Do You Avoid Soy Protein Isolate?

I don’t actually know the answer to this question! But since our friends at Well+Good are asking, it’s got me wondering. Do you avoid this super-processed soy? I’m about to go read a few labels…

Turn over many a nutrition bar or box of veggie burgers, and you’ll often find soy protein isolate (SPI) featured prominently on the ingredient list.

While there’s disagreement among nutritionists over whether soy is part of a healthy diet (some are concerned about its estrogenic properties but others like it as protein source for those who don’t eat meat), most agree that SPI, its super-processed offspring, should be avoided.

“A big issue with soy is that we’re eating more of it than ever before and in very processed forms like SPI,” says Middleberg Nutrition founder Stephanie Middleberg, MS, RD. So SPI may have started out as a plant, but once it gets to you, it’s far from it.

Here are four reasons nutritionists say you should probably ditch soy protein from your diet:

1. A lot of its nutrients have left the building. “Soybeans are a great quality protein because their amino acid content is similar to that in meat, and they’re a good source of fiber, minerals, and complex carbs,” says Middleberg. But to create SPI, soybeans are chemically engineered to “isolate” their protein, and this process strips out all of the other nutrients the original bean contained.

2. It contains unhealthy additives. Foodtrainers founder Lauren Slatyon, MS, RD, says that the chemical process used to isolate soy protein often leaves behind substances you don’t necessarily want to be eating, like aluminum and hexane. “Think of bathing in toxic bath oil,”Slayton says. “Even once you dry yourself off, some residue remains. Want to eat that residue?” The spray drying method used for soy can also form nitrites, compounds that can form carcinogens in the body, she explains.

3. It’s probably genetically modified. According to the USDA, over 90 percent of the soybeans grown in the U.S. are genetically modified, so most SPI comes from altered beans. “This means soy protein isolate is chemically modified, processed, and filled with pesticides,” says Middleberg.

Yikes! Finish the article here.

20 Responses to “Do You Avoid Soy Protein Isolate?”
  1. Amanda says:

    Yep, I avoid superprocessed anything, especially soy. I can make my own veggie burgers sans-crap-ingredients and as long as you’re eating a balanced diet with sufficient calories and stick to whole foods, protein shouldn’t really be an issue. It’s not very hard for me to avoid that kind of stuff.

  2. Alexandra says:

    @Amanda – Would you share your veggie burger recipe? :)

  3. Jay says:

    Yes, I too try to avoid all soy products. I used to drink tons of Silk soy-milk, but then I read about the possibility that it contained GMO soy. Most soy in the U.S. is GMO anyway.

  4. Silvy says:

    Yes! It makes me break out like crazy! I’m still trying to figure out if that includes tofu… and how much. But definitely no fake meat and no soy milk.

  5. Amy says:

    I avoid super processed ingredients, especially soy, as much as I can. I do still eat some soy (tempeh, edamame) but always make sure it’s non GMO. I’ve also noticed SPI tends to be in foods that are highly processed and have other ingredients I’m not okay with anyway. I don’t think it’s necessary to eat it for protein – there are so many better (vegan) options.

  6. Alex says:

    This has become a huge struggle for me because I am aware of it and it does bother me. The only soy I allow myself to eat is organic so that I know it is non-GMO and hexane free. (Something like 90% of U.S. soy is GMO!) But it seems like more and more soy is being thrown in because it’s a cheap byproduct like high fructose corn syrup. Chocolate…try and find chocolate without soy lecithin, which is used as an emulsifier. Nearly impossible! I try my best to eat a no-processed food diet, but sweets are usually an exception. And I can’t even imagine having a soy allergy…

  7. mangomadness says:

    Yup! I tend to avoid soy although I do indulge in a bit of tofu know and again.

    My homemade veggie burgers are way better than store-bought. Here’s my favorite recipe:

  8. comagirl says:

    I avoid processed food. I am tempted to take the Eating Rules Challenge for October. Has anyone else heard of this? It was in the LA Times recently.

  9. Natalie says:

    I have PCOS and so I avoid all soy as well since I’m already hormonally imbalanced/because most soy in the US is GMO.

  10. Beth says:

    I also avoid processed food. I try to make most of what we eat from scratch. We do eat tofu, edamame, tempe, or miso two or three times a week. All of the veggie burger recipes from Sarah Kramer’s cook books are pretty good .

    @ Alex – giddy yoyo chocolate bars are soy free, vegan, raw.

  11. Cole B. says:

    I avoid soy protein isolate, along with most other forms of soy. There are just so many better alternatives.

    @Alex Have you tried chocolate by the brand Enjoy Life? It is seriously the best grocery store chocolate. And no soy!

  12. JeanineD says:

    I avoid most soy products, except the little bits found in my organic gluten-free waffles and dark chocolate. According to the Weston Price Foundation, whenever soy was eaten in traditional diets it was always fermented (tofu, soy sauce, miso), not like we eat it in the US today, and of course it was never GMO. This is the type of soy consumption that is confirmed to be good for you. I am convinced that unless eaten this way, soy is not a healthy food.

  13. Rebecca Bailey says:

    I eat soy occasionally – tempeh and edamame. But I’ve avoided the soy protein isolates for many years. Generally, when we try to take apart a whole food, things go wrong!

  14. Vanessa says:

    I avoid soy most of the time primarily because I don’t like the taste of much of it and because I believe most soy products available to be unhealthy. I do make the occasion exception and enjoy types of fermented soy. SPI is tough to get away from. I try to avoid foods where it is a main ingredient. I will make exceptions for it in foods where it is way down on the ingredient list like on the granola bars I buy.

  15. Amanda says:

    Hey Alexandra- Here are the veggie burger recipes I’ve recently tried, all have turned out decent. The one thing I found is it helps to rinse and pat off any beans that you use to get rid of excess moisture, otherwise they turn out too mushy. If you’re a former-morningstar-addict like me, you can make a big batch then freeze them on wax paper so it’s easy to grab one and go :)

    Chickpea veggie burgers tutorial:

    Quinoa black bean burger:

    Cheddar quinoa burgers (these are my fave):

    Spicy black bean burgers (pretty close to morningstar, I add cayenne, chili powder, or use spicy peppers instead of hot sauce):

  16. Emma B says:

    I do eat quite a bit of soy, but like most people here I eat mostly unprocessed organic soy (milk, tofu, edamame, miso). I do have some processed tofu products about twice a month, mostly spicy tofu sausages. I actually just googled those, and it turns out they are made with non-GMO tofu. Most of the people I spend time with don’t eat the way I do, so sausages are a good compromise when I find myself at a BBQ.

    I have always had digestion problems though, and reading some comments on this blog has encouraged me to experiment with my diet. I’m sorry to report that so far I’ve tried eliminating dairy, soy, and wheat, and it hasn’t made much of a difference.

  17. Rebecca says:

    @Emma B, best of luck with finding the key to your digestive issues. Some other possible things to try would be sprouted grains in place of regular grain (you can find bread and pasta this way, but many do have sprouted wheat). If you are replacing wheat with something else you have a problem with that could be playing a role. For example, I have a problem with both wheat and quinoa, so if I had replaced wheat with quinoa I might not have been able to figure things out. Also, in addition to elimination, take a look that you are getting what you do need. Maybe try some fermented foods to get your microflora healthy.

  18. eva says:

    SPI just seems like a super strange compound anyways. Everybody’s body and preferences are different of course, but I just have to weigh in that I recently gone paleo, doing the Whole30, and my digestive issues have cleared up big time and so has my skin. It basically means no dairy, gluten, soy, sugar, seeds, legumes and any kind of grain – but lots and lots of veggies, fish, avocados, olives, and some meat. And…I feel great. Awesome, actually. And while I don’t know if it’s from cutting dairy or just eating more veggies, or my new Stark skin care, my skin looks absolutely fantastic. I suspect it’s that I, finally, eat what I call real food. Veggies. Meat, Eggs. Fish – recognizable stuff that’s just full of fuel. Absolutely no “fillers”, in terms of rice or bread or grains or whatever. Anyways, just wanted to throw out there that the paleo diet as done in Whole 30 has solved a lot of my problems, including hormonal imbalance, and a pesky back pain due to low-level inflammation, because there’s so much talk about eating vegetarian or vegan on this website. I always aspired to that and I ate really well, but as it turns out, I personally just really, really thrive with some high-quality, pastured, free range, humanely raised meat in my diet. Maybe it’ll work for others too?

  19. Rebecca says:

    @eva, though I personally eat vegan, I think you make a great point – good quality animal products can be healthy for many people.

  20. Saiule Sarin says:

    To clear up so much, it’s good to know that organic does not mean non-gmo. To certify organic they do not test the genetic structure of the items being certified. There is an organization that does specialize in certifying products non-gmo and it’s the Non-GMO Project. Just know that you should first trust the company you are purchasing from. An example of this is the many companies that are releasing organic products and they are not organic companies. Purchase from a non-gmo and organic based company to ensure trust in quality.

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