Health benefits of oats -mechanisms of action and potential for new product development

Purpose and goal

This multidisciplinary collaboration aims to explain the cholesterol-lowering effects of oats by use of an established mouse model. We could show that the polysaccharides, beta-glucans, present in high concentration in oats, do not lower cholesterol when given in pure concentrated form. This does not exclude that beta-glucans may have effects in combination with other oat components. Oil extracted from oats does however lower cholesterol as efficiently as whole oats and is thereby an interesting alternative as oat-based dietary component with beneficial health effects.

Results and expected effects

On the basis of established concepts we expected that addition of beta-glucans to the diet would have cholesterol-lowering effects. When this did not happen we concentrated on lipids and lipid-soluble substances in oats and found that that oat oil lowered cholesterol better and had more effect on atherosclerosis than a lipid-free fiber fraction containing beta-glucans as well as the oat-specific phenols avenanthramides. Preliminary results indicate that fractionation of the oil may enrich the cholesterol-lowering effect relative to the added amount.

Approach and implementation

Total-, LDL- and HDL-cholesterol as well as triglycerides in blood plasma were analyzed in diet studies on LDL-receptor knock-out mice fed a high-fat diet supplemented with oat components and corrected for protein, carbohydrate and lipid contents. Effects on bile acid excretion were determined and in a 20-week study atherosclerosis and inflammatory markers were evaluated. To clarify the effects on gene expression a transcriptome analysis on small intestine and liver was done. The results show that primarily the intestine reacts to oats in the diet by altered gene expression