This post was originally an email that I sent out to my email subscribers that got so much feedback & commentary I thought it really should be a blog, too. Caveat: this post is an overview, a skating over of all the *beef* I have with soy, with some loopholes and exclusions, and my ever-present tangential thoughts railing against nutrition dogma. Enjoy.
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Do you ever have the thought that the older you get and the more experiences you collect, the more you realize that you know less than you ever thought you did?
When I was 15 years old, boy, did I know everything. I knew everything there was to know about nutrition, the world, lame political figures and certainly everything everyone else needed to do to live their life appropriately.
Then I went to school. Not just university and med school and stuff, but the School of Life.
Where I learned that I didn’t really know that much at all. And the more “facts” I learned, the more questions were raised, the more gaps in knowledge were exposed. I know enough now to heartily tell you that I don’t know everything.
So, it always catches my eye/attention when I see, read or hear someone claiming that they ABSOLUTELY KNOW something to be true…particularly when it comes to nutrition, but we could really wax poetic on any subject here, right?
These types of statements catch my attention because a) they’re showing their ignorance, often on a professional platform because b) for any blanket statement you make, you can find an exception to it, particularly when it comes to nutrition.
I’m anti blanket statement. I’ve learned this the hard way, through eating my own words and being humbled and simply through experience. So I do my best to qualify what I say, offer context and stress the importance of individual preferences, sensitivities and unique makeup. I use guidelines and pretext and my professional and clinical judgement as well. Being a human, I know these are not infallible, so I’m not as attached to them as I once was. Things change. When we learn more, we can do better, and do better for others.
Such was the story with soy. About a decade ago, it was hailed as the panacea for everything. Great protein, anti-cancer, good for hot flushes. This was mostly due to an enormous push by the agriculture industry, but I think that is a post for another day.
Recommendations for soy consumption exploded. I still have people coming in to see me every day, eating soy bars and soy sprinkles and tofu and Morningstar farm burgers and all variety of soy-based things. This, despite the pendulum swinging the other way on soy.
We have newer and better and more accurate info on soy now. A result of this mega soy push was an increase in gut and hormone-related symptoms.
Soy is not the health panacea it was cracked up to be. There are a few issues with soy:
1. Soy contains protease inhibitors. Protease is the enzyme that breaks down proteins. When you eat soy, you are blunting protein digestion. When protein particles are not fully digested and remain large and unbroken and then they hit the small intestine, guess what happens? Bloating. Immune provocation. Gas.
2. Soy contains oligoasccharadies (carbohydrates with many sugars) that are unrecognizable by the human GI tract. If we can’t recognize them, we can’t break them down. If we can’t break something down, and it hits the small intestine, see above. And add to that list, you are giving your microbiome (the colony of beneficial bacteria living in your large intestine) a highly fermentable thing to “chew” on. So, more gas.
3. Compounds in soy slow the conversion of inactive thyroid hormone to active thyroid hormone. Lots of my soy-eaters were coming in with hypothyroid symptoms, and this is why. Soy, especially consumed at a high rate (1-2 servings/day) can act as a goitrogen – a harmer of and reducer of thyroid function.
4. Soy is a SERM, a Selective Estrogen Receptor Modifier. For some ladies, this means that using targeted soy compounds during hot flashes can help, but more often than not, soy actually exacerbates estrogen-driven dysfunction. Although I have seen some women do well on soy (specifically the compound genistein) I have seen more flail.
5. Soy is often heavily contaminated with aluminum – terrible for brain health and blood pressure. Like, really terrible.
6. The lion’s share of soy in the US is GMO. Say what you will about GMOs, but their safety as a food source has not been adequately vetted, in my opinion, and we are the living, breathing experiments for it at this time.
7. Soy is not-so-great for the wee ones, either, speeding up puberty in girls and slowing it in boys.
8. Conventionally grown soy is sprayed with Round Up (glyphosate) before harvest. There are several problematic things that happen with glyphosate – it interrupts gut flora, spurs the growth of pathogens, binds minerals so they cannot be used, disrupts cytochrome P450 enzymes and a host of other issues, including showing devastating effects in animal studies. We have not heard the last of this compound.
The exception to the above?
Fermented soy. Fermented soy, things like miso, soy sauce and natto, being partially digested through bacterial fermentation, do not have the same reactivity that edamame, tofu and soy sprinkles do. To avoid GMOs and Round Up, organic is a must.
I get this question all the time: “What about soy lecithin? It’s in everything!” Indeed it is, and what I have noticed is that only those who are exquisitely sensitive to soy will not be able to handle it. Most others seem a-ok. Truth is, you are going to find a lot of this stuff (along with soy oil) in the vast majority of processed/packaged foods, some supplements and things like protein bars and such.
It’s everywhere, due to the sweeping success of that agriculture campaign I alluded to above.
In general, my recommendation is that soy is a food to be minimized in most, for the reasons outlined above and because in my experience it’s one of those more prone to be allergenic (much like gluten and casein).
As ever, there are nuances: how much, what type and individual sensitivity. For most, a small bowl of edamame or some tofu in soup when you are out to eat at a sushi place once or twice a month are not going to make huge impacts, but for some that certainly will.
It all comes down to that bottom line, the place that only you yourself can get to: Know your body. Know your food.
I’ll take the tofu-free version, thank you…