Tofu

Tofu is one of those foods that sparks debate.

Some can’t rave enough about its health benefits, while others declare that it is a genetically-modified poison to be avoided at all costs.

This may leave you wondering whether you should eat tofu or not.

This article takes a detailed look at tofu and its health effects to determine whether it’s good for you.

What is tofu?

Tofu is a food made of condensed soy milk that is pressed into solid white blocks in a process quite similar to cheesemaking. It originated in China.

Rumor has it that a Chinese cook discovered tofu more than 2,000 years ago by accidentally mixing a batch of fresh soy milk with nigari.

Nigari is what remains when salt is extracted from seawater. It is a mineral-rich coagulant used to help tofu solidify and keep its form.

Most of the world’s soybeans are currently grown in the US, and a very large proportion is genetically modified (GMO).

Although GMOs are controversial, research has so far not found them to be harmful to human health.

However, if you’re worried about it, simply opt for non-GMO, organic tofu brands.

Summary: Tofu is made from condensed soy milk using a process similar to cheesemaking. Whether made from GMO soybeans or not, tofu is generally considered safe for human consumption.

Tofu contains many nutrients

Tofu is high in protein and contains all of the essential amino acids your body needs. It also provides fats, carbs, and a wide variety of vitamins and minerals.

One 3.5-ounce (100-gram) serving of tofu offers:

• Protein: 8 grams
• Carbs: 2 grams
• Fiber: 1 gram
• Fat: 4 grams
• Manganese: 31% of your daily need
• Calcium: 20% of your daily need
• Selenium: 14% of your daily need
• Phosphorus: 12% of your daily need
• Copper: 11% of your daily need
• Magnesium: 9% of your daily need
• Iron: 9% of your daily need
• Zinc: 6% of your daily need

This comes with only 70 total calories, which makes tofu a highly nutrient-dense food.

However, the micronutrient content of tofu can vary depending on the coagulant used. Nigari adds more magnesium while precipitated calcium increases the calcium content.

Summary: Tofu is low in calories but high in protein and fat. It also contains many important vitamins and minerals.

Tofu contains antinutrients

Like most plant foods, tofu contains several antinutrients.

Suggested read: Soy: Good or bad?

These include:

• Trypsin inhibitors: These compounds block trypsin, an enzyme needed to properly digest protein.
• Phytates: Phytates can reduce the absorption of minerals, such as calcium, zinc, and iron.

However, soaking or cooking soybeans can inactivate or eliminate some of these antinutrients.

Sprouting soybeans before making tofu reduces phytates by up to 56% and trypsin inhibitors by up to 81% while also increasing protein content by up to 13%.

Fermentation can also reduce antinutrients. For this reason, fermented, probiotic soy foods — such as miso, tempeh, tamari, or natto — are low in antinutrients.

Keep in mind that the antinutrient content of tofu is not a cause for concern unless you are following an imbalanced diet and relying on tofu as your main source of iron or zinc.

Summary: Tofu contains antinutrients like trypsin inhibitors and phytates. Soaking or fermenting soybeans before making tofu reduces these antinutrients, increasing their nutritional value.

Tofu contains beneficial isoflavones

Soybeans contain natural plant compounds called isoflavones.

These function as phytoestrogens, meaning that they can attach to and activate estrogen receptors in your body.

This produces effects similar to the hormone estrogen, although they are weaker.

Tofu contains 20.2–24.7 mg of isoflavones per 3.5-ounce (100-gram) serving.

Many of the health benefits of tofu are attributed to its high isoflavone content.

Summary: All soy-based products contain isoflavones, which are believed to have various health benefits.

Tofu may reduce heart disease risk

Only a few studies specifically look at tofu’s effects on heart health.

However, research has shown that a high intake of legumes, including soy, is linked to lower rates of heart disease.

Scientists have also discovered that soy isoflavones can reduce blood vessel inflammation and improve their elasticity.

One study found that supplementing with 80 mg of isoflavones per day for 12 weeks improved blood flow by 68% in people who were at risk of stroke.

Taking 50 grams of soy protein per day is also associated with improved blood fats and an estimated 10% lower risk of heart disease.

What’s more, in postmenopausal women, high soy isoflavone intake is linked to several heart-protective factors, including improvements to body mass index, waist circumference, fasting insulin, and “good” HDL cholesterol.

Finally, tofu contains saponins, compounds thought to have protective effects on heart health.

Animal studies show that saponins improve blood cholesterol and increase the disposal of bile acids — both of which can help lower heart disease risk.

Summary: Whole soy foods like tofu can improve several markers of heart health. This may lead to a reduced risk of heart disease.

Tofu may reduce the risk of some cancers

Studies have examined the effects of tofu on breast, prostate, and digestive system cancers.

Breast cancer

Research shows that women who eat soy products at least once a week have a 48–56% lower risk of breast cancer.

This protective effect is thought to come from isoflavones, which have also been shown to positively influence the menstrual cycle and blood estrogen levels.

It seems that exposure to soy during childhood and adolescence may be most protective, but that’s not to say that intake later in life is not beneficial.

Research shows that women who ate soy products at least once a week throughout adolescence and adulthood had a 24% lower risk of breast cancer, compared to those who ate soy during adolescence alone.

One frequent criticism of tofu and other soy products is that they may increase breast cancer risk. However, a two-year study in postmenopausal women who consumed two servings of soy per day failed to find an increased risk.

Suggested read: Soy protein: Nutrients, benefits, drawbacks, and more

Other studies report similar findings, including a review of 174 studies, which found no link between soy isoflavones and increased breast cancer risk.

Cancers of the digestive system

One study observed that higher intakes of tofu were linked to a 61% lower risk of stomach cancer in men.

Interestingly, a second study reported a 59% lower risk in women.

What’s more, a recent review of several studies in 633,476 people linked higher soy intake to a 7% lower risk of cancers of the digestive system.

Prostate cancer

Two review studies found that men consuming higher amounts of soy, especially tofu, had a 32–51% lower risk of prostate cancer.

A third review confirmed these results but added that the benefits of isoflavones may depend on the amount consumed and the type of gut bacteria present.

Summary: Research indicates that soy has a protective effect against breast, digestive, and prostate cancers.

Tofu may reduce the risk of diabetes

Several recent test-tube and animal studies show that soy isoflavones may boost blood sugar control.

In one study of healthy postmenopausal women, 100 mg of soy isoflavones per day reduced blood sugar levels by 15% and insulin levels by 23%.

For postmenopausal women with diabetes, supplementing with 30 grams of isolated soy protein lowered fasting insulin levels by 8.1%, insulin resistance by 6.5%, “bad” LDL cholesterol by 7.1%, and total cholesterol by 4.1%.

In another study, taking isoflavones each day for a year improved insulin sensitivity and blood fats while reducing heart disease risk.

However, these findings are not universal. A recent review of 24 human studies found that intact soy protein — as opposed to isoflavone supplements or protein extracts — was more likely to lower blood sugar.

Therefore, more studies are needed

Summary: Tofu may have positive effects on blood sugar control, but more studies are needed to confirm this link.

Other potential benefits of tofu

Due to its high isoflavone content, tofu may also have benefits for:

Suggested read: 11 foods high in phytoestrogens

• Bone health: Scientific data suggests that 80 mg of soy isoflavones per day may reduce bone loss, especially in early menopause.
• Brain function: Soy isoflavones may have a positive influence on memory and brain function, especially for women over 65.
• Menopause symptoms: Soy isoflavones may help reduce hot flashes. However, not all studies agree.
• Skin elasticity: Taking 40 mg of soy isoflavones per day significantly reduced wrinkles and improved skin elasticity after 8–12 weeks.
• Weight loss: In one study, taking soy isoflavones for 8–52 weeks resulted in an average weight loss of 10 pounds (4.5 kg) more than a control group.

Summary: Due to its high isoflavone content, tofu may have benefits for a variety of health conditions. However, more research is needed.

Tofu may cause problems for some people

Eating tofu and other soy foods every day is generally considered safe. That said, you may want to moderate your intake if you have:

• Breast tumors: Due to tofu’s weak hormonal effects, some doctors tell women with estrogen-sensitive breast tumors to limit their soy intake.
• Thyroid issues: Some professionals also advise individuals with poor thyroid function to avoid tofu due to its goitrogen content.

However, a recent report from the European Food Safety Authority (EFSA) concluded that soy and soy isoflavones pose no concerns for thyroid function or breast and uterine cancers.

Nevertheless, researchers agree that infants should not be exposed to soy isoflavones, which may disrupt the development of reproductive organs.

Although this has not been studied well in humans, some animal studies suggest that high amounts of soy may interfere with fertility.

If you have concerns, discuss soy consumption with your doctor.

Summary: Eating tofu is safe for most people. If you’re worried about negative health effects, it’s best to double-check with your healthcare provider.

Varieties and preparation of tofu

Tofu can be purchased in bulk or individual packages, refrigerated or not.

You can also find it dehydrated, freeze-dried, jarred, or canned.

Generally, heavy processing is unnecessary to make tofu, so choose varieties that have short ingredients lists.

Suggested read: 8 science-based health benefits of edamame

You can expect to see ingredients like soybeans, water, coagulants — such as calcium sulfate, magnesium chloride, or delta gluconolactone — and maybe some seasoning.

Once opened, tofu blocks need to be rinsed before use.

Leftovers can be kept in the refrigerator for up to one week by covering with water, as long as you change the water often.

Tofu can also be frozen in its original package for up to five months.

Finally, making your own tofu with soybeans, lemon, and water is also possible.

Summary: Tofu can be found in a variety of shapes and forms. Homemade tofu is also surprisingly easy to make.

Summary

Tofu is high in protein and many healthy nutrients.

Eating tofu may protect against a variety of health conditions, such as heart disease, diabetes, and even certain cancers.