Is Tofu Healthy? 2026 Research + a Dietitian’s Honest Take

Written by Heidi Moretti, MS, RD, CLT, a registered dietitian with 25+ years of clinical experience in functional nutrition and gut health, Certified LEAP Therapist, and author of the Fix Series. Updated September 2026 with new research.

Tofu is commonly thought of as a healthy food. But is this true?

When I first wrote this post in 2024, I took a fairly skeptical view of tofu. Since then, a wave of newer research on soy protein quality, hormones, and thyroid function has come out, and some of it changed my thinking. Some of it didn’t. So let’s take an honest, updated look at this very popular plant-based protein, so you can make an informed decision about a food that has changed a lot over the years.

Tofu Health Claims: What the Heart Research Really Shows

If you look at most websites today, tofu and other plant-based proteins get applauded because they are supposedly good for heart health and cardiovascular protection and lower the risk of many diseases.

According to the American Heart Association’s review of whether tofu is healthy, tofu is a heart-healthy food associated with slightly lower rates of cardiovascular disease. Soy foods like tofu have also been linked with a reduced risk of breast cancer in soy-eating women.

The newest numbers are fairly specific. A 2023 meta-analysis of soy intake, diabetes, and heart disease pooling 29 studies found that about 26.7 grams of tofu per day (roughly two tablespoons) was associated with an 18% lower risk of cardiovascular disease. Interestingly, tofu and natto were linked with benefit, while soy milk and miso soup were not.

But if you take a look at the research data with a fine-toothed comb, the benefits aren’t as clear as the headlines suggest. The benefits of tofu, at most, are modest in a best-case scenario. A similar reduction in heart disease death risk among regular fish eaters is seen for people eating fish regularly, with about a 15% reduction.

Most of the data on tofu comes from studies like the Nurses’ Health Study analysis of isoflavones and tofu, which rely on food frequency questionnaires. Can you remember exactly what you ate last month, let alone years ago? These long-term observational studies are prone to major recall errors, and they can’t prove that tofu itself caused the benefit.

Even the FDA has backed away. In 2017, the agency proposed revoking the soy protein heart health claim after concluding the evidence no longer met its standard for significant scientific agreement. It was the first time the FDA had ever moved to revoke an authorized health claim, and a final rule has remained on the federal regulatory agenda.

Hidden Soy: Why I Don’t Trust Most Soy Health Claims

Here’s the problem with the soy research that rarely gets talked about: most Americans are eating far more soy than they realize, and the studies don’t account for it.

Soy isn’t just tofu, edamame, and soy milk. It’s one of the cheapest ingredients in the food supply, and it’s hidden in almost every packaged, processed, and fast food you can buy. And with ultra-processed foods making up about 53% of U.S. adults’ calories, according to CDC data, that hidden soy adds up fast.

Soybean oil is the most consumed edible oil in the United States. It’s in fryer oil at fast food restaurants, chips, crackers, mayonnaise, salad dressings, frozen meals, and baked goods. Labels often just say “vegetable oil.”

Highly refined soybean oil is exempt from allergen labeling, so it often doesn’t trigger a “contains soy” warning. That exemption is based on classic IgE allergy, and refining doesn’t remove every trace of soy. Even soy industry sources acknowledge that residual protein in refined soybean oil is extremely difficult to measure. Food sensitivities are a different immune process than allergies, and you can be sensitive to any part of soy, including the oil. I see this in my own clients who react to soy.

Soybean oil is also a heavily processed, omega-6-rich oil and a marker of the kind of diet that makes up most of the calories Americans eat. I cover this in my list of seed oils to avoid.

Soy lecithin is an emulsifier used in chocolate, protein bars, breads, dressings, and even supplements. It can carry soy proteins and is a potential hidden allergen. Beyond lecithin, soy shows up as soy flour, textured vegetable protein (TVP), hydrolyzed soy protein, soy protein isolate, and “vegetable protein.” Additives like tocopherols (vitamin E) and mono- and diglycerides are often made from soybean oil too, though labels rarely tell you the source.

This one surprises people the most. Soy protein concentrate is widely used to stretch meat in burgers, sausages, meatballs, and deli meats. Greek food is a perfect example. Many foodservice gyro cones, the vertical rotisserie meat used in restaurants, list soy protein concentrate right after beef and water. One major supplier’s beef gyro cone lists beef, water, then soy protein concentrate, plus soybean oil in the seasoning. Another widely used brand includes a soy protein concentrate “vegetable protein product” along with soy-containing breadcrumbs.

And because restaurant food isn’t sold in a labeled package, you’ll never see that ingredient list when you order a gyro. You think you’re eating lamb and beef. You may be eating a meaningful amount of soy.

Most soy and health studies rely on food frequency questionnaires that ask how often people eat foods like tofu, soy milk, and edamame. They generally don’t capture the soy protein in a restaurant gyro, the soy flour in a hamburger bun, or the soy lecithin in a protein bar.

That means the “low soy” group in many Western studies may actually be eating plenty of soy, just in processed form. Meanwhile, people who eat tofu regularly often have healthier overall diets and lifestyles, which can make tofu look better than it really is. When you can’t accurately measure how much soy people eat, you can’t draw confident conclusions about what soy does. That’s a big reason I take most soy health claims, positive or negative, with a large grain of salt.

Does Tofu Affect Hormones and Breast Cancer Risk?

This is the question I get most often from clients, and it’s an area where the research has become much clearer since 2024.

Soy contains isoflavones, plant compounds often called phytoestrogens because they resemble estrogen in structure. That similarity led to decades of worry that soy “feminizes” men or fuels estrogen-sensitive cancers in women.

• Men: A 2021 meta-analysis of soy and male reproductive hormones including 38 clinical studies found no effect of soy or isoflavones on testosterone or estrogen levels in men. A 2025 dose-response meta-analysis on soy and male hormones agreed on testosterone but suggested estradiol and SHBG may rise somewhat at higher intakes, so very large amounts and concentrated supplements are still worth caution.
• Postmenopausal women: A 2024 meta-analysis of soy isoflavones and estrogenicity of randomized trials found isoflavones did not affect endometrial thickness, vaginal tissue, FSH, or estradiol, the markers that estrogen itself changes.
• Perimenopause: A 2025 meta-analysis of soy isoflavones for menopausal symptoms found a small but real improvement in symptoms like hot flashes.
• Breast cancer: Protective associations show up mainly in Asian populations who eat soy from childhood. In Western populations, a meta-analysis of soy isoflavones and breast cancer recurrence found soy was neutral for risk, and linked isoflavone intake with lower recurrence.

So the “soy is an estrogen bomb” idea doesn’t hold up at food-level intakes. That said, hormones are individual. In my practice, I look at the whole picture, including stress hormones, which I cover in depth in my book Cortisol Fix, before deciding whether soy fits someone’s plan.

GMO Soy, Glyphosate, and Glufosinate: What’s Sprayed on Soybeans

Having grown up on a farm and ranch, I pay close attention to what goes onto crops before they ever reach our plates. And with soy, that story changed dramatically in 1996, when the first genetically modified soybeans approved by the FDA hit the market.

Glyphosate (the active ingredient in Roundup) kills plants by blocking an enzyme called EPSPS, which plants need to make essential amino acids. Normally, that means glyphosate kills soybeans just as easily as it kills weeds.

To get around this, scientists took a version of the EPSPS gene from a soil bacterium, Agrobacterium strain CP4, the source of the Roundup Ready trait, and inserted it into soybean DNA. This was done in a lab, either by coating microscopic particles with DNA and shooting them into plant cells with a “gene gun,” or by using a modified bacterium to deliver the gene. The bacterial version of the enzyme isn’t blocked by glyphosate, so the soybean plant survives while the weeds around it die.

That’s what “Roundup Ready” means: the crop can be sprayed directly with glyphosate during the growing season, not just before planting. And that’s the key difference from traditional farming, where herbicides were mostly applied to the soil or to weeds before the crop came up.

Nearly all of it. According to the USDA, herbicide-tolerant soybeans made up 96% of U.S. soybean acres in 2024 and 2025, up from just 17% in 1997.

Here’s what most people don’t know: Roundup Ready is no longer the whole story. After decades of heavy glyphosate use, many weeds became resistant to it, so the seed industry moved to soybeans that tolerate multiple herbicides.

The biggest shift has been to Enlist E3 soybeans, which are engineered to tolerate three herbicides: 2,4-D choline, glyphosate, and glufosinate. According to the manufacturer, Enlist E3 soybeans were planted on about 65% of the U.S. soybean market in 2025. Other varieties are engineered to tolerate dicamba.

So yes, glufosinate is now very much part of soybean farming. It works differently from glyphosate: it blocks glutamine synthetase, an enzyme plants need to process nitrogen. Glufosinate-tolerant soybeans carry a gene from another soil bacterium, Streptomyces, that produces an enzyme called PAT, which neutralizes glufosinate before it can harm the soybean plant.

Why does this matter? Glufosinate has a more concerning safety profile in some regulators’ eyes. In the European Union, glufosinate lost its authorization in 2018 when the manufacturer did not seek renewal, and it is classified as a reproductive toxicant (Category 1B) under the global chemical labeling system. It remains approved for use in the U.S.

Stacking tolerance to three herbicides doesn’t mean farmers use all three every time. But it does mean glyphosate hasn’t gone away. It has simply been joined by more chemicals.

Regardless of what you think about GMO crops, the fact is that herbicide-tolerant soybeans led to a huge increase in the amount of chemicals sprayed on soybeans. The introduction of GMO soybeans and other risky food chemicals has increased the amount of glyphosate (Roundup) in our food supply by thousands of tons per year.

The problem is getting worse, not better. A 2019 evaluation of glyphosate-tolerant soybeans reported that conventional farmers now spray roughly twice as much glyphosate as they did in the late 1990s, largely because weeds have become resistant. And a 2024 review of glyphosate as a food contaminant noted that FDA testing detected glyphosate in about 61% of soybean samples in 2018 and 2019.

Tofu is no exception, because tofu is made directly from these beans. A 2014 Food Chemistry study of glyphosate residues in Roundup Ready soybeans tested 31 batches of soybeans from Iowa and found:

The organic soybeans in that study also had more protein and zinc than the GM soybeans. The researchers noted that allowable residue limits for glyphosate on soybeans have been raised over the years as residues climbed. In the U.S., the legal glyphosate tolerance for soybeans is 20 mg/kg. Some residue may be lost as soybeans are soaked, ground, and pressed into tofu, but I haven’t found research measuring glyphosate in finished tofu, so starting with clean beans is the safest bet.

This chemical isn’t just a concern for you. It affects soil, insects, and the whole environment.

Much of the research suggesting tofu is healthy was collected before herbicide-tolerant soy dominated our food supply, or in countries that don’t grow it. The long-term effects of eating these residues may never be fully known.

Glyphosate and cancer. This is where regulators disagree most. The International Agency for Research on Cancer classifies glyphosate as a probable human carcinogen, while the U.S. EPA and European Food Safety Authority have concluded it is not likely carcinogenic. A 2019 meta-analysis of glyphosate and non-Hodgkin lymphoma found a 41% higher lymphoma risk among the most highly exposed people. Those were mostly farmers and pesticide applicators, not people eating residues in food.

Two newer developments added fuel to the debate. A 2025 long-term rat study of glyphosate and glyphosate-based herbicides reported increases in multiple tumor types at doses regulators consider safe, though industry-aligned scientists have challenged its statistics. And in late 2025, a journal retracted a landmark 2000 glyphosate safety review that regulators had relied on for decades, citing concerns about undisclosed corporate involvement in drafting it.

Glyphosate and pregnancy. In an Indiana study of glyphosate exposure in pregnancy, more than 90% of pregnant women had detectable glyphosate in their urine, and higher levels were linked to shorter pregnancies. It was a small study of 71 women, so it needs confirmation in larger groups.

Glyphosate and the gut. This is the angle I watch most closely as a gut health dietitian. Glyphosate works by blocking the shikimate pathway, which humans don’t have, and that’s why it was originally considered harmless to people. But many gut bacteria and fungi rely on the shikimate pathway, and animal studies show glyphosate can shift the gut microbiome. Human data here is still limited.

Glufosinate. The human research is very thin, which is itself a concern given how widely it’s now sprayed on soybeans. Glufosinate inhibits glutamine synthetase, an enzyme found in the brain’s glial cells. In mice, low-dose exposure before and after birth caused autism-like behavioral changes in offspring, and a 2026 study found memory problems in offspring when only the father was exposed before conception. I’m not aware of any human studies on long-term, low-dose dietary exposure.

My read: high occupational glyphosate exposure shows a real cancer signal, and effects from dietary residues are plausible but unproven. Glufosinate has concerning animal data and almost no human safety data. You don’t have to settle the debate to make a smart choice, because organic tofu sidesteps both.

Is Tofu a Good Source of Protein? (Updated Research)

Tofu is unquestionably an important source of protein for many people on a vegetarian or vegan diet. The bigger question is quality.

Protein quality is now measured with DIAAS (Digestible Indispensable Amino Acid Score), which looks at how well each essential amino acid is absorbed at the end of the small intestine. A study measuring true ileal digestibility of plant-based protein foods found tofu protein was about 95% digestible, nearly on par with animal proteins. A 2024 study of protein quality in soybeans, soymilk, and tofu found that the tofu-making process dramatically improves digestibility compared with cooked whole soybeans, giving tofu “good” protein quality scores.

That’s a big improvement over earlier protein digestibility comparisons that ranked soy far below eggs.

• Sulfur amino acids: Tofu is lower in methionine and cysteine. The same digestibility research found the curd-making process actually lowers sulfur amino acid absorption compared with soy milk.
• No taurine: Plant foods contain essentially no taurine, which matters for heart rhythm, bile, and the brain.
• Anti-nutrients: Soy contains trypsin inhibitors that interfere with protein digestion, though heat and the tofu-making process reduce much of this activity.

Here’s why this matters more than ever: the 2025–2030 Dietary Guidelines for Americans, released in January 2026, raised the protein target to 1.2–1.6 grams per kilogram of body weight per day. That’s roughly 82 to 109 grams for a 150-pound person. Hitting that on tofu alone takes a lot of tofu.

So is tofu a good protein? Better than I gave it credit for. It clearly beats chia, flax, and hemp seeds for protein quality, as well as grains, beans, and nuts. But animal proteins like grass-fed beef, eggs, fish, and poultry still offer a more complete package of amino acids, B12, heme iron, and taurine.

Other Nutrients in Tofu, Thyroid Health, and Hashimoto’s

Tofu contains moderate amounts of vitamins and minerals listed in the USDA FoodData Central, including zinc, iron, potassium, and magnesium.

Calcium-set tofu (look for calcium sulfate on the label) can also be a meaningful source of calcium for people who avoid dairy.

However, anti-nutrients including lectins and phytates that reduce mineral absorption lower how much iron and zinc your body actually absorbs from soy.

There’s long been concern that soy harms the thyroid. A meta-analysis of soy and thyroid function of 18 studies found soy did not change T3 or T4 thyroid hormones, but it did slightly raise TSH. The clinical meaning of that small rise is unclear.

Those averages mostly come from people with healthy thyroids. The picture changes for people whose thyroid is already struggling.

The most important study here is a 2011 randomized crossover trial of soy phytoestrogens in subclinical hypothyroidism. Researchers gave 60 people with subclinical hypothyroidism 30 grams of soy protein containing either 2 mg of phytoestrogens (typical of a Western diet) or 16 mg (typical of a vegetarian diet) for 8 weeks each. Six women progressed to overt hypothyroidism on the 16 mg dose, which worked out to about a 3-fold higher risk. That’s a modest, food-level dose, not a megadose supplement.

Interestingly, the same 16 mg dose also lowered insulin resistance, inflammation (hsCRP), and blood pressure. Soy’s effects really do cut both ways.

Follow-up research points to the isoflavones as the culprit rather than soy protein itself. A 2017 trial of isoflavone-free soy protein in subclinical hypothyroidism found no effect on thyroid function. A 2018 high-dose phytoestrogen trial saw two more people progress to overt hypothyroidism, though average thyroid labs didn’t differ between groups.

What about thyroid antibodies? Direct research is surprisingly thin. The closest study, a 2007 study of soybean sensitization and anti-TPO antibodies, screened 260 people with autoimmune thyroid disease. Graves’ patients who were sensitized to soy had roughly double the anti-TPO antibody levels of those who weren’t. It was a conference abstract and it measured IgE allergy rather than delayed sensitivity, so it’s preliminary. But it lines up with what I see clinically: when the immune system is reacting to soy, the thyroid may pay a price.

Soy isoflavones can inhibit thyroid peroxidase, the enzyme that uses iodine to make thyroid hormone, and people who are low in iodine appear most vulnerable. Iodine deficiency is a silent problem that often goes unnoticed.

But more isn’t better, especially with autoimmunity. In a 2024 NHANES analysis of iodine and thyroid antibodies, adults with very high urinary iodine (500–800 μg/L) had a 57% higher risk of positive TPO antibodies than those in the adequate range. Aim for food sources like seafood and eggs rather than high-dose iodine supplements, unless your provider has tested you and recommends them.

Soy Allergy vs. Soy Sensitivity: Test, Don’t Guess

Here’s something the tofu debate usually leaves out: even if soy is “healthy” on paper, it may not be healthy for you.

First, it helps to separate two very different things: soy allergy and soy sensitivity.

Soy allergy is an IgE-mediated immune reaction, the kind that can cause hives, swelling, or even anaphylaxis. Soy is one of the nine major U.S. food allergens, but true allergy is relatively uncommon. A nationally representative study of food allergy in U.S. adults estimated soy allergy affects about 1.5 million adults. Among children, soy allergy affects about 0.5% of kids, and many outgrow it.

That same adult study found something telling: nearly 1 in 5 adults believed they had a food allergy, but only about 1 in 10 had symptoms consistent with a true allergy. Many of the rest were likely dealing with food intolerance or sensitivity, which standard allergy tests don’t measure.

Soy sensitivity is a non-IgE reaction, and it’s far more common in my practice than true allergy. It’s also much harder to pin down. Reactions can show up within minutes or be delayed by hours or even days, and they can look like bloating, headaches, joint pain, eczema, or brain fog. That’s why so many people never connect their symptoms to the tofu stir-fry they ate two days earlier.

As a Certified LEAP Therapist, I use MRT food sensitivity testing and the LEAP protocol to help clients find out which foods are actually driving inflammation for them, rather than cutting out entire food groups on a hunch. Soy is one of the foods on the test, and it’s one of the most reactive foods I see. By my estimate, about 60% of my clients come back reactive to soy.

If you’re working on gut healing, you may also find my guide to the autoimmune protocol (AIP) diet and soy reintroduction helpful. Food sensitivity testing isn’t a self-checkout option on my site. Reach out to me for a consultation if you’d like to see whether it’s a fit for you.

Fermented Soy: Natto, Tempeh, and Miso

If you enjoy soy, fermented soy foods may offer the most benefits. In the same 2023 meta-analysis mentioned above, just 11.1 grams of natto per day was linked with a 17% lower risk of cardiovascular disease, especially stroke.

Natto is also the richest known food source of vitamin K2 (MK-7), which I cover in my guide to the best vitamin K2 supplements and natto benefits. Fermentation also breaks down some of soy’s anti-nutrients.

One caution: fermented soy is high in histamine. If you have histamine intolerance, see my list of anti-histamine foods and high-histamine foods to avoid. Plain tofu is usually better tolerated.

Is Tofu Low-Calorie? How It Compares to Shrimp and Eggs

The best way to compare tofu for weight loss or weight gain is to compare it with other protein foods. Per half cup:

Shrimp turns out to be the lowest-calorie option of the three, and it also contains omega-3 fatty acids that tofu doesn’t. Eggs are similar in calories to tofu but provide brain-boosting choline, B12, and vitamin A. And if you’ve heard eggs are inflammatory, here’s the truth about whether eggs are inflammatory.

For a lean, omega-3 rich option, don’t overlook the healthiest canned sardine brands. Tofu sits in the middle: a decent protein per calorie, with fiber and calcium as bonuses.

Is Eating Tofu Better for the Environment than Other Protein?

It’s hard to answer this question honestly, because plant-based foods are often greenwashed by the media and search engines.

Consider that thousands of tons of chemicals enter the environment each year from conventional soy production. These chemicals can damage biodiversity and soil health, may raise cancer risk, and can harm the soil while reducing its water retention.

According to the USDA’s 2020 soybean agricultural chemical use survey, about 98% of surveyed soybean acres were treated with herbicides.

And while tofu’s protein is more digestible than I once thought, you still need more of it (and more total calories) to match the full amino acid, B12, iron, and taurine package in animal foods like eggs or grass-fed beef. Tofu isn’t going to save the earth on its own. Organic farming practices, whether for soy or for pasture-raised animals, matter more than the protein label.

How to Choose Healthier Tofu: 6 Simple Steps

1. Buy organic. Look for the USDA Organic seal or Non-GMO Project Verified label to limit glyphosate exposure.
2. Choose calcium-set tofu. Calcium sulfate on the ingredient list adds bone-supporting calcium.
3. Keep the ingredient list short. Soybeans, water, and a coagulant are all you need. Skip flavored and pre-fried tofu made with seed oils you should be avoiding.
4. Try fermented soy. Natto and tempeh add vitamin K2 and probiotics, if you tolerate histamine.
5. Rotate your proteins. Pair tofu with eggs, fish, or meat, or with other plant proteins, to cover methionine, B12, and taurine.
6. Watch your thyroid, iodine, and symptoms. Get adequate (not excessive) iodine from foods like seafood and eggs, be cautious with soy if you have Hashimoto’s or subclinical hypothyroidism, and consider MRT testing if soy seems to trigger symptoms.

Tofu FAQs

The Bottom Line: Is Tofu Healthy?

Tofu is healthier than its harshest critics claim, and less miraculous than its biggest fans suggest. Newer research shows its protein is highly digestible and that it doesn’t disrupt hormones at food-level intakes. But conventional soy’s glyphosate load, thyroid and iodine concerns, and individual soy sensitivity are real.

If you enjoy tofu and feel good eating it, choose organic, rotate it with other proteins, and enjoy it. If you suspect it’s working against you, test, don’t guess. #TheHealthyRD

Heidi Moretti, MS, RD, CLT is The Healthy RD. A registered dietitian for 25 years and the author of the bestselling Cortisol Fix, Period Fix, Gut Fix, and The Whole Body Guide to Gut Health, Heidi has a passion for functional nutrition and natural medicine. One of her biggest loves is helping people regain function and vitality by tackling the root causes of illness. See Heidi’s full bio

This article is for educational purposes and is not medical advice. Talk with your healthcare provider before making changes, especially if you have a thyroid condition or a history of hormone-sensitive cancer. This post contains affiliate links; I may earn a small commission at no extra cost to you.