FTC Disclosure: If you make a purchase through a link on this site, I may receive a small commission on the transaction. Clicking these links doesn't cost any more to you, and it does help me with my small business so I thank you so much for any support you want to give!

Soy Protein Isolate

by Kathleen
(Salina, KS)

Soy protein isolate is a problem for me.

I am a dedicated vegan since 1996, and vegetarian since 1989. I do have concerns about soy, on two fronts. First, I have read that soy products (as well as certain other foods such as cruciferous vegetables) can inhibit iodine absorption in the body and therefore create thyroid problems. However, I have also read that this problem of preventing iodine absorption can only happen with uncooked foods, and normally one would not be eating uncooked soy. I do have an underactive thyroid for which I have to take medication, so I do have concerns.

Second, and most importantly for me, many forms of soy I find very difficult to digest, especially soy protein isolate, soynuts, and edamame. These cause me intestinal cramping and irritation (I have this same problem with nutritional yeast.) I am wary of soy flour and soy oil as well on this basis. I have also read that soy oil is considered toxic in traditional Chinese medicine.

This is unfortunate because so many foods now have one or more of these ingredients, because they are so readily available and cheap, I think, especially soy protein isolate. I do not seem to have problems with tofu or tempeh, however, and continue to eat those in moderation, but not everyday.

I do wish that soy were not so ubiquitous, for several reasons. Based on my thyroid concerns, my digestive difficulty with many forms of soy, knowing that other people have similar digestive troubles with it, and the serious environmental ramifications of soy as a crop, I think it is very, very unfortunate that so many foods, as a matter of routine, have soy as an ingredient.

It's like putting too many eggs in one basket, so to speak, to use a non-vegan metaphor. All in all, this heavy reliance on soy does not seem balanced to me.

And to say a little more about the serious environmental ramifications: I have actually heard people use that as an excuse to put down vegetarians and vegans-- as though, well, if you're a vegetarian, of course you eat soy, and therefore you are harming the planet by stripping the forests and stripping the topsoils. I have a not-very-close friend who is a soil scientist who has not only said this to me, but also makes this point in public lectures he gives. This guy used to be a vegetarian, but now he uses the environmental harms of soy as an excuse not to be a vegetarian.

Again, if there hadn't been so much hype about soy being "the" vegetarian food, and if so many food products hadn't started loading up on soy ingredients, and if there were more variety in the vegetarian and vegan-themed foods out there (i.e., more veg friendly options out there that don't have soy in them), I think it would very much help the vegetarian and vegan cause by not limiting its image and reality to soy and its pitfalls.

Comments for Soy Protein Isolate

Average Rating starstarstarstarstar

Click here to add your own comments

Environmental Impact
by: Anonymous

Industrialised livestock is fed copious amounts of grains and beans, including soy. I don't see how eating a kilogram of steak, which requires >2 kilograms of soy (and other grains/beans) to be constructed, is MORE efficient than eating the soy and grains themselves.

I'm not sure who your contact is, but I'd very much like to hear his argument because the way I see it, this is a no-brainer. Assuming we are not grazing our own livestock purely on grass from our own homes, how can bypassing an inefficient converter of soy be, well...inefficient? Meat consumption demands more soy than a vegetarian could ever hope to eat.

Here is some data:


Too much soy.
by: Anonymous


Another reason it's so difficult to avoid soy is because it's nothing more than a cheap filler for food. And the food industry knows this. They use it as one way for profit, just like they do when they reduce the size of cans and raise the prices at the same time.

Btw, I also have the same concerns as you do because my thyroid was destroyed as a child via x-rays ( they didn't know much at the time about the dangers of x-rays in order to take preventative measures ). I also have to take a thyroid suppliment, and in spite of this, know that soy can still affect us. All in all, I believe that there is way too much soy around.

A Wisconsinite

Very useful
by: Flo

Thanks a lot for this post, clear and very useful.

Click here to add your own comments

Return to Soy Nutrition.

Follow Me on Pinterest

FREE Vegan Ezine! 2011 Subscribe to
Vegan Bytes
and get a FREE 5-page guide to weight loss!

Email Address
First Name

Your email address is completely secure. I will only use it to send our newsletter.

Site Reviews   |   Advertising Policy   |   Privacy Policy   |   Meet Me   |   Search this Site   |   Site Map

by Cathleen Woods   |   © Copyright 2008-2021  |   Vegan-Nutritionista.com

Disclaimer: Everything in this website is based upon information collected by Cathleen Woods, from a variety of sources. It is my opinion and is not intended as medical advice. We do not sell personal information.
It is recommended that you consult with a qualified health care professional before making a diet change.

As an Amazon Affiliate I earn from qualifying purchases.