Nutrition information comes from a wide variety of sources and companies these days. Soy foods are one category that will lend you completely opposite views in a lot of categories! For instance, some sources say that soy foods prevent cancer, and others say they cause it. Others report negative effects on men's health, while the next source reports positive effects. How about thyroid health and GMO risks? There's a lot to sift through here, and so I'll cover for you the short and sweet version of what the true, unadulterated research says.
Soy boasts a ton of different nutrients when it comes to plant foods. Soy can be part of a nutritionally complete plant-based diet when paired with other complementary proteins like whole grain brown rice. Many soy foods are richer in protein than eggs per gram!
Protein: soy is a complete protein - it provides all 9 amino acids needed by humans to build tissues!
Healthy Fats: soy contains mostly polyunsaturated and monounsaturated fats, as opposed to unhealthy saturated fats that are high in animal products
Isoflavones: a misunderstood molecule, isoflavones are protective against various cancers
Calcium: especially calcium-set tofu! Soy beverage provides just as much calcium as a glass of cow's milk at 298 milligrams! Make sure you select the commercial brand rather than the Asian counterpart, or homemade, if you are looking for a source of calcium.
Iron: soy contains almost TWICE* as much iron as red meat! WOW!
*(Comparing 100 grams of ground beef to 100 g of Soyganic firm tofu, beef = 250 calories, 26 grams protein, and 2.6 mg iron, whereas tofu = 80 calories, 8 grams of protein, and 5.4 mg iron. Calorie for calorie, and more accurately matching up protein provision, tofu would actually provide 25% of your daily iron intake, whereas beef provides only 14%)
Many sources and sites will claim that soy causes or is related to cancer. One of those statements is correct - soy is actually possibly INVERSELY related to many cancers, that is, it prevents cancer occurrence and recurrence. Large reviews of studies and population-wide analyses have assessed that soy foods are potentially protective against breast cancer in particular, and are even helpful One possible reason for this is that the isoflavones act as phytoestrogens in the body, which means they bind to the same receptors as estrogen. However, they tend to bind to cell receptors in such a way that is protective against bone loss AND breast cancer cell proliferation (multiplication and spreading of cancer cells). Fancy that! One point for soy.
2. Men's Health
Concerns around soy being harmful to men's health are rampant all over the world wide web, in particular, that soy foods encourage the growth of breast tissues and disrupt natural male reproductive health. There is in fact NO evidence that this is true. I'm calling their bluff on the "man boob" argument. Moderate consumption of soy foods (a healthy balanced diet wouldn't surpass 2 to 3 servings a day anyway, for the reason of incorporating variety) seems to have a positive effect on prostate health, and does not affect sexual development.
3. GMO foods
Whew, this is a whole other animal. To make the long story short, we don't yet know the entire effects of GMO foods on the body. There is no evidence that points to GMO foods being a cause of allergies or antibiotic resistance. In Canada, GMO foods are generally recognized as safe by standard food safety assessments. Ultimately, it is your choice. In Canada, if a food is labelled "organic", it must be free of genetically modified foods. Most soy available for human consumption is already organic or at least GMO-free. Most GMO soy is actually used as feed for animals. Which brings me to...
Some environmental advocates claim that soy is responsible for loads of deforestation, next to animal agriculture. Let's combine the two - most soy (over 80%) is used as animal feed. Thus, the remains are left to us,
5. Thyroid Health
There has been a bit of research done on thyroid health and soy, and the results lead me to caution people with hypothyroidism when taking soy foods. It turns out that the isoflavones in soy foods tend to interfere with the body's use of iodine - and so when your thyroid doesn't function correctly, you might need to either consume more iodine-rich foods like seaweed and table salt (depending on your doctor's recommendations) or avoid soy foods in order to be extra careful.
6. Heart Health
The unsaturated fats and plant sterols in soy foods could be cardio-protective for you - that is, they help to prevent heart attacks, and keep blood vessels more clean and healthy. To explain further, soy products help to lower Low Density Lipoprotein (LDL) cholesterol - that is, the type of cholesterol that is most clearly related to heart disease. Plant sterols such as those in soy foods are helpful in lowering high cholesterol, and using soy foods as a substitute for meats, eggs and dairy means you are cutting out dietary sources of cholesterol in your meal.
The Bottom Line
While you might encounter raised eyebrows and strong opinions about soy foods (like I do daily), now you know the whole truth, and can use it to your health's advantage! Soy can be a healthy part of a more (or entirely) plant-based diet. There are possible benefits to your heart health, cancer prevention of some cancers, and . Caution should be used with thyroid disorders, and of course, if you have a diagnosed soy allergy, you should not consume soy products.
Practical Uses of Soy!
The biggest barrier my clients encounter when attempting to incorporate soy foods, once we jump over the hurdle of misinformation, is how to cook with soy and make it taste good! You can use the following recipes and methods to incorporate soy foods healthfully into your diet.
- Snack on edamame beans and a dash of cracked sea salt and black pepper
- Try this cast-iron fried tofu recipe for a quick addition to salad, pasta bowls, Asian-inspired rice bowls, or just to dip in sauce and pop in your mouth!
- Make my perfected scrambled tofu instead of eggs - I tricked my husband into thinking these were eggs! See if you can trick your significant other or friends too :)
- Blend a mild white (Shiru) miso paste to Japanese-inspired soups or dressings or use a darker miso to flavour stir-fry sauces
- Make a beautiful light mousse dessert out of fresh pineapple, mango and silken tofu in a high-powered blender, and add a touch of agave syrup to taste!
Once you've adjusted to the unique taste of tofu in meals, feel free to explore more adventurous ways of using tofu in meals and recipes!
If you'd like to learn more about soy foods and the vegan diet, don't hesitate to grab a copy of "Becoming Vegan" by Registered Dietitians Brenda Davis and Vesanto Melina!
Enjoy your soy! ;)