Table 2 Major wholegrain phytochemicals, factors affecting their bioavailability and suggested mechanisms for promoting health
From: The potential role of phytochemicals in wholegrain cereals for the prevention of type-2 diabetes
Phytochemical | Major grain sources | Food & dietary factors affecting bioavailability | Other factors that enhance bioavailability | Potential mechanisms of action |
|---|---|---|---|---|
Phenolics | Â | Â | Â | Â |
free | Oats | Milk | Unknown | Increase plasma total antioxidant capacity to directly mitigate oxidative stress |
| Â | Â | Heme iron | Unknown | Indirect through cell signalling |
bound | Wheat, barley, oats, rye | Grain structure | Bio-processing of grain | Increase plasma total antioxidant capacity to directly mitigate oxidative stress |
| Â | Â | Colonic fermentation (limited evidence) | Indirect through cell signalling | |
Flavanoids | Wheat, barley | Grain structure | Unknown | Increase plasma uric acid levels which has reducing and free radical scavenging activities |
| Â | Â | Â | Â | Improve glutathione radical scavenging system |
Selenium | Wheat, barley, oats, rye | Not relevant as readily available | Not relevant as readily available | A cofactor for glutathione peroxidase, an enzyme that quenches reactive oxygen species |