It is well known that soy products contain phytoestrogens, and it has been reported that estrogen is the main cause of breast cancer. First of all, we must understand the following concepts.
1. What are phytoestrogens?
Phytoestrogens are a class of non-steroidal compounds naturally found in plants, named because their biological activity is similar to that of estrogen, and the soy isoflavones in soybeans are among them. Phytoestrogens are widely distributed in food, such as lignans in lentils and grains, and coumarins in soybean sprouts.
2. Phytoestrogens ≠ human estrogens
When it comes to estrogen, many people are concerned because excessive levels of estrogen can cause breast cancer, endometrial cancer, uterine fibroids and uterine bleeding. However, phytoestrogens are not the same as human estrogen. Studies have found that phytoestrogens play a two-way regulatory role on estrogen levels in women’s bodies. Phytoestrogens have a molecular structure similar to that of estrogen and can bind to estrogen receptors to produce effects similar to those of estrogen, but this effect is smaller than that of estrogen in the human body. When the estrogen in the body is insufficient, its binding can play a role in supplementing estrogen; while when the estrogen level in the body is too high, its binding plays an inhibitory role because it prevents the binding of estrogen, which is equivalent to lowering the estrogen level. Therefore, phytohormones are also known as the regulation of female estrogen levels.
3. What are soy isoflavones? How is soy milk metabolized in the body?
Soy isoflavones are flavonoids, a class of secondary metabolites formed during the growth of soybeans, which are biologically active substances. Because they are extracted from plants and have a similar structure to estrogen, soy isoflavones are also known as phytoestrogens.
The soy isoflavones in soy milk exist mainly in the form of glycosides. When the human body ingests soy and its products, the isoflavone glycosides are decomposed in the intestine by glycosidases, releasing glycosides and glycoside ligands with bioactive blood, and these active substances are absorbed directly in the intestine or are converted into the final metabolite —– estriol (equol).
4. Estriol and disease and health
Estriol is the end metabolite of the biotransformation of soy isoflavones and soy flavonoids by the action of colonic microflora, and has higher pharmacological activity than soy isoflavones, especially in the prevention of cardiovascular disease, breast cancer and prostate cancer. The biological activities of estradiol are most typically estrogenic and antioxidant.
I. Antitumor
Studies on the anticancer effects of esmolol have focused on breast cancer and prostate cancer. Epidemiological surveys have confirmed that a decrease in urinary 2 hydroxy ketone / 16α hydroxyestrone leads to an increase in the incidence of breast cancer. A case-control study showed that soy intake had no significant effect on this ratio, but the ratio was closely related to the serum and urinary levels of estradiol, suggesting that the inhibitory effect of soy isoflavones on breast cancer may be mainly attributed to its metabolite estradiol.
II. Improve menopausal symptoms, anti-cardiovascular disease
The consumption of soy isoflavones can compensate for the decrease in estrogen due to menopause, thus reducing or avoiding the menopause syndrome. Australian scientists have found that menopausal women who consume 45 grams of soy per day have a 40% reduction in the incidence of menopausal syndrome. A diet containing soy foods can relieve the symptoms of hot flashes and sweating in menopausal women. Soy isoflavones can also improve the elasticity of arteries throughout the body of women who are in or near menopause.
5, soy isoflavones – will not cause breast cancer
Contrary to what rumors say, numerous studies have confirmed that drinking soy milk in moderation can prevent breast cancer.
Epidemiological studies have shown that Asians have lower incidence and mortality rates of breast cancer and prostate cancer than Westerners due to their high intake of soy and soy products. The Shanghai Breast Cancer Status Survey studied 5,042 women aged 20-75 years with breast cancer in Shanghai and found that eating soy products significantly reduced the mortality rate of breast cancer patients. The results of a case-control study of Chinese women living in Singapore also showed that soy had a significant preventive effect on the development of breast cancer. Rather, they may reduce the risk of breast cancer, especially in Asian populations where soy consumption is high.
In addition, the International Guidelines for Breast Health and Cancer, an article published in the world’s leading medical journal Cancer, lists a number of ways to prevent breast cancer in countries around the world, one of which is to eat soy and its products in moderation.
Moderate intake of soy products is safe and does not induce breast cancer
Moderate intake of soy products is safe, does not induce breast cancer, and is a good food for women to prevent and reduce menopausal syndrome.
Contrary to the rumors, numerous studies have confirmed that drinking soy milk in moderation can prevent breast cancer.
Epidemiological studies have shown that Asians have lower incidence and mortality rates of breast and prostate cancer than Westerners due to their high intake of soy and soy products. The Shanghai Breast Cancer Status Survey studied 5,042 women aged 20-75 years with breast cancer in Shanghai and found that eating soy products significantly reduced the mortality rate of breast cancer patients. Results from a case-control study of Chinese women living in Singapore on diet and breast cancer also showed a significant preventive effect of soy on the development of breast cancer.