URINARY LIGNAN AND ISOFLAVONOID EXCRETION IN MEN AND WOMEN CONSUMING VEGETABLE AND SOY DIETS

Urinary lignan and isoflavonoid excretion were examined in 11 men and 9 women consuming four nine-day controlled experimental diets: basal ( vegetable free), carotenoid vegetable (carrot and spinach), cruciferou s vegetable (broccoli and cauliflower), and soy (tofu and textured veg etable protein product). Three-day urine collections (Days 7-9) were a nalyzed for lignans and isoflavonoids with use of isotope-dilution gas chromatography-mass spectrometry. Urinary excretion of the lignans en terodiol and enterolactone was higher during the carotenoid and crucif erous vegetable diets than during the basal diet (p = 0.0001), suggest ing that these vegetables may provide a source of mammalian lignan pre cursors. Urinary excretion of the isoflavonoids equol, O-desmethylango lensin, daidzein, and genistein was higher when subjects consumed soy diets than when they consumed the other test diets (p < 0.02). Gender differences in lignan excretion were observed. Men excreted more enter olactone (p = 0.006) and less enterodiol (p = 0.013) than women, imply ing a gender difference in colonic bacterial metabolism of lignans. Th ere was no effect of gender on isoflavonoid excretion.