Objective: We investigated the effect of isoflavone on postmenopausal symptoms, urinary isoflavone excretion and hormonal changes to know the effect on isoflavone in postmenopausal women.
Design and method: 30 postmenopausal women took part in this study. They are divided into 3 subgroups according to the dose of isoflavone supplementation of 100 ㎎/day, 150 ㎎/day, and 200 ㎎/day. Isoflavone were consumed for 6 months. To study the bioavailability of isoflavone, 24-hr urine was collected before and 7 day after each isoflavone supplementation. Initially LH, FSH, Prolactin, E1, E2, testosterone, DHEA-S were measured and 6 months after supplementation of isoflavone.
Results: The urinary isoflavone excretion was does dependent in postmenopausal women and average 24-hr urinary recoveries of daidzein and genistein were approximately 15% and 7% respectively. Isoflavone supplementations were effective in reducing the postmenopausal symptoms especially in hot flush(84.6%) and general weakness(69.2%). Serum LH, FSH, E1, E2, prolactin, DHEA-S level were not changed significantly but the level of testosterone increased significantly from 0.20±0 ng/㎖ to 0.51±0.21 ng/㎖ and from 0.26±0.1 ng/㎖ to 0.49±0.3 ng/㎖ in 100㎎ and 150㎎ isoflavone supplementation respectively. but not in 200㎎ isoflavone supplementation.
Conclusions: Isoflavone may improve the postmenopausal symptoms by increasing serum testosterone level in postmenopausal women.