An endocrinologist with 23 years of experience examines what science knows about the oncogenicity of soy
The most common question about soy is its effect on the thyroid gland. I mean it wrote a lot.
The second most common is the question of the "harmful" effect of soybeans on a man's body. And although I am too I wrote about it, questions remained.
I will try to clarify the question as a whole. oncogenicity of soy.
About the benefits of soy
One of the most reputable food and drug control agencies in the world FDA in 1999 gave permission to manufacturers of soy products to label them as healthy food for the health of the cardiovascular system.
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 safe, including for the reproductive system of both boys and girls.
In the same meta-analysis the following positive effects of soy in the human diet have been highlighted:
- For patients type 2 diabetes mellitus the indicators of the lipid profile (cholesterol) improved, but the indicators of carbohydrate metabolism did not change. Roughly speaking, "sugar did not increase";
- the use of soy or soy isoflavones (primarily daidzein and genostein) led to reduce the incidence of cancer the prostate gland;
- 👉🏻 in women, soy consumption contributed to decrease in the incidence 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.
Not everything is so simple
But there is one problem: the same FDA organization, indicating a decrease in the risk of 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 oncogenic beta receptors. It is in their nature of things, it cannot be canceled in any way.
This explains positive effects of soy, noted in the meta-analysis above: it reduces inflammation, normalizes hormonal balance, including in the prostate gland.
Also soy isofavones genostein and daidzein:
- 👉🏻 stimulate estrogen metabolism 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 maximize the risk of cancer.
So can you eat soy?
What follows from this:
Eat reasonable amounts of soy. According to American Cancer Society soy is safe to consume up to 3 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 approximately:
- 100 grams of tofu (about a third of the package)
- half a cup edamame
- a glass of soy drink.
American and British nutritionists do not set limits on the daily consumption of soybeans in healthy people.
In general, the fact that Asian women have about 30 percent fewer breast cancer rates than American women who eat less soy.
Your Doctor Pavlova
Is soy dangerous for men?
