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The American Journal of Clinical... Aug 2023Serving whey protein before a meal in order to lower postprandial blood glucose concentrations is known as a premeal. The underlying mechanisms are only partly... (Meta-Analysis)
Meta-Analysis
Whey Protein Premeal Lowers Postprandial Glucose Concentrations in Adults Compared with Water-The Effect of Timing, Dose, and Metabolic Status: a Systematic Review and Meta-analysis.
BACKGROUND
Serving whey protein before a meal in order to lower postprandial blood glucose concentrations is known as a premeal. The underlying mechanisms are only partly understood but may involve stimulation of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and insulin secretion together with a slower gastric emptying rate.
OBJECTIVES
The objective of this systematic review and meta-analysis was to review all randomized clinical trials investigating premeals with whey protein in comparison with a nonactive comparator (control) that evaluated plasma glucose, GLP-1, GIP, insulin, and/or gastric emptying rate. Secondary aims included subgroup analyses on the timing and dose of the premeal together with the metabolic state of the participants [lean, obese, and type 2 diabetes mellitus (T2DM)].
METHODS
We searched EMBASE, CENTRAL, PUBMED, and clinicaltrials.gov and found 16 randomized crossover trials with a total of 244 individuals. The last search was performed on 9 August, 2022.
RESULTS
Whey protein premeals lowered peak glucose concentration by -1.4 mmol/L [-1.9 mmol/L; -0.9 mmol/L], and the area under the curve for glucose was -0.9 standard deviation (SD) [-1.2 SD; -0.6 SD] compared with controls (high certainty). In association with these findings, whey protein premeals elevated GLP-1 (low certainty) and peak insulin (high certainty) concentrations and slowed gastric emptying rate (high certainty) compared with controls. Subgroup analyses showed a more pronounced and prolonged glucose-lowering effect in individuals with T2DM compared with participants without T2DM. The available evidence did not elucidate the role of GIP. The protein dose used varied between 4 and 55 g, and meta-regression analysis showed that the protein dose correlated with the glucose-lowering effects.
CONCLUSIONS
In conclusion, whey protein premeals lower postprandial blood glucose, reduce gastric emptying rate, and increase peak insulin. In addition, whey protein premeals may elevate plasma concentrations of GLP-1. Whey protein premeals may possess clinical potential, but the long-term effects await future clinical trials.
Topics: Humans; Adult; Whey Proteins; Glucagon; Blood Glucose; Diabetes Mellitus, Type 2; Water; Insulin; Glucagon-Like Peptide 1; Gastric Inhibitory Polypeptide; Glucose; Gastric Emptying; Postprandial Period
PubMed: 37536867
DOI: 10.1016/j.ajcnut.2023.05.012 -
Journal of Clinical Nursing Sep 2023Older adults frequently suffer from postprandial hypotension, associated with an increased risk of falls, syncope, acute cardiovascular and cerebrovascular diseases, and... (Review)
Review
BACKGROUND
Older adults frequently suffer from postprandial hypotension, associated with an increased risk of falls, syncope, acute cardiovascular and cerebrovascular diseases, and even death. Researchers use non-pharmacological interventions, but related literature is dispersed and lacks a latest summary.
OBJECTIVE
The aim of this study was to map and examine non-pharmacological interventions currently employed to assist older adults with postprandial hypotension and lay a solid foundation for future studies.
METHODS
This study adhered to the JBI methodology for scoping reviews and preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews. PubMed, Web of Science, Embase, Cochrane Library, CINAHL, SCOPUS, Chinese Biomedical Journal, China National Knowledge Infrastructure, VIP and WAN FANG Data were retrieved from their inception to 1 August 2022.
RESULTS
Two randomized controlled trials and seven quasi-experimental studies were included. Small meals, exercise interventions, fibre with meals, green tea and water therapy have been reported to prevent postprandial hypotension effectively; however, position changes have been reported to have no impact on postprandial blood pressure decrease. Additionally, the blood pressure determination methods and test meals may affect observed trial effects.
CONCLUSION
Large samples and long-term follow-up studies are needed to prove the efficacy and safety of existing non-pharmacological interventions. Future studies should develop a BP determination method based on the postprandial BP decline trajectory induced by a given test meal to improve the reliability of study results.
RELEVANCE TO CLINICAL PRACTICE
This review broadly summarizes existing studies on developing and validating non-pharmacological interventions for older adults with postprandial hypotension. It also analyses special factors that may influence the trial effects. This may provide a useful reference for future research.
Topics: Humans; Aged; Reproducibility of Results; Hypotension; Blood Pressure; Postprandial Period; Meals
PubMed: 37219354
DOI: 10.1111/jocn.16719 -
Journal of the American Nutrition... 2023Aberrations in glucose, insulin, and other postprandial (PP) markers are common in obesity and cardiometabolic disorders. One potentially simple lifestyle/dietary...
OBJECTIVE
Aberrations in glucose, insulin, and other postprandial (PP) markers are common in obesity and cardiometabolic disorders. One potentially simple lifestyle/dietary modification to manage these issues is to change the order in which foods are consumed within meals. Carbohydrate exerts the largest effect on PP glucose, and there is some evidence that ingesting dietary fat or protein before carbohydrate delays gastric emptying of carbohydrate and reduces PP glucose. Additionally, certain dietary proteins may augment insulin release if ingested with carbohydrate, thereby improving blood glucose clearance. This review aimed to systematically evaluate evidence from acute experiments that modified the order in which foods were consumed in isocaloric meals.
METHODS
Outcomes of interest were PP glucose and insulin (including area under the curve for both), C-peptide, gut hormones, and perceptual responses. Three databases were searched (PubMed, Cochrane CENTRAL, Web of Science) in February 2022. Additionally, reference lists of identified reports were searched, and an author of several studies was consulted to verify that relevant literature was included. The review included acute interventions that administered isocaloric meals of the same foods but with foods eaten in different orders. Studies were not excluded based on participant characteristics.
RESULTS
Eleven reports were identified. All reports that assessed glucose and insulin showed a tendency toward lower levels, at least over parts of the PP period, by consuming carbohydrates last. GLP-1 tended to be higher in carbohydrate-last conditions, though this was only measured in a few studies. Perceptual responses (hunger, fullness, etc.) were not consistently different between conditions in two studies, but the certainty of evidence was very low.
CONCLUSIONS
Findings indicate that, at least acutely, there may be benefits to eating carbohydrate after vegetable and/or protein-rich foods. The most consistent effect (judged as moderate certainty) is that carbohydrate-last meal orders tend to lower blood glucose and insulin excursions.
PubMed: 36574255
DOI: 10.1080/27697061.2022.2161664 -
Consumption of sourdough bread and changes in the glycemic control and satiety: A systematic review.Critical Reviews in Food Science and... 2024The aim of this study was to carry out a systematic review of clinical trials followed by meta-analysis, to evaluate the effect of sourdough bread on glycemic control... (Meta-Analysis)
Meta-Analysis
The aim of this study was to carry out a systematic review of clinical trials followed by meta-analysis, to evaluate the effect of sourdough bread on glycemic control and appetite and satiety regulators such as leptin, ghrelin, GLP-1 (glucagon-like peptide-1), GLP-2 (glucagon-like peptide-2), NPY (neuropeptide Y), AgRP (agouti-related protein), PYY (peptide YY), and GIP (glucose-dependent insulinotropic polypeptide). Clinical trials compared the intake of sourdough bread to that of an industrially fermented one or control glucose solution in adults over 18 years of age. This systematic review included all randomized, parallel, or crossover trials published up to June 2021 in the EMBASE, MEDLINE, Scopus, and Web of Science databases. After the selection process, 18 studies were included. The analysis of the final average difference of the change in serum glucose after 60 minutes for the intervention indicated that the consumption of sourdough bread has a lower impact on blood glucose compared to that of industrial bread or glucose (MD = -0.29, IC 95% = [-0.46; -0.12]; I = 0%). The evaluation of blood glucose 120 minutes after the consumption of the intervention also indicated a lower increment in blood glucose when compared to the consumption of other types of bread or the same amount of glucose (MD = -0.21, IC 95% = [-0.32; -0.09]; I = 0%). The certainty of evidence varied from low to very low. The results showed that sourdough is effective in reducing the increment of postprandial glycemia, especially when prepared with whole wheat flour, although it does not reduce fasting serum insulin, nor does it change plasma PYY.
Topics: Blood Glucose; Bread; Flour; Glycemic Control; Triticum; Glucagon-Like Peptide 1; Postprandial Period; Insulin
PubMed: 35943419
DOI: 10.1080/10408398.2022.2108756