title: Yeast-leavened oat breads with high or low molecular weight beta-glucan do not differ in their effects on blood concentrations of lipids, insulin, or glucose in humans.
abstract: Increased intestinal viscosity appears to be the major mode of action by which dietary oat beta-glucan increases the fecal excretion of bile acids and thereby lowers blood cholesterol concentrations. The objective of this experiment was to investigate whether there is a difference in effects on blood lipids between two yeast-leavened oat bran breads containing beta-glucan (6 g/d) of low or high average molecular weight (HMW) (217 or 797 kDa, respectively). The breads were fed to 22 volunteers (women, n = 11; men, n = 11) in a randomized, double-blind, crossover design. The participants ate one bread for 3 wk as part of their normal diet and switched breads after a 2-wk washout period. Blood samples were drawn from fasting subjects and analyzed for lipids, insulin, glucose, and alpha- and gamma-tocopherol. The two experimental oat breads did not differ in their effects on any of the variables measured. Compared to baseline, however, consumption of HMW bread increased serum insulin by 22.6% (P < 0.03) and decreased blood glucose concentrations by 3.4% (P < 0.05). These results suggest that the molecular weight, when beta-glucan is consumed in oat bran breads as part of the habitual diet, does not play an important physiological role in moderately hypercholesterolemic humans.
authors.affiliation: Department of Food Science, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Frank
authors.forename: Birgitta
authors.initials: B
authors.lastname: Sundberg
authors.forename: Afaf
authors.initials: A
authors.lastname: Kamal-Eldin
authors.forename: Bengt
authors.initials: B
authors.lastname: Vessby
authors.forename: Per
authors.initials: P
authors.lastname: Aman
mesh_terms: D000328:Adult; D018554:Avena; D001786:Blood Glucose / Q000032:analysis*; D001939:Bread / Q000032:analysis*; D005260:Female; D005936:Glucans / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D007328:Insulin / Q000097:blood*; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009994:Osmolar Concentration; D015003:Yeasts; D047071:beta-Glucans
chemical_list: D001786:Blood Glucose; D005936:Glucans; D007328:Insulin; D008055:Lipids; D047071:beta-Glucans; C067858:beta-glucan, (1-3)(1-4)-