Effect of 6 weeks' consumption of β-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 beta-glucan at levels of 3.0 g/d. The present study aimed to test whether 1.5g/d beta-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 beta-glucan (control); (2) low-dose oat beta-glucan (1.5 g beta-glucan; oats low - OL) or (3) higher dose oat beta-glucan (3.0 g beta-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 (-78 (SD 13.8)%, -7.2 (SD 12.4)% and -55 (SD 9.3)% in the OH, OL and control groups), as did LDL-C (-84 (SD 18.5)%, - 8.5 (SD 18.5)% and -55 (SD 12.4)% in the OH, OL and control groups), but between-group differences were not significant. In responders only (n 60), beta-glucan groups had higher reductions in LDL-C (-18.3 (SD 11.1)% and -18.1 (SD 9.2)% in the OH and OL groups) compared with controls (-11.7 (SD 7.9)%; P=0.044). Intakes of oat beta-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 beta-glucan.