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Dietary protein and exercise for preservation of lean mass and perspectives on type 2 diabetes prevention.
de Sousa, MV, da Silva Soares, DB, Caraça, ER, Cardoso, R
Experimental biology and medicine (Maywood, N.J.). 2019;(12):992-1004
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Abstract
UNLABELLED Sedentary lifestyle and aging favor the increasing prevalence of obesity and type 2 diabetes and their comorbidities. The loss of lean body mass reduces muscle strength, resulting in impaired functional capacity and leading to increased risks of chronic diseases with advancing age. Besides aging, conditions such as inappetence, social isolation, and inadequate dietary intake cause the loss of lean body mass and increased abdominal fatty mass, resulting in sarcopenic obesity and predisposition to type 2 diabetes. Compared to younger people, this condition is more common in the elderly owing to natural changes in body composition associated with aging. Lifestyle changes such as increased physical activity and improved dietary behaviors are effective for preventing the occurrence of comorbidities. Regarding muscle nutrition, besides caloric adequacy, meeting the requirements for the consumption of dietary amino acids and proteins is important for treating sarcopenia and sarcopenic obesity because muscle tissue mainly consists of proteins and is, therefore, the largest reservoir of amino acids in the body. Thus, this review discusses the effects of dietary protein on the preservation of lean body mass, improvements in the functional capacity of muscle tissue, and prevention of chronic diseases such as type 2 diabetes. In addition, we address the effects of regular physical training associated with dietary protein strategies on lean body mass, body fat loss, and muscle strength in the elderly at a risk for type 2 diabetes development. IMPACT STATEMENT Diabetes mellitus is a worldwide health problem associated with obesity and sedentary lifestyle, which predisposes affected individuals to mortality and morbidity. Additionally, aging and unhealthy lifestyle behaviors increase inflammation and insulin resistance, contributing to the reduction of cytokines related to muscle nutrition and the suppression of lipogenesis, resulting in the development of sarcopenic obesity. One strategy for the prevention of T2D is the avoidance of secondary aging by participating in healthy action programs, including exercise and nutritional interventions. This minireview of several studies demonstrates the impact of physical activity and nutritional interventions on gaining or preserving muscle mass and on the functional aspects of muscles with aging. It provides information on the effect of protein, leucine, β-hydroxy-β-methylbutyrate (HMB), and creatine supplementation on muscle mass, strength, and volume gain and on the prevention of the progressive decrease in muscle mass with aging in combination with maintaining regular physical activity.
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Dietary protein affects both the dose and pattern of insulin delivery required to achieve postprandial euglycaemia in Type 1 diabetes: a randomized trial.
Evans, M, Smart, CEM, Paramalingam, N, Smith, GJ, Jones, TW, King, BR, Davis, EA
Diabetic medicine : a journal of the British Diabetic Association. 2019;(4):499-504
Abstract
AIM: To quantify the insulin requirement for a high-protein meal compared with a low-protein meal, controlling for carbohydrate and fat content. METHODS In this crossover study, young people with Type 1 diabetes were randomized to consume a high- (60 g) or low-protein meal (5 g), each containing 30 g carbohydrate and 8 g fat. A variation of the insulin clamp technique was used to determine the insulin requirements to maintain euglycaemia for the following 5 h. RESULTS A total of 11 participants (mean ± sd age 16.5 ± 2.7 years, HbA1c 52 ± 8.7 mmol/mol [6.9 ± 0.8%], diabetes duration 6.9±5.1 years) completed the study. The mean insulin requirements for the high-protein meal were higher than for the low-protein meal [10.3 (CI 8.2, 12.57) vs 6.7 units (CI 4.7, 8.8); P=0.001], with inter-individual requirements ranging from 0.9 to six times the low-protein meal requirement. Approximately half the additional insulin [1.1 units/h (CI 0.5, 1.8; P=0.001)] was given in the first 2 h, compared with an additional 0.5 units/h (CI -0.2, 1.2; P=0.148) in the second 2 h and 0.1 units (CI -0.6, 0.8; P=0.769) in the final hour. CONCLUSIONS A high-protein meal requires ~50% more insulin to maintain euglycaemia than a low-protein meal that contains the same quantity of carbohydrate. The majority is required within the first 2 h. Inter-individual differences exist in insulin requirements for dietary protein.
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A High-Fiber Diet Decreases Postabsorptive Protein Turnover but Does Not Alter Insulin Sensitivity in Men with Type 1 Diabetes Mellitus.
Bruttomesso, D, Tessari, P
The Journal of nutrition. 2019;(4):596-604
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Abstract
BACKGROUND High-fiber diets (HFDs) are recommended in the diet of persons with diabetes, yet such diets can impair macronutrient digestion and/or absorption, modify insulin sensitivity, and reset metabolism. OBJECTIVES We studied the effects of a HFD on the kinetics of whole-body protein, a macronutrient that could be affected by dietary fiber, in type 1 diabetes mellitus (T1DM), under both basal-low insulinemic and hyperinsulinemic conditions. METHODS Eight men with T1DM (body mass index range: 21.8-27.8 kg/m2) were studied twice - before and after the addition of guar gum (∼15 g/d) to their usual diet for ∼4 mo. Whole-body protein degradation (i.e., the rate of appearance [Ra] of endogenous leucine), leucine disposal to protein synthesis (PS), deamination, and reamination, were determined before and after the HFD, both in the postabsorptive state and following a euglycemic, hyperinsulinemic, hyperaminoacidemic clamp, using isotope dilution methods. RESULTS After the HFD, mean values (± SEs) for postabsorptive leucine Ra decreased by ∼20%: from 2.52 (0.15) to 2.03 (0.16) μmol x kg-1 x min-1, P < 0.049, after vs. before the HFD respectively. PS also decreased, by ∼25%: from 2.03 (0.15) to 1.57 (0.15), P < 0.045. Leucine concentration (P = 0.1) and reamination (P = 0.095) decreased moderately, whereas deamination was unchanged. Following the clamp, plasma amino acid concentrations (P < 0.001), leucine deamination (+ ∼50%, P < 0.00002), reamination (+ ∼30%, P < 0.0007), and PS (+ ∼35%, P < 0.00001) were all increased compared with postabsorptive state values, whereas endogenous leucine Ra was suppressed (by 15%, P < 0.00001, and by 25%, P < 0.001, with the primary or the reciprocal pool models, respectively). No significant differences in these insulin effects before compared with after the HFD were observed. Metabolic control (glycated hemoglobin), daily insulin requirement, and insulin-mediated glucose disposal were unchanged after the HFD. CONCLUSIONS A HFD downregulates postabsorptive protein turnover in men with T1DM, by decreasing both protein degradation and synthesis, possibly due to a subtle decrease and/or delay in amino acid absorption. It does not significantly affect the insulin (and amino acid sensitivity) to protein turnover, glucose disposal, and metabolic control.
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Protein supplementation elicits greater gains in maximal oxygen uptake capacity and stimulates lean mass accretion during prolonged endurance training: a double-blind randomized controlled trial.
Knuiman, P, van Loon, LJC, Wouters, J, Hopman, M, Mensink, M
The American journal of clinical nutrition. 2019;(2):508-518
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Abstract
BACKGROUND Endurance training induces numerous cardiovascular and skeletal muscle adaptations, thereby increasing maximal oxygen uptake capacity (VO2max). Whether protein supplementation enhances these adaptations remains unclear. OBJECTIVE The present study was designed to determine the impact of protein supplementation on changes in VO2max during prolonged endurance training. METHODS We used a double-blind randomized controlled trial with repeated measures among 44 recreationally active, young males. Subjects performed 3 endurance training sessions per week for 10 wk. Supplements were provided immediately after each exercise session and daily before sleep, providing either protein (PRO group; n = 19; 21.5 ± 0.4 y) or an isocaloric amount of carbohydrate as control (CON group; n = 21; 22.5 ± 0.5 y). The VO2max, simulated 10-km time trial performance, and body composition (dual-energy X-ray absorptiometry) were measured before and after 5 and 10 wk of endurance training. Fasting skeletal muscle tissue samples were taken before and after 5 and 10 wk to measure skeletal muscle oxidative capacity, and fasting blood samples were taken every 2 wk to measure hematological factors. RESULTS VO2max increased to a greater extent in the PRO group than in the CON group after 5 wk (from 49.9 ± 0.8 to 54.9 ± 1.1 vs 50.8 ± 0.9 to 53.0 ± 1.1 mL · kg-1 · min-1; P < 0.05) and 10 wk (from 49.9 ± 0.8 to 55.4 ± 0.9 vs 50.8 ± 0.9 to 53.9 ± 1.2 mL · kg-1 · min-1; P < 0.05). Lean body mass increased in the PRO group whereas lean body mass in the CON group remained stable during the first 5 wk (1.5 ± 0.2 vs 0.1 ± 0.3 kg; P < 0.05) and after 10 wk (1.5 ± 0.3 vs 0.4 ± 0.3 kg; P < 0.05). Throughout the intervention, fat mass reduced significantly in the PRO group and there were no changes in the CON group after 5 wk (-0.6 ± 0.2 vs -0.1 ± 0.2 kg; P > 0.05) and 10 wk (-1.2 ± 0.4 vs -0.2 ± 0.2 kg; P < 0.05). CONCLUSIONS Protein supplementation elicited greater gains in VO2max and stimulated lean mass accretion but did not improve skeletal muscle oxidative capacity and endurance performance during 10 wk of endurance training in healthy, young males. This trial was registered at clinicaltrials.gov as NCT03462381.
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Preliminary effect and feasibility of physiotherapy with strength training and protein-rich nutritional supplement in combination with anabolic steroids in cross-continuum rehabilitation of patients with hip fracture: protocol for a blinded randomized controlled pilot trial (HIP-SAP1 trial).
Hulsbæk, S, Ban, I, Aasvang, TK, Jensen, JB, Kehlet, H, Foss, NB, Bandholm, T, Kristensen, MT
Trials. 2019;(1):763
Abstract
BACKGROUND A 2014 Cochrane review evaluating the effect of anabolic steroids after hip fracture concluded that the quality of the studies was insufficient to draw conclusions on the effects and recommended further high-quality trials in the field. Therefore, the aim of this pilot trial is to determine the preliminary effect and feasibility of a 12-week multimodal intervention consisting of physiotherapy (with strength training), protein-rich nutritional supplement and anabolic steroid on knee-extension muscle strength and function 14 weeks after hip fracture surgery. METHODS We plan to conduct a randomized, placebo-controlled pilot trial with 48 patients operated for acute hip fracture. The patients are randomized (1:1) to either (1) physiotherapy with protein-rich nutritional supplement plus anabolic steroid or (2) physiotherapy with protein-rich nutritional supplement plus placebo. Outcome assessments will be carried out blinded at baseline (3-10 days after surgery) and at 14 weeks after entering the trial. Primary outcome is the change from baseline to follow-up in maximal isometric knee-extension muscle strength in the fractured limb. Secondary outcomes are physical performance test, patient-reported outcomes, and measures of body composition. DISCUSSION If the trial is found feasible and the results show an indication of anabolic steroid being a relevant addition to further enhance the recovery of muscle strength and function in an enhanced recovery after surgery program, this trial will constitute the basis of a larger confirmatory trial. TRIAL REGISTRATION ClinicalTrials.gov, NCT03545347. Preregistered on 4 June 2018.
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The Nutritional Value and Biological Activity of Concentrated Protein Fraction of Potato Juice.
Kowalczewski, PŁ, Olejnik, A, Białas, W, Rybicka, I, Zielińska-Dawidziak, M, Siger, A, Kubiak, P, Lewandowicz, G
Nutrients. 2019;(7)
Abstract
Potato protein is recognized as one of the most valuable nonanimal proteins due to the high content of essential amino acids. So far, it has not been used in human nutrition on a large scale due to technological limitations regarding its acquisition. In this study, the protein fraction of potato juice was concentrated with the use of membrane separation. The obtained potato juice protein concentrate (PJPC) was characterized in terms of nutritional value and biological activity, and the amino acid composition, mineral content, and antioxidant properties were determined. Moreover, in vitro cytotoxic activity against cancer cells of the gastrointestinal tract was investigated. The results of the present study indicate that PJPC is an excellent source of lysine and threonine, while leucine is its limiting amino acid, with an amino acid score (AAS) of 65%. Moreover, PJPC contains substantial amounts of Fe, Mn, K, and Cu. As demonstrated experimentally, PJPC is also characterized by higher antioxidant potential than potato itself. Biological activity, however, is not limited to antioxidant activity alone. Cytotoxicity studies using a gastric cancer cell line (Hs 746T), a colon cancer cell line (HT-29), and human colon normal cells (CCD 841 CoN) proved that PJPC is characterized by selective activity against cancer cells. It can thus be concluded that the developed method of producing protein concentrate from potato juice affords a product with moderate nutritional value and interesting biological activity.
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Energy and Protein Intake of Alzheimer's Disease Patients Compared to Cognitively Normal Controls: Systematic Review.
Doorduijn, AS, van de Rest, O, van der Flier, WM, Visser, M, de van der Schueren, MAE
Journal of the American Medical Directors Association. 2019;(1):14-21
Abstract
OBJECTIVES Protein and energy malnutrition and unintended weight loss are frequently reported in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Possible underlying mechanisms include increased energy expenditure, altered uptake of nutrients, a reduced nutritional intake, or a combination of these 3. We aimed at systematically reviewing the literature to examine potential differences in energy and protein intake in patients with MCI and AD compared to controls as a possible mechanism for unintended weight loss. DESIGN Systematic review and meta-analysis. SETTING PubMed and Cochrane Electronic databases were searched from inception to September 2017 for case control studies. PARTICIPANTS Patients with MCI or AD compared to cognitive healthy controls, all adhering to a Western dietary pattern. MEASUREMENTS Energy and protein intake. RESULTS The search resulted in 7 articles on patients with AD versus controls, and none on patients with MCI. Four articles found no differences in energy and protein intakes, 1 found higher intakes in patients with AD, and 1 article found lower intakes in patients with AD compared to controls. One article reported on intakes, but did not test differences. A meta-analysis of the results indicated no difference between patients with AD and controls in energy [-8 kcal/d, 95% confidence interval (CI): -97, 81; P = .85], or protein intake (2 g/d, 95% CI: -4, 9; P = .47). However, heterogeneity was high (I2 > 70%), and study methodology was generally poor or moderate. CONCLUSION Contrary to frequently reported unintended weight loss, our systematic review does not provide evidence for a lower energy or protein intake in patients with AD compared to controls. High heterogeneity of the results as well as of participant characteristics, setting, and study methods was observed. High-quality studies are needed to study energy and protein intake as a possible mechanism for unintended weight loss and malnutrition in both patients with MCI and AD.
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Effects of higher habitual protein intake on resistance-training-induced changes in body composition and muscular strength in untrained older women: A clinical trial study.
Nabuco, HC, Tomeleri, CM, Junior, PS, Fernandes, RR, Cavalcante, EF, Nunes, JP, Cunha, PF, Dos Santos, L, Cyrino, ES
Nutrition and health. 2019;(2):103-112
Abstract
BACKGROUND Aging is accompanied by progressive and accentuated decline in muscular strength and skeletal muscle mass, affecting health and functional autonomy. Both resistance training (RT) and diet are strategies that may contribute to improvement in the health of the elderly. AIM: The purpose of this study was to evaluate the effects of higher habitual protein intake on RT-induced changes in body composition and strength in untrained postmenopausal women. METHODS Seventy older women were submitted to an RT program. Body composition, muscular strength, and dietary intake (24 h dietary recall) were performed pre- and post-intervention. To verify different intervention effects according to protein intake of the participants, the sample was separated into tertiles according to protein intake: low, moderate, and high protein intake. RESULTS A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with low protein intake, for skeletal muscle mass (5.3% vs. 1.3%), lower limb lean soft tissue (4.9% vs. 1.4%), upper lean soft tissue (4.9% vs. 1.2%), preacher curl (24% vs. 15.2%), and total strength (16.4% vs. 11.7%). A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with moderate protein intake, for skeletal muscle mass (5.3% vs. 3.2%). In all groups, a main effect of time ( p < 0.05) was observed for knee extension and chest press. CONCLUSIONS We conclude that intake of >1.0 g/kg/day of protein promotes gains in skeletal muscle mass and muscular strength after RT in untrained older women.
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Effects of Blood Flow Restriction Training with Protein Supplementation on Muscle Mass And Strength in Older Men.
Centner, C, Zdzieblik, D, Roberts, L, Gollhofer, A, König, D
Journal of sports science & medicine. 2019;(3):471-478
Abstract
Blood flow restriction (BFR) training has been shown to induce favorable changes in muscle mass and strength with a considerably low training load (20 - 30% 1RM). However, it has never been evaluated if an additional post-exercise protein supplementation enhances the effects of this training regimen. Thirty healthy older men (60.1 ± 7.6 years) were enrolled in the 8-week intervention and randomly allocated to one of the following groups: low-load BFR training with protein (collagen hydrolysate) supplementation (BFR-CH), low-load BFR training with placebo (BFR-PLA), or a control group without training, but with protein supplementation (CON). Muscle cross-sectional area (CSA), muscle strength, circulating reactive oxygen species and IGF-1 were measured before and after the intervention. Muscle CSA increased in both BFR-CH and BFR-PLA groups by 6.7 ± 3.2 % (p < 0.001) and 5.7 ± 2.7 % (p < 0.001) respectively. No significant changes were observed in the CON group (1.1 ± 1.7 %, p = 0.124). Evaluation of isometric strength (p = 0.247), insulin-like growth factor 1 (p = 0.705) and the production of reactive oxygen species (pt1 = 0.229; pt2 = 0.741) revealed no significant interaction effect but a significant long-term time effect (p < 0.001). Our results demonstrate that BFR training is an effective alternative for increasing muscle CSA in older men. Although there was a trend towards greater muscle mass adaptations in the BFR-CH group, these findings showed no statistical significance. Further research with larger sample sizes is needed to confirm these results.
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Are dietary amino acids prospectively predicts changes in serum lipid profile?
Teymoori, F, Asghari, G, Salehi, P, Sadeghian, S, Mirmiran, P, Azizi, F
Diabetes & metabolic syndrome. 2019;(3):1837-1843
Abstract
BACKGROUND Besides of dietary fat and carbohydrate, amino acids(AAs), as constituent components of dietary protein have been related with serum lipid levels. This study aims to examine the association between dietary AAs and prospective changes in serum lipid profile in adults. METHODS Analyses were conducted on 3881 participants aged, 18-75 years of Tehran lipid and Glucose study, at baseline (2008-2011) and were followed for 3 years (2011-2014) to ascertain serum lipid profile changes. Dietary intakes of AAs were collected at baseline using food frequency questionnaire. Multiple linear regression adjusted for age, sex, body mass index, physical activity, smoking and daily intakes of energy, total fat, and fiber were used. RESULTS The median(IQR) changes in triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C) were 6.0(-19.0, -35.5), 9.0(7.0, -24.0), 1.0(-3.0, -6.0), and 5.2(-8.0, -18.6) mg/dl, respectively. Higher intakes of isoleucine, lysine, tyrosine, alanine, threonine, methionine, valine, histidine, aspartic acid, and branched chain, alkaline, and alcoholic AAs were positively associated with TGs-changes in the final adjusted model, whereas tryptophan, glutamic acid, and acidic AAs were negatively related to TG-changes. Alanine and tryptophan were associated with higher and lower LDL-C-changes, respectively. Lysine, alanine, methionine, aspartic acid, and alkaline AAs showed positive association with changes in TC, whereas tryptophan and glutamic acid had a negative association with TC-changes. CONCLUSION Our findings showed that some dietary amino acids have the potential to increase or decrease serum lipid profile.