Chances are, somewhere in the middle of nutrition articles, click-baits, or health books you’ve come across some negative press about soy. Maybe it’s about concerns of soy being one of the most plentiful genetically modified organisms (GMOs) or that soy can wreak havoc on your hormones or thyroid. There are many opinions about this controversial food and all you have to do is type “soy” into an internet search bar to be overwhelmed by differing opinions and contradicting science. If you follow a diet that’s heavy in plant foods, there are probably some things you should know when it comes to soy consumption. Let’s separate fact from fiction and talk about which studies you should trust, and which concerns you really don’t need to pay any mind to.
Soy gets a bad rap, in part, because it contains “isoflavones” also known as phytoestrogens. Phytoestrogens are similar in chemical structure to human estrogen but are much weaker. They can bind to estrogen receptors in the body, but don’t exert the same effects. Studies have examined these isoflavones in relation to health and found mixed results. Some studies regarding mammary and thyroid tissues showed a possibility of excess phytoestrogen promoting dysfunction. The problem is that many of these studies were done on rodents (who use estrogen differently in their bodies than us humans), or used doses of soy that would be almost impossible for people to ingest on a daily basis. When you look at longer-term studies done on actual populations (for instance, Japanese people who consume soy daily) they saw a health benefit! The risk of coronary heart disease decreases, risk of breast and prostate cancers decreases and there is an improvement of bone mineral density in people who consume soy regularly (1,2). What’s more is that the phytoestrogens in soy can help some people alleviate symptoms of menopause such as hot flashes. Over many years of review the United States Food and Drug Administration, World Health Organization, European Food Safety Authority and other governing bodies of food safety have concluded soy to be safe. In addition to being safe, soy can actually be a great addition to plant based diets because it is so rich in nutrients.
Soy is a highly nutritious food. Soy beans are a complete protein, meaning they contains all of the essential amino acids that are needed by our bodies. Soy’s protein profile is especially beneficial for vegetarian athletes because it is high in the branched-chain amino acids (BCAAs) that are so crucial for building and maintaining muscle mass (3). Apart from high quality protein, soy also contains healthy fats. Soy is rich in unsaturated fat and contains those heart-healthy omega-3s. There is also a lot of fiber, iron, calcium, magnesium, vitamin K, and other important nutrients in soy. In fact, it’s is so nutritious that soy milk is the only milk recognized as a good alternative for dairy milk by the National School Lunch Program.
Don’t let the negative press keep you from enjoying soy! Here are 3 tips for making sure you are consuming the best sources of soy and capitalizing on the great nutrition that can be had when you consume it!
- Eat fermented soy products: Soy is found in many forms, and that is something that shouldn’t be overlooked when talking about its benefits. Soy tends to be difficult for some people to digest due to anti-nutrients that interfere with absorption. However, fermenting seems to improve the digestibility of soy while maintaining all its other benefits. These fermented varieties have been eaten by Asian cultures for thousands of years and include tempeh, miso, natto and soy sauce.
- Eat edamame and other “whole-food” sources of soy: Many of the studies that put soy in a negative light are those which use very processed forms of soy as their subject matter. Obviously, nothing in its most processed form is going to be beneficial for the body (think corn vs high fructose corn syrup) so avoid things like “hydrolyzed soy” “soy isoflavones” or “soy protein concentrate” these products are the protein or phytoestrogens of the soy without all the fiber, antioxidants, and other beneficial nutrients. Stick to the less processed versions of soy-based foods such as edamame, dried soy beans, tofu, and some soy milks and yogurts (check the labels!) Look for Organic or non-GMO project verified stickers to ensure you are getting the most nutritious varieties.
- Eat in Moderation: Since the only negative effects were seen in extreme overconsumption, it’s purdent not to go overboard with soy. As with any food, enjoy it in moderation and avoid having it at every single meal all day long. A varied diet is always best and will ensure that you are getting a full spectrum of nutrients, flavors, and benefits.
Soy can have a place in your healthy diet, just eat the right sources in moderate amounts and you can reap all the benefits of this highly nutritious, protein packed food! If you haven’t tried soy in its many forms, try this low carb (but high flavor!) Asian “noodle” bowl recipe below which features edamame and soy sauce!
- Xiao CW. Health effects of soy protein and isoflavones in humans.J Nutr. 2008;138(6):1244S-1249S.
- Zhang X, Shu XO, Gao YT, et al. Soy food consumption is associated with lower risk of coronary heart disease in Chinese women.J Nutr. 2003;133(9):2874-2878.
- Messina M, Messina V. The role of soy in vegetarian diets.Nutrients. 2010;2(8):855-888.
Asian Sesame Bowl for One
10 minutes total prep time
- ½ daikon radish, spiralized into noodles
- 1 cup assorted veggies (bell peppers, radishes, green onion, carrot)
- 1/3 cup edamame
- 1 tsp sesame oil
- Sprinkle of sesame seeds
- 1-2 Tbsp thai peanut sauce
Assemble all ingredients in a bowl, top with Thai peanut sauce and a sprinkle of sesame seeds.
Thai peanut sauce
- 1 tsp dried ginger (or use ½ Tbsp fresh)
- 1 garlic clove, crushed
- ½ cup peanut butter
- 2 Tbsp Soy Sauce
- ½ lime juiced
- Red pepper flakes or sriracha to taste
- 1 tsp maple syrup
- Warm water to thin
Mix together in a small bowl, let sit for 20 minutes before serving so flavors fully combine. Refrigerate for up to one week.