Know2eat

Tofu

Glycine max

What tofu has been studied for

4 associations assessed — 3 with at least some human evidence behind them. Strongest first.

  • 1 Moderate
  • 2 Limited
  • 1 Insufficient
4 things to know first — allergies, interactions and intake limits

About tofu

Soy milk curdled with a coagulant and pressed into blocks, the firmness depending on how much whey is pressed out. The USDA reference entry is firm tofu set with calcium sulfate, which is what makes some tofu a significant calcium source and other tofu not.

Also known as Bean curd, Doufu, Dubu

Women's HealthBone HealthMen's HealthHeart Health

The evidence in depth

Best supported: Moderate

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how impressive the food is. How we rate evidence.

Menopausal symptoms

Women's Health
Moderate evidence

Some trials report fewer and less severe hot flushes with soy isoflavones, but results are heterogeneous and part of the variation is explained by whether a person carries the gut bacteria that convert daidzein to equol. Most trials used isoflavone extracts rather than tofu.

Moderate evidence. Several human studies point the same way, with real caveats.

3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Bone mineral density

Bone Health
Limited evidence

Evidence is limited and mixed. Some trials of soy isoflavones report small gains in bone mineral density in postmenopausal women; others find nothing, and fracture data is essentially absent. Calcium-set tofu contributes calcium regardless of the isoflavone question.

Limited evidence. Early human work, or mostly lab and animal research.

4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Prostate health

Men's Health
Limited evidence

Observational data links higher soy intake in East Asian populations with lower prostate cancer incidence, but the association is confounded by the rest of the diet and lifestyle, and intervention trials are short and use markers rather than outcomes.

Limited evidence. Early human work, or mostly lab and animal research.

1 source

Deep research mode adds each paper’s own conclusion and stated limitations.

Blood lipid profile

Heart Health
Insufficient evidence

Meta-analyses of soy protein trials report a small but consistent LDL reduction, of the order of a few percent, when soy foods replace animal protein. The effect is smaller than the 1990s health-claim literature suggested and depends on what soy is displacing.

What may be going on: Soy protein appears to affect hepatic LDL receptor activity, and replacing animal protein also lowers saturated fat intake, so part of the effect is substitution rather than soy itself.

Insufficient evidence. Not enough human research to say anything useful yet.

No source is attached to this association yet, so it is rated insufficient by default. It is listed because people commonly ask about it — not because there is evidence for it.

Ask about Tofu

Ask about Tofu

Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.

AI explanations are not switched on for this site, so there is nothing to ask here. Everything above is read straight from the database and does not need them.

Key nutrients

Nutrient content per 100 grams
NutrientAmount% DV
Macronutrients
Calories144 kcal7%
Protein17.3 g35%
Total fat8.72 g11%
Carbohydrate2.78 g1%
Fibre2.3 g8%
Water69.8 g—
Fats
Saturated fat1.26 g6%
Monounsaturated fat1.93 g—
Polyunsaturated fat4.92 g—
Cholesterol0 mg0%
Linoleic acid (omega-6)4.34 g—
Vitamins
Vitamin C0.2 mg0%
Vitamin D0 µg0%
Thiamin (B1)0.158 mg13%
Riboflavin (B2)0.102 mg8%
Niacin (B3)0.381 mg2%
Pantothenic acid (B5)0.133 mg3%
Vitamin B60.092 mg5%
Folate29 µg7%
Vitamin B120 µg0%
Minerals
Calcium683 mg53%
Iron2.66 mg15%
Magnesium58 mg14%
Phosphorus190 mg15%
Potassium237 mg5%
Sodium14 mg1%
Zinc1.57 mg14%
Copper0.378 mg42%
Manganese1.18 mg51%
Selenium17.4 µg32%
Other measured compounds
Ash1.4 g—

Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.

Source record: Tofu, raw, firm, prepared with calcium sulfate (USDA FoodData Central, FDC ID 172475).

% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.

Bioactive compounds

Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.

How preparation changes things

Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.

  • fermentedIncreases isoflavone aglycones

    Fermenting tofu, as in Chinese sufu or in tempeh and miso made from whole beans, converts isoflavone glycosides to aglycones that are absorbed faster. Whether that changes any health outcome is not established.

Things to know

Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.

  • Allergy

    Soy allergy

    Soy is one of the major regulated allergens. Reactions are more common in children than adults, most are mild to moderate, but anaphylaxis is documented.

  • Interaction

    Thyroid medication and iodine

    Soy can reduce absorption of levothyroxine, so tablets are usually taken well away from soy foods. In people with adequate iodine, soy has not been shown to cause hypothyroidism; in iodine deficiency, the picture is less settled.

  • Worth knowing

    Calcium depends on the coagulant

    Tofu set with calcium sulfate carries several times the calcium of tofu set with magnesium chloride nigari or with glucono-delta-lactone. The label, not the word "tofu", tells you which you have.

  • Worth knowing

    Isoflavones and hormone-sensitive conditions

    Isoflavones bind oestrogen receptors weakly and selectively. Large cohort studies, including in breast cancer survivors, have not found soy foods to worsen outcomes, and several report the opposite association. Concentrated isoflavone supplements are a different matter from tofu and have not been shown to be equivalent.