Reference Number: 44
The prevalence of obesity is increasing worldwide and prevention is needed. Whole grain has shown potential to lower the risk of obesity, cardiovascular disease and type 2 diabetes. One possible mechanism behind the benefits of whole grain is the gut fermentation of dietary fiber (DF), e.g. non-starch polysaccharides and resistant starch (RS), in whole grain. The purpose of the study is to investigate the effect of whole grain rye-based products on glucose- and appetite regulation.
Twenty-one healthy subjects were provided four rye-based evening test meals in a crossover overnight study design. The test evening meals consisted of either whole grain rye flour bread (RFB) or a 1:1 ratio of whole grain rye flour and rye kernels bread (RFB/RKB), with or without added resistant starch (+RS). White wheat flour bread (WWB) was used as reference evening meal. Blood glucose, insulin, PYY, FFA, IL-6 as well as breath H2 and subjective rating of appetite were measured the following morning at fasting and repeatedly up to 3.5 h after a standardized breakfast consisting of WWB. Ad libitum energy intake was determined at lunch, 14.5 h after evening test and reference meals, respectively.
The evening meal with RFB/RKB + RS decreased postprandial glucose and insulin responses (iAUC)(P < 0.05) and increased the gut hormone PYY in plasma the following morning 0–120 min after the standardized breakfast, compared to WWB (P = 0.01). Moreover, RFB increased subjective satiety and decreased desire to eat, and both RFB and RFB/RKB decreased feeling of hunger (AUC 0–210 min). All rye-based evening meals decreased or tended to decrease fasting FFA (P < 0.05, RFB/RKB: P = 0.057) and increased breath hydrogen concentration (0–120 min, P < 0.001). No effects were noted on energy intake at lunch or inflammatory marker IL-6 (0 + 180 min) after the rye-based evening meals, compared to WWB.
SIGNIFICANCE OF THIS STUDY
The current study showed that whole grain rye bread has the potential to improve cardiovascular health. The combination rye flour brad and rye kernel bread with added resistant starch (a form a insoluble fibre) positively affected glucose response and appetite regulation. The effects seen in the current probably emanate from gut fermentation events since fibre known to have positive effects on the gut micro biome which holds the key to the optimum functioning of many of physiological parameters.