Is soy sauce “safe” for people with Celiac?

Just recently my husband and I were talking about soy sauce.  I know, it’s not your typical lovey-dovey conversation, but really – who has those everyday and/or posts them on their blogs?    But in all honesty, our discussion has often bounced back to soy sauce in regard to Celiac/Gluten Free diet.

You see, the reality of my life is this:  soy sauce is in everything (well… almost everything) my in-laws cook.  And while we sadly have not been able to travel in years (read: 2003) to visit them, we would like to.  We want to bring these beautiful babies toddlers (!) we have back to see the rest of our family.  So we start talking about the added expense of traveling when you need to buy food and/or cook.

Primarily while staying at someone else’s home, I don’t want them to feel put-out that I don’t eat what they are serving.  At my parent’s house, I have no problem sliding in to the kitchen and cooking.  In fact, I love it!  But at my in-laws, the kitchen is laid out differently and they do a different style of cooking than what I grew up with.  It makes cooking for them a bit more of a hurdle.  Add to that the fact that food intolerances/allergies are truly not a common topic nor common in the general Asian population (aside from dairy/lactose which isn’t really in the main diet plan anyway) and well… it can lead to some hurdles.

So back to the soy sauce.

When we traveled in 2003, I just bought a bottle of San-J when we arrived for cooking.  It was a great conversation starter (lol!) as we talked about the salty (or non-salty) factor compared to the sauces they liked to use.  (Yes, each varies significantly in saltiness, thickness, etc.)  At one resturant, my father-in-law tried to help my by explaining that I can have wheat/soy sauce and he beamed with pride when the wait-staff and chef told him there was no wheat in what they made.  And then out came the wheat-puffed pancakes for the wheat-soy sauced laden Peking Duck.  (PS.  The “dao mew” – snow pea pods shoots – were AWESOME that night.)

Soy sauce is everywhere in the Asian diet.

And I don’t always trust the labels.

And then I found this study by Frederik Janssen on the GlutenTox blog.  (I am not associated with them, just found them via my search about gluten and soy sauce).  (Copy of the PDF is here:  Safety-of-Asian-soy-sauce-in-gf-diet).

Approaching the gluten free diet frustration of eating-out and the common exposure/concern of soy sauce, the study looked at the varying ingredients found in different soy sauce brands (European based) and analyzed them for their gliadin content.  Remember, the protein that causes the damage to the intestinal track for Celiac patients (like myself) is this protein.  Truly, it is a speck within the wheat grain.

From the anecdotal piece of their survey, Celiac patients who self-reported information regarding how they approach soy sauces responded with the following commentaries:

  • avoided all products with wheat listed on the label
  • consumed soy sauce with wheat listed on label with non-typical reactions that could not be attributed to the wheat/soy sauce
  • consumed soy sauce with wheat on the label with “ease since they know the proteins in these sauces were almost completely degraded; consequently they did not experience any symptoms.” (p.56/Jannsen)

The report further states that “given the results of our analysis, it is quite remarkable that symptoms occurred in some coeliacs after these products were eaten.”

The scientific analysis appears to demonstrate that the levels of gliadin are slightly lower (on average) that the proposed levels (20ppm in the EU).  Most surprising to me was this statement:

“Given the amount of soy sauce used in Asian dishes this level might be irrelevant.   


“There seems to be no correlation between gluten content and the declaration of wheat on the product label.”

The attached PDF (referenced above) then continues on to discuss the types of labeling laws now required (and those not, like for wheat starch) in the EU as well as whether or not the methodology available for analyzing such materials is suitable for the hydrolyzed gluten proteins found in the fermented goods like soy sauce.

As a result of their analysis (please, read it for yourselves) are the following recommendations:

  • that, as far as possible, Coeliacs should choose Asian soy sauces which do not include wheat.
  • if such information (ingredient listing) is not available, they should not be worried about the ingestion of gluten as investigation have shown that hte level so fgluten are almost insignificant in relation to the safe dose as reported by Catassi…
  • Coeliacs should, however, still avoid dishes with very high levels of soy sauce.

Truly I am awed.

I have always wondered.  And in all honesty, have not worried too much about soy sauce.  I have a good handle on food prep/recipes in Asian (mainly Chinese) foods and have felt fairly confident selecting my items with care.  But soy sauce remained one of those ingredients that I question.  NOT because I think it is “bad” but because I wonder what the levels truly are.  This paper has brought the conversation back to our dinner table.

I’d love for it to begin conversation here.

What do you think?  I’d love to collect some info/ideas from you all to post in a follow up post.  I will NOT share you personal information ever.  The results will be tabulated into a graph for sharing.  If you are willing, please click here.

Is soy sauce ‘safe” for the gluten free diet?


  1. I have accidentally eaten a dish with soy sauce in it and been violently ill. This dish is identical to one I normally eat, same restaurant, etc. except they accidentally gave me the plate with the wheat-containing soy sauce instead of the tamari (wheat-free) soy sauce. I realize I’m a highly reactive celiac but I think relying on “symptoms” to tell you whether damage is being done in a disease that many sufferers do not have immediate or overt symptoms is a bad idea.

    For myself, at least, I am not going to take that chance nor suffer days of vomiting and illness because “the amount might be so small”.

    • GF and more says:

      I was just about to write the same response! Agree 100% with this. For me, no amount, not even the most miniscule, is safe. Better to avoid things all together, especially given the internal effects.

    • Me too! Once at PF Changs, I found this out after the fact, they didn’t have their usual hot sauce and the substitute was apparently too spicy, so they added soy sauce. The server saw me eating the hot sauce and told me “Don’t eat that!” and explained the situation. I had a really intense DH rash for over 2 weeks. That’s the only time that I know I consumed wheat (vs cross contamination) and by far the worst reaction to gluten that I’ve had since going gluten free.

  2. Marleena A says:

    Even without symptoms you are doing damage. There are many walking around who are Silent Celiacs they don’t have symptoms but they have damage. Why chance it? If you know you are Celiac you are at advantage you can avoid items that will cause you harm.

  3. I have eaten soy sauce by accident multiple times. A couple of those times I have had a notable immediate reaction. And a few more times I had no reaction or such a minor reaction I didn’t notice it.

    This is also an interesting question for me. I’m going to China for 2 weeks with my MBA program. All of the meals will be with the group, so I don’t think I will have much choice about where I can eat. The school has promised to help me request food made without soy sauce or wheat, but I am still worried.

    Any ideas about what I can request?

    • Mary Garrard says:

      Hi, I traveled to China a couple of years ago. Our guide called ahead to order our food. We ate family-style at tables with our dishes placed on big lazy susans in the center. We had a number of food issues, in addition to my gluten-free needs: someone else couldn’t eat spicy foods, others were vegetarian, etc. So our guide ordered food for the least common denominator, and they put various sauces including soy sauce and hot sauce on the tables so those people who could eat anything/everything could flavor-up their food. Even though our guide pre-ordered and asked for everything to be made without soy sauce and that only non-gluten starches be used in the sauces, I inspected each dish and didn’t eat anything that looked brown-ish. It wasn’t fancy food but we ate adequately.

      From our experience in China, I would be more concerned about getting an intestinal bacteria or virus. I made it through with good intestinal health (except constipation, but that’s a different problem!) but others in my group did not and some got quite ill. I attribute my good outcome to lavish use of hand cleanser and soap and water wherever I could find it. If you can get everyone in your group to use it so much the better! Also if you haven’t done so already, get a Hepatitis-A vaccine. I didn’t, and I wish I had. I didn’t get hepatitis, but once you see where some of the food is grown, you will want to know you are protected!

      Overall, I had enough to eat. I did buy some food at groceries (with our guide translating for me) like peanuts and other snacks I could eat if I was unsure of the dishes.

      I hope you have a great time. China is a wonderful country and I would go again at the drop of a hat, despite the food issues.

  4. I agree with Marleena. I have also discovered, the longer one is gluten free, the more reactive I have become if there is cross contamination of ANY kind. We only have gluten free Tamari Sauce in our home, and only eat at restaurants I know will be 100% safe. It does make traveling a huge challenge.

  5. Ahorsesoul says:

    I agree. I do not eat anything with soy sauce unless I know the soy sauce is gluten free. I carry a small bottle in my purse if I’m going for sushi. More and more places are offering gf soy sauce if you ask for it.

  6. Emily at GlutenTox told me about this info some time ago, but I will never eat soy sauce unless it is specifically gluten free. As one who is SUPER sensitive, studies like these showing a product is less than 20 ppm don’t help me at all. I’ve reacted to products certified to well less than 10 ppm,even less than 5 ppm.

    I still travel and still dine with friends and family. I just make it work by focusing on foods and dishes that are naturally gluten free. The whole meal doesn’t have to revolve around me though. I know you wouldn’t approach it that way either, Kate, so I’m sure you could make a visit work out. 🙂


  7. Katherine Kelley says:

    I avoid soy sauce. The couple of times I have accidentally consumed it I got sick. It does make traveling a challenge, but I’m sure they don’t want you to become ill. I imagine a compromise of some sort can be worked out.

  8. Interesting discussion. I have little or sometimes no reaction when eating foods with regular soy sauce, and eat it regularly now by taking enzymes for digesting gluten.

    With regards to gluten labeling, I’ve wondered whether or not labeling foods with under 20ppm gluten as “gluten free” will work for those who are extremely sensative to gluten.

    II think this a good example of how some gluten-sensative people are fine eating foods with under 20 ppm gluten, while other people really do require 0 ppm gluten.

    Thank you for researching this.


  9. elizabeth Kohnen says:

    I read a study that said that if you are diagnosed with celiac and cheat, even if it doesn’t make you sick, you have a 10 times greater risk of developing colon cancer. That’s enough of a risk for me to avoid soy all together. That said, I do use tamari, which is gluten free and makes a fine substitute.


    • Mary Garrard says:

      Hi, can you locate that study? I’d be interested in seeing it. I couldn’t find anything in the literature correlating colon cancer to untreated celiac sprue. The increased cancer risk from celiac sprue is for non-Hodgkin’s lymphoma and small intestine malignancies, not colon cancer. Furthermore, a gluten free diet may be fully or partially protective for lymphoma and small bowel cancers, but that’s not been proven as there is some evidence that it is not protective. And, it’s also not known how much gluten one must ingest in the minuscule amounts found in soy sauce over what period of time in order to be at higher risk of these cancers after going gluten free.

      My best practice has been to avoid consuming soy sauce that I know contains wheat, but it seems from this information that it might not be much of an issue, especially since one of the findings is that some sauces NOT labeled as containing wheat, did actually have detectable, although low, levels of gluten. I don’t have reactions to inadvertent gluten exposures (I never cheat, but have been inadvertently exposed several times over the 12 years since my diagnosis), so my main concern for myself is preventing associated conditions like malignancies or nutritional deficiencies.

      See this article: for a good review of malignancies in celiac sprue.

      • peter williams says:

        Hi Mary, Thanks for this response. It would seem we are both asymptomatic coeliacs? If that is the case I wondered whether you knew of any research that explains why some coeliacs have no symptoms and others have extreme reactions to gluten?

  10. sandygoral says:

    I have ingested soy sauce in error and was sick for a week after. I am not super sensitive to gluten, but that made me really sick. Also for your info, my mother died from pancreatic cancer and I am told that it was due to undiagnosed celiac disease. I am not eating anything that can cause that or colon cancer.

  11. sandygoral says:

    Recently I ingested soy sauce in a restaurant, they omitted the soy sauce for me but apparently did not clean the wok before they prepared my meal. I was sick for a week. I don’t consider myself super sensitive to gluten, but that made me really sick. Further, fyi, my mother died of pancreatic cancer and I have been told it was because she had undiagnosed celiac disease. I am not going to eat anything containing gluten as I don’t want pancreatic or colon cancer.

  12. missdarque says:

    Soy sauce/”shoyu” is in so many recipes here in Hawai‘i. It’s so difficult to explain to people in restaurants that I’m not allergic to soy, but the wheat that is in soy sauce. The majority of people don’t even realize there is wheat in soy sauce. I didn’t until I had to stop eating gluten.

  13. I have been pondering the “soy sauce issue” for several years now. My daughter is a celiac and we just moved to Hong Kong (we lived in China when she was first diagnosed).

    This is something that the great magazine, Gluten Free Living discussed back in 2009. Basically, they said that there was not (yet) a good enough test to determine the effective level of gluten in soy sauce. In their next issue they plan to revisit this same question. I’m waiting with baited breath.

    We take a bottle of gf soy sauce everywhere. We eat lots of sushi but avoid Chinese places (because of the kinds of communication problems your father-in-law and you experienced….)

    Finally, also having lived in the UK, I’m quite comfortable with the 20ppm rule that the EU uses (and is proven not to cause damage in the great majority of celiacs).

    Finally, finally, folks suffering very bad reactions, might be reacting to the MSG, which a lot of non-celiacs have a problem with as well.

    • I’m sure my reaction to the food was to the soy sauce as the restaurant is MSG free.

      That said, only you can determine what you consider an acceptable level of risk for yourself. I consider soy sauce to be an unacceptable level of risk for ME.

      • I agree completely. And I haven’t ever given regular soy sauce to my celiac daughter for the same reason. But a girl can dream (as it would greatly simplify our lives!).

  14. For those of you who got sick after ingesting gluten in soy sauce, I heard that if you take Gluten Ease enzymes and a benadryl you can minimize the effects of the gluten. I am going to try this to test it out and will report back.

    • I take GlutenEase whenever I eat anything that I haven’t prepared myself. It does seem to help with symptoms from cross contamination (sometimes I still get a very mild DH rash, but no belly ache), but I have no doubt that my body is still being damaged by any cross contamination. It’s a nice safety net, but I certainly wouldn’t deliberately consume gluten even with the benefit of the enzymes.

  15. I only ever eat soy sauce that is made by a reputable company known to be gluten-free. I asked my doctor about sauces, etc. (especially soy sauce…I love Asian cuisine!), and he said if it isn’t labeled gluten-free, or you cannot call and verify every ingredient with the company, then don’t try it. However, this is my doctor’s plan for me. I know I’m one of those lucky ultra-sensitive Celiacs. I love the San-J Organic Tamari Gluten Free Soy Sauce. It is Certified Gluten Free by the Gluten-Free Certification Organization and they have individual packets you can bring with you when you eat out!! Yum!

  16. No way Jose on the wheat derived soy sauce. There was a time after I was dx’ed where I would eat and get sick and I couldn’t figure out what the heck I was eating that did it (BTW, my first symptom that I’ve been glutened is vomiting. No fun.) Anyway, after a week, I figured out that it was the particular kimchi I was buying at the Asian market which had, surprise, surprise, wheat derived soy sauce in it.

    I have since figured out through accidental ingestion that wheat derived soy sauce does cause me HUGE problems. And I don’t have trouble with other soy products such as tofu, soy milk or edamame so I know it has to be the soy sauce.

  17. I don’t have celiac, but I do react strongly to wheat. I’ve accidentally eaten food with soy sauce in it before and gotten all the symptoms – headache, brain-fog, stuffed sinuses – except the gut ache and bloating. I don’t think I’ve gotten that from any cross contamination since I’ve eliminated gluten from my diet. But, the brain/head/sinus symptoms are bad enough for me to never want to mess with soy sauce with wheat again.

  18. Oh God- I hope/wish this were true. Shoyu is in literally everything out here in Hawaii. Not having to worry about ingesting it would make my life so much easier.

  19. Mary Garrard says:

    Thanks so much for posting this. I too hope that the soy sauce issue might go the way that distilled vinegar went 10 years ago. That made life so much easier, as would not having to worry about soy sauces. Some people still avoid distilled vinegar, but they might have an atypical reaction and in that case it’s an individual decision, like this may turn out to be.

  20. I personally don’t avoid wheat-containing soy sauces when I dine out because I haven’t ever reacted to them, so I’m fairly well convinced that whatever protein degradation/destruction occurs during the fermentation process, along with the small amount of sauce consumed with most dishes, is good enough in my specific case. I use San-J at home, and try to remember to bring some when we have sushi out, but it’s one of the few things I feel comfortable making an exception for.
    However, my assistant here in the Philippines cooked lunch for my husband and me one day soon after she started working for me, she used Silver Swan brand, which I didn’t realize until after we ate. I became super sick very quickly, and looked at the package of soy sauce she had used. The third ingredient was flour. So I guess it’s used as a thickener in this brand? Since it’s such a popular brand here, I do ask at restaurants what brand they use, which I don’t tend to do back home in the US.

  21. Thanks for this post, like you I have been pondering on the soy sauce issue for quite some time. Living in Singapore, soy sauce is ubiquitous, and I love Asian food.
    I am not a coeliac, but a AS (ankylosing spondilytis) suffering combined with IBS, and react strongly to gluten. Probably not as much as some here, I can eat spelt in moderation, but no wheat, rye or barley. My response to soy sauce is mixed.
    I find the article above confusing, their conclusions are not clear and a bit contradictory. I am a food scientist myself but have not studied the matter too thoroughly.
    What I do know is that it depends on the type of soy sauce. Naturally fermented soy sauce contains undetectable amounts of gluten, and are often safe to use for most people (unless you are extremely sensitive, only one way to find out). Many of the cheaper brands though are made chemically and the wheat is still there. This might explain my personal experience, some soy sauce is fine for me, other are not, but my reaction is typically quite mild opposed to other things (for instance just a touch of barley malt gives a bad reaction).
    So look out for naturally fermented soy sauce. Whether you can have it or not might be a personal things, depending on how sensitive you are. I find that occasionally eating out and having a bit of soy sauce is not too bad, but 2 or 3 days in a row will set me off .
    At home I prefer to stick to gluten free tamari just to be on the safe side… The indonesian soy sauce, ketjap manis, is quite often wheat free too but it depends on the brand.

  22. I have celiac, and avoid restaurant eating for the most part when at home, partly because of your fabulous blog–why go out to eat if I’ve learned to cook gf food that tastes better than the boring plain grilled chicken, rice, and salad I seem to be limited to at most restaurants?

    But on work trips to China, I ate soy-sauce laden foods and was fine.

    It’s worth noting that my adult-onset celiac (triggered by all the vaccines my employer made me get for my first work trip to China) was caught within a few years, which is relatively quick. And I was “gluten-lite” anyway, as we eat mostly Asian food anyway. So the gluten damage for me was probably much lighter than for most celiacs, and I think that that makes a big difference when it comes to reaction severity.

    Other than work trips to China (which are only every few years) and the rare Chinese meal at a restaurant (even rarer these days, thanks to the economy), though, I stick with San-J and don’t cheat. My gluten reactions are all autoimmune, including DH, which is horrible–SO not worth the risk if easy to avoid.


  1. […] The best scientific and nutritional analyses to date have shown overall that gluten-freers should opt for gluten-free soy sauce (obvious), but also that small to moderate amounts of the stuff might actually have no effect on those with a gluten intolerance (interesting). To read a little more about gluten and soy sauce, take a look at fellow wordpresser ‘Gluten Free Gobsmacked’s great post on the raging debate: […]

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