Jw. Lampe et al., URINARY LIGNAN AND ISOFLAVONOID EXCRETION IN PREMENOPAUSAL WOMEN CONSUMING FLAXSEED POWDER, The American journal of clinical nutrition, 60(1), 1994, pp. 122-128
Lignans and isoflavonoid phytoestrogens, produced from plant precursor
s by colonic bacteria, may protect against certain cancers. We examine
d the effects of flaxseed consumption on urinary lignans and isoflavon
oids. Eighteen women consumed their usual omnivorous diets for three m
enstrual cycles and their usual diets supplemented with flaxseed powde
r (10 g/d) for three cycles in a randomized crossover design. Three-da
y urine samples from follicular and luteal phases were analyzed for li
gnans and isoflavonoids by isotope-dilution gas chromatography-mass sp
ectrometry. Excretion of the lignans enterodiol and enterolactone incr
eased with flaxseed from 1.09 +/- 1.08 and 3.16 +/- 1.47 to 19.48 +/-
1.10 and 27.79 +/- 1.50 mu mol/d, respectively (P < 0.0002). Enterodio
l and enterolactone excretion varied among subjects in response to fla
xseed (3- to 285-fold increase). There were no differences in excretio
n of isoflavonoids (daidzein, genistein, equol, and O-desmethylangofen
sin) or the lignan matairesinol with flaxseed. Excretion was not alter
ed by phase of menstrual cycle or duration of flaxseed consumption.