Residents of Suwannee County who are considering adopting a plant-based diet have probably noticed that a lot of vegetarian and vegan dishes contain some form of soy. The ubiquity of soy in plant-based meals, from tofu and tempeh to soy protein isolate in mock meats, has led to numerous rumors about whether consuming soy is actually beneficial to health. To unravel the truth, we turned to experts in the field.
Understanding Soy
Soy products originate from the soybean plant, a member of the legume family. Its seeds are commonly known as edamame. The United States, including our region of North Florida, is the largest grower of soybeans globally, according to the Department of Agriculture.
This crop is vital, not only for providing protein for animals and humans, but also for its use in the creation of biofuel, vegetable oil, and a plethora of other food products. Common soy-based food products include tofu, edamame, tempeh, miso, soy milk, soy sauce, soy protein isolate, soybean oil, and textured vegetable protein.
Debunking Myths about Soy
The apprehensions about soy primarily originated from two studies conducted in 1987 and 1998. These studies explored the effects of raw soybeans on mice, specifically their hormone levels and health outcomes. Disturbingly, they found that soy increased the mice’s risk of cancer and stimulated breast growth. Soy, being a source of phytoestrogens, can potentially mimic and increase estrogen activity in the body. This finding spurred fears that consuming soy, due to its phytoestrogen content, could increase the risk of breast cancer, as estrogen activity can promote cancer growth.
Other concerns about soy suggested it could potentially inhibit thyroid function based on animal and test-tube studies. However, registered dietitian Lauren McNeill, who specializes in plant-based nutrition, argues that these studies are fundamentally flawed. According to McNeill, “Soy is not inherently what mice eat in general…it’s not a good study to be doing to translate into humans.” More recent studies and reviews of research have debunked concerns about soy being harmful to human health.
Research has found that soy has no significant impact on thyroid function—though this relationship is still being investigated. A 2010 study also tested what kind of impact soy had on male reproductive hormones and found no impact from soy on testosterone or other sex hormones in men.
“We now have very clear human data showing there’s no association between soy consumption and increase of cancer risk and increase of cancer recurrence,” states Dr. Neil Iyengar, a breast medical oncologist at Memorial Sloan Kettering Cancer Center in New York.
Health Benefits of Soy
Several studies have indicated that eating soy not only helps lower your cancer risk, but can also broadly improve health outcomes. Soy foods like tofu, edamame, and tempeh are packed with fiber, protein, vitamins, and minerals. They are also plant-based, which Dr. Iyengar sees as beneficial due to the overall health and longevity benefits that come from a plant-forward diet.
A 2009 study of female breast cancer survivors in China found that those with higher soy diets had a significantly lower risk of death and cancer recurrence. Additionally, for men, soy consumption appears to help lower their risk of prostate cancer, according to a 2018 study. Other benefits of soy include:
- Lower total cholesterol
- Reduced hypertension
- Lower fasting blood sugar levels
- Appetite suppression
- Minimizing skin aging
Optimal Ways to Consume Soy
While some forms of soy are more processed than others, such as soy protein isolate or textured vegetable protein found in protein powders and vegan meat alternatives, and soybean oil, which is found in many processed food products, it’s best to stick to minimally processed soy foods. These include tofu, edamame, tempeh, and soy milk.
McNeill’s favorite way to prepare tofu is by tossing it in olive oil, garlic powder, salt, paprika, and nutritional yeast, then baking it in the oven or air fryer to add to stir-fries, salads, and wraps. “The less processing the better,” advises Iyengar, who recommends one to two servings of soy per day to reap the health benefits observed across numerous studies.
Whether you’re a Suwannee County resident considering a shift to a more plant-based diet or merely seeking to incorporate more nutritious food into your meals, the key takeaway here is that soy can be a healthy addition to your diet. As always, moderation is key and it’s essential to maintain a balanced diet that incorporates a variety of nutrient-dense foods.
