Department of Process and Life Science Engineering, Lund University.
Abstract
The global prevalence of lifestyle-related diseases, including obesity, type 2 diabetes andcardiovascular diseases, continues to increase. Dietary habits are the most significant contributingmodifiable factor in this context. A healthy diet must thus form part of successful preventive strategies tocombat cardiometabolic diseases.Oats are a sustainable cereal, rich in potential health-promoting bioactive compounds, such as polarlipids, soluble dietary fibres like beta-glucans and arabinoxylans, antioxidants and avenanthramides.The present thesis explores the health potential of oat-derived bioactives, focusing on polar lipids andbeta-glucans. Four intervention studies in healthy young adults were conducted to investigatepostprandial metabolic effects of test foods enriched with oat polar lipids (OPL) or beta-glucans.Postprandial metabolic regulation, e.g. control of glycemia and triglyceridemia, is an importantdeterminant of the development of cardiometabolic disorders. In this thesis work, the test products wereconsumed at breakfast and cardiometabolic disease-related biomarkers were measured in bloodrepeatedly, both after breakfast and after a standardised lunch without the bioactive compounds.The results indicate that OPL (12–15g) included in a breakfast (liquid or solid meal) beneficially impactblood glucose regulation and circulating triglyceride (TG) concentrations acutely after the breakfast, butalso after the standardised lunch meal. Furthermore, OPL increase the release of satiety-promoting guthormones such as GLP-1 and PYY, and reduce the release of the hunger-inducing hormone ghrelin.Since GLP-1 analogues are effective drugs against type 2 diabetes and obesity, the effects of OPL onthe release of gut hormones become interesting. It was also shown that a commercially available polarlipid preparation (sunflower lecithin) exerts similar effects to those of OPL.This work also demonstrates that consumption of beta-glucans from oats improves postprandialglycaemic responses and subjective appetite sensations acutely after breakfast and after the subsequentlunch. Also noteworthy was that 2g oat beta-glucans lower the blood glucose peak after a meal, which isan appreciably lower dose than the 4g dosage stated in the health claim of the European Food SafetyAuthority (EFSA). This finding may facilitate the commercial application of beta-glucans in products forthe dietary management of postprandial glycemia.In conclusion, the thesis shows that consumption of OPL and beta-glucans included in a meal improvesacute and second-meal postprandial glucose tolerance, reduces circulating TG and enhances secretionof appetite-regulating hormones in healthy young adults. Another remarkable observation is thatrelatively low amounts of beta-glucans may reduce blood glucose peaks, in doses below the EFSA’srecommended ones. The new knowledge generated in this doctoral thesis can contribute to thedevelopment of innovative food products with preventive potential against cardiometabolic diseases
