One-year soy isoflavone supplementation prevents early postmenopausal bone loss but without a dose-dependent effect.
It is believed that soy isoflavone has much potential effectiveness on the postmenopausal status; however, the optimal dose for preventing postmenopausal bone loss still remains unclear. This open-labeled, self-controlled pilot study was undertaken to determine the effect of 1-year supplementation of different high dosages of soy isoflavone in postmenopausal Taiwanese women. Forty-three women aged 45-67 years were enrolled and randomly assigned into a control (C), 100 mg/day isoflavone (IF100) and 200 mg/day isoflavone (IF200) groups for 1 year. Dual-energy X-ray absorptiometry and other related biochemical markers of bone metabolism were measured. Results indicated that the decrease in bone mineral density (BMD) was significant for lumbar vertebrae L1-3, L1-4 and the femur neck in the C group; surprisingly, the BMD of L1-3 was significantly elevated in the IF100 group; however, there were no consistent responses in the IF200 group. No significant change except loss of the bone mineral content of Ward's triangle (P=.003) was found in the IF200 group after treatment. The percentage change at L1-3 was less (P=.04) in the IF200 group when compared to the IF100 group. A relatively uniform direction of bone formation in expanding the weight and area with different rates of change resulted in different BMD changes. Both indicated a change of bone formation patterns with the higher-dose supplement. A protective effect of IF100 on estrogen-related bone loss was observed. A lack of a benefit such as high safety in the IF200 group for 1-year administration was ensured and lacked undesirable side effects.
Huang
Hui-Ying
HY
School of Pharmaceutical, Taipei Medical University, Taipei 110, Taiwan. sihuang@tmu.edu.tw
Yang
Hsiao-Ping
HP
Yang
Hui-Ting
HT
Yang
Tung-Chuan
TC
Shieh
Ming-Jer
MJ
Huang
Shih-Yi
SY
D015502:Absorptiometry, Photon; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density; D016723:Bone Remodeling; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000097:blood; D005260:Female; D005269:Femur; D006801:Humans; D007529:Isoflavones / Q000008:administration & dosage*; D008159:Lumbar Vertebrae; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D013025:Glycine max / Q000737:chemistry*; D013624:Taiwan
D007529:Isoflavones; D004958:Estradiol; D000469:Alkaline Phosphatase