isoflavones




Isoflavones prevent bone loss following ovariectomy in young adult rats..

Author: Tsuang YH, Chen LT, Chiang CJ, Wu LC, Chiang YF, Chen PY, Sun JS, Wang CC. .
Publication: Journal of Orthopaedic Surgery and Research 2008, 3:12.

Osteoporosis is a bone disease that leads to bone loss, a reduced bone mineral density and an increased risk of fracture. Osteoporosis is most common in women after menopause, when it is called postmenopausal osteoporosis, but may also develop in men. Bone loss can be prevented with lifestyle advice (preventing fall, doing exercise that puts strain in the bones) and sometimes medication (calcium, vitamin D, bisphosphonates). Epidemiological studies indicate that the incidence of bone loss is influenced by genetic factors, ethnic factors, geographic factors and nutrition. Although calcium is required for bone building and a high intake is generally considered as being necessary for preventing bone loss, more recent studies show the opposite: populations with the highest intake of calcium show the highest rates of osteoporosis. Arena et al. previously showed the beneficial effects of phytoestrogens on bone health: the intake of 90 mg of isoflavones for 6 months increased the bone mineral density.

The aim of this study was to determine the effect of isoflavones intake on the rapid bone loss on ovariectomized rats (surgical castration). The rats were divided in 4 groups:
  • Group A: control group
  • Group B: ovariectomized
  • Group C: ovariectomized, isoflavones intake only before (1 month) ovariectomy
  • Group D: ovariectomized, isoflavones intake before (1 month) and after (2 months) ovariectomy
Two months after the ovariectomy, the rats were sacrificed. The scientists determined the following parameters: bone markers, bone ash of the long bones and whole lumbar spine, and histological study of cancellous bone. As expected, the ovariectomy significantly reduced the bone mass. When the isoflavones were administered only before ovariectomy no protective effect was observed. The scientists had no explanation for this lack of effect. However, the bone mass of the rats of group D, which were continuously fed with an isoflavones-rich diet, was higher than that of Group A. The bone mineral densities of long bones increased by up to 60%. A histological study revealed that the porocity was improved (less thinning and more connections of trabeculae). They concluded that long-term ingestion of an isoflavones-rich diet increased the bone mineral contents after ovariectomy in young rats.

The quantity of isoflavones (25mg/day) used in this experiment is quite high. This quantity corresponds to daily intake of 7000 mg isoflavones (or 20 kg tofu) for a adult of 70 kg.Dietary isoflavones: biological effects and relevance to human health. J Nutr. 1999 Mar;129(3):758S-767S

The clinical use of a preparation based on phyto-oestrogens in the treatment of menopausal disorders. Acta Biomed Ateneo Parmense. 2003 Dec;74(3):137-43

Soy protein and isoflavones: their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr. 1998 Dec;68(6 Suppl):1375S-1379S

Effect of a phytoestrogen food supplement on reproductive health in normal males. Clin Sci (Lond). 2001 Jun;100(6):613-8

Antioxidant and antipromotional effects of the soybean isoflavone genistein. Proc Soc Exp Bio Med 1995 Jan; 208(1)124-130

Soy isoflavone supplementation in healthy men prevents NF-kappaB activation by TNF-alpha in blood lymphocytes. Free Radic Biol Med 2001;30:1293-1302

Chemoprevention by Grape Seed Extract and Genistein in Carcinogen-induced Mammary Cancer in Rats Is Diet Dependent. J. of Nutr. 2004 Dec;134(12):3445S-52S

Isoflavones from red clover improve systemic arterial compliance but not plasma lipids in menopausal women. J Clin Endocrinol Metab 1999 Oct;84(10):3647

Soy isoflavones have a favorable effect on bone loss in Chinese postmenopausal women with lower bone mass: a double-blind, randomized, controlled trial. J Clin Endocrinol Metab. 2003 Oct;88(10):4740-7

Prevention of spontaneous prostate-related cancer in Lobund-Wistar rats by a soy protein isolate - isoflavone diet. Prostate 2000 Oct 1;45(2):101-5

Effects of a soy milk supplement on plasma cholesterol levels and oxidative DNA damage in men--a pilot study. Eur J Nutr. 1999 Jun;38(3):143-8

Soy isoflavones in the treatment of prostate cancer. Nutr Cancer 2003;47(2):111-7

A biochanin-enriched isoflavone from red clover lowers LDL cholesterol in men. Eur J Clin Nutr. 2004 Mar;58(3):403-8

The effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial. Am J Clin Nutr. 2004 Feb;79(2):326-33

Soy, isoflavones, and breast cancer risk in Japan. Journal of the National Cancer Institute, Vol. 95, No. 12, 906-913, June 18, 2003

Antioxidant activity of phytoestrogenic isoflavones. Free Radic Res. 1997 Jan;26(1):63-70

Biological effects of a diet of soy protein rich in isoflavones on the menstrual cycle of premenopausal women. Am J Clin Nutr. 1994 Sep;60(3):333-40

The long term effects of soy-based formula on isoflavone concentration of plasma and urine, and growth and recognition development at 10 and 20 months old infants. Asia Pac J Clin Nutr. 2004;13(Suppl):S123

Dietary soybean protein prevents bone loss in an ovariectomized rat model of osteoporosis. J Nutr. 1996 Jan;126(1):161-7

Beneficial effect of soy isoflavones on bone mineral content was modified by years since menopause, body weight, and calcium intake: a double-blind, randomized, controlled trial. Menopause. 11(3):246-254, 2004

Breast and Uterine Effects of Soy Isoflavones and Conjugated Equine Estrogens in Postmenopausal Female Monkeys. The Journal of Clinical Endocrinology & Metabolism Vol. 89, No. 7 3462-3468

Vasomotor symptom relief by soy isoflavone extract tablets in postmenopausal women: a multicenter, double-blind, randomized, placebo-controlled study. Menopause. 2000 Jul-Aug;7(4):236-42

Soy isoflavones enhance coronary vascular reactivity in atherosclerotic female macaques. Fertility and Sterility. 1997, 67, 148-154

Soybean phytochemicals inhibit the growth of transplantable human prostate carcinoma and tumor angiogenesis in mice. J Nutr. 1999 Sep;129(9):1628-35

Pharmacokinetics of isoflavones, daidzein and genistein, after ingestion of soy beverage compared with soy extract capsules in postmenopausal Thai women. BMC Clin Pharmacol. 2005 Mar 3;5(1):2

Isoflavones from red clover (Promensil) significantly reduce menopause hot flush symptoms compared with placebo. Peter H. M. van de Weijera et al

Intake of Soy Porducts is Associated with Better Plasma Lipid Profiles in the Hong Kong Chinese Population. Journal of Nutrition. 2000;130:2590-2593

Environmental Influence on Isoflavones and Saponins in Soybeans and Their Role in Colon Cancer. Journal of Nutrition 135: 1239-1242, 2005

Meta-Analysis of the Effects of Soy Protein Intake on Serum Lipids. New England Journal of Medicine. 1995 Aug 3;333(5):276-82

Soyfood Intake during Adolescence and Subsequent Risk Of Breast Cancer among Chinese Women. Cancer Epidemiology, Biomarkers and Prevention. 2001 May;10(5):483-8

Influences of dietary soy isoflavones on metabolism but not nociception and stress hormone responses in ovariectomized female rats. Reprod Biol Endocrinol. 2005; 3: 58

Dietary Soy Isoflavones and Estrone Protect Ovariectomized ERKO and Wild-Type Mice from Carcinogen-Induced Colon Cancer. Journal of Nutrition:179-182, January 2004

Phytoestrogens: the biochemistry, physiology, and implications for human health of soy isoflavones. American Journal of Clinical Nutrition, Vol 68, 1333S-1346S

Soya food intake and risk of endometrial cancer among Chinese women in Shanghai: population based case-control study. British Medical Journal, 2004 May 29; 328(7451):1285

Chemoprevention of Breast Cancer, Proteomic Discovery of Genistein Action in the Rat Mammary Gland. Journal of Nutrition, 135:2953S-2959S, December 2005

Soy intake related to menopausal symptoms, serum lipids, and bone mineral density in postmenopausal Japanese women. Obstet Gynecol. 2001 Jan;97(1):109-15

Soy Protein Has a Greater Effect on Bone in Postmenopausal Women Not on Hormone Replacement Therapy, as Evidenced by Reducing Bone Resorption and Urinary Calcium Excretion. The Journal of Clinical Endocrinology & Metabolism Vol. 88, No. 3 1048-1054

Effects of Phytoestrogens on Bone Turnover in Postmenopausal Women with a History of Breast Cancer. The Journal of Clinical Endocrinology and Metabolism Vol. 89, No. 3 1207-1212

Isoflavones and Functional Foods Alter the Dominant Intestinal Microbiota in Postmenopausal Women. Journal of Nutrition 135:2786-2792, December 2005

Trifolium pratense (Red Clover) Exhibits Estrogenic Effects In Vivo in Ovariectomized Sprague-Dawley Rats. J. Nutr. 132:27-30, 2002

Daidzein is more efficient than genistein in preventing ovariectomy-induced bone loss in rats. J Nutr. 2000 Jul;130(7):1675-81

Factors Affecting the Bioavailability of Soy Isoflavones in Humans after Ingestion of Physiologically Relevant Levels from Different Soy Foods. J. Nutr. 136:45-51, January 2006

Soy Protein Containing Isoflavones Reduces the Size of Atherosclerotic Plaques without Affecting Coronary Artery Reactivity in Adult Male Monkeys.. Journal of Nutrition, December 2005, 135:2852-2856

Intake of Fermented Soybeans, Natto, Is Associated with Reduced Bone Loss in Postmenopausal Women: Japanese Population-Based Osteoporosis (JPOS) Study. Journal of Nutrition. 136:1323-1328, May 2006

The Soybean Isoflavone Genistein Induces Differentiation of MG63 Human Osteosarcoma Osteoblasts.. Journal of Nutrition. 2006 May;136(5):1166-70

Soy isoflavones attenuate bone loss in early postmenopausal Chinese women : A single-blind randomized, placebo-controlled trial.. Eur J Nutr. 2006 Jun 8

Bioavailability of Isoflavones after Ingestion of Soy Beverages in Healthy Adults. J. Nutr. 136:2291-2296, September 2006

Method of defining equol-producer status and its frequency among vegetarians. J Nutr. 2006 Aug;136(8):2188-93

Soy isoflavones attenuate human monocyte adhesion to endothelial cell-specific CD54 by inhibiting monocyte CD11a. J Nutr. 2006 Sep;136(9):2384-90

Exposure to soy-based formula in infancy and endocrinological and reproductive outcomes in young adulthood.. JAMA. 2001 Aug 15;286(7):807-14

Prolonged intake of dietary fermented soybeans (natto) with the reinforced vitamin K2 (menaquinone-7) enhances circulating gamma-carboxylated osteocalcin concentration in normal individuals.. Journal of Health Science, 51,191-196, 2005

Soy isoflavones increase preprandial peptide YY (PYY), but have no effect on ghrelin and body weight in healthy postmenopausal women.. Journal of Negative Results in BioMedicine 2006, 5:11

Isoflavones prevent bone loss following ovariectomy in young adult rats.. Journal of Orthopaedic Surgery and Research 2008, 3:12

Soy Isoflavones Modulate Azoxymethane-Induced Rat Colon Carcinogenesis Exposed Pre- and Postnatally and Inhibit Growth of DLD-1 Human Colon Adenocarcinoma Cells by Increasing the Expression of Estrogen Receptor-beta.. J Nutr. 2009 Mar;139(3):474-81

Dietary isoflavones may protect against prostate cancer in Japanese men. J Nutr. 2007 Aug;137(8):1974-9.

Effect of soy isoflavones on breast cancer recurrence and death for patients receiving adjuvant endocrine therapy. CMAJ. 2010 Oct 18

Isoflavone-rich soy protein isolate suppresses androgen receptor expression without altering estrogen receptor-beta expression or serum hormonal profiles in men at high risk of prostate cancer. J Nutr. 2007 Jul;137(7):1769-75

Isoflavones decrease insomnia in postmenopause. Menopause. 2010 Aug 19

Soy isoflavones exert differential effects on androgen responsive genes in LNCaP human prostate cancer cells. J Nutr. 2007 Apr;137(4):964-72
e-mail - Disclaimer, privacy policy, copyright - ©2018, Isoflavones.info