title: Soya isoflavone-enriched cereal bars affect markers of endothelial function in postmenopausal women.
abstract: Soya isoflavones are thought to be cardioprotective due to their structural similarity to oestrogen. In order to investigate the effect of soya isoflavones on markers of endothelial function we conducted a randomised, double-blind, placebo-controlled, cross-over study with thirty healthy postmenopausal women. The women consumed cereal bars, with or without soya isoflavones (50 mg/d), for 8 weeks, separated by an 8-week washout period. Systemic arterial compliance (SAC), isobaric arterial compliance (IAC), flow-mediated endothelium-dependent vasodilation (FMD) and nitroglycerine-mediated endothelium-independent vasodilation (NMD) were measured at the beginning of the study and after each intervention period. Blood pressure (BP) and plasma concentrations of nitrite and nitrate (NOx) and endothelin-1 (ET-1) were measured at the beginning and end of each intervention period. NMD was 13.4 (SEM 2.0)% at baseline and 15.5 (SEM 1.1) % after isoflavone treatment compared with 12.4 (SEM 1.0)% after placebo treatment (P=0.03). NOx increased from 27.7 (SEM 2.7) to 31.1 (SEM 3.2) microM after isoflavones treatment compared with 25.4 (SEM 1.5) to 20.4 (SEM 1.1) microM after placebo treatment (P=0.003) and a significant increase in the NOx:ET-1 ratio (P=0.005) was observed after the isoflavone treatment compared with placebo. A significant difference in SAC after the isoflavone and placebo treatment was observed (P=0.04). No significant difference was found in FMD, IAC, BP and ET-1. In conclusion, 8 weeks' consumption of cereals bars enriched with 50 mg soya isoflavones/d increased plasma NOx concentrations and improved endothelium-independent vasodilation in healthy postmenopausal women.
authors.affiliation: Department of Human Nutrition, Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark. jeha@kvl.dk
authors.forename: J
authors.initials: J
authors.lastname: Hallund
authors.forename: S
authors.initials: S
authors.lastname: Bügel
authors.forename: T
authors.initials: T
authors.lastname: Tholstrup
authors.forename: M
authors.initials: M
authors.lastname: Ferrari
authors.forename: D
authors.initials: D
authors.lastname: Talbot
authors.forename: W L
authors.initials: WL
authors.lastname: Hall
authors.forename: M
authors.initials: M
authors.lastname: Reimann
authors.forename: C M
authors.initials: CM
authors.lastname: Williams
authors.forename: N
authors.initials: N
authors.lastname: Wiinberg
mesh_terms: D015415:Biomarkers / Q000097:blood; D001916:Brachial Artery / Q000502:physiology; D003327:Coronary Disease / Q000378:metabolism / Q000517:prevention & control; D003718:Denmark; D019332:Endothelin-1 / Q000097:blood; D004730:Endothelium, Vascular / Q000378:metabolism*; D004812:Epidemiologic Methods; D005260:Female; D005527:Food, Fortified; D005858:Germany; D006801:Humans; D007529:Isoflavones / Q000627:therapeutic use*; D007558:Italy; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D009569:Nitric Oxide / Q000097:blood; D008517:Phytotherapy; D017698:Postmenopause / Q000378:metabolism*; D013025:Glycine max; D006113:United Kingdom; D014655:Vascular Resistance; D014664:Vasodilation
chemical_list: D015415:Biomarkers; D019332:Endothelin-1; D007529:Isoflavones; D009569:Nitric Oxide