Nutritional Quality of Oats Lena Dimberg Department of Food Science Swedish University of Agricultural Sciences

Outline  Metabolic syndrom  Oats   -Glucan -structure and bioactivity  Avenanthramides -structure and bioactivity  Concluding remarks

Metabolic Syndrome Obesity Diabetes Type II fat cells insulin resistance Oxidative stress Chronical inflammation Hypertension glucose/insulin imbalance High TGA & cholesterol CVD

Why Oats? A wonderful reservoir of natural nutrients and biologically active substances Lásztity; Food Rev. Int., 14, (1998)

Characteristics of oats   starch-energy   vitamins (B and E) and minerals   high protein content - well balanced amino acid composition, no gluten   high lipid content, good FA composition -C18:1 (37%), C18:2 (37%), C18:3 (4%)   high content of dietary fibres -e.g.  -glucan   high content of bioactive phytochemicals e.g. tocopherols/tocotrienols, avenanthramides -

Whole Grain Cereal aleuron layer(s) germ starchy endosperm fruit and seed coats Fruit coat Seed coat Aleurone layers Bran Effective compounds? Dietary fibres? Phytochemicals ?

 -1  3,1  4-Glucan

Health effects of  -glucan? Weight control Improve glucose/insulin balance Decrease blood cholesterol level Inhibit constipation May stimulate immune defence May protect from colon cancer development

Health effects of  -glucan? Weight control – –Less energy supply – –Usually less fat and sugar supply- incapsulated – –Bulky, satiety feeling – –Slow gastric emtying- delayed hunger – –Low GI

Physiological effects of β-glucan Untreated cereals β-Glucanase treated cereals

Health effects of  -glucan, cont? Glucose/insulin balance – –Low absorption of glucose – –Decrease insulin release – –Improve insulin sensibility

Decrease blood cholesterol level – –Excretion of bile acids-new bile acids produced from cholesterol Health effects of  -glucan?, cont

Health effects of  -glucan, cont? Inhibit constapation – –Enlarged stool – –Speed up transit time - stimulate muscle movements

Health effects of  -glucan, cont? May decrease colon cancer development – –Dilution and binding of cancer causing agents – –Provocative agents short time in intestine – –Prebiotic-lower pH; produce LMW fatty acids – –Attached bioactive components- dietary complex

 -1  3,1  4-Glucan

To much fibers? Encapsulate compounds May result in energy and nutrient deficiencies May cause dehydration Causes gas production

Metabolic Syndrome Obesity Diabetes Type II fat cells insulin resistance Oxidative stress Chronical inflammation Hypertension glucose/insulin imbalance High TGA & cholesterol CVD

Oxidative Stress/ Inflammation in artherial walls  Free radicals  Cell proliferation, migration, accumulation and attachment  Release of pro- inflammatory signalling and adhesion substances  Plaque formation  Increased blood pressure  Infarct

Tocopherols/tocotrienols, hydroxycinnamic acids, avenanthramides RO, ·O 2 - HO· HOO· H 2 O 2, H 2 O 2, ROO, 1 O 2, Antioxidants Oxidant : RO, O 2 - HO, HOO, H 2 O 2 ROO, 1 O 2

Avenanthramides Anthranilic acid moiety Hydroxycinnamic acid moiety R=H, OH or OCH 3 ; n=1 or 2

Health effects of avenanthrmides? Antioxidants Anti-inflammatory Anti-atherosclerotic Anti-cancer

Avenanthramides -antioxidant effects?-  Hydrogen donators  Radical scavangers  Metal ion chelators  Lipoxygenase inhibitors  Decrease reactive oxygen species (ROS) production  LDL-oxidation inhibitors  Enhance activities of antioxidative enzymes

Avenanthramides -anti-inflammatory effects?-  Supress secretion of pro-inflammatory compounds  Inhibit NF-kB activation  Reduce skin itch and irritation  Lipoxygenase inhibitor

Avenanthramides -anti-atherosclerotic effects?-  Inhibit proliferation of vascular smooth muscle cells  Supress release of adhesion molecules   Decrease cell adhesion   Increase NO production

Avenanthramides -anti-cancer effects?-   Inhibit cancer cell proliferation

Tranilast

Tranilast Metabolites Oat avenanthramide

Supression of Vascular Stenosis by Tranilast Control Tranilast Fukuyama et. al European Journal of Pharmacology, 318,

Concluding Remarks OATS Decrease the risk for the metabolic syndrome development The whole is more than the refined  -Gucan and avenanthramides exert health- beneficial properties Good candidate for a healthy food

Thank you!