Soy foods, including tofu, edamame, miso, soy sauce, and soy milk, are some of the most widely consumed foods on the planet. As more people embrace plant-based diets, their popularity is increasing.
Yet soy is known to produce phytoestrogens in the body, and estrogen has been linked to breast cancer. Is there any reason to be concerned about breast cancer if you eat foods containing soy?
Researchers say no. In fact, there’s solid evidence that eating foods rich in soy may actually lower your risk of developing breast cancer.
This article explores some of the research into soy foods and breast cancer. It also discusses some of the other benefits and risks of including soy in your diet.
Why was there a concern about the relationship between consuming soy and developing breast cancer? In some
However, animal studies don’t always translate well to humans. In this case, it’s important to note that there are at least two reasons why these mice might have a different response to dietary soy than humans.
Differences in how soy is processed
First, mice process the soy differently than humans do. To understand how, a little background is necessary. Soy contains several kinds of phytoestrogens (isoflavones). Phytoestrogens are plant-based substances that act like estrogen in the body.
According to the
In fact, soy has been proven to
Higher concentrations of isoflavones in mouse studies
Because of the differences in how soy isoflavones are metabolized in mice and humans, the mice in these
When researchers conducted similar soy
What human studies show
A number of long-term studies involving human populations have shown that eating soy foods does not increase the risk of breast cancer. On the contrary: Studies show that diets rich in soy may actually help to protect you from developing breast cancer.
If you have been diagnosed with breast cancer or are a survivor, you may be wondering whether you should be cautious about consuming soy. Experts at the
If you have breast cancer
If you are a breast cancer survivor
In 2019, researchers analyzed
The soy that we eat can impact our bodies in a multitude of ways. There are benefits of eating soy related both to fighting breast cancer and our general health.
Soy products are a great source of protein. As opposed to some other plant proteins, soy proteins contain all nine essential amino acids that the body cannot make, making it a complete protein. Replacing red meat with soy protein may also help reduce your risk of certain cancers, because eating red meat has been linked to higher cancer risk.
Fermented soy foods like miso, natto, and tempeh are cultured with beneficial bacteria. These bacteria boost the health of our microbiome, which can improve our heart health, brain health, and regulate weight.
How to incorporate more soy into your diet
A diet rich in soy can be healthy, delicious, and fulfilling. Eating soy goes beyond enjoying a block of tofu. Here are some forms of soy you can incorporate into your diet:
- Soy milk. Try using soy milk as a replacement for animal milk in your cereal, your coffee, or even your baking.
- Extra-firm tofu. This form of tofu can be a great replacement for animal protein in your main courses. Alternatively,
- Soft-tofu. This form of tofu is a delicious add-in for soups and stews.
- Soy cheese. If you are sensitive to dairy or looking to cut back on your intake of cheese, consider eating soy cheese as a replacement.
- Miso. This is a great base for soup stocks, salmon marinades, and even desserts.
- Natto. If you’re feeling extra adventurous, the fermented soybean called natto can be found at most Asian grocery stores. It is great over rice, in sushi, or with curry.
- Tempeh. Another meat substitute, tempeh, is a delicious and protein-packed addition to any meal.
- Soy sauce. This is another great base for marinades, soups, dressings, or dipping sauces.
It is worth noting that most of the studies regarding soy as a cancer-fighting food are observational, and more detailed studies need to be done. The relationship between soy consumption and breast health may additionally be related to the lifestyle and other dietary habits of people who eat soy products.
While there is no link believed to exist between soy and breast cancer, there might be other reasons for you to consider eating less soy.
While soy foods are safe and have a number of health benefits, there is not enough data to say for sure that soy supplements are equally beneficial. At least one
One form of fermented soy, soy sauce, contains tyramine and monosodium glutamate (MSG). Some researchers once thought tyramine triggered migraine attacks by constricting and dilating blood vessels. However, blood vessel dilation is not considered the cause of most migraine.
While there is
Genetically Modified Organisms (GMOs)
Many soy products may be created with genetically modified soybeans. Some people are concerned that GMO foods may be linked to cancer and allergies; however, there are no long-term human studies linking GMOs to cancer or allergies. More research is needed.
There is no known link between breast cancer and eating tofu, miso, edamame, soy milk, soy sauce, or any other soy food. In fact, researchers have found that consuming soy foods can actually lower your breast cancer risk.
Soy foods can also benefit your health in other ways: protecting you from bone loss, boosting the beneficial bacteria in your gut, and increasing healthy sources of plant protein in your diet. It’s important to note that soy isn’t entirely risk-free, however. Soy may be a migraine trigger in some people, and it may be genetically modified, which some people choose to avoid.
More research needs to be done before scientists can say with certainty that soy supplements are as healthful and safe as foods that contain soy.