# Soybean (Glycine max)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/soybean
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-01
**Evidence Score:** 2 / 10
**Category:** Legume
**Also Known As:** soya bean, soja, edamame bean, Chinese bean, miracle bean, yellow bean, vegetable meat, field pea, soy, soja bean

## Overview

Soybean (Glycine max) contains isoflavones like genistein and daidzein that act as phytoestrogens, modulating estrogen receptors and [inflammatory pathway](/ingredients/condition/inflammation)s. These compounds provide metabolic benefits and reduce inflammatory markers like C-reactive protein.

## Health Benefits

• May improve metabolic outcomes and [body composition](/ingredients/condition/weight-management) - fermented soy showed benefits across 15 RCTs (2025 meta-analysis, strong evidence)
• Reduces [inflammatory](/ingredients/condition/inflammation) markers - significant reduction in C-reactive protein (-0.27 mg/L) in meta-analysis of 51 trials (PMID: 32979840, strong evidence)
• May lower inflammatory cytokines with long-term use - IL-6 and TNF-α decreased with ≥12 weeks supplementation at <100mg/day isoflavones (moderate evidence)
• No adverse effects on male hormones - meta-analysis confirmed no alteration of bioavailable [testosterone](/ingredients/condition/hormonal) (PMID: 19524224, strong evidence)
• Potential [cardiovascular](/ingredients/condition/heart-health) benefits in type 2 diabetes - systematic review conducted through 2021 (evidence quality not specified)

## Mechanism of Action

Soybean isoflavones, primarily genistein and daidzein, bind to estrogen receptors (ERα and ERβ) as selective estrogen receptor modulators. These compounds inhibit inflammatory cytokines including TNF-α and IL-6 while activating PPAR-γ pathways that improve [insulin sensitivity](/ingredients/condition/weight-management). The [anti-inflammatory](/ingredients/condition/inflammation) effects occur through NF-κB pathway suppression and enhanced [antioxidant](/ingredients/condition/antioxidant) enzyme activity.

## Clinical Summary

Meta-analysis of 15 RCTs showed fermented soy significantly improved metabolic outcomes and [body composition](/ingredients/condition/weight-management) in 2025. A comprehensive meta-analysis of 51 trials (PMID: 32979840) demonstrated significant reduction in C-reactive protein levels by 0.27 mg/L. Most studies used 40-80mg isoflavone doses daily for 8-12 weeks. Evidence is strongest for [anti-inflammatory](/ingredients/condition/inflammation) effects and metabolic benefits, particularly with fermented soy products.

## Nutritional Profile

Per 100g mature raw soybeans: Protein 36.5g (complete protein with all essential amino acids, though slightly limiting in methionine; digestibility ~90% for processed forms like tofu/soymilk, lower for whole beans). Fat 19.9g (predominantly polyunsaturated: linoleic acid ~50%, oleic acid ~23%, alpha-linolenic acid ~7%). Carbohydrates 30.2g, dietary fiber 9.3g (both soluble and insoluble). Key micronutrients: manganese (2.5mg, ~109% DV), copper (1.7mg, ~189% DV), phosphorus (704mg, ~100% DV), magnesium (280mg, ~67% DV), iron (15.7mg, ~87% DV, non-heme form with ~5-10% bioavailability, enhanced by vitamin C co-consumption), potassium (1797mg, ~38% DV), zinc (4.9mg, ~45% DV), calcium (277mg, bioavailability ~30% in calcium-set tofu), folate (375µg, ~94% DV), thiamine (0.87mg, ~73% DV), riboflavin (0.87mg, ~67% DV), vitamin K1 (47µg, ~39% DV). Bioactive compounds: Isoflavones (total 100-300mg/100g depending on cultivar and processing) — primarily genistein (40-90mg), daidzein (30-70mg), and glycitein (5-20mg), present as glycoside conjugates in raw beans with bioavailability significantly improved by fermentation (converting to aglycones); equol, a daidzein metabolite with higher estrogenic activity, is produced by ~30-50% of individuals depending on [gut microbiome](/ingredients/condition/gut-health) composition. Saponins (group A and B soyasaponins, ~2-5g/100g), which may contribute to cholesterol-lowering effects. Phytosterols (~160-170mg/100g, primarily β-sitosterol, campesterol, stigmasterol). Lectins (soybean agglutinin, inactivated by adequate heat processing). Protease inhibitors (Bowman-Birk inhibitor, Kunitz trypsin inhibitor — largely denatured by cooking/processing). Phytic acid (1.0-2.2g/100g), which reduces mineral bioavailability but is decreased by fermentation, soaking, and sprouting. Oligosaccharides (raffinose ~1.1%, stachyose ~3.8%) contribute to flatulence but serve as prebiotics. Lunasin, a bioactive peptide with proposed [anti-inflammatory](/ingredients/condition/inflammation) and epigenetic modulating properties. Phospholipids including lecithin (phosphatidylcholine ~1.5g/100g). Note: Processing substantially affects nutrient and bioactive profiles — fermented forms (tempeh, miso, natto) have higher isoflavone aglycone bioavailability and reduced antinutrient content; natto uniquely contains nattokinase and menaquinone-7 (vitamin K2, ~1000µg/100g).

## Dosage & Preparation

Clinical studies suggest low-dose isoflavone supplementation (<100 mg/day) combined with long-term intervention (≥12 weeks) for [anti-inflammatory](/ingredients/condition/inflammation) effects. Fermented soy products and natural soy foods have been studied in various forms and doses, though specific standardization protocols vary by product type. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Soybean is generally well-tolerated with mild gastrointestinal effects reported in some individuals. May interact with thyroid medications and warfarin due to isoflavone content affecting [thyroid function](/ingredients/condition/hormonal) and vitamin K absorption. Contraindicated in individuals with soy allergies and should be used cautiously in hormone-sensitive cancers. Generally considered safe during pregnancy and lactation when consumed as food, but supplement forms require medical supervision.

## Scientific Research

Multiple recent meta-analyses have examined soybean's clinical effects: a 2025 review of 15 RCTs on fermented soy and metabolic outcomes, a 2020 meta-analysis of 51 trials (PMID: 32979840) showing CRP reduction, and a 2021 analysis of 25 RCTs (PMID: 33399974) on natural soy products and [inflammation](/ingredients/condition/inflammation). Additional meta-analyses investigated effects on menopausal symptoms (17 RCTs, PMID: 22433977), [testosterone levels](/ingredients/condition/hormonal) (PMID: 19524224), and adiponectin (7 RCTs, 2022).

## Historical & Cultural Context

Soybeans have been cultivated in East Asia for thousands of years as a protein-rich food source. While specific traditional medicine uses are not detailed in the provided research, the legume's long history of cultivation indicates extensive traditional dietary use across Asian cultures.

## Synergistic Combinations

Turmeric, Omega-3 fatty acids, Green tea extract, [Probiotic](/ingredients/condition/gut-health)s, Vitamin D

## Frequently Asked Questions

### How much soybean isoflavones should I take daily?

Clinical studies typically use 40-80mg of isoflavones daily, equivalent to 1-2 servings of soy foods. Higher doses up to 150mg have been used safely in research studies for specific health outcomes.

### Does soybean affect thyroid function?

Soybean isoflavones may interfere with thyroid hormone synthesis and iodine absorption. Individuals with hypothyroidism should maintain adequate iodine intake and monitor thyroid function when consuming large amounts of soy products.

### Is fermented soy better than regular soy?

Fermented soy products like miso and tempeh showed superior metabolic benefits in clinical trials compared to non-fermented forms. Fermentation increases bioavailability of isoflavones and reduces antinutrients like phytic acid.

### Can soybean help with menopause symptoms?

Soy isoflavones may reduce hot flashes and other menopausal symptoms through their phytoestrogen activity. Studies show modest benefits, with genistein being particularly effective for vasomotor symptoms when taken as 40-60mg daily.

### Does soybean interact with blood thinners?

Soybean contains vitamin K and may reduce warfarin effectiveness when consumed in large quantities. Patients on anticoagulants should maintain consistent soy intake and monitor INR levels regularly.

### What is the difference between soybean extract and whole soy food sources in terms of inflammatory marker reduction?

Both forms reduce inflammatory markers like C-reactive protein, but concentrated soybean extracts may produce more rapid effects due to higher isoflavone bioavailability, while whole soy foods provide additional fiber and nutrients that support long-term anti-inflammatory benefits. Meta-analyses of 51 trials show consistent C-reactive protein reduction of approximately 0.27 mg/L across both forms, though individual response varies based on baseline inflammation levels and supplementation duration.

### How long does it typically take soybean supplementation to reduce inflammatory cytokines like IL-6 and TNF-α?

Research indicates that meaningful reductions in inflammatory cytokines IL-6 and TNF-α require at least 12 weeks of consistent soybean supplementation, with greater reductions observed in studies extending 12+ weeks duration. This timeline aligns with the bioaccumulation of soy isoflavones and their effects on immune system modulation, meaning short-term use may not produce measurable cytokine changes.

### Is soybean supplementation effective for improving body composition, and what type of soybean product shows the strongest evidence?

Fermented soybean products demonstrate the strongest clinical evidence for improving metabolic outcomes and body composition, with 15 randomized controlled trials showing consistent benefits in a 2025 meta-analysis. Fermentation enhances bioavailability of isoflavones and may improve glycemic control and fat mass reduction compared to unfermented soy, making it the preferred form for body composition goals.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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