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Systematic Reviews Apr 2022The evidence base for the role of dietary protein in maintaining good muscle health in older age is strong; however, the importance of protein source remains unclear....
BACKGROUND
The evidence base for the role of dietary protein in maintaining good muscle health in older age is strong; however, the importance of protein source remains unclear. Plant proteins are generally of lower quality, with a less favourable amino acid profile and reduced bioavailability; therefore, it is possible that their therapeutic effects may be less than that of higher quality animal proteins. This review aims to evaluate the effectiveness of plant and animal protein interventions on muscle health outcomes.
METHODS
A robust search strategy was developed to include terms relating to dietary protein with a focus on protein source, for example dairy, meat and soy. These were linked to terms related to muscle health outcomes, for example mass, strength, performance and sarcopenia. Five databases will be searched: MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Embase and Web of Science. Studies included will be randomised controlled trials with an adult population (≥ 18) living in the community or residential homes for older adults, and only English language articles will be included. Two independent reviewers will assess eligibility of individual studies. The internal validity of included studies will be assessed using Cochrane Risk of Bias 2.0 tool. Results will be synthesised in narrative format. Where applicable, standardised mean differences (SMD) (95% confidence interval [CI]) will be combined using a random-effects meta-analysis, and tests of homogeneity of variance will be calculated.
DISCUSSION
Dietary guidelines recommend a change towards a plant-based diet that is more sustainable for health and for the environment; however, reduction of animal-based foods may impact protein quality in the diet. High-quality protein is important for maintenance of muscle health in older age; therefore, there is a need to understand whether replacement of animal protein with plant protein will make a significant difference in terms of muscle health outcomes. Findings from this review will be informative for sustainable nutritional guidelines, particularly for older adults and for those following vegan or vegetarian diets.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD420201886582.
Topics: Aged; Animals; Dietary Proteins; Humans; Meta-Analysis as Topic; Muscle Strength; Muscles; Physical Functional Performance; Plant Proteins; Sarcopenia; Systematic Reviews as Topic
PubMed: 35418173
DOI: 10.1186/s13643-022-01951-2 -
Saudi Medical Journal Oct 2020Food containing gluten and casein could play a role in autism spectrum disorders (ASD) symptoms. The present review aimed to update the evidence about the role of the...
Food containing gluten and casein could play a role in autism spectrum disorders (ASD) symptoms. The present review aimed to update the evidence about the role of the gluten- and casein-free diet (GCFD) on the management of ASD. Web of Science, Science Direct, Google Scholar, and PubMed databases were used to search for randomized controlled trials (RCT) conducted between January 2000 and February 2020. In total, 9 RCT were included (521 participants) with age range between 2 to 18 years. Four of these studies did not show a significant improvement regarding the symptoms of ASD. The rest of these studies (n=5) showed improvement in communication, stereotyped movements, aggressiveness, language, hyperactivity, tantrums, and signs of attention deficit hyperactivity disorder compared to control group. Hence, the data remains insu cient to support the use of GCFD to improve the symptoms of ASD in children.
Topics: Adolescent; Autism Spectrum Disorder; Caseins; Child; Child, Preschool; Clinical Decision-Making; Diet, Gluten-Free; Diet, Protein-Restricted; Dietary Proteins; Female; Humans; Male
PubMed: 33026043
DOI: 10.15537/smj.2020.10.25308 -
The Journals of Gerontology. Series A,... Jun 2023This narrative review describes foundational and emerging evidence of how dietary protein intakes may influence muscle-related attributes of older adults. (Review)
Review
BACKGROUND
This narrative review describes foundational and emerging evidence of how dietary protein intakes may influence muscle-related attributes of older adults.
METHODS
PubMed was used to identify pertinent research.
RESULTS
Among medically stable older adults, protein intakes below the recommended dietary allowance (RDA) (0.8 g/kg body weight [BW]/d) exacerbate age-related reductions in muscle size, quality, and function. Dietary patterns with total protein intakes at or moderately above the RDA, including one or preferably more meals containing sufficient dietary protein to maximize protein anabolism, promote muscle size and function. Some observational studies suggest protein intakes from 1.0 to 1.6 g/kg BW/d may promote greater muscle strength and function more so than muscle size. Experimental findings from randomized controlled feeding trials indicate protein intakes greater than the RDA (averaging ~1.3 g/kg BW/d) do not influence indices of lean body mass or muscle and physical functions with non-stressed conditions, but positively influence changes in lean body mass with purposeful catabolic (energy restriction) or anabolic (resistance exercise training) stressors. Among older adults with diagnosed medical conditions or acute illness, specialized protein or amino acid supplements that stimulate muscle protein synthesis and improve protein nutritional status may attenuate the loss of muscle mass and function and improve survival of malnourished patients. Observational studies favor animal versus plant protein sources for sarcopenia-related parameters.
CONCLUSIONS
Quantity, quality, and patterning of dietary protein consumed by older adults with varied metabolic states, and hormonal and health status influence the nutritional needs and therapeutic use of protein to support muscle size and function.
Topics: Humans; Muscle, Skeletal; Sarcopenia; Nutritional Status; Muscle Strength; Body Composition; Dietary Supplements; Dietary Proteins
PubMed: 37325954
DOI: 10.1093/gerona/glad038 -
Current Opinion in Critical Care Aug 2022Critically ill patients experience skeletal muscle wasting that may contribute to the profound functional deficits in those that survive the initial injury. Augmented... (Review)
Review
PURPOSE OF REVIEW
Critically ill patients experience skeletal muscle wasting that may contribute to the profound functional deficits in those that survive the initial injury. Augmented protein delivery has the potential to attenuate muscle loss, yet the ability for dietary protein to improve patient outcomes is reliant on effective protein metabolism. This review will discuss the recent literature on protein delivery and digestion, amino acid absorption, and muscle protein synthesis (MPS) in critically ill adults.
RECENT FINDINGS
Critically ill patients are prescribed protein doses similar to international recommendations, yet actual delivery remains inadequate. The majority of trials that have achieved higher protein doses have observed no effect on muscle mass, strength or function. Critically ill patients have been observed to have minimal deficits in protein digestion and amino acid absorption when delivery bypasses the stomach, yet postprandial MPS is impaired. However, the literature is limited due to the complexities in the direct measurement of protein handling.
SUMMARY
Postprandial MPS is impaired in critically ill patients and may exacerbate muscle wasting experienced by these patients. Studies in critically ill patients require assessment not only of protein delivery, but also utilization prior to implementation of augmented protein doses.
Topics: Adult; Amino Acids; Critical Illness; Dietary Proteins; Humans; Muscle Proteins; Muscle, Skeletal; Muscular Atrophy
PubMed: 35792908
DOI: 10.1097/MCC.0000000000000959 -
Nutrients Sep 2023Proteins and polysaccharides are versatile natural macromolecules that are ubiquitous in nature, and a tailored diet that is fortified with them has been developed to...
Proteins and polysaccharides are versatile natural macromolecules that are ubiquitous in nature, and a tailored diet that is fortified with them has been developed to ameliorate a wide array of diseases [...].
Topics: Food, Fortified; Diet; Nutrition Policy; Dietary Proteins
PubMed: 37836421
DOI: 10.3390/nu15194137 -
Nutrients Oct 2023Osteoporosis is a frequent yet unsolved health problem among older people. The influence of dietary protein still raises many questions regarding its quality and... (Review)
Review
Osteoporosis is a frequent yet unsolved health problem among older people. The influence of dietary protein still raises many questions regarding its quality and quantity in the context of bone health. The aim of this manuscript is to review the latest evidence on plant and animal protein influences on bone health in various groups of patients. The review is based on original studies, meta-analyses, randomized controlled trials, and prospective cohort studies published in PubMed and Cochrane databases during the last five years. Combining plant and animal protein with physical activity has the best effect on bones (muscle strengthening and reducing the risk of falls), while high protein intake can have adverse effects during bed rest. Despite the content of isoflavones, plant protein is not more beneficial than animal protein (dairy products) and can increase bone resorption markers. Hypoestrogenism due to menopause or eating disorders leads to low bone density and an increased risk of osteoporosis. A well-balanced diet with sufficient energy supply and protein intake (both of plant and animal origins) and adequate physical activity are crucial to ensure bone health. Dietary interventions should consider the quantity and quality of protein in patients with other comorbidities, particularly in an aging society.
Topics: Aged; Female; Humans; Bone Density; Bone Diseases, Metabolic; Dietary Proteins; Osteoporosis; Plant Proteins; Prospective Studies
PubMed: 37960234
DOI: 10.3390/nu15214581 -
Analytical Biochemistry Jul 2022Hepatic encephalopathy (HE) is a decline in brain function arising due to liver insufficiency. The liver's diminished capacity to clear ammonia, and the subsequent... (Review)
Review
Hepatic encephalopathy (HE) is a decline in brain function arising due to liver insufficiency. The liver's diminished capacity to clear ammonia, and the subsequent accumulation of it, is highly implicated in pathogenesis of HE. Ammonia is endogenously generated from the catabolism of amino acids derived from dietary protein intake. Therefore, a conflict arises in cirrhosis where dietary protein intake may increase ammonia and precipitate HE, and at the same time, cirrhotic patients require high daily protein intake due to altered nutrient metabolism. A nutritional solution is needed to deliver sufficient doses of protein to patients without increasing the risk of HE. In order to address this issue, this review will discuss the catabolism of individual amino acids with a special focus on ammonia-generating steps and highlight a subset of amino acids that have the potential to generate multiple equivalents of ammonia. Following, studies investigating the effects of individual amino acids in cirrhosis on blood ammonia levels as well as development of HE will be reviewed.
Topics: Amino Acids; Ammonia; Dietary Proteins; Hepatic Encephalopathy; Humans; Liver Cirrhosis
PubMed: 35500655
DOI: 10.1016/j.ab.2022.114696 -
The Proceedings of the Nutrition Society May 2021The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic... (Review)
Review
The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic and catabolic effects of dietary protein on bone health. Adequate protein intake provides the amino acids used in building and maintaining bone tissue, as well as stimulating the action of insulin-like growth factor 1, which in turn promotes bone growth and increases calcium absorption. However, the metabolism of dietary sulphur amino acids, mainly from animal protein, can lead to increased physiological acidity, which may be detrimental for bone health in the long term. Similarly, cereal foods contain dietary phytate, which in turn contains phosphate. It is known that phosphate consumption can also lead to increased physiological acidity. Therefore, cereal products may produce as much acid as do animal proteins that contain sulphur amino acids. The overall effect of dietary protein on physiological acidity, and its consequent impact on bone health, is extremely complex and somewhat controversial. The consensus is now moving towards a synthesised approach. Particularly, how anabolic and catabolic mechanisms interact; as well as how the context of the whole diet and the type of protein consumed is important.
Topics: Animals; Bone Density; Bone and Bones; Calcium, Dietary; Diet; Dietary Proteins
PubMed: 33183359
DOI: 10.1017/S0029665120007909 -
Kidney360 Aug 2023It has been estimated that over a fifth of deaths worldwide can be attributed to dietary risk factors. A particularly serious condition is salt-sensitive (SS)... (Review)
Review
It has been estimated that over a fifth of deaths worldwide can be attributed to dietary risk factors. A particularly serious condition is salt-sensitive (SS) hypertension and renal damage, participants of which demonstrate increased morbidity and mortality. Notably, a large amount of evidence from humans and animals has demonstrated that other components of the diet can also modulate hypertension and associated end-organ damage. Evidence presented in this review provides support for the view that immunity and inflammation serve to amplify the development of SS hypertension and leads to malignant disease accompanied by tissue damage. Interestingly, SS hypertension is modulated by changes in dietary protein intake, which also influences immune mechanisms. Together, the evidence presented in this review from animal and human studies indicates that changes in dietary protein source have profound effects on the gut microbiota, microbiota-derived metabolites, gene expression, immune cell activation, the production of cytokines and other factors, and the development of SS hypertension and kidney damage.
Topics: Animals; Humans; Dietary Proteins; Blood Pressure; Kidney Diseases; Hypertension; Kidney; Sodium Chloride, Dietary
PubMed: 37424061
DOI: 10.34067/KID.0000000000000210 -
Current Hypertension Reports Feb 2020This review will provide an in-depth coverage of the epidemiological and pre-clinical literature surrounding the role of dietary protein in hypertension, with a special... (Review)
Review
PURPOSE OF REVIEW
This review will provide an in-depth coverage of the epidemiological and pre-clinical literature surrounding the role of dietary protein in hypertension, with a special emphasis on the history of our work on the Dahl salt-sensitive rat.
RECENT FINDINGS
Our studies have dedicated much effort into understanding the relationship between dietary protein and its effect on the development of salt-sensitive hypertension and renal injury. Our evidence over the last 15 years have demonstrated that both the source and amount of dietary protein can influence the severity of disease, where we have determined mechanisms related to immunity, the maternal environment during pregnancy, and more recently the gut microbiota, which significantly contribute to these diet-induced effects. Deeper understanding of these dietary protein-related mechanisms may provide insight on the plausibility of dietary modifications as future therapeutic avenues for hypertension and renal disease.
Topics: Animals; Blood Pressure; Dietary Proteins; Female; Humans; Hypertension; Kidney; Kidney Diseases; Pregnancy; Rats; Rats, Inbred Dahl; Sodium Chloride, Dietary
PubMed: 32016562
DOI: 10.1007/s11906-020-1018-8