Tofu, soymilk, miso, tempeh, edamame—these and other soy products, including the soybeans themselves, are high in nutrients you tend to associate with other legumes, including fiber, iron, magnesium, potassium, protein, and zinc.
Soybeans naturally contain a class of phytoestrogens called isoflavones. People hear the word “estrogen” in the word “phytoestrogens” and assume that means soy has estrogen-like effects. Not necessarily. Estrogen has positive effects in some tissues and potentially negative effects in others. For example, high levels of estrogen can be good for the bones but can increase the likelihood of developing breast cancer. Ideally, you’d like what’s called a “selective estrogen receptor modulator” in your body that would have proestrogenic effects in some tissues and antiestrogenic effects in others. Well, that’s what soy phytoestrogens appear to be. Soy seems to lower breast cancer risk, an antiestrogenic effect, but can also help reduce menopausal hot-flash symptoms, a proestrogenic effect. So, you may be able to enjoy the best of both worlds.
What about women with breast cancer? Overall, researchers have found that women diagnosed with breast cancer who ate the most soy lived significantly longer and had a significantly lower risk of breast cancer recurrence than those who ate less. The quantity of phytoestrogens found in just a single cup of soymilk may reduce the risk of breast cancer returning by 25 percent. The improvement in survival for those eating more soy foods was found both in women whose tumors were responsive to estrogen (estrogen-receptor positive breast cancer) and those whose tumors were not (estrogen-receptor negative breast cancer). This also held true for both young women and older women. In one study, for example, 90 percent of the breast cancer patients who ate the most soy phytoestrogens after diagnosis were still alive five years later, while half of those who ate little to no soy were dead.
Soy consumption has also been shown to benefit our kidneys, which appear to handle plant protein very differently from animal protein. Within hours of eating meat, our kidneys rev up into hyperfiltration mode. But, an equivalent amount of plant protein causes virtually no noticeable stress on the kidneys. Eat some tuna, and within three hours, your kidney filtration rate can shoot up 36 percent. But eating the same amount of protein in the form of tofu doesn’t appear to place any additional strain on the kidneys.
The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.
Image Credit: margouillatphotos / Thinkstock. This image has been modified.
Popular Videos for Soy
All Videos for Soy
Fighting the Ten Hallmarks of Cancer with Food
The foundation of cancer prevention is plants, not pills.
The Side Effects of 3-MCPD in Bragg’s Liquid Aminos
Chlorohydrin contaminates hydrolyzed vegetable protein products and refined oils.
The Healthiest Natural Source of Iodine
How much nori, dulse, or arame approximate the recommended daily allowance for iodine?
Is Heme Iron the Reason Meat Is Carcinogenic?
Rectal biopsies taken before and after eating meat determine the potentially DNA-damaging dose of heme.
Heme-Induced N-Nitroso Compounds and Fat Oxidation
What do clinical studies show about the role of heme in the formation of a class of carcinogenic compounds?
What About the Heme in Impossible Burgers?
Is heme just an innocent bystander in the link between meat intake and breast cancer, diabetes, heart disease, stroke, and high blood pressure?
The Health Effects of Mycoprotein (Quorn) Products vs. BCAAs in Meat
Clinical trials on Quorn show that it can improve satiety and help people control cholesterol, blood sugar, and insulin levels.
Plant-Based Meat Substitutes Put to the Test
What are the effects of plant-based meats on premature puberty, childhood obesity, and hip fracture risk?
Plant-Based Protein: Are Pea and Soy Protein Isolates Harmful?
What are the different impacts of plant protein versus animal protein, and do the benefits of plant proteins translate to plant protein isolates?
The Environmental Impacts of Plant-Based Meat Substitutes
Environmental assessment of 50 different plant-based meats show them to be vastly more sustainable.