Mayo Clinic Minute: Does soy increase breast cancer risk? - Mayo Clinic News Network (2024)

FAQs

Mayo Clinic Minute: Does soy increase breast cancer risk? - Mayo Clinic News Network? ›

Soy contains isoflavones, which are plant estrogens. High estrogen levels have been linked to an increased risk of breast cancer. However, studies show that soy products don't contain high enough levels of estrogen to increase the chances of developing breast cancer.

It was once thought that soy foods increase the risk of breast cancer. However, eating a moderate amount of soy foods does not increase risk of breast cancer — or other types of cancer. A moderate amount is one to two servings a day of whole-soy foods, such as tofu, soy milk and edamame.

Not enough evidence exists to suggest a link between soy consumption and hormone changes in the body such as increased serum estrogen, breast cancer risk, thyroid hormone imbalances, and infertility.

Phytoestrogens are plant nutrients found in several different types of food such as soy products, grains, beans, and some fruits and vegetables. Phytoestrogens, especially when consumed regularly during childhood, have been linked to a decreased risk of breast cancer.

Soy foods are safe for patients with cancer

“Soy is a great alternative to animal protein to include in your daily diet,” she says. “There's no reason to avoid eating soy.” Soy contains phytoestrogens – the plant form of hormone estrogen.

Limit concentrated sweets, added sugar from processed foods, and sugary beverages as these foods provide calories, but few nutrients. A high intake of sugar can increase insulin levels as well as encourage weight gain, both possibly leading to cancer.

Soybeans and foods derived from them have been part of the human diet for centuries. Nevertheless, some people worry about including soy in their diet due to the following areas of concern: Estrogen-mimicking effects. Soy isoflavones are often thought to mimic the female reproductive hormone estrogen.

You Could Be Getting Less Iron Than You Think

This means that if you follow a vegetarian or a vegan diet relying on plant-based proteins such as soy as your protein source, you may have lower iron stores, per a 2018 review published in Critical Reviews in Food Science and Nutrition.

The reason why cutting soy from your diet is usually a good idea, is because naturally you will be cutting out a lot of processed foods from your diet. These processed foods also often contain refined sugar so you are also in turn eliminating sugar from your diet, which offers even more health benefits!

Many of soy's health benefits have been linked to isoflavones—plant compounds that mimic estrogen. But 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.

Does soy increase breast size? ›

Therefore, many people, especially women, believe that soybean-derived food can help their breasts grow bigger. This is in fact not correct. There is no evidence showing that phytoestrogen can make your breasts bigger, as the level of isoflavone found in soybeans is not high, and thus, not largely effective.

Because it is a hormonally active diet, however, soya can also be endocrine disrupting, suggesting that intake has the potential to cause adverse health effects in certain circ*mstances, particularly when exposure occurs during development.

However, concentrated sources of soy, including soy pills, powders and foods containing soy protein isolate, are not recommended for women with estrogen-positive breast cancer. Because soy is high in fiber and low in saturated fat and sodium, it can be a great alternative to animal protein.

"Cancer-fighting foods"

The list is usually topped with berries, broccoli, tomatoes, walnuts, grapes and other vegetables, fruits and nuts. "If you look at the typical foods that reduce cancer risk, it's pretty much all plant foods that contain phytochemicals," says Wohlford.

For example, many studies have found that Western-type dietary patterns characterized by high intakes of red meat, processed foods, sweets, dairy, and refined grains are consistently associated with higher estrogen levels ( 3 , 15 , 16 , 17 ).

Previous to this study, the American Institute for Cancer Research found no evidence linking dairy or dairy milk to breast cancer risk.

Menopause. Soy isoflavones may help reduce hot flashes and night sweats that many women have during menopause. In clinical studies, postmenopausal women who eat high amounts of dietary soy protein (20 to 60 g per day) generally have fewer and less intense hot flashes and night sweats than those who eat less soy.

Soy is an excellent dietary addition for patients with joint pain. It is rich in omega-3 fatty acids, meaning it may reduce inflammation within the body. Inflammatory chemicals attack the joint tissues, leading to more fluid in the joints and cartilage damage. This causes the painful symptoms patients experience.

Most, though not all, breast cancers are fueled by hormonal fluctuations. The prevailing view of estrogen's role in breast cancer is that it acts as a catalyst for cancer growth because it stimulates the division and proliferation of breast tissue, a process that carries the risk for cancer-causing mutations.