Postprandial Glucose and Gastrointestinal Hormone Responses of Healthy Subjects to Wheat Biscuits Enriched with L-Arginine or Branched-Chain Amino Acids of Plant Origin.

The study investigates the effects of wheat biscuits supplemented with plant flours originating from legumes/seeds enriched either in L-arginine (L-arg) or branched-chain amino acids (BCAAs) on postprandial glucose response of healthy subjects. Gastrointestinal hormone and amino acid responses as well as subjective appetite sensations are also evaluated. Subjects consumed wheat-based biscuits, enriched either in L-arg (ArgB) or BCAAs (BCAAsB) or a conventional wheat biscuit (CB) or a glucose solution (GS) in an acute randomized crossover design. Responses of glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and glicentin, as well as those of L-arginine, L-leucine, L-isoleucine and L-valine, were evaluated over 180 min. Consumption of ArgB and BCAAsB elicited lower glucose iAUC compared to GS (p < 0.05). A lower iAUC for insulin was observed after consumption of BCAAsB (p < 0.05 compared to CB and ArgB), while ArgB elicited higher iAUC for GLP-1 accompanied by higher glicentin response (p < 0.05 compared to CB). BCAAsB and ArgB increased postprandial amino acid concentrations and caused stronger satiety effects compared to CB. Increasing protein content of wheat biscuits with supplementation of plant flours originating from legumes/seeds decreases postprandial glycemia and provides with healthier snack alternatives which can easily be incorporated into diet.

Controlling type-2 diabetes by inclusion of Cr-enriched yeast bread in the daily dietary pattern: a randomized clinical trial.

PURPOSE: Chromium (Cr)-enriched yeast supplementation to whole wheat bread (WWCrB) has been shown to ameliorate postprandial glycemic response in healthy subjects. The present study investigates the long-term benefit of WWCrB consumption for patients with type-2 diabetes mellitus (T2DM). METHODS: Thirty patients with T2DM were randomly assigned to a group receiving WWCrB or the plain whole wheat bread (WWB) group. Plasma glucose, insulin, glycosylated hemoglobin (HbA1c) and insulin resistance were determined, and oral glucose tolerance test (OGTT) was performed at the beginning and the end of the dietary intervention, which lasted for 12 weeks. Biochemical parameters related to the disease, markers of inflammation as well as body weight and energy balance were examined. RESULTS: At the end of the study, subjects of WWCrB group exerted lower levels of glucose, insulin and HbA1c and improved insulin resistance (P < 0.05 against before treatment). Area under the glucose curve attained during OGTT decreased after the intervention (28,117.5 ± 1266.4 vs. 31,588.5 ± 1187.5 mg min/dL before treatment, P < 0.05) with significantly lower values of glucose concentration at 0 and 60 min. A significant reduction in body weight and systolic blood pressure (SBP) was observed (P < 0.05 against before treatment). Markers of inflammation and lipid profiles were not affected by WWCrB consumption. CONCLUSIONS: Inclusion of WWCrB in the daily dietary pattern of diabetic patients resulted in improvement of glucose tolerance and insulin resistance, significant reduction in HbA1c, weight loss and lower SBP. Patients with inadequate glycemic control may benefit from the consumption of WWCrB.

Effect of Saffron on Metabolic Profile and Retina in Apolipoprotein E-Knockout Mice Fed a High-Fat Diet.

Saffron is a spice that has been traditionally used as a regimen for a variety of diseases due to its potent antioxidant attributes. It is well documented that impaired systemic oxidative status is firmly associated with diverse adverse effects including retinal damage. The aim of this study was to investigate the role of saffron administration against the retinal damage in apoE -/- mice fed a high-fat diet, since they constitute a designated experimental model susceptible to oxidative stress. Twenty-one mice were allocated into three groups: Group A (control, n = 7 c57bl/6 mice) received standard chow diet; Group B (high-fat, n = 7 apoE -/- mice) received a high-fat diet; and Group C (high-fat and saffron, n = 7 apoE -/- mice) received a high-fat diet and saffron (25 mg/kg/d) through their drinking water. The duration of the study was 20 weeks. Lipidemic profile, glucose, C-reactive protein (CRP), and total oxidative capacity (PerOX) were measured in blood serum. Histological analysis of retina was also conducted. Administration of saffron resulted in enhanced glycemic control and preservation of retinal thickness when compared with apoE -/- mice fed a high-fat diet. The outcomes of the study suggest the potential protective role of saffron against retinal damage induced by oxidative stress. Nevertheless, verification of these results in humans is required before any definite conclusions can be drawn.

Cr-enriched yeast: beyond fibers for the management of postprandial glycemic response to bread.

PURPOSE: Efforts regarding the amelioration of postprandial glycemic response to bread are mainly focused in the addition of soluble dietary fibers. The current study presents another approach which is based on the supplementation of flour with Cr-enriched yeast. Cr is known for its beneficial effects on improvement of glucose tolerance and enhancement of insulin sensitivity. METHODS: Twelve normoglycemic subjects were provided with white bread (WB, reference food) or whole wheat bread with Cr-enriched yeast (WWCrB, rich in insoluble fibers) or white wheat bread with Cr-enriched yeast (WCrB, poor in fibers) or whole wheat-rye-barley bread enriched with oat beta glucans (BGB, rich in soluble fibers) with 1-week intervals in amounts that yielded 50 g of available carbohydrates. Postprandial glucose, insulin and ghrelin responses as well as glycemic index (GI) were evaluated. RESULTS: Ingestion of WWCrB, WCrB and BGB elicited lower incremental area under the curve (iAUC) for 120-min glycemic response compared to WB (1033.02 ± 282.32, 701.69 ± 330.86 and 748.95 ± 185.42 vs 2070.87 ± 518.44 mg/dL min, respectively, P < 0.05 for WCrB and BGB). The GI was calculated as 62.35 ± 11.78 for WWCrB, 34.22 ± 11.93 for WCrB and 37.90 ± 5.00 for BGB (P < 0.05 vs WB, GI = 100). iAUC for 120-min insulin response to BGB was significantly lower than WB (2780.04 ± 303.26 vs 3915.53 ± 490.57 µU/mL min, P < 0.05), while ghrelin remained suppressed for almost 120 min after the consumption of WWCrB and BGB. CONCLUSIONS: Supplementation of flour with Cr-enriched yeast induces milder postprandial glycemic response to bread without the necessity of high fiber amounts, providing with another strategy for the management of glycemic control.