Doctor with 24 years of experience - what science today knows about the benefits and harms of soy
About the benefits of soy
One of the most reputable food and drug control agencies in the world, the FDA in 1999 authorized soybean food manufacturers to label them as healthy foods for cardiovascular health.
To deserve the right to such labeling, a product must not only be useful for one system of the body, but also generally safe for humans.
Moreover, a huge number of clinical research the safety of soy-based baby food (data has been used since 1909!).
And scientists came to the conclusion that soy formula for baby food is safe, including for the reproductive system of both boys and girls.
In the same meta-analysis highlighted the following positive effects of soy in the human diet:
- at patients with type 2 diabetes (in both men and women) the lipid profile (cholesterol) indicators improved, but the carbohydrate metabolism indicators did not change. Roughly speaking, "sugar did not increase";
⁃ the use of soy or soy isoflavones (primarily daidzein and genostein) led to reducing the incidence of prostate cancer;
⁃ in women, soy consumption contributed to decrease in frequency development of estrogen-dependent oncological diseases, that is, the uterus, ovaries and mammary gland (less convincing data, but still);
⁃ also a diet containing soy contributed to strengthening bone tissue in menopause.
What is the danger of soy
But there is one problem: the same FDA organization, indicating a decrease in the risk of developing coronary heart disease with regular use of soy products, ranked the same soybeans as dangerous plants in relation to the development of goiter, growth problems, impaired absorption of minerals, amino acid deficiency, pathology of the endocrine system and even carcinogenesis.
The situation is, to put it mildly, ambiguous. How to interpret this?
Daidzein and genostein have been proven to have multiple effects on estrogen receptors. They block oncogenic alpha-receptors and activate oncoprotective beta-receptors. It is in their nature of things, it cannot be canceled in any way.
This explains the positive effects of soy noted in the meta-analysis above: it reduces inflammation, normalizes hormonal balance, including in the prostate gland.
Also soy isoflavones genostein and daidzein:
- stimulate the metabolism of estrogen in the liver in a safe way, when 2-hydroxyestrogen is produced, that is, a harmless product;
- do not produce oncogenic metabolites such as 4-hydroxyestrogens, which lead to the maximum increased risk of cancer.
What does this mean in simple words
What follows from this:
Soy should be consumed in reasonable amounts.. According to American Cancer Society soy is safe to consume up to three servings a day, even for breast cancer survivors. True, it is this group that is recommended to eat tofu, edamame beans and soy milk, and not soy powder (isolate), since it is more active and can easily be overdose.
One serving of soybeans for an adult is about 100 grams of tofu (about a third of the package) / half a glass of edamame / a glass of soy drink.
American and British nutritionists do not set limits on the daily intake of soy in healthy people.
Overall, it is very optimistic that Asian women have about 30 percent fewer breast cancer rates than American women who eat less soy.
Your Doctor Pavlova
Breast cancer is one third less common in Asia than in the United States. It's all about soy!
Is soy dangerous for men?
