Why Avoid Soy?

Why Avoid Soy? 

Soy is an excellent plant-based protein alternative, including soy milk, soybeans, edamame, tofu, and even soy protein supplements. 

So why does soy cause controversy? 

Whether it is suggesting that we choose cow’s milk or soy milk over the other milk alternatives or indicating that it is okay to eat a soy-based veggie burger or eat tofu, some people cannot get it out fast enough that I am wrong about soy food. 

SOY is a complete protein. 

What does this mean, and why is that noteworthy? 

Amino acids are the building blocks of protein. We know of 20 of them, and nine must be consumed from food (the other 11 we can make in our body as long as we get those nine). 

A “complete” protein is any food that provides those nine essential amino acids in one package. Complete proteins include foods of animal origin, including eggs, dairy foods, and meats, including beef, pork, poultry, and seafood. 

Only a few plant foods are considered a complete protein, with soy being one of those foods because soy foods contain all nine essential amino acids without looking for other plant-based proteins to complete the profile. 

SOY is a good source of protein.

As I wrote in my post about the various “milk” alternatives, very few non-dairy beverages (like almond, coconut, and oat milk) have much protein. Most have one gram or less per cup. 

Cow’s milk has about 8 grams of protein per cup, and soymilk does, also. 

So, if people want to skip cow’s milk, soymilk is the only dairy alternative I recommend since it has the protein and other nutrients we need. It isn’t flavored sugar water like the others.  

It isn’t just soy beverages, but soybeans, nuts, tofu, tempeh, and other soy foods that provide protein. 

SOY is low in saturated fat and high in nutrients.   

And while there is plenty of protein in soy foods, it doesn’t tend to come with the saturated fat associated with animal-based protein. 

Soy foods also come with vitamins and minerals – some are naturally occurring (like potassium and folate), while others may be added, such as calcium, vitamin D, and vitamin B12. 

SOY has health benefits, or is that risky?

The number one question is whether it is safe to consume soy foods. People have many concerns related to thyroid issues, a history of certain types of cancer, and concerns by men that estrogen-like components in soy may affect their health. 

Many things are associated with health benefits, including reducing the risk of heart disease, and may help reduce menopause symptoms, including hot flashes and potentially help with bone health. 

Some people still think soy food may increase the risk of certain types of cancer, specifically breast cancer; however, research does not support this. Human studies suggest that consuming soy foods will not negatively impact cancer risk (meaning it does not increase risk) and may even reduce the risk of reoccurrence even after a diagnosis. 

The American Cancer Society and the American Institute for Cancer Research state that breast cancer patients can safely consume soy foods but should skip the supplements.

Prostate cancer has similar results – in that soy foods may reduce the risk of prostate cancer. 

And with thyroid issues, clinical evidence indicates that soy foods do not adversely affect thyroid function in people with normal-functioning thyroids. Soy foods are also not restricted for hypothyroid patients taking thyroid hormones, although when patients first add soy foods to the diet, it is prudent to monitor thyroid function.

SOY and gynecomastia

And what about those “man boobs” – one of the most common questions I get. 

The short answer is that, in the amount that most people in the United States reasonably consume, this is a non-issue. 

Phytoestrogens, a component of soy products, have estrogen-like properties, and in large amounts, they can lead to gynecomastia. Here is a summary of an unusual case of gynecomastia associated with soy product consumption: 

“A 60-year-old man was referred to the endocrinology clinic for evaluation of bilateral gynecomastia of 6 months’ duration. He reported erectile dysfunction and decreased libido. On further review of systems, he reported no changes in testicular size, no history of testicular trauma, no sexually transmitted diseases, no headaches, no visual changes, and no change in muscular mass or strength. Initial laboratory assessment showed estrone and estradiol concentrations to be 4-fold increased above the upper limit of the reference range. Subsequent findings from testicular ultrasonography; computed tomography of the chest, abdomen, and pelvis; and positron emission tomography were normal. Because of the normal findings from the imaging evaluation, the patient was interviewed again, and he described a daily intake of 3 quarts of soy milk. After he discontinued drinking soy milk, his breast tenderness resolved and his estradiol concentration slowly returned to normal.”

Even if one consumes soy foods daily, consuming four cups or servings daily with no adverse effects and plenty of health benefits is safe. 

Much research on the long-term health effects of soy consumption does come from studies from Japan and China in which soy is a central part of the typical diet over a lifetime. 

Bottom line: don’t concern yourself with soy’s risk or possible adverse effects, but the potential benefits of adding soy to your diet. 

Why avoid soy? If you have a soy allergy or your physician has specifically told you within the last 3-5 years NOT to consume soy foods. Additionally, if your physician told you not to consume soy several years ago, check in and see if that reason is still accurate. 

For everyone else, it should be safe.