# Soy Isoflavones and PCOS: Role in Hormonal and Metabolic Mechanisms
## 4 Polycystic Ovary Syndrome and Soy Isoflavones
### Endocrine Mechanisms
#### 4.1.3. Aromatase and Oestrogens  
Under physiological conditions, androgens produced by theca cells are converted to oestrogens by the enzyme aromatase (CYP19A1) [122]. Aromatase is active in many tissues, including the gonads, brain, adrenal glands, adipose tissue, and bones [60]. In PCOS, reduced expression of this enzyme in the ovaries and decreased production of oestradiol (E2) in the granulosa cells of the ovary to lower normal values or slightly lower values are observed [123]. Researchers suggest that this is most likely due to hypermethylation of the CYP19A1 promoter region, resulting in excessive accumulation of androgens and E2 deficiencies in the ovaries [124]. In turn, in patients with PCOS and excessive adipose tissue, its increased amount is responsible for the increased conversion of androgens to estrone (E1) [125]. However, there are also reports suggesting that high leptin levels, visceral obesity, and related inflammatory processes and hyperinsulin may lead to a decrease in the methylation of this gene and a decrease in aromatase activity in adipocytes [126; 127]. Studies show that AMH levels are higher in women with PCOS, correlate with hyperadenism, and may explain reduced oestrogen levels [128; 129; 130]. Elevated AMH may also directly stimulate theca cells to overproduce androgens [130]. It has been proven in both animal models and studies involving women that PCOS may have its origins in foetal life. High AMH and hyperandrogenism in pregnant women led to a decrease in aromatase activity in the placenta and foetal exposure to excess oestrogen [128; 129]. Research also suggests that there is a link between PCOM and hormonal dysregulation, including elevated AMH levels [131]. Depending on the phenotype of PCOS, its cause, and the accompanying complications, pharmacological therapy, nutritional interventions, supplementation, or the use of functional foods may have varying degrees of effectiveness. In the case of hyperandrogenism, soy isoflav can be an effective support method (Table 1). Studies involving women diagnosed with PCOS suggest a reduction in biochemical markers of hyperandrogenism, including a decrease in hormone levels such as total and free T, LH, and DHEAS, and a reduction in FAI in response to soy isoflavupplementation or consumption of functional foods (soy bread) [14; 15; 16; 132]. One study also reported an increase in SHBG levels [132]. These studies showed an improvement in hormonal parameters, but for most parameters, the differences were not statistically significant [14; 15; 16; 132]. Previous studies conducted with PCOS patients confirm an improvement in the levels of certain hormones compared to the period before soy isoflavupplementation [14; 15; 16; 132]. In summary, previous studies conducted with PCOS patients confirm a slight or significant improvement in the levels of certain hormones compared to the placebo group, despite the lack of statistical significance of the results [14; 132]. One of them confirms a significant improvement in this regard in female patients compared to the period before soy isoflavupplementation [15]. However, in the case of consumption of bread containing soy isoflav, long-term consumption is suggested in order to observe statistically significant benefits [132]. In a pilot study by [PERSON] et al. [16], no statistical significance was found in terms of the hormonal profile. Nevertheless, there was a significant and statistically significant improvement in lipid profile parameters, which may also indirectly affect disease control and improve patient outcomes [16]. A larger number of studies on the relationship between soy isoflavues and endocrine mechanisms in PCOS have been conducted on animal models (Table 2) [133; 134; 135; 136; 137; 138]. Preclinical studies have shown a reduction in hormonal parameters such as total T, DHT, and LH [133; 137; 138].