Abstract
The effects of dietary isoflavone supplementation using a purified extract of red
clover containing approximately biochanin A 26 mg, formononetin 16 mg, daidzein 0.5
mg and genistein 1 mg per tablet at doses of one or two tablets per day were compared
to placebo in a three-period, randomised, double blind, ascending dose study in 66
post menopausal women with plasma cholesterol levels between 5.0 and 9.0 mmol/l. Each
treatment period lasted 4 weeks and a further nine women received placebo for the
full 12-week period. All women consumed a low isoflavone diet for 2 weeks preceding
the commencement of the study and for the 12-week study period. Urinary isoflavone
excretion was very low in subjects receiving placebo but increased in a dose-dependent
manner during therapy with one and two of isoflavone tablets. Dietary supplementation
with isoflavones did not significantly alter total plasma cholesterol, LDL cholesterol,
HDL cholesterol or plasma triglyceride levels. However, inverse correlations were
found between urinary genistein excretion and plasma triglyceride levels and between
urinary O-DMA excretion (an isoflavone metabolite) and plasma triglyceride levels
in subjects receiving one isoflavone tablet, suggesting a weak relationship between
isoflavone intake and plasma triglycerides which may be influenced by individual differences
in isoflavone absorption or metabolism. The results suggest that isoflavone phytoestrogens
from red clover in the proportions and quantities studied do not significantly alter
plasma lipids in post menopausal women with moderately elevated plasma cholesterol
levels.
Keywords
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Article Info
Publication History
Published online: August 16, 2004
Accepted:
October 15,
1999
Received in revised form:
September 28,
1999
Received:
May 11,
1999
Identification
Copyright
© 2000 Elsevier Science Ireland Ltd. Published by Elsevier Inc. All rights reserved.
