Tofu is made from soybean curds. It is naturally gluten-free and low in calories. It contains no cholesterol and is an excellent source of iron and calcium.
It is an important source of protein, especially for vegans and vegetarians. Tofu is available for purchase in health food stores and online.
It also contains isoflavones such as phytoestrogens. Isoflavones may have both estrogen-agonist or estrogen-antagonist properties. These may help protect against some cancers, heart disease, and osteoporosis. However, overconsumption may also present some risks.
Tofu is made by coagulating soymilk to create curds. The curds are then pressed and compacted into the gelatinous white blocks recognized as tofu.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods.
It can enhance the skin and hair, boost energy, and help maintain a healthy weight.
Research has linked tofu, with its high levels of isoflavones, to a lower risk of several age- and lifestyle-related diseases.
1. Cardiovascular disease
Soy isoflavines have been found to help reduce levels of LDL "bad" cholesterol, although it does not seem to increase HDL or "good" cholesterol levels.
Studies have indicated that daily consumption of soy may decrease markers for cardiovascular disease risk, including weight, body mass index (BMI), and total cholesterol. The FDA has set 25 g a day of soy protein as the minimum intake needed to impact cholesterol levels.
2. Breast and prostate cancer
In the past, confusion has arisen about the safety of consuming soy after a breast cancer diagnosis. This is because isoflavones have a chemical structure similar to that of estrogen, and high levels of estrogen can increase the risk of breast cancer.
However, consuming moderate amounts, or less than two servings a day, of whole soy foods, does not appear to affect tumor growth or the risk of developing breast cancer.
Instead, there is growing evidence that regular soy intake may decrease breast cancer recurrence. However, the evidence is not yet strong enough to recommend soy to all breast cancer survivors.
Researchers call for more studies to confirm how genistein works, how it could be used therapeutically, and its bioavailability, or how well the body can absorb it.
3. Type 2 diabetes
People with type 2 diabetes often experience kidney disease, causing the body to excrete an excessive amount of protein in the urine.
Evidence from one study has indicated that those who consumed only soy protein in their diet excreted less protein than those who only consumed animal protein.
The researchers propose that this could benefit patients with type 2 diabetes.
4. Kidney function
Protein, and particularly soy protein, may enhance renal function, and it could have benefits for people who are undergoing dialysis or kidney transplantation.
One meta analysis of nine trials showed a positive effect of soy on some biomarkers of those with chronic kidney disease.
This may be due to its protein content, but also because of its impact on lipid levels in the blood.
Soy isoflavones may help reduce bone loss and increase bone mineral density, especially after menopause. They have also been reported to reduce some other symptoms of menopause.
6. Symptoms of menopause
Some research has suggested that consuming soy products may help relieve symptoms of menopause, such as hot flashes, because of the phytoestrogens they contain.
While symptoms may differ between women, hot flashes appear to be far less common in Asian countries, where people consume more soy.
Conflicting results have been produced, but there is evidence that consuming soy products that are rich in genistein may help reduce the frequency and severity of hot flashes.
However, more studies are needed to establish exactly what happens and why.
7. Liver damage
One study in rats has suggested that any type of tofu that has been curdled with various coagulants may help prevent liver damage caused by free radicals.
8. Age-related brain diseases
Population studies have indicated that, in regions where people consume more soy, there is a lower incidence of age-related mental disorders.
However, results have been mixed.
One research group found that treatment with soy isoflavones was linked to better performance in nonverbal memory, verbal fluency and other functions.
When the same group carried out a further small study, involving 65 people over the age of 60 years with Alzheimer's, they did not find that soy isoflavines offered any cognitive benefits.
However, findings published in 2017 suggested that soy products may help people with Alzheimer's due to their lecithin content, which helps the body produce the phospholipids phosphatidic acid (PA) and phosphatidylserine (PS). PA and PS play an important role in the functioning of neurones.
One block of hard tofu, weighing 122 grams (g) contains:
- 177 calories
- 5.36 g of carbohydrate
- 12.19 g of fat
- 15.57 g of protein
- 421 mg of calcium
- 65 of magnesium
- 3.35 mg of iron
- 282 mg of phosphorus
- 178 mg of potassium
- 2 mg of zinc
- 27 micrograms (mcg) of folate, DFE
Soy is the prime component of tofu. It is a complete source of dietary protein, which means it provides all of the essential amino acids needed in the diet. Soybeans are also high in healthy polyunsaturated fats, especially omega-3 alpha-linolenic acid.
The isoflavones in soy foods have been linked to a range of health benefits, but also some risks.
The calcium and magnesium in soy may help strengthen bones, lessen symptoms of PMS, regulate blood sugar, and prevent migraine headaches.
Tofu comes in several different consistencies: Extra firm, firm, soft, or silken.
- Firm and extra-firm tofu is denser than soft or silken tofu and retains more of its shape when cooked. This makes it suitable for grilling and stir-frying.
- Soft tofu works well in casseroles and soups.
- Silken tofu is best for puddings and dips, and it can be blended into smoothies for added protein.
Tofu is commonly found in Asian cuisine, particularly in East and Southeast Asia. Its neutral flavor allows it to be easily incorporated into any recipe.
Tofu is used in many meat substitutes, such as tofu sausages and tofu burgers. These taste and feel like the meat they are imitating.
The following healthful dishes incorporate tofu:
Soy foods can be a healthful alternative to meat products, but there is some controversy about a number of their health effects.
Breast cancer risk
Some researchers have suggested that a high soy intake could be related to higher rates of breast cancer.
However, geographical studies show that in areas where women consume more soy, rate of breast cancer are lower. there is not enough evidence from human clinical trials to confirm this risk.
Moreover, the impact appears to relate only to a specific type breast cancer, which is estrogen-receptor positive.
Some early rodent studies suggested that a high intake of soy may increase tumor growth, but later studies found that rats metabolize soy differently from humans, making the early results invalid.
Moderate amounts of whole soy foods are currently not thought to affect tumor growth or the risk of developing breast cancer.
In fact, other investigators have concluded that consuming at least 10 milligrams (mg) of soy each day may decrease breast cancer recurrence by 25 percent.
Others suggest that, because of the ways soy isoflavones work, they may help protect the body from disease. They call for further investigation.
Effects of processing
Findings from animal models have also suggested that the level of risk of tumor growth depends on the degree to which an isoflavone-containing product has been processed.
It is better to consume tofu and other soy foods that have undergone minimal amounts of processing, like soybeans or edamame, tofu, tempeh, and soymilk.
Products made from tofu, such as tofu sausages, may contain additives such as sodium and flavorings that make them less healthful. It is important to check the nutrition label when buying processed foods.
Feminization and fertility
A further concern with a high soy intake is that the phytoestrogen in soy produce may have a mildly feminizing effect, and that this could lead to complications such as gynecomastia (breast development in men), or that it could impact fertility.
However, the impact is probably not severe enough to prevent the use of soy in infant and other foods.
Genetically modified soy
Soy products originating in the U.S. are often genetically modified (GM). Soy products may also be processed with hexane, a solvent that is used to extract oil from soy beans.
For anyone who is concerned about genetic modification or hexane processing, organic food may be a good choice.
The key to good health is a healthful lifestyle, with a balanced and varied diet and regular exercise, rather than focusing on one dietary item.
A range of tofu products are available for purchase online.