Soy isoflavones are naturally occurring phytoestrogens found in soybeans and their products. They have an estrogen-like effect, but they can both mimic and modulate the effects of endogenous estrogens.
1. What are soy isoflavones?
Isoflavones belong to the class of flavonoids and include three main compounds::
- Genistein (most active)
- Daidzein
- Glycitein
In the body, they are metabolized into more active forms:
- Daidzein → Equol (under the action of intestinal microflora)
- Genistein → 8-hydroxygenistein
2. Mechanism of action
Isoflavones interact with estrogen receptors (ERa and ERb), but their activity is weaker than that of estradiol (approximately 100-1000 times).
Oestrogen-like effects (in case of oestrogen deficiency):
- Bone support (prevention of osteoporosis).
- Improvement of skin and hair condition.
- Reduce menopausal symptoms (hot flashes, sweating).
🔹 Anti-estrogenic effects (if there is an excess of estrogens):
- They compete with estradiol for receptors, reducing its activity.
- May reduce the risk of endometrial hyperplasia and breast cancer.
🔹 Other effects:
- Antioxidant effect (neutralization of free radicals).
- Anti-inflammatory effect (inhibition of NF-kB).
- Lower LDL (‘bad’ cholesterol) levels.
3. Use and application
① For women
✔ Menopause and postmenopause
- Reduce hot flashes, night sweats, mood swings.
- Alternative to HRT (hormone replacement therapy).
✔ Prevention of osteoporosis
- Stimulate osteoblasts, slow down bone loss.
✔ Hormone Balance
- When estrogendominirovaniyu can reduce the excess of estrogens.
- With hypoestrogenism (for example, after 40 years) – gently fill in the deficit.
② For men
- Prevention of prostate adenoma (genistein inhibits 5-alpha reductase).
- Reduce the risk of prostate cancer (block excess DHT).
- Support of the cardiovascular system (improvement of the lipid profile).
, General effects
Сердечно Cardiovascular protection – lowering cholesterol, improving vascular elasticity.
✅ Anticarcinogenic effect -especially in hormone-dependent tumors (breast, prostate).
Улучшение Improvement of skin condition-stimulation of collagenCollagen is a fibrillar protein, one of the main building elements of the body. It constitutes a significant part of connective tissues such as skin, tendons, joints, bones, and cartilage. Collagen provides strength, elasticity, and structural integrity to these tissues, giving them the ability to resist stretching. synthesis, protection against photoaging.
4. Dosages and dosage forms
Стандартная Standard dose: 40-100 mg / day (based on aglycones).
During menopause: up to 120 mg / day.
📌 For prevention: 50-80 mg / day.
Main sources:
- Soy and soy products (tofu, tempeh, soy milk).
- Dietary supplements (isolated isoflavones in capsules).
Best forms:
- Aglycones (genistein, daidzein) are more bioavailable.
- Glycosides (genistin, daidzin) – require fermentation in the intestine.
5. Side effects and contraindications
⚠ Possible negative effects:
- Bloating, flatulence (due to fermentation in the intestines).
- Headache (rarely, with individual sensitivity).
- Allergy (with soy intolerance).
🚫 Contraindications:
- Hormone-dependent tumors (ambiguous data, need a doctor’s consultation).
- Hypothyroidism (isoflavones can inhibit thyroid function).
- Pregnancy and lactation (insufficient safety data available).
6. Isoflavones vs. Other phytoestrogens
| Фитоэстроген | Источник | Активность | Основные эффекты |
|---|---|---|---|
| Изофлавоны сои | Соя, бобовые | Умеренная | Баланс эстрогенов, защита сердца, антиоксидант |
| Лигнаны | Лен, кунжут, злаки | Слабая | Детокс, антиканцерогенное действие |
| Куместаны | Люцерна, клевер | Низкая | Редко используются |
7. Withdrawal
Soy isoflavones are valuable phytoestrogens with many useful properties:
✔ For women -Menopause relief, bone and skin protection.
✔ For men – prostate and cardiovascular support.
✔ Antioxidant and anti-inflammatory effects.
Recommendations:
- Start with 50 mg / day, monitor the body’s response.
- With hypothyroidism -control TSH, it is possible to take with selenium and zinc.
- Choose dietary supplements with aglycone forms (more effective).