A randomised controlled trial to investigate the effect of a high fibre diet on blood pressure and plasma fibrinogen.

Two hundred and one subjects (147 men and 54 women) were randomly allocated to either a high cereal fibre diet or a low cereal fibre diet for four weeks. Each group then followed the alternative diet for a further four weeks. Cereal fibre intakes were 19g/d (31 g/d 21 g/d total fibre) and 6g/d (19g/d total fibre) on the high and low fibre diets respectively (p less than 0.001). Energy, protein, fat, carbohydrate, and alcohol intakes calculated from weighed intake records did not differ between the two diets, although there was a slight difference in body weight, the mean being 0.3 kg heavier at the end of the high fibre period. The high cereal fibre diet had no detectable effect on blood pressure or plasma fibrinogen.