What Happens To Your Body When You Eat Tofu Every Day

Despite being a staple in parts of Asia, tofu was somewhat of a niche product in the United States until recently (via Medical News Today). A growing interest in "flexitarian" eating, coupled with shortages and sky-high prices for beef, pork, and chicken at the beginning of the pandemic, has created a sort of American tofu renaissance. In fact, sales of tofu jumped a whopping 40% in the first half of 2020 (via The Washington Post). In July 2021, approximately 9.5 million Americans reported buying one or two packages of tofu in the previous month, while 3.6 million bought three or four packages and roughly 3 million bought five or more packages (via Statista).

So even if you never ate tofu in the "before times," it's likely a permanent fixture on your grocery list these days. But what exactly is tofu? According to WebMD, "tofu — or bean curd — is made by pressing curdling soy milk into a solid block." Depending on how much water is pressed out of the curd, tofu can range in texture from soft (silken) to extra firm. It can be used in a variety of ways and is excellent at absorbing the flavors of the foods you cook it with. But does tofu deserve all the health hype it gets? Are there any risks to eating tofu on a daily basis?

Your isoflavone intake will increase

Much of the buzz (both positive and negative) surrounding tofu and other soy products centers on their isoflavone content. Isoflavones are a type of phytoestrogen. Phytoestrogens are substances found in plants that can both mimic estrogen and block its effects in the body (via Oregon State University). Soy is the richest source of isoflavones, although tofu isn't the most isoflavone-packed form of soy available. Three ounces of soft tofu, for instance, contain 19.2 milligrams of total isoflavones, while the same size serving of tempeh contains 51.5 milligrams, 1 ounce of dry-roasted soybeans contains 41.6 milligrams, and a half-cup of soy yogurt contains 21.3 milligrams. Tofu does, however, have more isoflavones than soy milk and heavily processed forms of soy such as meat substitutes and soy cheese.

Many researchers believe isoflavones can improve health. According to one 2008 study published in Inflammopharmacology, "the potential health benefits of isoflavones may include protection against age-related diseases including cardiovascular disease, osteoporosis, hormone-dependent cancer and loss of cognitive function." But a 2009 article published in Scientific American noted that "animal studies suggest that eating large amounts of those estrogenic compounds might reduce fertility in women, trigger premature puberty, and disrupt development of fetuses and children."

Your cholesterol may go down

Has your doctor told you that you need to lower your cholesterol? If so, adding tofu to your diet on a regular basis might help you get your numbers under control. In a meta-analysis published in The American Journal of Clinical Nutrition in 2007, soy isoflavones were shown to reduce both total cholesterol and low-density lipoprotein (LDL, or "bad") cholesterol. The research team examined 11 large randomized and controlled studies conducted between 1990 and 2006 and concluded that soy isoflavones lowered total cholesterol by about 1.7% and LDL by about 3.5%. The isoflavones appeared to have no effect on triglycerides or high-density lipoprotein (HDL, or "good") cholesterol, however. Harvard Medical School noted that consuming 10 ounces of tofu a day could reduce LDL by 5 to 6%.

While those may sound like relatively modest decreases in risk, eating more tofu would be a step in the right direction for the approximately 95 million Americans with a total cholesterol level greater than 200 mg/dL. According to the Centers for Disease Control and Prevention (CDC), having high cholesterol increases your risk for heart disease (America's number one killer) and stroke.

Weight loss is possible

While there's no magic-bullet solution for weight loss, eating tofu every day could help you reach your goals because it's a low-calorie yet satiating food. According to the Cooper Institute, how full you feel after eating something can depend on the macronutrient content of that meal. Protein and fiber have the biggest role to play in controlling when you'll be hungry again. Tofu isn't high in fiber, but it's packed with protein for very few calories. A half-cup serving of tofu has 10 grams of protein and just 94 calories (via the U.S. Soybean Export Council).

In a 2007 study published in the International Journal of Medical Sciences, the researchers concluded that "consumption of plant-based protein, particularly soy protein, may suppress food intake and increase satiety and/or energy expenditure that may reduce body fat gain and result in weight reduction, effects that may be useful for the prevention and treatment of obesity."

According to the Centers for Disease Control and Prevention (CDC), more than a third of Americans have overweight (a body mass index [BMI] of 25 to 29.9), a third have obesity (a BMI of 30 or more), and about 7.6% have extreme obesity (a BMI of 40 or more). The CDC noted that being overweight or obese puts individuals at higher risk for a number of chronic health conditions, including type 2 diabetes and cardiovascular issues.

Eating tofu every day is a great way to get plant-based protein

Whether you're eating it because you're following a meat-free diet, you want a bit more variety on your plate, or you simply like the taste, tofu is an excellent source of plant-based protein. What makes tofu an even bigger protein powerhouse is the fact that, unlike most plant foods, soy is a complete protein (via American Family Physician).

According to the National Institutes of Health (NIH), all proteins are made up of some combination of 20 different amino acids. Nine of these amino acids are considered essential because our bodies can't produce them and must get them from food. Any food that contains all nine essential amino acids (phenylalanine, valine, tryptophan, threonine, isoleucine, methionine, histidine, leucine, and lysine) in appropriate quantities is considered a complete protein.

Soy protein, however, isn't considered as high-quality as protein from meat, eggs, or dairy. As a 2004 paper published in the Journal of Sports Science & Medicine explained, our bodies are less efficient at absorbing and actually using soy protein compared to protein from animal foods.

You'll get more omega-3s (but there's a catch)

Omega-3 fatty acids get a lot of media attention, and there's a good reason for that. This group of polyunsaturated fats have anti-inflammatory properties and have been credited with reducing the risk of heart attack, obesity, and many chronic health conditions. There are three types of omega-3s: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is found mostly in plant foods (including tofu), while EPA and DHA are found mostly in fatty fish (via Medical News Today). The National Institutes of Health recommend that adult women get 1,100 milligrams of ALA a day for optimal health, while adult men should aim for 1,600 milligrams. Guidelines have not been set for EPA and DHA specifically.

Firm tofu is one of the best sources of omega-3s. A 1-cup serving contains a whopping 1,467 milligrams — more than the daily recommended amount for women and about 92% of the recommended daily amount for men. But it's important to note that tofu is also very high in omega-6 fatty acids. For every 1 milligram of omega-3s, tofu contains 7 milligrams of omega-6s (via MyFoodData). As WebMD explained, "Too much omega 6 can raise your blood pressure, lead to blood clots that can cause heart attack and stroke, and cause your body to retain water." So, while eating tofu regularly will definitely boost your levels of ALA, you won't get much EPA or DHA and your body may not appreciate the high omega-6 content.

You'll get more magnesium

Tofu is an excellent source of the trace mineral magnesium. According to the U.S. Soybean Export Council, a half-cup serving of tofu has 127 milligrams of magnesium. That's 30% of the 420 milligrams recommended for adult men and 39% of the 320 milligrams recommended for adult women (via the National Institutes of Health). Magnesium plays a role in more than 300 biochemical reactions in the body. It assists with the synthesis of protein, DNA, and RNA and is required for energy production inside cells. Magnesium also plays a role in regulating blood pressure and controlling blood glucose levels. Nerves and muscles can't function properly without magnesium, and, along with calcium, magnesium provides structure for bone. Low magnesium levels in the blood can lead to vomiting, fatigue, numbness and tingling, and muscle weakness and cramps. Severely low levels of magnesium can cause seizures, irregular heartbeat, and electrolyte imbalances (via the National Institutes of Health).

According to Oregon State University, most Americans aren't getting the magnesium they need. Average daily intake from all sources is only about 290 milligrams, and a whopping 60.9% of adults aren't meeting the estimated average requirement (EAR) for magnesium. The EAR is a guideline of how much of a particular micronutrient someone needs in order to avoid negative health consequences. The EAR for magnesium is only 350 milligrams per day for adult men and 265 milligrams per day for adult women (via the U.S. Department of Agriculture).

If you're worried about breast cancer, you should know it's okay to eat tofu every day

The statistics on breast cancer in the United States are frightening. It's the most commonly diagnosed cancer in American women; one in eight women will get breast cancer in her life (via BreastCancer.org). More than 40,000 die of the disease every year, making it the second deadliest cancer for women. Men aren't immune either — more than 2,600 cases of male breast cancer are diagnosed each year.

As the Mayo Clinic explained, researchers formerly speculated that the estrogen-like effect of soy isoflavones might increase breast cancer risk, since this is a largely estrogen-dependent cancer. But while tofu is a rich food source of isoflavones, it doesn't contain them in high enough quantities to increase breast cancer risk. (High-dose isoflavone supplements, on the other hand, may slightly increase breast cancer risk for some individuals.) In fact, numerous studies have shown that moderate soy intake — one to two servings a day — is not associated with an increased risk of any type of cancer and may even provide some protection against breast cancer, especially among women who begin eating it at an early age.

Tofu may have an impact on your fertility

The isoflavones in tofu may have an impact on your ability to become pregnant, but the jury's still out on how the two are connected. In a 2014 study published in the International Journal of Women's Health, researchers examined how soy intake impacted the likelihood of becoming a parent. The study focused on more than 11,500 North American Adventist women. The researchers chose women from this particular religious denomination because, as a group, they had a generally healthy lifestyle and an average daily isoflavone intake much higher than the typical North American woman. The study concluded that the women who ate more than 40 milligrams of isoflavones a day had a 3% lower chance of giving birth to a live child during their lifetime. These women were also 13% less likely to ever become pregnant.

However, other evidence suggests that a high intake of tofu and other soy products may actually be beneficial for women experiencing infertility. A 2015 study published in Fertility & Sterility found "significant positive associations of soy intake with live births, clinical pregnancy, and fertilization rates" among women using assisted reproductive technology. According to the Office of Women's Health, about 10% of women of childbearing age (more than 6 million Americans) have difficulty becoming pregnant or carrying a pregnancy to term.

Is eating tofu every day bad for your thyroid?

Even though you probably don't think about your thyroid much, it has a big role to play. This butterfly-shaped gland located in the neck regulates how quickly or slowly cells use energy. It does this by producing two hormones: T3 (triiodothyronine) and T4 (thyroxine). The thyroid uses iodine to make these hormones. The thyroid is in turn controlled by the pituitary gland, which releases thyroid-stimulating hormone (TSH). TSH prompts the thyroid to produce more T3 and T4 when circulating levels have dropped too low (via Endocrineweb).

According to the Kresser Institute, some foods, including tofu, may negatively affect the thyroid. That's because soy is a goitrogen, meaning it interferes with the thyroid's ability to take up the iodine it needs. But not everyone agrees that tofu is bad for the thyroid. One meta-analysis published in Scientific Reports in 2019 concluded that while soy may raise the amount of TSH, it had no effect on circulating levels of T3 and T4 and that the change in TSH was therefore not "clinically significant."

Although the Mayo Clinic states that those with an underactive thyroid don't need to avoid tofu and other soy products, it does suggest that these individuals wait at least four hours after taking their thyroid medication before eating soy, since it can interfere with the body's ability to absorb the medication.

Eating tofu might make it harder for you to absorb certain minerals

No matter how nutritious the food you eat is, none of that matters if your body can't actually absorb those nutrients. Phytic acid, also known as phytate, is found in all edible seeds, grains, nuts, and legumes, including soy. It allows these parts of the plant to store phosphorous, which they'll need to grow into new plants. Tofu is considered a high-phytate food, containing up to 2.9% phytic acid by dry weight. Phytic acid content, however, is highly variable, and some tofu may have as little as just 0.1% by dry weight (via Healthline).

Many studies, including a paper published in 2009 in the journal Molecular Nutrition & Food Research, have found that the phytic acid in plants can impair the absorption of iron, zinc, and calcium in humans. According to Harvard Medical School, these minerals are among those essential for human health. Calcium is considered a major mineral because significant amounts are needed regularly. Iron and zinc are considered trace minerals because, although just as important, less is needed to maintain good health. But the story of phytate is more complex than you might think. The Soy Nutrition Institute reports that phytate in soybeans doesn't impair calcium as much as originally thought and may actually reduce your risk of developing colon cancer. They also note that tofu is often fortified (or "set") with calcium, and in this case, the added calcium offsets the modest negative impact of phytate.

You could have high levels of cadmium

Despite its many health benefits, tofu may contain high levels of cadmium. Cadmium is a heavy metal found both naturally in the Earth's crust and as part of many fertilizers. Certain plants, including soybeans, are particularly good at taking up cadmium from the soil. Somewhere between 1% and 10% of the cadmium in the food you eat will be absorbed by your body. If you're low on iron (as many American women are), you may absorb even more. Chronic, low-level exposure to cadmium can cause kidney damage and brittle bones. A number of organizations have also declared cadmium either a known or probable carcinogen. Other plant foods that tend to be high in cadmium include lettuce and spinach, potatoes, grains, peanuts, and sunflower seeds (via the Agency for Toxic Substances and Disease Registry).

A 2011 study published in Science of the Total Environment found that soy plants uptake a significant amount of cadmium from the soil, and the beans can contain three to four times the maximum limit for cadmium set by the Codex Alimentarius Commission of 0.2 mg/kg. Another study, published in the same journal in 2011, observed that tofu, tempeh, and products such as tofu hot dogs, soy burgers, and tofu cheese had the highest concentrations of cadmium of all the foods they tested.

Tofu is typically genetically modified

Trying to cut GMOs out of your diet because you're worried about how they may affect your health? You're not alone. AG Week reported on a 2018 survey conducted by the International Food Information Council Foundation, which found that nearly half (47%) of Americans make at least some effort to avoid GMOs. Another 19% of consumers say they avoid GMOs completely. Among individuals nixing GMOs, 95% do so because of health concerns.

Common reasons people give for steering clear of GMOs include fears about their "genetic instability"; their perceived potential to cause allergic reactions, cancer, and immune system disruptions; and concerns about lower nutritional value (via Center for Food Safety). The Food and Drug Administration (FDA) asserts, however, that GMOs have been extensively studied and are just as safe and health-promoting as their non-GMO counterparts.

If you're still looking for non-GMO tofu, you'll have to look pretty hard. Almost all of the soybeans grown in the U.S. are genetically modified (via Scientific American). However, if you spot a package with the Non-GMO Project Verified label, you can rest assured it contains no GMOs.

Eating tofu is dangerous if you have a soy allergy

It should probably go without saying, but if you're allergic to soy, you shouldn't be eating tofu. As the American College of Allergy, Asthma, & Immunology explained, food allergies occur when the body's immune system mistakes a harmless food for a dangerous invader and launches an attack. This misguided immune response can vary from mild to life-threatening. Common symptoms include vomiting, hives, swelling of the tongue, shortness of breath, and dizziness. Anaphylaxis may occur in the most sever cases, leading to a "whole-body allergic reaction that can impair your breathing, cause a dramatic drop in your blood pressure and affect your heart rate."

According to Food Allergy Research & Education (FARE), soy allergy is more common among infants and young children. In fact, about 0.4% of infants are allergic to soy. But the allergy rarely lasts into adulthood. Even so, according to a 2019 study published in JAMA, soy allergy affects roughly 1.5 million American adults.

Although it's easy enough to steer clear of tofu, other forms of soy can be more difficult to avoid because they find their way into a variety of packaged foods. Fortunately, soy is one of eight allergens that must be clearly listed on a product's packaging under the 2004 Food Allergen Labeling and Consumer Protection Act (via Food and Drug Administration).

You may experience GI distress

Even if you don't have a true soy allergy, regularly consuming large quantities of tofu can be hard on the digestive system for some individuals. That's because some forms of tofu are considered high-FODAMP foods. As Healthline explained, FODMAPs (fermentable oligo-, di-, mono-saccharides and polyols) are a group of carbohydrates that are resistant to digestion. When the FODMAPs travel undigested to the large intestine, our friendly gut bacteria begin using them for fuel. While this is great for your bacteria, it can lead to gas, bloating, cramps, abdominal pain, and constipation in some people. These individuals can find relief by sticking to a low-FODAMP diet. Soybeans and soy products are particularly high in two groups of FODAMPs called galactans and fructans.

But not all tofu is problematic. According to Monash University, silken tofu is a high-FODMAP food, whereas firm or extra-firm tofu is considered a low-FODAMP food. The reason for the discrepancy is that FODMAPs are water-soluble, so getting rid of a food's water content significantly reduces its FODMAP content. Silken tofu is very water-rich, but firmer varieties have had much more of the water pressed out of them. Since tofu is usually packed in water, it's also important to thoroughly drain it to remove FODMAPs that heave leached into the water.