A great source of complete plant protein, soy has been a staple in Asian diets for thousands of years. There’s no debating it — soy can be found in pretty much anything these days. And we’re not talking about tofu and soy sauce here
A great source of complete plant protein, soy has been a staple in Asian diets for thousands of years. There’s no debating it — soy can be found in pretty much anything these days. And we’re not talking about tofu and soy sauce here. From protein bars and veggie burgers to chicken noodle soup, soy has become ubiquitous in the food system in one form or another. It’s inexpensive, packed with protein and relatively tasteless. Additionally, some soy foods are made with calcium sulfate, which makes them good sources of calcium, too.
However, some fear that these foods may not be safe because soy contains certain estrogenlike compounds — and high levels of estrogen have been linked to increased breast cancer risk. Let’s dig a little deeper to find out whether or not this is true.
Understanding the Soy-Cancer Connection
The question around the safety of soy stems from isoflavones, a group of estrogenlike compounds made by certain plants that can mimic the actions of estrogen. While high levels of estrogen have been associated with an increased breast cancer risk, interestingly enough soy actually seems to protect against breast cancer, prostate cancer and even heart disease in human studies. This cancer-fighting effect likely comes in part from other phytochemicals in soy that reduce inflammation and prevent activation of proteins that promote cell growth commonly seen with certain cancers. As an added bonus for women, soy may also provide relief from menopausal symptoms, though the jury is still out on whether or not soy protects against osteoporosis.
Since Americans don’t eat large quantities of soy, it’s not easy to conduct observational studies comparing how various intakes link to cancer risk. In Asia, where soy is a staple and women consume 1–2 servings per day, population studies link regular consumption with lower breast cancer risk. (One serving being equivalent to 1/3 cup tofu, 1 cup soy milk, ½ cup edamame or 1 ounce soy nuts.)
What about cancer survivors? According to 