Soy isoflavones

DUNCAN A M, MERZ B E, XU X, NAGEL T C, PHIPPS W R, KURZER M S (1999a) Soy isoflaVOneS exert modest hormonal effects in premenopausal women. J Clin Endocrinol Metab. 84 192-7. 

PATISAUL H B, DiNDO M, WHITTEN p L, YOUNG L J (2001) Soy isoflavone Supplements antagonize reproductive behavior and oestrogen receptor alpha- and beta-dependent gene expression in the brain. Endocrinol. 142 2946-52. 

SETCHELL K D (1998) Ph)doestrogens the biochemistry, physiology, and implications for hiunan health of soy isoflavones. Am J Clin Nutr. 68 1333-46. 

UPMALIS D H, LOBO R, BRADLEY L, WARREN M, CONE F L, LAMIA C A (2000) VaSOmotor symptom relief by soy isoflavone extract tablets in postmenopausal women a multicenter, double-blind, randomized, placebo-controlled study. Menopause. 1 236-42. 

WANG w, HiGUCHi c M, ZHANG R (1997) Individual and combinatory effects of soy isoflavones on the in vitro potentiation of lymphocyte activation. Nutr Cancer. 29 29-34. 

ZHOU J R, MUKHERJEE P, GUGGER E T, TANAKA T, BLACKBURN G L, CLINTON S K (1998) Inhibition of murine bladder tumorigenesis by soy isoflavones via alterations in the cell cycle, apoptosis and angiogenesis. Cancer. Res. 58 5231-8. 

The mean dietary intake of soy isoflavones in Asian populations consuming soy-based diets ranges from 20-40 mg isoflavones/day, with upper percentile consumer intakes of 70 mg/day (corresponding to around 1 mg/kg body weight). In the six month intervention studies in Western postmenopausal women, the effective dose for improved BMD was around 80-90 mg/day, while in the one year, randomized, double-blind, placebo controlled clinical trial, the effective dose was 54 mg/day. Overall, the dietary recommendation is to consume 50 mg isoflavones/day in combination with standard nutritional requirements for calcium and vitamin D. 

ANDERSON J J, CHEN X, BOASS A, SYMONS M, KOHLMEIER M, RENNER J B, GARNER S C (2002) Soy isoflavones no effects on bone mineral content and bone mineral density in healthy, menstruating young adult women after one year. J Am Coll Nutr 21, 388-393. 

ARJMANDi B H and SMITH B J (2002), Soy isoflavones osteoprotective role in postmenopausal women mechanism of action. J Nutr Biochem 13, 130-37. 

HSU 0 s, SHEN w w, HSUEH, Y M and YEH s L (2001) Soy isoflavone supplementation in postmenopausal women. Effects on plasma lipids, antioxidant enzye activities and bone density. JReprod Med 46, 221-6. 

Soy isoflavone aglycones are asborbed faster and in higher amoimts than their... 

ROWLAND I R, WISEMAN H, SANDERS T A, ADLERCREUTZ H and BOWEY E A (2000) luteriudividual variation in metabolism of soy isoflavones and lignans influence of habitual diet on equol production by the gut microflora. Nutr Cancer 36, 27-32. 

SETCHELL K D R, BROWN N M, DESAI P, ZIMMER-NECHEMIAS L, WOLFE B E, BRASHEAR W T, KIRSCHNER A s, CASSIDY A and HEUBI J E (2001) BioavailabUity of pure isoflavones in healthy humans and analysis of commercial soy isoflavone supplements. JNutr 131, 1362S-75S. 

Upid metabolism abnormality in ovariectomized rats by soy isoflavones, daidzin, genistin, and glycitin. Biol Pharm Bull 24, 368-72. 

VINCENT A and Fitzpatrick l a (2000) Soy isoflavones are they useful in menopause Mayo Clin Proc 75, 1174-84. 

The mucosa of the GIT represents an interface between the external and internal environments. The expansive surface area is necessary for the efficient hydrolysis of foodstuffs and the absorption of energy and nutrients. The mucosa also influences the systemic availability of non-nutrient compounds in the diet, both beneficial and detrimental. Digestion and absorption of glucosinolates are critical determinants of health benefits (see Chapter 4) Similarly, the bioavailability and health benefits of phytoestrogens, such as genistein (see Chapters 5 and 10) are at least partly dependent on the carrier-mediated processes of absorption associated with the GIT (Oitate et al, 2001). Moreover, the metabolic activities of the mucosa can influence the systemic concentrations and forms of dietary phytochemicals, as exemplified by research with soy isoflavones (Andlauer et al., 2000). 

Since 1999, when the Food and Drug Administration allowed the first health claim for soy-fortified foods in the USA, there has been a large increase in the sales of food products claiming to contain soy isoflavones. At the same time, over-the-counter supplements have become widely available. However, concerns have been raised about the real health benefits of such supplements in the absence of adequate information about bioavailability, pharmacokinetics and safety. To fill this gap, an extensive study on pure isoflavones and commercial soy isoflavone supplements has recently been carried out (Setchell et al, 2001). A selection of 31 commercially available supplements showed a wide variation in isoflavone composition and in the amount provided by one tablet. Furthermore, a lower isoflavone content, with respect to the claimed levels, has been observed in almost 50% of the analysed products. In one case, no isoflavones at all could be detected (Setchell et al, 2001). 

Many clinical studies have been performed on human subjects to assess the effect of soy isoflavones on chronic disease risk factors with no ill-effects (see Section 10.4). The safety profile of isoflavones is, however, difficult to establish because of the limited sample sizes and short periods of investigation of such studies. At present the upper tested limits are ... 

DOERGE D R and SHEEHAN D M (2002) Goitrogenic and estrogenic activity of soy isoflavones. Environ Health Perspect. 110 (Suppl 3) 349-53. 

HONORE E K, WILLIAMS J K, ANTHONY M s and CLARKSON T B (1997) Soy isoflavones enhance coronary vascular reactivity in atherosclerotic female macaques. FertiV Steril. 67 (1) 148-54. 

KIM H, PETERSON T G and BARNES s (1998) Mechanism of action of the soy isoflavone genistein emerging role for its effects via transforming growth factor 3 signalling pathways. J Clin Nutr. 68 (6 Suppl) 1418S-1425S. 

MERZ-DEMLOW B E, DUNCAN A M, WANGEN K E, XU X, CARR T P, PHIPPS W R and KURZER M S (2000) Soy isoflavones improve plasma lipids innormocholesterolemic, premenopausal women. Am J Clin Nutr. 71 (6) 1462-9. 

Soy isoflavones improve systemic arterial compliance but not plasma lipids in menopausal and perimenopausal women. Arterioscler Thromb Vase Biol. 17 (12) 3392-8. 

SETCHELL K D (2001) Soy isoflavones-benefits and risks from nature s selective estrogen receptor modulators (SERMs). J Am Coll Nutr. 20 (5 Suppl) 354S-362S. 

---