However, a number of studies since have tempered that finding. Such reductions, if sustained over time, could mean a greater than 20% lower risk of heart attack, stroke, or other forms of cardiovascular disease. Soy protein took center stage after research showed that it might lower levels of harmful cholesterol. Understanding this distinction is crucial for evaluating soy’s potential health effects. However, these isoflavones are not estrogen, and they don’t undergo a direct conversion within the body. It stems from the fact that soy contains isoflavones, which have a chemical structure similar to estrogen. No, soy does not directly convert to estrogen in the human body. In addition, they created a comprehensive database from thousands of scientific studies on how different substances interact with hormones. Environmental Protection Agency (EPA) to develop and validate integrated, high throughput testing strategies to detect substances that could disrupt endocrine functions by interacting with the hormones estrogen and androgen. This work began with studies on the endocrine-disrupting effects of the drug diethylstilbestrol (DES). It has been proposed that changes in estrogen levels induced by dietary phytoestrogens could depend on the individual capacity to produce equol 59,60, mainly the S-equol enantiomer, due to its high affinity for β-ER . In a randomized controlled cross-over trial conducted in 12 healthy premenopausal women, those consuming a high-soy diet for three menstrual cycles had lower urinary concentrations of total estrogens (E1, E2, E3), and some metabolites compared to individuals on a low-soy diet . A 6-month randomized controlled study evaluating the effects of isoflavone on men at high risk of developing advanced PCa found an increase in concentrations of the estrogen hormones estrone (E1), E2, 2-hydroxi-estradiol (2-OH-E2), and 16α-OH-E1. There is weak evidence that phytoestrogens contribute to reducing the risk of prostate cancer (PCa). In a randomized clinical study in Japanese healthy male volunteers consuming 60 mg per day of soy isoflavones, no changes in serum levels of E2 and total testosterone were observed compared to the baseline at the end of the 3-month intervention. Dietary phytoestrogens seem to be transferred from maternal blood to the fetus, but there is no evidence that they alter sex hormones in infants 25,26,27. In addition, phytoestrogens inhibit aromatase and other enzymes involved in the synthesis of steroid hormones . In rodents, estrogens (which are locally aromatized from androgens in the brain) play an important role in psychosexual differentiation, for example, by masculinizing territorial behavior; the same is not true in humans. The associations between binge eating, menstrual-cycle phase and ovarian hormones correlated. Progesterone may moderate the effects of low estradiol (such as during dysregulated eating behavior), but that this may only be true in women who have had clinically diagnosed binge episodes (BEs). These effects produce menstrual cycle changes, which result in hormone release leading to behavioral changes, notably binge and emotional eating. It is hypothesized that these changes occur due to brain changes across the menstrual cycle that are likely a genomic effect of hormones. It is also suggested that there is an interaction between hormone levels and eating at different points in the female menstrual cycle. Getting less than 7 hours of sleep regularly can drop your testosterone by 10–15%. This might explain why some men report feeling sensitive to these foods while others don't notice a thing. If you're downing multiple protein shakes with soy isolate every day or drinking liters of soy milk daily for months, you might be getting amounts far beyond what any research has tested. You need it to maintain bone density, cognitive function, cardiovascular health, and even sexual function. The concentration of these compounds varies based on growing conditions, processing methods, and food preparation techniques. These compounds exist in varying concentrations in many different plants. Whereas no significant changes in thyroid function were observed, a decrease of free-T3 was found in healthy young females. For example, in one RCT the mean daily isoflavone intake in the highest tertile was 11.4 mg as opposed to a total mean intake of 0.06 mg in an observational study . Similarly, women with metabolic syndrome who consumed 54 mg of genistein had lower levels of fasting insulin and HOMA-IR, and higher levels of adiponectin than the placebo group 155,156. Similar results were obtained after 12 and 24 months of intervention in a related study in 389 osteopenic postmenopausal women, who received the same dose of genistein plus calcium and vitamin D , the values remaining consistent after an extra year of follow-up in a sub-cohort . After a 6-month intervention in 60 healthy women, a decrease in insulin and insulin resistance was observed . Interventions included isoflavones 149,150, soy nuts , daidzein , genistein , and S-equol administered for periods ranging from 4 weeks to 6 months. They found a significant decrease of insulin sensitivity with the higher intake of isoflavones.
