Health benefits of oat (Avena sativa) bioactives. Acute and second-meal effects of oat polar lipids and beta-glucans.
Author
Summary, in English
cardiovascular diseases, continues to increase. Dietary habits are the most significant contributing
modifiable factor in this context. A healthy diet must thus form part of successful preventive strategies to
combat cardiometabolic diseases.
Oats are a sustainable cereal, rich in potential health-promoting bioactive compounds, such as polar
lipids, 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 and
beta-glucans. Four intervention studies in healthy young adults were conducted to investigate
postprandial 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 important
determinant of the development of cardiometabolic disorders. In this thesis work, the test products were
consumed at breakfast and cardiometabolic disease-related biomarkers were measured in blood
repeatedly, 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 impact
blood glucose regulation and circulating triglyceride (TG) concentrations acutely after the breakfast, but
also after the standardised lunch meal. Furthermore, OPL increase the release of satiety-promoting gut
hormones 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 on
the release of gut hormones become interesting. It was also shown that a commercially available polar
lipid preparation (sunflower lecithin) exerts similar effects to those of OPL.
This work also demonstrates that consumption of beta-glucans from oats improves postprandial
glycaemic responses and subjective appetite sensations acutely after breakfast and after the subsequent
lunch. Also noteworthy was that 2g oat beta-glucans lower the blood glucose peak after a meal, which is
an appreciably lower dose than the 4g dosage stated in the health claim of the European Food Safety
Authority (EFSA). This finding may facilitate the commercial application of beta-glucans in products for
the dietary management of postprandial glycemia.
In conclusion, the thesis shows that consumption of OPL and beta-glucans included in a meal improves
acute and second-meal postprandial glucose tolerance, reduces circulating TG and enhances secretion
of appetite-regulating hormones in healthy young adults. Another remarkable observation is that
relatively low amounts of beta-glucans may reduce blood glucose peaks, in doses below the EFSA’s
recommended ones. The new knowledge generated in this doctoral thesis can contribute to the
development of innovative food products with preventive potential against cardiometabolic diseases.
Department/s
Publishing year
2024
Language
English
Full text
Document type
Dissertation
Publisher
Department of Process and Life Science Engineering, Lund University.
Topic
- Nutrition and Dietetics
Status
Published
ISBN/ISSN/Other
- ISBN: 978-91-8096-042-7
- ISBN: 978-91-8096-043-4
Defence date
13 June 2024
Defence time
09:00
Defence place
Lecture Hall KC:A, Kemicentrum, Naturvetarvägen 14, Faculty of Engineering LTH, Lund University, Lund
Opponent
- Jonas Burén (Doc.)