Is Soy Bad for You?

I'm thrilled to introduce my dear friend, fellow dietitian, and cookbook author, Desiree Nielsen. With a focus on plant-based nutrition and gut health, she is here to address a commonly held nutrition belief about soy and use evidence-based understanding to provide clarity and truth. Here she is!

I had the unfortunate experience of having a post go viral-ish a few weeks ago… I say unfortunate because when a post gets sent out to strangers, the comment section gets filled up with lots of misinformation and name-calling. The experience reminded me that SO many people believe things that aren't actually true. So, it's high time to bust one of those myths. Let's do this!

Myth: Soy is Bad For Your Hormones

I'm choosing soy because, well, a lot of people avoid soy foods because they've heard that soy is 'high in estrogen'. Like most wellness myths, they always start with a kernel of truth. So let's start there.

The Truth

Soybeans contain phytochemicals called isoflavones, like genistein and daidzen. Isoflavones have what is called phyto-estrogenic activity. Sounds like the estrogen in our bodies, right? Except that it's not: phytoestrogens have very weak estrogenic activity, essentially 1000x weaker than the estrogen in our bodies. What's more, phytoestrogens appear to interact with different estrogen receptors (beta type) than our own estrogen does (alpha type).

So, if isoflavones are phytoestrogens, what do they actually do? They appear to MODERATE estrogen in the body. For example, blocking the effects when estrogen levels are too high and standing in when estrogen levels are too low.

The Evidence

Still unsure? The mechanisms of action are one thing, but you have to feed people soy and see what happens to be sure, right?

Well, we have DECADES of research to suggest that:

A) soy doesn't harm your thyroid;

B) it doesn't mess with male reproductive hormones;

C) it lowers your risk of breast cancer, heart disease and even death.

The Bottom Line

So, unless you are allergic or intolerant to soy (it is a common allergen), you can feel really good about eating this protein-and-mineral-rich food.

This is all a big oversimplification of course, but if you want to dive into more information, I have a blog on the health benefits of tofu and a podcast on the science of soy with Dr. Matthew Nagar.

Closing Note

I want to thank Desiree for sharing her wealth of knowledge with our audience. For those eager to dive deeper into her expertise, I highly recommend checking out her Instagram, listening to her podcast, subscribing to her newsletter and exploring her articles.