She completed specializations in sports medicine, ultrasound, toxicology, anesthesiology and resuscitation, he alth management.
He has many years of experience in the field of sports medicine, prevention, nutrition, weight loss, recovery and biostimulation.
Dr. Yanakieva, ingredients called phytoestrogens are common in nutritional supplements and cosmetics. They are credited with such miraculous effects that at some point we ask ourselves: are they really that useful? What's your opinion?
- The word “estrogens” (female sex hormones) is softened by the suffix “phyto”. If the hype is to be believed, they can do anything. They have a beneficial effect on the skin and hair follicles. Dryness and laxity disappear from the skin and it becomes more elastic.They slow down aging, prevent cardiovascular diseases, osteoporosis, even Alzheimer's disease. Complaints caused by the hormonal changes of menopause disappear. How much truth is there in this? Phytoestrogens are not plant hormones. In the human body, they can act not only as estrogens, but also as anti-estrogens.
Do they actually have a hormone-like effect? Should we also ask ourselves about their safety?
- If they really have a hormone-like effect, we must also ask ourselves the question how pronounced it is and whether it can lead to the development of malignant tumors of the uterus and mammary glands? Adding to these questions, there are reports from time to time that certain pesticides, cosmetic preservatives, and sunscreens are dangerous because they have an estrogen-like effect.
At the end of the last century, it was noticed that the inhabitants of Southeast Asia had a significantly lower mortality rate from cardiovascular diseases.Breast cancer is less common in women and the unpleasantness of menopause is less pronounced. These features are attributed to the significant use of soy, which contains substances similar in structure to estrogens. Of course, this fact cannot be linked to only one product, the peculiarities of the lifestyle as a whole must be taken into account.
Several types of substances can act as weak estrogens and anti-estrogens. These are isoflavones, coumestans, lignans, mycoestrogens. They are similar in structure to 17-beta-estradiol, the main female sex hormone. Hormones work by binding to receptors on the surface of cells. By virtue of their chemical similarity, phytoestrogens are able to bind to the same receptors as estrogens, but they hinder rather than help estrogens.
In their deficiency, receptors can be weakly activated, and in excess - they can compete with estrogens for the receptors. Whether phytopreparations can have a balancing effect is unclear.
The action of which phytoestrogens have been best studied so far?
- So far, the phytoestrogens of soy are the most studied. First of all, the isoflavones genistein and daidzein. Glycitein accumulates primarily in soybean sprouts. Isoflavones in plants are in the form of glycosides - joined with sugars. In the intestines, under the action of intestinal microorganisms, glycosides are broken down into sugar and non-sugar components. Glycosides are practically not capable of causing an estrogenic effect. The activity of the non-sugar part is not much higher. The most significant effect in the estrogenic action is brought by equol - a product of the further breakdown of daidzein. In structure, it most resembles estradiol.
So does soy have an effect on reproductive function and menopause in women?
- Most of the experiments show that a diet enriched with soy products, as well as the intake of standardized soy extracts, have no noticeable effect on the reproductive function of women.Regarding the course of the climacteric period, there is data that the soy diet reduces hot flashes by 45%. But in the same study, it turned out that two-thirds of the effect was due to the placebo. There is some evidence of an effect on the lipid profile with a reduction in the risk of cardiovascular disease, for delaying the development of osteoporosis. All isoflavones are antioxidants and can neutralize active oxygen radicals. It is possible that they slow down the growth of malignant tumors and reduce the likelihood of cancerous cell regeneration, but there is not enough data to rely on this alone.
Most phytoestrogens act as weak anti-androgens - they reduce the influence of male sex hormones
This action is used in acne, when excess androgens overstimulate the production of sebaceous glands in the skin, and hormone-dependent baldness. The most effective are equol and genistein, as well as the product of lignan microbial metabolism in the intestine - enterolactone.
Is there any use of phytoestrogens in cosmetics?
- Unlike steroid hormones, phytoestrogens are not absorbed through the skin and have no effects through this route. In general, the substances contained in the plant extracts are weakly effective, and the main part of the compounds with estrogen-like activity are formed in the intestines. No pronounced effects can be expected from phytoestrogens applied to the skin. In addition to the specific action on acne and baldness.