There has been a controversy in the society whether breast cancer patients can drink soy milk and whether eating soy products will affect breast disease. We believe that soy milk can still be drunk, but we just have to be careful with the method. As we all know, the development of breast cancer is related to the high level of estrogen in human body. The soy isoflavones contained in soybeans are an important phytoestrogen that may cause the estrogen levels in breast cancer patients to rise and cause harm. Therefore, there is quite a lot of concern. However, soy isoflavones have positive effects, such as inhibiting the activity of tyrosine kinase, which causes cancer cells to develop; controlling the growth of blood vessels on which cancer cells grow and slowing down their growth; eliminating reactive oxygen species and acting as an antioxidant; and regulating the cell cycle, differentiation and apoptosis. Its estrogen-like effect can also effectively reduce estrogen levels in the body, thus reducing the occurrence of breast tumors. Moreover, soy products contain high levels of vegetable protein, which is good for the body, so you cannot choke on it and reject it altogether. In addition, these phytoestrogens can only be absorbed and used through digestion and decomposition. It is not easy to determine how much estrogen can be absorbed by the body during the metabolism of soy products, and the daily intake of soy products is not too much, and the amount of soy isoflavones that can be absorbed is also limited, so it does not generally have a great impact on the hormone levels of the human body. Preliminary studies have shown that the daily intake of isoflavones, which play a biological role in the human body, is best at 30-50 mg, which is equivalent to at least 1 cup of 250 ml of soy milk and 200-300 grams of soy products per day. Although soy consumption does have beneficial effects on breast cancer prevention, it is important to be careful about how it is consumed, for example, it is best not to consume it in powder form. In general, unless you are really diagnosed with protein malnutrition or protein deficiency, it is sufficient to supplement from your daily diet.