Is There Anything Unhealthy About Tofu? The Truth About Soy and Your Health

October 27, 2025 •

4 min read

Based on a 2023 meta-analysis of 29 studies, soy intake was associated with a 21% lower risk of heart disease. Despite this and other benefits, many people question: is there anything unhealthy about tofu? Most experts agree the negative stigmas surrounding this plant-based staple are largely unwarranted and outdated.

Quick Summary

While generally safe and nutritious, tofu has potential downsides like antinutrients and goitrogens. These affect some individuals more than others. Proper preparation and moderate intake are key. Soy allergies and certain medical conditions require caution.

Key Points

Hormone Myths Debunked: Current research indicates that moderate tofu consumption does not negatively impact hormone levels in men and may reduce breast cancer risk in women.
Antinutrients are Overstated: While tofu contains antinutrients like phytates, their impact is minimal in a varied diet and can be reduced by proper cooking.
Thyroid Caution for Some: Individuals with hypothyroidism should eat tofu in moderation, especially if iodine-deficient, and separate intake from medication timing.
Allergy is a Real Risk: For people with a soy allergy, tofu must be completely avoided as soy is a common allergen.
Digestion Improves with Time: Digestive issues like gas and bloating can occur due to oligosaccharides, but symptoms often subside as your body adjusts.
Preparation is Key: To reduce antinutrients and improve digestibility, utilize cooking, soaking, sprouting, or fermentation methods.
Choose Minimally Processed Options: Organic, non-GMO tofu is the healthiest choice, avoiding potential pesticide residues and unnecessary additives.

Tofu, a food made from condensed soy milk that is pressed into solid white blocks, has been a dietary staple in Asia for centuries. Rich in high-quality protein, vitamins, minerals, and beneficial isoflavones, it has gained popularity worldwide as a versatile meat alternative. However, its reputation has been plagued by misconceptions, often fueled by poor science and a misunderstanding of its compounds. The reality is that for most people, consuming tofu in moderation as part of a balanced diet poses little to no health risk, but there are specific considerations to be aware of.

Unpacking the Misunderstood Aspects of Tofu

The Phytoestrogen and Hormone Myth

One of the most persistent fears about soy, and by extension tofu, centers on its isoflavone content. Isoflavones are a type of phytoestrogen, plant-based compounds that can mimic the effects of human estrogen, albeit much more weakly. This has led to worries about hormonal imbalance in both men and women.

For Men: Fears that soy lowers testosterone or causes 'feminizing' effects have been largely debunked by human studies. A meta-analysis published in 2022 confirmed that soy protein and isoflavone intake do not significantly affect testosterone or estrogen levels in men, regardless of dose or study duration.
For Women: Early, poorly-designed studies in rodents suggested a link between soy and increased breast cancer risk. However, rigorous human studies and meta-analyses have refuted this, with some suggesting that soy consumption may even reduce breast cancer risk, especially among Asian women. Still, some doctors advise caution and moderation for individuals with estrogen-sensitive breast tumors.

Antinutrients: A Minimal Concern

Like many plant-based foods, tofu contains compounds called antinutrients, which can reduce the body's ability to absorb certain minerals. The two primary types in tofu are:

Phytates: These can bind to minerals such as calcium, zinc, and iron, inhibiting their absorption.
Trypsin inhibitors: These can interfere with the digestion of protein.

For those on a varied, nutrient-rich diet, these antinutrients are rarely a cause for concern. Furthermore, traditional preparation methods like cooking, soaking, sprouting, and fermentation can significantly reduce their content. Fermented soy products like tempeh and miso are notably easier to digest.

Impact on Thyroid Function

Soy is one of several foods that contain goitrogens, compounds that can potentially interfere with thyroid function. For most healthy individuals with sufficient iodine intake, this effect is insignificant. However, for those with pre-existing thyroid conditions, particularly hypothyroidism, and especially if iodine-deficient, moderate consumption is advised.

One key consideration is the timing of thyroid medication. As soy can interfere with its absorption, the Mayo Clinic recommends waiting at least four hours after consuming soy-based foods before taking medication.

Situations Where Tofu May Be Unhealthy

While most concerns about tofu are overblown, there are legitimate scenarios where caution or avoidance is necessary:

Soy Allergy: Soy is one of the most common allergens. Individuals with a soy allergy should avoid tofu completely to prevent reactions, which can range from hives and itching to severe anaphylaxis.
Digestive Discomfort: Some people, especially those new to eating plant-based foods, may experience gas, bloating, or diarrhea from tofu due to its oligosaccharide content. Choosing firm tofu or fermented products can help.
Kidney or Gallbladder Stones: For those prone to kidney or gallbladder stones, tofu's oxalate content may be a concern. A healthcare provider can offer personalized guidance.
Highly Processed Products: Not all soy is created equal. Heavily processed soy products, like certain powders and supplements, can have unnecessary additives and fillers. Organic, non-GMO tofu is generally the healthiest choice.

Tofu vs. Chicken: A Nutritional Snapshot

To provide perspective, here is a comparison of 100g of firm tofu (prepared with calcium sulfate) versus 100g of roasted chicken meat, based on data from Food Struct.


Nutrient	Firm Tofu (100g)	Roasted Chicken (100g)	Key Difference
Calories	144 kcal	239 kcal	Chicken has 66% more calories.
Protein	17.3 g	27.3 g	Chicken has 58% more protein.
Total Fat	8.72 g	13.6 g	Chicken has 56% more total fat.
Saturated Fat	1.26 g	3.79 g	Chicken has 200% more saturated fat.
Cholesterol	0 mg	88 mg	Tofu is cholesterol-free.
Dietary Fiber	2.3 g	0 g	Tofu contains dietary fiber.
Calcium	201 mg	4.5 mg	Tofu has 46 times more calcium.
Iron	2.9 mg	1.12 mg	Tofu has 2.6 times more iron.
Manganese	1.13 mg	0.019 mg	Tofu has 59 times more manganese.

Making the Healthiest Choices with Tofu

To maximize the health benefits and minimize any potential drawbacks, consider the following:

Choose Organic and Non-GMO: Opting for certified organic or non-GMO tofu ensures you avoid potential pesticide residues and genetically modified soybeans.
Vary Your Protein Sources: As with any food, moderation is key. Rotate tofu with other healthy protein sources to ensure a wide range of nutrients and prevent overconsumption of any single compound.
Use Proper Preparation: Techniques like cooking, sprouting, and fermentation can reduce antinutrient levels and improve digestibility. Fermented soy products like tempeh or natto are particularly beneficial for gut health.
Listen to Your Body: If you experience digestive issues or have specific health conditions, adjust your intake and consult a healthcare professional. Many find that digestive symptoms improve as their body adapts to a higher-fiber diet.

Conclusion When considering if there is anything unhealthy about tofu, the answer is nuanced but overwhelmingly positive for most people. The bulk of the negative stigma surrounding soy has been disproven by modern, high-quality human research. While specific groups, including those with soy allergies, hypothyroidism, or a predisposition to kidney stones, should exercise caution, for the general population, tofu is a nutrient-dense, cholesterol-free, and protein-rich food with numerous health benefits. By choosing minimally processed, organic versions and preparing it properly, tofu can be a very healthy and beneficial addition to your diet. For more insights on balanced nutrition, the Harvard Medical School offers excellent resources on healthy eating.

Frequently Asked Questions

No, moderate consumption of tofu does not cause hormonal imbalance in men. Studies show soy isoflavones are weak phytoestrogens that do not significantly affect testosterone levels or cause feminizing effects in typical dietary amounts.

Tofu contains goitrogens, which can interfere with thyroid function, particularly in individuals with pre-existing hypothyroidism or low iodine intake. However, it is generally not a concern for healthy people with sufficient iodine levels. If you are on thyroid medication, it's best to consume soy several hours before or after your medication.

For most people consuming a balanced diet, the antinutrients in tofu (phytates and trypsin inhibitors) are not a concern. Traditional cooking methods like soaking and cooking significantly reduce their content.

Yes, some people may experience digestive issues like gas and bloating from tofu due to its oligosaccharide content. This is more common in individuals new to a high-fiber diet, and symptoms often decrease over time. Opting for firmer tofu or fermented soy products can also help.

Fermented soy products like tempeh and miso are often easier to digest and have lower antinutrient levels than unfermented tofu. Fermentation enhances the nutritional benefits, but both can be part of a healthy diet.

Current research shows that soy consumption is generally safe for breast cancer survivors and may even reduce recurrence risk. However, some doctors advise limiting soy intake for individuals with estrogen-sensitive tumors, so it is best to consult your healthcare provider.

To minimize potential downsides, choose organic and non-GMO tofu, vary your protein sources, and prepare tofu properly. Cooking, soaking, and opting for fermented products can reduce antinutrients and improve digestibility.