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Nutrients Feb 2021Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass... (Meta-Analysis)
Meta-Analysis
Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass and muscle strength needs to be systematically reviewed. This study aimed to examine potential differences in the effect of animal vs. plant protein on lean mass and muscle strength, and the possible influence of resistance exercise training (RET) and age. The following databases were searched: PubMed, Embase, Scopus and CINAHL Plus with Full Text, and 3081 articles were screened. A total of 18 articles were selected for systematic review, of which, 16 were used for meta-analysis. Total protein intakes were generally above the recommended dietary allowance at the baseline and end of intervention. Results from the meta-analyses demonstrated that protein source did not affect changes in absolute lean mass or muscle strength. However, there was a favoring effect of animal protein on percent lean mass. RET had no influence on the results, while younger adults (<50 years) were found to gain absolute and percent lean mass with animal protein intake (weighted mean difference (WMD), 0.41 kg; 95% confidence interval (CI) 0.08 to 0.74; WMD 0.50%; 95% CI 0.00 to 1.01). Collectively, animal protein tends to be more beneficial for lean mass than plant protein, especially in younger adults.
Topics: Adult; Age Factors; Aged; Animal Proteins, Dietary; Female; Humans; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Nutritional Physiological Phenomena; Plant Proteins, Dietary; Randomized Controlled Trials as Topic; Resistance Training
PubMed: 33670701
DOI: 10.3390/nu13020661 -
The Cochrane Database of Systematic... Jan 2023Diabetic kidney disease (DKD) continues to be the leading cause of kidney failure across the world. For decades dietary protein restriction has been proposed for... (Review)
Review
BACKGROUND
Diabetic kidney disease (DKD) continues to be the leading cause of kidney failure across the world. For decades dietary protein restriction has been proposed for patients with DKD with the aim to retard the progression of chronic kidney disease (CKD) towards kidney failure. However, the relative benefits and harms of dietary protein restriction for slowing the progression of DKD have not been addressed.
OBJECTIVES
To determine the efficacy and safety of low protein diets (LPD) (0.6 to 0.8 g/kg/day) in preventing the progression of CKD towards kidney failure and in reducing the incidence of kidney failure and death (any cause) in adult patients with DKD. Moreover, the effect of LPD on adverse events (e.g. malnutrition, hyperglycaemic events, or health-related quality of life (HRQoL)) and compliance were also evaluated.
SEARCH METHODS
We searched the Cochrane Kidney and Transplant Register of Studies up to 17 November 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) or quasi-RCTs in which adults with DKD not on dialysis were randomised to receive either a LPD (0.6 to 0.8 g/kg/day) or a usual or unrestricted protein diet (UPD) (≥ 1.0 g/kg/day) for at least 12 months.
DATA COLLECTION AND ANALYSIS
Two authors independently selected studies and extracted data. Summary estimates of effect were obtained using a random-effects model. Results were summarised as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) or standardised MD (SMD) with 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.
MAIN RESULTS
We identified eight studies involving 486 participants with DKD. The prescribed protein intake in the intervention groups ranged from 0.6 to 0.8 g/kg/day. The prescribed protein intake in the control groups was ≥ 1.0 g/kg/day, or a calculated protein intake ≥ 1.0 g/kg/day if data on prescribed protein intake were not provided. The mean duration of the interventions was two years (ranging from one to five years). Risks of bias in most of the included studies were high or unclear, most notably for allocation concealment, performance and detection bias. All studies were considered to be at high risk for performance bias due to the nature of the interventions. Most studies were not designed to examine death or kidney failure. In low certainty evidence, a LPD may have little or no effect on death (5 studies, 358 participants: RR 0.38, 95% CI 0.10 to 1.44; I² = 0%), and the number of participants who reached kidney failure (4 studies, 287 participants: RR 1.16, 95% CI 0.38 to 3.59; I² = 0%). Compared to a usual or unrestricted protein intake, it remains uncertain whether a LPD slows the decline of glomerular filtration rate over time (7 studies, 367 participants: MD -0.73 mL/min/1.73 m²/year, 95% CI -2.3 to 0.83; I² = 53%; very low certainty evidence). It is also uncertain whether the restriction of dietary protein intake impacts on the annual decline in creatinine clearance (3 studies, 203 participants: MD -2.39 mL/min/year, 95% CI -5.87 to 1.08; I² = 53%). There was only one study reporting 24-hour urinary protein excretion. In very low certainty evidence, a LPD had uncertain effects on the annual change in proteinuria (1 study, 80 participants: MD 0.90 g/24 hours, 95% CI 0.49 to 1.31). There was no evidence of malnutrition in seven studies, while one study noted this condition in the LPD group. Participant compliance with a LPD was unsatisfactory in nearly half of the studies. One study reported LPD had no effect on HRQoL. No studies reported hyperglycaemic events.
AUTHORS' CONCLUSIONS
Dietary protein restriction has uncertain effects on changes in kidney function over time. However, it may make little difference to the risk of death and kidney failure. Questions remain about protein intake levels and compliance with protein-restricted diets. There are limited data on HRQoL and adverse effects such as nutritional measures and hyperglycaemic events. Large-scale pragmatic RCTs with sufficient follow-up are required for different stages of CKD.
Topics: Adult; Humans; Kidney Failure, Chronic; Diet, Protein-Restricted; Diabetic Nephropathies; Renal Insufficiency, Chronic; Malnutrition; Hyperglycemia; Diabetes Mellitus; Randomized Controlled Trials as Topic
PubMed: 36594428
DOI: 10.1002/14651858.CD014906.pub2 -
Nutrients Aug 2019Weight regain after a successful weight loss intervention is very common. Most studies show that, on average, the weight loss attained during a weight loss intervention... (Meta-Analysis)
Meta-Analysis
Weight regain after a successful weight loss intervention is very common. Most studies show that, on average, the weight loss attained during a weight loss intervention period is not or is not fully maintained during follow-up. We review what is currently known about dietary strategies for weight loss maintenance, focusing on nutrient composition by means of a systematic review and meta-analysis of studies and discuss other potential strategies that have not been studied so far. Twenty-one studies with 2875 participants who were overweight or obese are included in this systematic review and meta-analysis. Studies investigate increased protein intake (12 studies), lower dietary glycemic index (four studies), green tea (three studies), conjugated linoleic acid (three studies), higher fibre intake (three studies), and other miscellaneous interventions (six studies). The meta-analysis shows a significant beneficial effect of higher protein intake on the prevention of weight regain (SMD (standardized mean difference) -0.17 (95% CI -0.29, -0.05), = 2.80, = 0.005), without evidence for heterogeneity among the included studies. No significant effect of the other strategies is detected. Diets that combine higher protein intake with different other potentially beneficial strategies, such as anti-inflammatory or anti-insulinemic diets, may have more robust effects, but these have not been tested in randomized clinical trials yet.
Topics: Adolescent; Adult; Aged; Diet, Healthy; Dietary Fiber; Dietary Proteins; Dietary Supplements; Energy Intake; Female; Glycemic Index; Humans; Linoleic Acids, Conjugated; Male; Middle Aged; Nutritive Value; Obesity; Recurrence; Treatment Outcome; Weight Gain; Weight Loss; Young Adult
PubMed: 31443231
DOI: 10.3390/nu11081916 -
The British Journal of Nutrition Mar 2023Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND AND AIMS
Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers.
METHODS
We conducted a systematic literature search of randomised controlled trials (RCT) through MEDLINE, Web of Science, Scopus and Cochrane Library databases from inception until September 2021. To determine the effectiveness of isolated proteins on circulating levels of C-reactive protein (CRP), IL-6 and TNF-α, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42021252603).
RESULTS
Thirty-one RCT met the inclusion criteria and were included in the systematic review and meta-analysis. A significant reduction of circulating IL-6 levels following whey protein [Mean Difference (MD): -0·79, 95 % CI: -1·15, -0·42, I = 96 %] and TNF-α levels following soy protein supplementation (MD: -0·16, 95 % CI: -0·26, -0·05, I = 68 %) was observed. The addition of soy isoflavones exerted a further decline in circulating TNF-α levels (MD: -0·20, 95 % CI: -0·31, -0·08, I = 34 %). According to subgroup analysis, whey protein led to a statistically significant decrease in circulating IL-6 levels in individuals with sarcopenia and pre-frailty (MD: -0·98, 95 % CI: -1·56, -0·39, I = 0 %). These findings may be dependent on participant characteristics and treatment duration.
CONCLUSIONS
These data support that whey and soy protein supplementation elicit anti-inflammatory effects by reducing circulating IL-6 and TNF-α levels, respectively. This effect may be enhanced by soy isoflavones and may be more prominent in individuals with sarcopenia.
Topics: Humans; Aged; Soybean Proteins; Whey Proteins; Cytokines; Whey; Tumor Necrosis Factor-alpha; Interleukin-6; Sarcopenia; C-Reactive Protein; Inflammation; Dietary Supplements; Isoflavones
PubMed: 35706399
DOI: 10.1017/S0007114522001787 -
Nutrients Oct 2022(1) Background: Whey protein (WP) in combination with resistance training (RT) is beneficial in improving sarcopenic obesity and its damaging effects in older adults,... (Meta-Analysis)
Meta-Analysis
(1) Background: Whey protein (WP) in combination with resistance training (RT) is beneficial in improving sarcopenic obesity and its damaging effects in older adults, while the difference between men and women should be considered while interpreting results. This review aims to investigate WP's efficacy on postmenopausal women with or without RT; (2) Material and Methods: We searched electronic databases including PubMed, EMBASE, and the Cochrane Library from inception to August 2021 for randomized controlled trials that included comparison groups to evaluate WP's efficacy in women aged 55 years and above. The outcomes included body composition, muscular strength, functional capacity, and dietary intake. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to estimate the effect of WP. We also performed subgroup analysis with or without RT; (3) Results: We included 14 studies in the systematic review and 10 studies in the meta-analysis. Subgroup analyses showed RT was a major confounder for muscle strength, lean mass, and dietary protein intake (PI). In the RT subgroup, WP supplementation had a significant positive effect on biceps curl strength (BC) (SMD: 0.6805, 95% CI: 0.176, 1.185, : 0%), and lower limb lean-mass (LLLM) (SMD: 1.103, 95% CI: 0.632, 1.574, : 14%). In the subgroup without RT, a significant negative effect on PI (SMD: -0.4225, 95% CI: -0.774, -0.071, : 47%) was observed, while no significant effect on muscle strength or lean mass was revealed. WP supplementation did not show a significantly different effect on fat mass or body weight loss in both the subgroups; (4) Conclusions: In postmenopausal women, WP supplementation only in combination with RT enhances BC and LLLM compared to placebo controls. Without RT, WP has no significant benefit on muscle strength or lean mass.
Topics: Aged; Body Composition; Dietary Proteins; Dietary Supplements; Female; Humans; Male; Muscle Strength; Muscle, Skeletal; Postmenopause; Resistance Training; Whey Proteins
PubMed: 36235862
DOI: 10.3390/nu14194210 -
Journal of Clinical Medicine Mar 2020Dietary patterns may play an important role in musculoskeletal well-being. However, the link between dietary patterns, the components of patients' diet, and chronic... (Review)
Review
Dietary patterns may play an important role in musculoskeletal well-being. However, the link between dietary patterns, the components of patients' diet, and chronic musculoskeletal pain remains unclear. Therefore, the purpose of this review was to systematically review the literature on the link between dietary patterns, the components of patients' diet and chronic musculoskeletal pain. This review was conducted following the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) guidelines and was registered in PROSPERO with the registration number CRD42018110782. PubMed, Web of Science, and Embase online databases were searched. After screening titles and abstracts of 20,316 articles and full texts of 347 articles, 12 eligible articles were included in this review, consisting of nine experimental and three observational studies. Seven out of nine experimental studies reported a pain-relieving effect of dietary changes. Additionally, protein, fat, and sugar intake were found to be associated with pain intensity and pain threshold. In conclusion, plant-based diets might have pain relieving effects on chronic musculoskeletal pain. Patients with chronic rheumatoid arthritis pain can show inadequate intake of calcium, folate, zinc, magnesium, and vitamin B6, whilst patients with fibromyalgia can show a lower intake of carbohydrates, proteins, lipids, vitamin A-E-K, folate, selenium, and zinc. Chronic pain severity also shows a positive relation with fat and sugar intake in osteoarthritis, and pain threshold shows a positive association with protein intake in fibromyalgia.
PubMed: 32150934
DOI: 10.3390/jcm9030702 -
Nutrition Reviews Apr 2022It has been suggested that a gluten-free and casein-free (GFCF) diet may alleviate the symptoms of autism spectrum disorder (ASD) and facilitate neurodevelopment of... (Meta-Analysis)
Meta-Analysis
CONTEXT
It has been suggested that a gluten-free and casein-free (GFCF) diet may alleviate the symptoms of autism spectrum disorder (ASD) and facilitate neurodevelopment of children with ASD. Studies to date have been inconclusive.
OBJECTIVE
This study aimed to evaluate (through quantitative meta-analysis) the efficacy and safety of a GFCF diet for children with ASD. To our knowledge, this is the first time such an analysis has been carried out.
DATA SOURCES
Eight electronic databases were searched, from the establishment of each database up to March 27, 2020: PubMed, Web of Science, Embase (Ovid), PsycINFO (Ovid), Cochrane Library, CNKI, Wanfang, and VIP databases.
DATA EXTRACTION
Two authors independently performed the data extraction and risk-of-bias assessment.
DATA ANALYSIS
A quantitative meta-analysis was performed with standard procedures by using Stata SE 15 software. Within the total of 8 studies, with 297 participants, 5 studies reported significant reductions in stereotypical behaviors [standard mean difference (SMD) = -0.41, 95% confidence interval (CI): -0.68 to -0.15], and 3 studies reported improvements in cognition (SMD = -0.46, 95% CI: -0.91 to -0.01) following GFCF dietary intervention . No statistically significant changes were observed in other symptomatic categories (all P > 0.05).
CONCLUSION
The current meta-analysis showed that a GFCF diet can reduce stereotypical behaviors and improve the cognition of children with ASD. Though most of the included studies were single-blind, the benefits of a GFCF diet that have been indicated are promising. Additional studies on a larger scale are warranted.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO registration no. CRD42020177619.
Topics: Autism Spectrum Disorder; Caseins; Child; Diet, Gluten-Free; Humans; Single-Blind Method
PubMed: 34617108
DOI: 10.1093/nutrit/nuab073 -
Diabetes Care Jun 2015Continuous glucose monitoring highlights the complexity of postprandial glucose patterns present in type 1 diabetes and points to the limitations of current approaches... (Review)
Review
Impact of fat, protein, and glycemic index on postprandial glucose control in type 1 diabetes: implications for intensive diabetes management in the continuous glucose monitoring era.
BACKGROUND
Continuous glucose monitoring highlights the complexity of postprandial glucose patterns present in type 1 diabetes and points to the limitations of current approaches to mealtime insulin dosing based primarily on carbohydrate counting.
METHODS
A systematic review of all relevant biomedical databases, including MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials, was conducted to identify research on the effects of dietary fat, protein, and glycemic index (GI) on acute postprandial glucose control in type 1 diabetes and prandial insulin dosing strategies for these dietary factors.
RESULTS
All studies examining the effect of fat (n = 7), protein (n = 7), and GI (n = 7) indicated that these dietary factors modify postprandial glycemia. Late postprandial hyperglycemia was the predominant effect of dietary fat; however, in some studies, glucose concentrations were reduced in the first 2-3 h, possibly due to delayed gastric emptying. Ten studies examining insulin bolus dose and delivery patterns required for high-fat and/or high-protein meals were identified. Because of methodological differences and limitations in experimental design, study findings were inconsistent regarding optimal bolus delivery pattern; however, the studies indicated that high-fat/protein meals require more insulin than lower-fat/protein meals with identical carbohydrate content.
CONCLUSIONS
These studies have important implications for clinical practice and patient education and point to the need for research focused on the development of new insulin dosing algorithms based on meal composition rather than on carbohydrate content alone.
Topics: Blood Glucose; Blood Glucose Self-Monitoring; Cross-Over Studies; Diabetes Mellitus, Type 1; Dietary Fats; Dietary Proteins; Glycemic Index; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Infusion Systems; Meals; Postprandial Period
PubMed: 25998293
DOI: 10.2337/dc15-0100 -
Clinical Nutrition (Edinburgh, Scotland) Mar 2023We conducted a systematic review and meta-analysis of current evidence for the association between food groups, dietary patterns, and breast cancer risk among the Asian... (Meta-Analysis)
Meta-Analysis
BACKGROUND & AIMS
We conducted a systematic review and meta-analysis of current evidence for the association between food groups, dietary patterns, and breast cancer risk among the Asian population.
METHODS
This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. We performed a systematic literature search up to December 2022 in English in the PubMed, Web of Science, Embase, and Cochrane databases. Risk ratios (RRs) with 95% confidence intervals (CIs) were extracted as effect sizes. Publication bias was estimated by two different funnel plot methods.
RESULTS
We collected the data from 15 cohort studies and 34 case-control studies meeting the search criteria. The meta-analysis found that the consumption of fruits and, likewise, vegetables were associated with a 29% lower risk of breast cancer, respectively [RR = 0.71 (0.55, 0.93); RR = 0.71 (0.53, 0.95)]. By contrast, no significance was found between meat, soy foods, and green tea consumption and breast cancer risk (P > 0.05). However, soy protein and isoflavone intake could lower breast cancer risk by 35% and 32%, respectively [RR = 0.65 (0.51, 0.83); RR = 0.68 (0.55, 0.82)]. As for the dietary pattern, high adherence to a healthy dietary pattern and, similarly, to a healthy eating index was associated with a 38% and 51% reduction in breast cancer risk, respectively [RR = 0.62 (0.44, 0.88; RR = 0.49 (0.27, 0.87)], while high adherence to an unhealthy dietary pattern was associated with a 44% increased risk [RR = 1.44 (1.06, 1.96)]. Considering alcohol consumption, a 75% increased risk of breast cancer was found [RR = 1.75 (1.33, 2.30)].
CONCLUSION
The present meta-analysis found that high intakes of fruits, vegetables, soy protein, and soy isoflavone significantly reduced the risk of breast cancer, while high intake of alcohol had a significantly increased risk. Meat, soy food, and green tea consumption were not significantly associated with breast cancer risk. Considering dietary patterns, high adherence to a healthy eating index and a healthy dietary pattern may reduce breast cancer risk. Conversely, adherence to unhealthy dietary patterns may increase breast cancer risk. However, further studies are needed to confirm the associations between dietary patterns and breast cancer in the Asian population.
Topics: Humans; Female; Breast Neoplasms; Risk Factors; Soybean Proteins; Diet; Vegetables; Isoflavones; Tea
PubMed: 36731160
DOI: 10.1016/j.clnu.2023.01.003 -
European Journal of Nutrition Mar 2018Effective treatments for core symptoms of autism spectrum disorders (ASD) are lacking. We systematically updated evidence on the effectiveness of a gluten-free and... (Review)
Review
PURPOSE
Effective treatments for core symptoms of autism spectrum disorders (ASD) are lacking. We systematically updated evidence on the effectiveness of a gluten-free and casein-free (GFCF) diet as a treatment for ASD in children.
METHODS
The Cochrane Library, MEDLINE, and EMBASE databases were searched up until August 2016, for randomized controlled trials (RCTs); additional references were obtained from reviewed articles.
RESULTS
Six RCTs (214 participants) were included. With few exceptions, there were no statistically significant differences in autism spectrum disorder core symptoms between groups, as measured by standardized scales. One trial found that compared with the control group, in the GFCF diet group there were significant improvements in the scores for the 'communication' subdomain of the Autism Diagnostic Observation Schedule and for the 'social interaction' subdomain of the Gilliam Autism Rating Scale. Another trial found significant differences between groups in the post-intervention scores for the 'autistic traits', 'communication', and 'social contact' subdomains of a standardized Danish scheme. The remaining differences, if present, referred to parent-based assessment tools or other developmental/ASD-related features. No adverse events associated with a GFCF diet were reported.
CONCLUSIONS
Overall, there is little evidence that a GFCF diet is beneficial for the symptoms of ASD in children.
Topics: Autism Spectrum Disorder; Caseins; Child; Child Nutritional Physiological Phenomena; Communication Disorders; Diet, Gluten-Free; Diet, Protein-Restricted; Evidence-Based Medicine; Humans; Randomized Controlled Trials as Topic; Reproducibility of Results; Severity of Illness Index; Social Behavior Disorders
PubMed: 28612113
DOI: 10.1007/s00394-017-1483-2