Edamame and tofu: big associations, one flat trial

The one randomized trial here that tested tofu against heart markers found no edge. In 45 Dutch adults aged 40 to 70 with mildly raised cholesterol, 4 weeks of frozen Kori-tofu lowered LDL, HbA1c and systolic pressure no more than a whey protein control, which lowered them too. The bigger numbers are observational. Pooled studies, mostly case-control, link high tofu intake with 22% lower total cancer risk, RR 0.78 (0.70 to 0.86). In 29 studies, 26 of them in Asia, eating 0.94 oz (26.7 g) of tofu a day went with 18% lower cardiovascular risk. These are associations, and the only direct test on this page came out flat. Edamame has no trials of its own here. Per 100 g boiled, UK tables give it 142 calories, 12.2 g protein and 5.9 g fiber, against 73 calories and 8.1 g protein for steamed tofu.

How much is actually in it

• Per 100 g, UK tables give boiled edamame 142 calories and 12.2 g protein, and steamed tofu 73 calories and 8.1 g protein. — CoFID 2021 composition entries (n = 2 foods) Evidence E source
  Edamame 142 calories, 12.2 g protein, 5.9 g fiber, 88 mg Ca; tofu 73 calories, 8.1 g protein, 4.2 g fat
• US lab samples of prepared frozen edamame average 185 ug folate per 3.5 oz (100 g) but range from 127 to 255 ug. — USDA Foundation Foods, 4 samples (n = 4 samples) Evidence E source
  Folate 185.3 ug (126.6-255.0); fiber 6.233 g (5.55-6.97); potassium 519.5 mg (423.0-573.0)

What a real portion looks like

• US dietary survey coding counts a cup of cooked edamame as 160 g and an unspecified serving as 80 g. — USDA FNDDS portion measures (n = 3 measures) Evidence E source
  1 cup 160 g; quantity not specified 80 g; 1 pod yields 2 g

What your body absorbs

• In a crossover RCT in 14 vegetarian women, adding 303 mg vitamin C to 6.1 oz (173 g) of tofu a day for 30 days raised hemoglobin more than tofu alone. — premenopausal lacto-ovo vegetarian women, two 30-day periods (n = 14) Evidence B source
  Greater hemoglobin rise with vitamin C (p = 0.036 and p = 0.009); ferritin no difference
• In a crossover RCT in 7 women, a high wheat-fiber diet (40 g) cut plasma genistein from tofu or soy protein by 55% at 24 hours. — healthy women, single soy dose 0.9 mg isoflavones/kg (n = 7) Evidence B source
  Plasma genistein -55% (P < 0.05); urinary genistein -20% (P < 0.03)
• In crossover studies in women, 38-51% of daidzein was recovered in urine whether it came from tofu, tempeh, cooked soybeans or soy protein. — women 20-41 y, casseroles with tofu, tempeh, soybeans or TVP (n = 8) Evidence B source
  Urinary daidzein 38-51%, genistein 9-16% of dose, no difference by soy food

What cooking and storage change

• Frying steamed tofu raises it from 73 to 261 calories and from 4.2 to 17.7 g fat per 3.5 oz (100 g) in UK tables, mostly through water loss and oil uptake. — CoFID 2021, steamed vs steamed and fried tofu (n = 2 entries) Evidence E source
  73 to 261 calories; fat 4.2 to 17.7 g; water 85.0 to 51.0 g; protein 8.1 to 23.5 g
• By the USDA table for Vegetables and Vegetable Products cooked from frozen, boiled and drained, about 70% of folate and 90% of potassium remain. — USDA retention factors, vegetable group, not product-specific (n = 1 method) Evidence E source
  Folate 70%, vitamin C 80%, potassium 90%, iron 95%, magnesium 95%

What it does to your health

• Observational data from 52 studies link high tofu intake with 22% lower total cancer risk, and each extra 2.2 oz (61 g) of tofu a day with 12% lower risk. — 17 cohort and 35 case-control studies, searched to October 2023 (n = 52 studies) Evidence C source
  Tofu RR 0.78 (95% CI 0.70-0.86); per 61 g/day -12%; fermented soy RR 1.18 (0.95-1.47)
• Observational data link eating 0.94 oz (26.7 g) of tofu a day with 18% lower cardiovascular disease risk. — 29 cohort and case-control studies, 54,213 CVD events, follow-up 2.5-24 years (n = 29 studies) Evidence C source
  Tofu 26.7 g/day TRR 0.82 (95% CI 0.74-0.92) for CVD

Safety, limits and interactions

• In 142 Japanese oral challenges with 3.5 oz (100 g) of silken tofu, done to diagnose soy allergy or confirm tolerance in patients averaging 2.8 years, 38.7% reacted, and 7 had anaphylaxis. — 125 patients, mean age 2.8 y, Japan, 2004-2010 (n = 142 challenges) Evidence C source
  Positive 38.7%; skin 81.8%; anaphylaxis in 7
• Two infants developed food protein-induced enterocolitis, with repeated vomiting and in one case shock, after tofu given as weaning food. — 2 infants, Japan (n = 2) Evidence D source
  Repetitive vomiting; one needed IV fluids for compensated shock; soy IgE negative

What people believe that the data does not support

• In a double-blind crossover RCT in 45 adults with raised cholesterol, 4 weeks of frozen Kori-tofu did not improve heart markers more than a whey protein control. — adults 40-70 y with mildly elevated cholesterol, Netherlands, 4-week periods (n = 45) Evidence B source
  Within-group falls in LDL, HbA1c, systolic BP in both arms; no between-treatment difference except adiponectin
• US rules still let soy foods claim that soy protein in a low saturated fat diet may help reduce heart disease risk, though FDA proposed revoking this in 2017. — 21 CFR 101.82 (n = 1 claim) Evidence E source
  Authorized health claim, proposed for revocation on 31 Oct 2017 (Federal Register 2017-23629), no final rule found

Who this works differently for

• Observational studies link the highest tofu intake with 22% lower odds of breast cancer, about 10% less per extra 10 g a day. — 2 cohort and 12 case-control studies (n = 14 studies) Evidence C source
  OR 0.78 (95% CI 0.69-0.88); per 10 g/day -10% (7%-13%)
• In an RCT in 32 older women doing 5 months of interval walking, a daily dried tofu snack with 9.6 g protein did not add muscle strength or size over placebo. — women about 65 y, interval walking training, 5 months (n = 32) Evidence B source
  No difference in thigh strength or cross-sectional area (all P > 0.2)

What is still unknown

• Prospective cohorts of 565,810 people link tofu with 8% lower type 2 diabetes risk, though the evidence quality was rated low. — 15 prospective cohorts, 32,093 incident cases (n = 565810) Evidence C source
  Tofu RR 0.92 (0.84-0.99); total soy RR 0.83 (0.68-1.01), NS; quality low

The bottom line

Prospective cohorts of 565,810 people link tofu with 8% lower type 2 diabetes risk, RR 0.92 (0.84 to 0.99), an interval that nearly touches no effect, with evidence quality rated low. In women, 14 mostly case-control studies link the highest tofu intake with 22% lower odds of breast cancer, OR 0.78 (0.69 to 0.88). In 32 women around 65 doing 5 months of interval walking, a daily dried tofu snack with 9.6 g protein added no strength or muscle size over placebo. Tofu iron goes further with vitamin C. In 14 vegetarian women eating 6.1 oz (173 g) of tofu a day, adding 303 mg of vitamin C for 30 days raised hemoglobin more than tofu alone, ferritin did not differ, and the abstract gives no size. The soy food you pick seems not to change how much isoflavone reaches you. Women excreted 38 to 51% of daidzein in urine whether they ate tofu, tempeh, cooked soybeans or soy protein. A high wheat fiber diet of 40 g cut plasma genistein 24 hours after a soy dose by 55%, in only 7 women. UK tables put steamed tofu at 73 calories and 4.2 g fat per 3.5 oz (100 g) and fried tofu at 261 calories and 17.7 g fat, with water falling from 85 to 51 g. Those are two separate entries and not one paired measurement. Frozen edamame from 4 US samples averaged 185 ug folate per 3.5 oz (100 g), ranging from 126.6 to 255, and a cup of cooked edamame is 160 g. US rules still let soy foods say that soy protein in a diet low in saturated fat may help reduce heart disease risk, though FDA proposed revoking that claim in 2017 and we found no final rule. Soy is a real allergen in small children. In 142 food challenges at one Japanese clinic with 3.5 oz (100 g) of silken tofu, in patients averaging 2.8 years old who were being tested for soy allergy or for outgrowing it, 38.7% reacted and 7 had anaphylaxis. Two Japanese infants given tofu as a weaning food developed food protein-induced enterocolitis with repeated vomiting, one of them in compensated shock, and soy IgE tests were negative in both. We found no study of tofu or edamame in pregnancy or alongside medicines.

Sources

1. edt-daily-r4-13 · composition dataset
   Beans, edamame, frozen, boiled in unsalted water, CoFID 13-667: Energy 142 kcal, Protein 12.2 g, AOAC fibre 5.9 g, Calcium 88 mg; Tofu, soya bean, steamed, CoFID 13-570: Energy 73 kcal, Protein 8.1 g, Fat 4.2 g
   CoFID 2021 (Public Health England), codes 13-667 and 13-570 · checked 2026-09-29
2. edt-daily-r4-15 · composition dataset
   Edamame, frozen, prepared: Folate, total 185.3 ug, range 126.6-255.0, 4 samples; Fiber, total dietary 6.233 g, range 5.55-6.97, 4 samples; Potassium, K 519.5 mg, range 423.0-573.0, 4 samples
   USDA FoodData Central, Foundation Foods, release 2026-04-30, Edamame, frozen, prepared · checked 2026-09-29
3. edt-daily-r4-17 · portion dataset
   Edamame, cooked, FNDDS code 41420020, fdc_id 2707436: 1 pod, yields, measure 64556, 2 g; 1 cup, measure 10205, 160 g; Quantity not specified, measure 90000, 80 g
   USDA FNDDS, food code 41420020, FDC 2707436 · checked 2026-09-29
4. edt-daily-r4-07 · randomized crossover trial
   For the first 30 days, one half of the subjects (n = 7) received 6 oz (173 grams) of tofu/day (T) while the other half of the subjects (n = 7) received 6 oz of tofu/day along with 303 mg of vitamin C/d (TO). ... In conclusion, bioavailability of iron from tofu is enhanced by supplementation with ascorbic acid.
   Plant Foods Hum Nutr, 2002 · checked 2026-09-29
5. edt-daily-r4-08 · randomized crossover trial
   The fiber-rich diet produced 55% lower plasma genistein at 24 h after soy dosing (P < 0.05) and reduced total urinary genistein by 20% (P < 0.03).
   J Nutr, 1996 · checked 2026-09-29
6. edt-daily-r4-09 · randomized crossover trial
   Urinary recoveries of D over 24 h from the various soy foods were 38-51%, and of G, 9-16% of the dose given. ... Therefore, isoflavone bioavailability may not be affected by choice of background diet or food source of isoflavones.
   J Nutr, 2000 · checked 2026-09-29
7. edt-daily-r4-14 · composition dataset
   Tofu, soya bean, steamed, CoFID 13-570: Energy 73 kcal, Fat 4.2 g, Protein 8.1 g, Water 85.0 g; Tofu, soya bean, steamed, fried, CoFID 13-571: Energy 261 kcal, Fat 17.7 g, Protein 23.5 g, Water 51.0 g
   CoFID 2021 (Public Health England), codes 13-570 and 13-571 · checked 2026-09-29
8. edt-daily-r4-16 · retention dataset
   VEG,OTHER,CKD FROM FRZN(BLD,DRAIND), Retn_Code 3789: folate_total_ug 70%, vitamin_c_mg 80%, potassium_mg 90%, iron_mg 95%, magnesium_mg 95%
   USDA Table of Nutrient Retention Factors, Release 6 (2007), USDA-RETN-R6:3789 · checked 2026-09-29
9. edt-daily-r4-01 · meta-analysis of observational studies
   High consumption of total soy products (RR: 0.69; 95% CI: 0.60, 0.80), tofu (RR: 0.78; 95% CI: 0.70, 0.86), and soymilk (RR: 0.75; 95% CI: 0.60, 0.93) were associated with reduced total cancer risk. ... A 54 g per day increment of total soy products reduced cancer risk by 11%, a 61 g per day increment of tofu reduced cancer risk by 12%, and a 23 g per day increment of soymilk reduced cancer risk by 28%, while none of the other soy products were associated with cancer risk.
   Nutrients, 2024 · checked 2026-09-29
10. edt-daily-r4-02 · meta-analysis of observational studies
    A daily intake of 26.7 g of tofu reduced CVDs risk by 18% (TRR = 0.82, 95% CI: 0.74-0.92) and 11.1 g of natto lowered the risk of CVDs by 17% (TRR = 0.83, 95% CI: 0.78-0.89), especially stroke.
    Nutrients, 2023 · checked 2026-09-29
11. edt-daily-r4-10 · retrospective cohort
    Between July 2004 and May 2010, 142 cases (125 patients) underwent food challenge tests (100 g of silken tofu) for the diagnosis of soybean allergy or confirmation of their tolerance. ... The positive rate for the challenge test was 38.7%.
    Allergol Int, 2016 · checked 2026-09-29
12. edt-daily-r4-11 · case report
    Herein, we report two pediatric cases of FPIES to solid soy foods, such as tofu. The patients presented with repetitive vomiting after eating the trigger food as infant food.
    Cureus, 2023 · checked 2026-09-29
13. edt-daily-r4-05 · randomized crossover trial
    Due to the lack of significant effects as compared to control, there is, however, currently no substantiating evidence to claim that Kori-tofu has beneficial effects on cardiometabolic health.
    Nutrients, 2022 · checked 2026-09-29
14. edt-daily-r4-12 · regulatory text
    (3) Scientific evidence demonstrates that diets low in saturated fat and cholesterol may reduce the risk of CHD. Other evidence demonstrates that the addition of soy protein to a diet that is low in saturated fat and cholesterol may also help to reduce the risk of CHD.
    21 CFR 101.82, Health claims: Soy protein and risk of coronary heart disease · checked 2026-09-29
15. edt-daily-r4-04 · meta-analysis of observational studies
    The overall OR of breast cancer for highest vs lowest intake of tofu was 0.78 (95% CI 0.69-0.88), with moderate heterogeneity (P = 0.011, I2 = 49.7%). Dose-response analysis based on 5 case-control studies revealed that each 10 g/d increase in tofu intake was associated with 10% reduction in the risk of breast cancer (95% CI 7%-13%, P = 0.037, I2 = 40.8%).
    PLoS One, 2020 · checked 2026-09-29
16. edt-daily-r4-06 · randomized controlled trial
    No significant differences were observed in increases in thigh muscle strength or cross-sectional area between the groups (all, P > 0.2).
    J Physiol Sci, 2018 · checked 2026-09-29
17. edt-daily-r4-03 · meta-analysis of cohort studies
    The summary RRs (95% CIs) of incident type 2 diabetes were 0.95 (0.79, 1.14; NS) for total legumes, 0.83 (0.68, 1.01; NS) for total soy, 0.89 (0.71, 1.11; NS) for soy milk, 0.92 (0.84, 0.99) for tofu, 0.84 (0.75, 0.95) for soy protein, and 0.88 (0.81, 0.96) for soy isoflavones, respectively.
    Am J Clin Nutr, 2020 · checked 2026-09-29