PHYSIOLOGICAL-EFFECTS OF CEREAL DIETARY FIBER

Cereal dietary fibre constitutes about half of the total fibre intake in Sweden. The amount of fibre available is 21 g/person/day or 1.75 g/ MJ. Increased faecal bulk and shortening of intestinal transit time ar e well-documented effects, that are inversely proportional to the ferm entability of the dietary fibre. Wheat bran, oat husks, and com bran a re fibre sources with high bulking effect, whereas fibre from the endo sperm of cereals is more extensively fermented. Resistant starch in pr ocessed cereals has properties similar to dietary fibre, and must be c onsidered in analysis as well as regarding physiological effects of di etary fibre. Oat groats and oat bran have serum cholesterol lowering e ffects related to the viscous soluble beta-glucans. Rye and barley con tain similar levels of viscous soluble fibre but are not as thoroughly investigated. Effects on postprandial glucose and insulin levels are also partly related to viscous soluble dietary fibre, but structural p roperties in, e.g., whole kernels and pasta products are more importan t in this respect Phytate in whole grain flour and bran preparations i nhibits iron and zinc absorption in single meal tests. Its role for mi neral status in persons consuming a mixed, Western diet remains to be established.