Effect of an (-)-Epicatechin Intake on Cardiometabolic Parameters-A Systematic Review of Randomized Controlled Trials.

Growing evidence exists that consumption of cocoa-rich food improves the parameters of cardiometabolic health. These effects are ascribed to cocoa flavanols, particularly to (-)-epicatechin (EC), a natural ingredient of cocoa. Hence, to evaluate if EC may explain the effects of cocoa, this systematic review aimed to provide an overview on randomized controlled trials (RCTs) investigating the impact of an EC intake on cardiometabolic biomarkers. For this, the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 statement was considered and the risk of bias (RoB) was assessed by using the Cochrane RoB 2 tool. In total, 11 studies were included examining parameters on vascular function, glucose/lipid metabolism, oxidative stress, inflammation, appetite sensations, and body weight before and after EC treatment. Except for a dose-dependent acute increase in flow-mediated dilatation (FMD) and in the peripheral arterial tonometry (PAT) index in healthy young adults, effects by EC treatment were not observed. For most trials, some concerns exist for overall RoB. Thus, EC intake may improve endothelial function in healthy young adults. For further parameters (mostly secondary outcomes), it remains unclear if EC has no effect or if this was not detectable. Unbiased RCTs on the impact of an EC intake are needed, which should also investigate the additive or synergistic effects of EC with other cocoa ingredients.

Fortifying a meal with oyster mushroom powder beneficially affects postprandial glucagon-like peptide-1, non-esterified free fatty acids and hunger sensation in adults with impaired glucose tolerance: a double-blind randomized controlled crossover trial.

PURPOSE: Impaired glucose tolerance (IGT) is a pathophysiological condition characterized by insulin resistance with known metabolic consequences such as postprandial hyperglycemia and hypertriglyceridemia. We hypothesized that fortifying a meal with mushrooms rich in ß-glucans may diminish glucose and triglyceride responses by improving postprandial gastrointestinal hormone release. METHODS: In a randomized controlled crossover study, 22 subjects with IGT ingested a meal either enriched with 20 g powder (8.1 g ß-glucans) of oven-dried Pleurotus ostreatus (enriched meal, EN) or without enrichment (control meal, CON). Blood was collected before and repeatedly within 4 h after the meal to determine AUC of glucose (primary outcome), insulin, triglycerides, non-esterified free fatty acids (NEFAs), glucagon-like peptide-1 (GLP-1), gastric inhibitory polypeptide (GIP) and ghrelin. Appetite sensations (hunger, satiety, fullness, and desire to eat) were assessed before and after meal consumption by visual analog scales. RESULTS: Postprandial glucose, insulin, triglycerides, GIP and ghrelin concentrations as well as the corresponding AUCs did not differ between EN and CON. NEFAs-AUC was 14% lower (P = 0.026) and GLP-1-AUC 17% higher (P = 0.001) after EN compared to CON. Appetite ratings did not differ between treatments, except for hunger (AUC 22% lower after EN vs. CON; P = 0.031). CONCLUSION: The observed immediate postprandial metabolic changes indicate that an easily manageable fortification of a single meal with powder from dried oyster mushrooms as ß-glucan source may improve postprandial metabolism. If the effect is preserved long term, this measure can diminish the risk for further development of overweight/obesity and type 2 diabetes in subjects with IGT. CLINICAL TRIAL REGISTRATION: German Clinical Trial Register on 09/08/2018; trial-ID: DRKS00015244.

Effect of the Intake of Oyster Mushrooms (Pleurotus ostreatus) on Cardiometabolic Parameters-A Systematic Review of Clinical Trials.

Cardiometabolic diseases are a leading global health challenge. Their incidence as well as progression is strongly affected by diet. Consumption of Pleurotus ostreatus (P. ostreatus), an edible oyster mushroom rich in functional ingredients (e.g., ß-glucans), may improve glucose and lipid metabolism, blood pressure, body weight and appetite sensations. Hence, this systematic review aimed to provide an overview on the effects of P. ostreatus intake on cardiometabolic parameters from clinical trials, taking into account risk of bias (RoB). Relevant studies were investigated for details with consideration of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The Cochrane Collaboration's tool was used to assess the RoB. In total, eight trials included observed beneficial effects of P. ostreatus intake on glucose metabolism (reduction in fasting and/or 2 h postprandial glucose) and lipids (decrease in total cholesterol, LDL-cholesterol and/or triglycerides), and some found a reduction in blood pressure. In contrast, body weight did not change. Appetite sensations were not assessed. In most studies, the RoB was high or unclear due to methodological weaknesses and/or inadequate reporting. Thus, P. ostreatus intake may improve cardiometabolic health, but evidence for this is low. Hence, further clinical trials with an adequate study design are warranted to validate these suggestions.

Impact of a Usual Serving Size of Flavanol-Rich Cocoa Powder Ingested with a Diabetic-Suitable Meal on Postprandial Cardiometabolic Parameters in Type 2 Diabetics-A Randomized, Placebo-Controlled, Double-Blind Crossover Study.

Randomized controlled trials indicate that flavanol-rich cocoa intake may improve postprandial glucose and lipid metabolism in patients with type 2 diabetes (T2D), based on studies with meals that impose a strong metabolic load. Hence, the aim of the present study was to investigate whether flavanol-rich cocoa powder ingested as part of a diabetic-suitable meal may beneficially affect glucose, lipid metabolism, and blood pressure (BP) in patients with T2D. Twelve adults with T2D, overweight/obesity, and hypertension ingested capsules with 2.5 g of flavanol-rich cocoa or microcrystalline cellulose with a diabetic-suitable breakfast in a randomized, placebo-controlled, double-blind crossover study. BP was measured and blood samples were taken before, 2 and 4 h after breakfast and capsule intake. Cocoa treatment did not affect glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), triglycerides, total cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol, and BP. For glucose, insulin and HOMA-IR, only effects by time were observed after both treatments. Thus, 2.5 g of flavanol-rich cocoa powder ingested as part of a diabetic-suitable meal does not seem to affect postprandial glucose and lipid metabolism and BP in stably-treated diabetics. Nevertheless, future studies with close-meshed investigations are desirable, providing realistic amounts of cocoa together with realistic meals rich in carbohydrates to subjects with T2D or metabolic syndrome, which do not afford pharmacological treatment.

Regular Intake of a Usual Serving Size of Flavanol-Rich Cocoa Powder Does Not Affect Cardiometabolic Parameters in Stably Treated Patients with Type 2 Diabetes and Hypertension-A Double-Blinded, Randomized, Placebo-Controlled Trial.

Regular cocoa consumption has been shown to improve blood pressure (BP), insulin sensitivity, and lipid levels in patients with type 2 diabetes (T2D), using up to 100 g of chocolate or 54 g of cocoa. These effects, attributed to cocoa flavanols, would be beneficial for patients with T2D if they could be achieved by a usual serving size of flavanol-rich cocoa. Forty-two hypertensive patients with T2D (stable pharmacological treatment, with good adjustment for glucose metabolism, lipids, and BP) ingested capsules with 2.5 g/day of a flavanol-rich cocoa or cocoa-free capsules for 12 weeks in a double-blinded, randomized, placebo-controlled study with parallel group design. Participants had to maintain diet, lifestyle, and medication. Before and after intervention, fasting blood samples were collected; BP and nutritional status were investigated. Cocoa treatment did not affect BP, nor glucose metabolism (glucose, HbA1c, insulin, HOMA-IR) and lipids (triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol). Body weight, fat mass, and nutrient supply remained unchanged. Changes in the placebo group did not occur. Regular intake of a usual serving size of flavanol-rich cocoa does not improve cardiometabolic parameters in stably treated patients with T2D and hypertension. As the medication modulates partly the same targets as cocoa flavanols, future studies should focus on the preventive effect of cocoa against diabetes and other cardiometabolic diseases in individuals with preexisting abnormalities that do not require any pharmacological treatment.