Hormonal effects of soy in premenopausal women and men.
ABSTRACT Over the past few years, there has been increasing interest in the possible hormonal effects of soy and soy isoflavone consumption in both women and men. Soy consumption has been suggested to exert potentially cancer-preventive effects in premenopausal women, such as increased menstrual cycle length and sex hormone-binding globulin levels and decreased estrogen levels. There has been some concern that consumption of phytoestrogens might exert adverse effects on men's fertility, such as lowered testosterone levels and semen quality. The studies in women have provided modest support for beneficial effects. One cross-sectional study showed serum estrogens to be inversely associated with soy intake. Seven soy intervention studies controlled for phase of menstrual cycle. These studies provided 32-200 mg/d of isoflavones and generally showed decreased midcycle plasma gonadotropins and trends toward increased menstrual cycle length and decreased blood concentrations of estradiol, progesterone and sex hormone-binding globulin. A few studies also showed decreased urinary estrogens and increased ratios of urinary 2-(OH) to 16alpha-(OH) and 2-(OH) to 4-(OH) estrogens. Soy and isoflavone consumption does not seem to affect the endometrium in premenopausal women, although there have been weak estrogenic effects reported in the breast. Thus, studies in women have mostly been consistent with beneficial effects, although the magnitude of the effects is quite small and of uncertain significance. Only three intervention studies reported hormonal effects of soy isoflavones in men. These recent studies in men consuming soyfoods or supplements containing 40--70 mg/d of soy isoflavones showed few effects on plasma hormones or semen quality. These data do not support concerns about effects on reproductive hormones and semen quality.
SourceAvailable from: Steven J Schwartz
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ABSTRACT: There is growing recognition: (1) that sex (male and female) and sex hormones (androgens and estrogens) are important for physiologic functions outside those pertaining expressly to reproduction, and (2) that both classes of sex hormones are active in both sexes, and moreover are produced locally in non-gonadal tissues throughout the body. The visual system, in addition to being of tremendous inherent importance, is unique in a very distinctive way; it possesses an organ – the eye – having a window allowing its interior to be examined with exquisite precision and control in both laboratory and clinical settings. Plus, many diseases manifest in the eye or are exclusive to the eye. This special issue of Current Eye Research contains 12 review articles, each addressing a different topical area important for Sex, Eyes, and Vision: Male/Female Distinctions in Ophthalmic Disorders. Of course, the distinctions between topical areas are blurred, and the overlap between the various lines of knowledge and investigation likewise is substantial. Eye diseases can be both neurodegenerative and involve altered blood flow, for instance. In fact, the thematic overlap is greater yet, in that the articles for this special issue address matters of interest to clinicians and scientists who may identify more with women’s health or sex & gender fields than with eye & vision fields. Nevertheless, because this special issue needs a home, the following 12 topical areas each have here their own dedicated review: age-related maculopathy, central nervous system function and cognition & perception, diabetic retinopathy, dry eye, glaucoma, inherited diseases, lens and cataract, neuro-ophthalmology, ocular blood flow, ocular inflammatory disorders, optical coherence tomography, and sex/gender eye care disparities. This overview article itself raises additional points expressly concerning: (1) the estrogen therapy timing hypothesis, and (2) breast cancer treatment with aromatase inhibitors.Current Eye Research 10/2014; 40(2):1-6. DOI:10.3109/02713683.2014.975368 · 1.66 Impact Factor
Article: Is It Safe to Eat Soy?[Show abstract] [Hide abstract]
ABSTRACT: No doubt you've heard lots of good things about soyfoods. According to a health claim sanctioned by the FDA, they can help to fight heart disease. 1 They may also make your bones stronger. 2, 3 And the biggest news about soyfoods over the past decade has been that they contain cancer-fighting compounds. 4 But just as it seemed that things couldn't get any better for soy, articles began to pop up on the internet saying that the pro-soy stories are nothing more than hype--and that the real scoop on soy is not nearly as positive. In fact, the stories say, eating soy could endanger your health. These claims against soy include allegations that it raises cancer risk, and causes nutrient deficiencies, osteoporosis, thyroid problems, reproductive difficulties, and Alzheimer's Disease. Making your way through the controversy can be confusing, especially since some of what the soy naysayers claim is based on some scientific data--although this doesn't mean that their conclusions are right. And it's true that some soy proponents may overstate the benefits of soy. Hopefully, we can tread a more even path here and convince you that, while soyfoods may not be the answer to all your problems, and while there certainly are a few unanswered questions, you can include soyfoods in a balanced and healthful vegan diet.