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NutrInsight • Whole grain and health: new evidence
2.7 How might whole grain cause these beneficial health effects?
Evidence from observational studies indicates that consumption of whole grain reduces the risk of chronic diseases as described above. One of the objectives of the nutrition module of HEALTHGRAIN was to identify mechanisms involved. HEALTHGRAIN has revealed novel insights but corresponding mechanisms remain only partially elucidated.
Possible mechanisms for beneficial whole grain effects:
• Lowered inflammatory status,
• Improved insulin response,
• Improving vascular function and blood pressure,
• Modified blood lipid profiles,
• Facilitated weight control,
• Deliver bioactive components to the gut (fibre, prebiotics, “antioxidants”) and affect digestion of diet.
Figure 5 is an overview of the possible ways in which whole grain intake may exert health effects. The dietary fibre and associated components, oligosaccharides, and the resistant starch that reach the colon are fermented by intestinal microflora to SCFA which may inhibit inflammation and thus improve insulin sensitivity and blood lipid profile. Other bioactive components present in whole grain can affect colonic fermentation (“antioxidants”, polyphenols and phytate) or may lower homocysteine concentrations (choline, betaine) and thus improve vascular function.
Whole grain intake
Dietary Oligo-saccharides, fibre Resistant starch
Bioactive components
(Viscosity/ (Colonic
food structure) metabolites e.g.
(Tocopherols
and phenolic antioxidants
e.g.
Ferulic-, coumaric-, sinapic acid, lignans, alkylresorcinols)
(Physiological methyl donors e.g. betaine, choline, folate)
GI
SCFA, phenolic metabolites)
Colonic fermentation
Antioxidant/anti- inflammatory status
Insulin sensitivity
Type 2 diabetes
(e.g. Mg)
Blood lipids
Homocysteine
C V D
Figure 5: Some suggested mechanisms for metabolic benefits of whole grain
Source: HEALTHGRAIN
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