Effects of Unfermented and Fermented Whole Grain Rye Crisp Breads Served as Part of a Standardized Breakfast, on Appetite and Postprandial Glucose and Insulin Responses: A Randomized Cross-over Trial

Abstract

BackgroundWhole grain rye products have been shown to increase satiety and elicit lower postprandial insulin response without a corresponding change in glucose response compared with soft refined wheat bread. The underlying mechanisms for these effects have not been fully determined The primary aim of the study was to investigate if whole grain rye crisp bread compared to refined wheat crisp bread, elected beneficial effects on appetite and postprandial insulin response, similarly as for other rye products.MethodsIn a randomized cross-over trial, 23 healthy volunteers, aged 27-70 years, BMI 18-31.4 kg/m2, were served a standardized breakfast with unfermented whole grain rye crisp bread (uRCB), fermented whole grain rye crisp bread (RCB) or refined wheat crisp bread (WCB), Appetite was measured using a visual analogue scale (VAS) until 4 h after breakfast. Postprandial glucose and insulin were measured at 0-230 min. Breads were chemically characterized including macronutrients, energy, dietary fiber components, and amino acid composition, and microstructure was characterized with light microscopy.ResultsReported fullness was 16% higher (P<0.001), and hunger 11% and 12% lower (P<0.05) after ingestion of uRCB and RCB, respectively, compared with WCB. Postprandial glucose response did not differ significantly between treatments. Postprandial insulin was 10% lower (P<0.007) between 0-120 min but not significantly lower between 0-230 min for RCB compared with WCB. uRCB induced 13% (P<0.002) and 17% (P<0.001) lower postprandial insulin response between 0-230 min compared with RCB and WCB respectively.ConclusionWhole grain rye crisp bread induces higher satiety and lower insulin response compared with refined wheat crisp bread. Microstructural characteristics, dietary fiber content and composition are probable contributors to the increased satiety after ingestion of rye crisp breads. Higher insulin secretion after ingestion of RCB and WCB compared with uRCB may be due to differences in fiber content and composition, and higher availability of insulinogenic branched chain amino acids.Trial RegistrationClinicalTrials.gov NCT02011217

Consumption of whole grains in relation to mortality from all causes, cardiovascular disease, and diabetes

“…To date, there are many controlled trials that directly investigated the effects of whole-grain interventions on putative intermediate biomarkers. [9,37] For example, results from a clinical trial in North Europe suggested that a greater proportion of whole grain rye in a Nordic diet is associated with favorable outcomes in LDL-cholesterol and log triglyceride concentrations. [9] A randomized cross-over trial suggested that consumption of unfermented and fermented whole grain rye crisp bread led to lower postprandial glucose and insulin response compared with refined wheat crisp bread.…”

“…[9] A randomized cross-over trial suggested that consumption of unfermented and fermented whole grain rye crisp bread led to lower postprandial glucose and insulin response compared with refined wheat crisp bread. [37] All such clinical trials recruited small numbers of participants and were of short-term duration (<1 year). In addition, participants always consumed controlled portions of the foods, but not mimic ordinary daily consumption.…”

Effects of whole-grain rye porridge with added inulin and wheat gluten on appetite, gut fermentation and postprandial glucose metabolism: a randomised, cross-over, breakfast study

“…Whole-grain rye food products that are naturally rich in dietary fibre, such as porridge, soft bread and crisp bread, have consistently shown appetite-suppressing effects in human studies (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) .…”

Whole-grain consumption and the risk of all-cause, CVD and cancer mortality: a meta-analysis of prospective cohort studies

“…Clinical trials have suggested that consumption of whole grains may positively affect risk factors for CVD and cancer, including hypertension ( 31 , 32 ) , weight gain/obesity ( 4 , 5 , 33 , 34 ) , total and LDL-cholesterol ( 35 , 36 ) and type 2 DM ( 6 , 7 , 37 , 38 ) . For instance, Magnusdottir et al .…”