Effect of 6 weeks consumption of b-glucan rich oat products on cholesterol levels in mildly hypercholesterolaemic overweight adults

Several regulatory bodies have approved a health claim on the cholesterol-lowering effects of oat b-glucan at levels of 3·0 g/d. The present study aimed to test whether 1·5 g/d b-glucan provided as ready-to-eat oat flakes was as effective in lowering cholesterol as 3·0 g/d from oats porridge. A 6-week randomised controlled trial was conducted in eighty-seven mildly hypercholesterolaemic ($5 mmol/l and ,7·5 mmol/l) men and women assigned to one of three diet arms (25 % energy (E%) protein; 45 E% carbohydrate; 30 E% fat, at energy requirements for weight maintenance): (1) minimal b-glucan (control); (2) low-dose oat b-glucan (1·5 g b-glucan; oats low – OL) or (3) higher dose oat b-glucan (3·0 g b-glucan; oats high – OH). Changes in total cholesterol and LDL-cholesterol (LDL-C) from baseline were assessed using a linear mixed model and repeated-measures ANOVA, adjusted for weight change. Total cholesterol reduced significantly in all groups (27·8 (SD 13·8) %, 27·2 (SD 12·4) % and 25·5 (SD 9·3) % in the OH, OL and control groups), as did LDL-C (28·4 (SD 18·5) %, 28·5 (SD 18·5) % and 25·5 (SD 12·4) % in the OH, OL and control groups), but between-group differences were not significant. In responders only (n 60), b-glucan groups had higher reductions in LDL-C (218·3 (SD 11·1) % and 218·1 (SD 9·2) % in the OH and OL groups) compared with controls (211·7 (SD 7·9) %; P1⁄40·044). Intakes of oat b-glucan were as effective at doses of 1·5 g/d compared with 3 g/d when provided in different food formats that delivered similar amounts of soluble b-glucan.