needs. This view, however, is incorrect. Instead, humans at rest or during exercise have requirements for dietary amino acids (AAs), and dietary protein is a source of AAs in the body. The requirements for AAs must be met each day to avoid a negative nitrogen balance in individuals with moderate or intense physical activity. By properly meeting increased requirements for AAs through increased intake of high-quality protein (the source of AAs) plus supplemental AAs, athletes can improve their overall athletic performance. AAs or metabolites that are of special importance for exercising individuals include arginine, branched-chain AAs, creatine, glycine, taurine, and glutamine. The AAs play vital roles as both substrates for protein synthesis and molecules for regulating blood flow and nutrient metabolism. The functional roles of AAs include the maintenance of cell and tissue integrity; stimulation of mechanistic target of rapamycin and AMP-activated protein kinase cell signaling pathways; energy sources for the small intestine, cells of the immune system, and skeletal muscle; antioxidant and anti-inflammatory reactions; production of neurotransmitters; modulation of acid-base balance in the body. All of those roles are crucial for the overall goal of improving exercise performance. Therefore, adequate intakes of proteinogenic AAs and their functional metabolites, especially those noted in this review, are essential for optimal human health (including optimum muscle mass and function) and should be a primary goal of exercising individuals.
Topics: Amino Acids; Diet; Dietary Proteins; Exercise; Humans; Nutritional Status
PubMed: 34251643
DOI: 10.1007/978-3-030-74180-8_9 -
Advances in Food and Nutrition Research 2020Proteins and its building blocks, amino acids, have many physiological roles in the body. While some amino acids can be synthesized endogenously, exogenous protein and... (Review)
Review
Proteins and its building blocks, amino acids, have many physiological roles in the body. While some amino acids can be synthesized endogenously, exogenous protein and amino acids are necessary to maintain homeostasis. Because skeletal muscle contains a large portion of endogenous protein and plays important roles in movement, regulation, and metabolism, imbalanced protein and amino acid availability may result in clinical conditions including skeletal muscle atrophy, impaired muscle growth or regrowth, and functional decline. Aging is associated with changes in protein metabolism and multiple physiological and functional alterations in the skeletal muscle that are accentuated by decreased dietary protein intake and impaired anabolic responses to stimuli. Inactivity and chronically elevated inflammation of the skeletal muscle can initiate and/or augment pathological remodeling of the tissue (i.e., increase of fat and fibrotic tissues and atrophy of the muscle). Defining an adequate amount of dietary protein that is appropriate to maintain the availability of amino acids for biological needs is necessary but is still widely debated for older adults. This chapter will provide (i) an overview of dietary protein and amino acids and their role in skeletal muscle health; (ii) an overview of skeletal muscle structure and function and the deterioration of muscle that occurs with advancing age; (iii) a discussion of the relationship between protein/amino acid metabolism and skeletal muscle decline with aging; and (iv) a brief discussion of optimal protein intakes for older adults to maintain skeletal muscle health in aging.
Topics: Aging; Amino Acids; Dietary Proteins; Humans; Muscle, Skeletal; Muscular Diseases
PubMed: 32035599
DOI: 10.1016/bs.afnr.2019.08.002