Edamame and soybeans: one bean picked at two ages

By a meta-analysis of 43 trials, about 25 g of soy protein a day for a median of 6 weeks lowered LDL cholesterol by 4.76 mg/dL (95% CI 2.80 to 6.71) in adults whose LDL started between 110 and 201 mg/dL. That is roughly 3 to 4 percent, and it came mostly from soy protein isolates. We found no trial that tested edamame itself, so every health number on this page belongs to soy protein or soy foods in general. In a second meta-analysis, 29 randomized trials in 2,457 postmenopausal women, unfermented soy products, some of them isolates, lowered total cholesterol by 9.46 mg/dL. The LDL change in those women did not reach significance. Edamame is the same plant as the dry soybean, picked green. In one lab analysis of one cultivar the immature seeds held about 67 percent water against 13 percent in mature dry seeds, which is why the two look so different on a label. A cup of cooked edamame (160 g) gives about 18.5 g of protein and a cup of cooked mature soybeans (185 g) about 31.3 g, both recalculated by USDA from values per 3.5 oz (100 g).

How much is actually in it

• Cooked frozen edamame carries about 185 micrograms of folate per 3.5 oz (100 g), but four USDA samples ranged from 127 to 255 micrograms, so one bag can hold twice the folate of another. — USDA Foundation Foods samples of Edamame, frozen, prepared (n = 4 samples) Evidence E source
  Folate 185.3 ug per 3.5 oz (100 g) (range 126.6 to 255.0), iron 2.33 mg (1.92 to 2.85), potassium 519.5 mg (423 to 573), magnesium 72.75 mg (67.8 to 76.6)
• The UK food table gives boiled frozen edamame 12.2 g of protein, 7.6 g of fat and 142 calories per 3.5 oz (100 g), with 5.9 g of fiber. — CoFID record Beans, edamame, frozen, boiled in unsalted water (n = 1 record) Evidence E source
  Protein 12.2 g, fat 7.6 g, carbohydrate 6.5 g, AOAC fiber 5.9 g, energy 142 calories, water 68.3 g per 3.5 oz (100 g)
• Laboratory analysis found immature soybeans of the edamame stage hold about 67% water against 13% in mature dry soybeans, which is why per-gram numbers differ so much between the two. — immature (R6) and mature (R8) soybean seeds of one cultivar Evidence D source
  Water 66.87% immature vs 13.04% mature

What a real portion looks like

• A cup of cooked edamame (160 g) gives about 18.5 g of protein, while a cup of cooked mature soybeans (185 g) gives about 31.3 g. — FNDDS foods Edamame, cooked (41420020) and Soybeans, cooked (41107010) (n = 2 foods) Evidence E source
  Protein 11.54 g per 3.5 oz (100 g) edamame vs 16.92 g per 3.5 oz (100 g) cooked soybeans; 1 cup 160 g = 18.5 g vs 1 cup 185 g = 31.3 g
• US dietary surveys record a typical unspecified serving of cooked edamame as 80 g and of cooked soybeans as 92 g, and a single edamame pod yields about 2 g of beans. — FNDDS portion weights for Edamame, cooked and Soybeans, cooked (n = 2 foods) Evidence E source
  Edamame: 1 pod yields 2 g, 1 cup 160 g, quantity not specified 80 g; soybeans: 1 cup 185 g, 1 oz dry yields 72 g cooked, quantity not specified 92 g

What your body absorbs

• In an RCT on 63 young women, eating about 19 g of soy protein a day from soy foods for 10 weeks did not change iron or zinc status compared with animal foods. — nonsmoking premenopausal women aged 18 to 28, soy food n=31 vs animal food n=32, 10 weeks (n = 63) Evidence B source
  No significant change in hemoglobin, ferritin, serum iron or transferrin receptor; plasma zinc fell 0.8 umol/L in both groups
• ESPGHAN notes that soy protein is digested and absorbed less well than cow's milk protein and is lower in methionine, and soy formulae carry phytate, aluminum and isoflavones. — infants, soy protein infant formulae (committee commentary) Evidence E source
  Lower digestibility and bioavailability, lower methionine (no size given)

What cooking and storage change

• Boiling vegetables from frozen and draining them keeps about 70% of folate and 80% of vitamin C by the USDA table, so edamame loses more folate in the pot than its minerals. — USDA retention factors for the group Vegetables and Vegetable Products, cooked from frozen, boiled, drained Evidence E source
  Folate 70% retained, vitamin C 80%, potassium 90%, iron 95%, magnesium 95%, zinc 95%
• Laboratory data suggest wet heating such as boiling breaks down malonyl isoflavones in soybeans more than dry heating does, at both the immature and the mature stage. — immature and mature soybean seeds, wet vs dry heating Evidence D source
  Malonyl isoflavone deglycosylation greater with wet than dry heating at both maturities (direction only)

What it does to your health

• By a meta-analysis of 43 trials FDA had collected, about 25 g of soy protein a day for a median of 6 weeks lowered LDL cholesterol by 4.76 mg/dL, roughly 3 to 4%. — adults with baseline LDL 110 to 201 mg/dL, soy protein vs non-soy protein, median 25 g/d, median 6 weeks (n = 43 trials) Evidence A source
  LDL -4.76 mg/dL (95% CI -6.71 to -2.80), total cholesterol -6.41 mg/dL (95% CI -9.30 to -3.52)
• By a meta-analysis of 29 RCTs in 2,457 postmenopausal women, unfermented soy products lowered total cholesterol by 9.46 mg/dL but did not significantly change LDL. — postmenopausal women off hormone therapy, 29 RCTs (n = 2457) Evidence A source
  Total cholesterol -9.46 mg/dL (95% CI -15.04 to -3.89), triglycerides -10.86 mg/dL, HDL +2.32 mg/dL, LDL -4.55 mg/dL (95% CI -10.90 to 1.80, not significant)
• By a meta-analysis of 15 RCTs, fermented soy products lowered fasting glucose by 6.39 mg/dL and total cholesterol by 5.0 mg/dL against controls. — adults in 15 RCTs of fermented soy products (n = 15 trials) Evidence A source
  Fasting glucose -6.39 mg/dL (95% CI -10.38 to -2.40), total cholesterol -5.0 mg/dL (95% CI -6.60 to -3.39), waist -0.59 in (-1.50 cm)

Safety, limits and interactions

• Pooled European studies put challenge-confirmed soy allergy at about 0.3% of people and self-reported lifetime soy allergy at 0.5%. — European populations, all ages, 93 studies (n = 93 studies) Evidence C source
  Challenge-verified point prevalence 0.3% (95% CI 0.1 to 0.4), self-reported lifetime 0.5% (0.3 to 0.7)
• The FDA-approved levothyroxine label warns that soybean flour may bind the drug and reduce its absorption. — people taking levothyroxine sodium Evidence E source
  Reduced absorption (no size given)
• A USDA systematic review found limited evidence of no link between eating soybeans in pregnancy and food allergy in the child, based on two cohort studies. — pregnant women and their children, 2 cohort studies (about 600 and 11,352 participants) (n = 2 cohorts) Evidence C source
  No association (grade limited)

What people believe that the data does not support

• The EU refused a health claim that isolated soy protein lowers blood cholesterol and heart disease risk, so soy foods cannot carry it on EU labels. — EU Register on nutrition and health claims Evidence E source
  Claim non-authorized
• The US soy protein heart health claim is still in 21 CFR 101.82, and whole soybean foods may use it without meeting the low fat rule if they add no fat. — US food labeling, 21 CFR 101.82 Evidence E source
  Authorized health claim with whole-soybean fat exemption
• FDA published a proposed rule on October 31, 2017 to revoke the authorized soy protein and heart disease claim, the first time it moved to withdraw such a claim. — US food labeling Evidence E source
  Proposal to revoke (no final rule found as of 2026-09-29)

What is still unknown

• By a network meta-analysis of 60 RCTs in 6,284 healthy women, no whole soy or dairy food improved bone density against control, and only soybean protein as a component raised total body BMD by 0.03 g/cm2. — healthy adult women, mean age 54.2, 60 RCTs (n = 6284) Evidence A source
  Soybean protein total body BMD MD 0.03 g/cm2 (95% CI 0.01 to 0.05); food-level soy interventions not significant

The bottom line

Frozen edamame, cooked, averages about 185 micrograms of folate per 3.5 oz (100 g), but the four USDA samples ran from 127 to 255, so one bag can carry twice the folate of another. Boiling vegetables from frozen and draining them keeps about 70 percent of folate and 95 percent of iron by the USDA retention table, a group factor never measured on edamame by name. In a randomized trial on 63 women aged 18 to 28, about 19 g of soy protein a day from soy foods for 10 weeks left iron and zinc status unchanged compared with animal foods. Bone is where the soy story runs thin. A network meta-analysis of 60 trials in 6,284 healthy women found that no whole soy food improved bone density against control. Soybean protein as an isolated component raised total body bone density by 0.03 g/cm2 (95% CI 0.01 to 0.05), a small shift. Fermented soy is a separate case. By a meta-analysis of 15 trials it lowered fasting glucose by 6.39 mg/dL, but natto, tempeh and miso are what was tested, and edamame is none of them. Labels disagree across the Atlantic. The US soy protein heart claim still stands in 21 CFR 101.82, and whole soybean foods may carry it without meeting the low fat rule. FDA proposed revoking that claim on October 31, 2017, and we found no final rule. The EU refused the same cholesterol claim for isolated soy protein. Who should be careful. Pooled European studies, mostly at moderate risk of bias, put challenge-confirmed soy allergy at about 0.3 percent of people. The approved levothyroxine label warns that soybean flour may bind the drug and reduce its absorption, with no size given, and it names the flour rather than whole beans. If you take levothyroxine, how you time it around soy meals is a question for the person who prescribes it. ESPGHAN rates soy protein below cow milk protein for digestibility and methionine in infant formula, a 2006 position about formulae made from isolates. For pregnancy, a USDA review found limited evidence, from two cohort studies, of no link between eating soybeans and food allergy in the child.

Sources

1. eds-r2-01 · USDA FoodData Central Foundation Foods, dataset
   Edamame, frozen, prepared (Foundation Foods, release 2026-04-30): Folate, total 185.3 UG range 126.6-255.0, 4 samples; Iron, Fe 2.33 MG range 1.92-2.85; Potassium, K 519.5 MG range 423.0-573.0; Magnesium, Mg 72.75 MG range 67.8-76.6; Vitamin C 11.36 MG range 1.2-18.3
   USDA FoodData Central, Foundation Foods, release 2026-04-30, Edamame, frozen, prepared · checked 2026-09-29
2. eds-r2-02 · CoFID 2021, dataset
   CoFID 13-667 Beans, edamame, frozen, boiled in unsalted water: Protein 12.2 g; Fat 7.6 g; Carbohydrate 6.5 g; AOAC fibre 5.9 g; Energy 142 kcal; Water 68.3 g per 100 g
   CoFID 2021, Public Health England, OGL v3.0, code 13-667 · checked 2026-09-29
3. eds-r2-06 · food chemistry analysis
   The water contents of the immature and mature seeds were 66.87% and 13.04%, respectively.
   Molecules, 2021 · checked 2026-09-29
4. eds-r2-03 · USDA FNDDS, dataset
   FNDDS 41420020 Edamame, cooked (fdc_id 2707436): Protein 11.54 G per 100 g; 1 cup = 160 g = 18.5 G; FNDDS 41107010 Soybeans, cooked (fdc_id 2707388): Protein 16.92 G per 100 g; 1 cup = 185 g = 31.3 G
   USDA FNDDS, fdc_id 2707436 and 2707388 · checked 2026-09-29
5. eds-r2-04 · USDA FNDDS, dataset
   FNDDS 41420020 Edamame, cooked: 1 pod, yields 2 g; 1 cup 160 g; Quantity not specified 80 g. FNDDS 41107010 Soybeans, cooked: 1 cup 185 g; 1 oz dry, yield after cooking 72 g; Quantity not specified 92 g
   USDA FNDDS, fdc_id 2707436 and 2707388, portions · checked 2026-09-29
6. eds-r2-08 · RCT
   Incorporating ∼19 g soy protein from soy foods for 10 weeks had no significant effect on iron or zinc status, bone resorption or formation, or thyroid hormone status in premenopausal women.
   J Womens Health (Larchmt), 2011 · checked 2026-09-29
7. eds-r2-09 · guideline
   Soy is a source of protein that is inferior to cows' milk, with a lower digestibility and bioavailability as well as a lower methionine content.
   J Pediatr Gastroenterol Nutr, 2006 · checked 2026-09-29
8. eds-r2-05 · USDA Table of Nutrient Retention Factors, dataset
   USDA-RETN-R6:3789 VEG,OTHER,CKD FROM FRZN(BLD,DRAIND), group Vegetables and Vegetable Products: folate_total_ug 70% retained, vitamin_c_mg 80%, potassium_mg 90%, iron_mg 95%, magnesium_mg 95%, zinc_mg 95%
   USDA Table of Nutrient Retention Factors, Release 6, 2007, Retn_Code 3789 · checked 2026-09-29
9. eds-r2-07 · food chemistry analysis
   The deglycosylation of the three types of malonyl isoflavones was more severe in wet- than in dry-heating regardless of the seed maturity.
   Molecules, 2021 · checked 2026-09-29
10. eds-r2-10 · meta-analysis of RCTs
    Soy protein at a median dose of 25 g/d during a median follow-up of 6 wk decreased LDL cholesterol by 4.76 mg/dL (95% CI: -6.71, -2.80 mg/dL, P < 0.0001; I2 = 55%, P < 0.0001) and decreased TC by 6.41 mg/dL (95% CI: -9.30, -3.52 mg/dL, P < 0.0001; I2 = 74%, P < 0.0001) compared with non-soy protein controls.
    J Nutr, 2019 · checked 2026-09-29
11. eds-r2-11 · meta-analysis of RCTs
    Twenty-nine RCTs involving 2,457 participants were included. The results showed that, compared with the control group that did not consume unfermented soy products, consumption of unfermented soy products significantly reduced total cholesterol (TC) (MD, -9.46 mg/dL
    J Acad Nutr Diet, 2024 · checked 2026-09-29
12. eds-r2-12 · meta-analysis of RCTs
    A total of 2205 records were found, of which 15 RCTs were eligible. Results demonstrated significant beneficial effects of fermented soy on body mass index (WMD = -0.14 kg m-2, 95% CI: -0.28, -0.01, P = 0.039), waist circumference (WMD = -1.50 cm, 95% CI: -2.94, -0.07, P = 0.04), visceral fat (WMD = -692.17 mm2, 95% CI: -1011.58, -372.77, P < 0.001), fasting plasma glucose (WMD = -6.39 mg dL-1, 95% CI: -10.38, -2.40, P = 0.002), and total cholesterol (WMD = -5.0 mg dL-1, 95% CI: -6.60, -3.39, P < 0.001) compared with controls.
    Food Funct, 2025 · checked 2026-09-29
13. eds-r2-14 · meta-analysis of observational studies
    The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4)
    Allergy, 2023 · checked 2026-09-29
14. eds-r2-15 · FDA drug label
    Soybean flour, cottonseed meal, walnuts, and dietary fiber may bind and decrease the absorption of levothyroxine sodium from the gastrointestinal tract.
    Levothyroxine sodium, FDA drug label (DailyMed, set f059a576-bb4b-441d-917e-4338bc3df403), 2026 · checked 2026-09-29
15. eds-r2-19 · USDA NESR systematic review
    The following conclusion statement was supported by two cohort studies4,12 and was graded “limited.” The individual grading elements are discussed below. “Limited evidence suggests no relationship between soybean consumed during pregnancy and risk of food allergy in the child.”
    USDA Nutrition Evidence Systematic Review, Maternal Diet during Pregnancy and Lactation and Risk of Child Food Allergies, 2020 · checked 2026-09-29
16. eds-r2-16 · EU claims register
    POL-HC-6237 Isolated soy protein Protein-rich soybean component has been shown to lower/reduce blood cholesterol; blood cholesterol lowering may reduce the risk of (coronary) heart disease. -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6237, snapshot 2026-09-21 · checked 2026-09-29
17. eds-r2-17 · US federal regulation
    (C) The food shall meet the nutrient content requirement in § 101.62 for a “low fat” food, unless it consists of or is derived from whole soybeans and contains no fat in addition to the fat inherently present in the whole soybeans it contains or from which it is derived.
    21 CFR 101.82, Health claims: soy protein and risk of coronary heart disease · checked 2026-09-29
18. eds-r2-18 · FDA constituent update
    The FDA published the proposed rule, "Food Labeling: Health Claims; Soy Protein and Coronary Heart Disease," on October 31, 2017.
    US FDA, constituent update on soy protein health claim, 2018 · checked 2026-09-29
19. eds-r2-13 · network meta-analysis of RCTs
    At the food level, no dairy or soy interventions significantly improved outcomes versus control, although milk + yogurt ranked numerically highest based on SUCRA values. At the bioactive-component level, the combination of casein + whey protein (MD 0.04 g/cm2, 95% CI 0.01-0.06) and soybean protein (MD: 0.03 g/cm2, 95% CI: 0.01-0.05) significantly increased TB BMD.
    Nutrients, 2025 · checked 2026-09-29