Psst... We're working on the next generation of Chowhound! View >
HOME > Chowhound > Not About Food >
Jun 29, 2012 10:58 AM

Challenge: Looking for runners who get what I am dubbing “Tortilla Chip Flush”

I am a runner. I am also the brother of "Karl S" who is a pretty active Chowhound member; he pointed me to these forums (Thanks!)

Over the last several years, I have paid close attention to something that happens occasionally to me, and I am wondering if there are other people who get the same thing, but haven't been able to isolate it.

Here's the deal:

For many years, there were times I would go out for a training run (typically 10K, but could be 5K, 10 miles, whatever), and during the run, I would develop a tingly, itchy, red, hot rash over most of my body (most noticeably in my trunk). The rash would usually go away within a couple of hours of finishing my run.

It took me a really long time to figure out what was causing the rash. At first I thought it was just heat or dehydration, but that proved not to be the case. (Medical review revealed that it's not an allergy as well).

Then I thought it might have to do with my vitamin supplements, since the reaction was very similar to a "niacin flush" that I had experienced when taking Niacin several years ago (something I never did again!). So I stopped taking them for a while.

No change.

Of course, I considered what I had eaten, and noticed that it would almost always occur after having a meal of Mexican food.

But not always!

Several more months go by, and...

Lo and behold, I discovered that it was *tortilla chips* that caused the rash! And the more I ate, the worse the rash was. But even if it was just 10 or so, I would get the rash. (I had to run within an hour or two of eating the chips; longer waits eliminate the issue consistently.)

So, I wondered something: is there some sort of extra amount of niacin in tortilla chips?

Product packaging didn't seem to note it. But then again, snack food manufacturers don't have to report all vitamins that occur in their foods, unless they happen to add the vitamins as supplements.

So I did some research about how corn is prepared for tortilla chips, and, well, wouldn't you know - when ground corn is processed in its usual manner (with lye, etc.), it releases a fair amount of niacin! This was discovered during the fight against Pellagra in the 1930s:

More information is here:

You can Google the rest.

So: Tortilla chips + running shortly thereafter = handy way to get a niacin flush? Indeed, at least for me.

Here's my point: I read things all the time (including in Runner's World) about people having mysterious rashes that sound suspiciously like what I am dubbing "Tortilla Chip Flush" - but I don't think there has been a study with a group of runners to get a sense for how common this condition might be.

Is anyone out there willing to risk a Tortilla Chip Flush in the interest of science?

(Also posted in




  1. Click to Upload a photo (10 MB limit)
  1. Karl S. is one of our brightest and clearest posters. Perhaps that runs in the family.

    Though a niacin skin flush is common, tortilla chips have very little niacin. They usually have only 2% of the ADA for niacin, so niacin probably isn't it. Tortillas have more.

    So what *might* be happening is this. It's just a guess. The process of treating corn with an alkaline substance -- nixtamalization -- during the tortilla chip manufacturing process creates common corn mycotoxins that can cause a rash.

    The corn mycotoxins are called fumonisin, You can think of them as almost like ergot on rye.
    You may be especially sensitive to fumonisins,

    Here's some research.

    Fate of fumonisins during the production of fried tortilla chips.

    Toxic Mold and Mycotoxins -- Food Toxicology

    Fumonisin Rash:

    Finally, it could be something else in the tortilla chips -- a preservative, perhaps -- or something in the salsa or whatever else you're consuming at the same time as the chips. Do some forensics and let us know.

    Or the trigger could be the alkaline agent used for the nixtamalization.

    If you still think it's the niacin, do a control test just before running.

    6 Replies
    1. re: maria lorraine

      Thank you. Not just for the compliment to me, but for a well-explained good lead for my brother!

      1. re: maria lorraine


        Thanks for the thoughtful response. I have some thoughts and questions to add to the discussion:

        - I have tried several brands and forms of tortilla chips, and they have all led to this effect, whether store-bought (several brands, including those made with white and yellow corn), and house-made.

        - It seems like mycotoxins should vary, at least somewhat. However, there is absolutely no variation in what happens to me!

        - Salsa and all other foods have been eliminated as culprits. A pure meal of plain tortilla chips does it for me (Yes, I can do that. I love them.)

        - I may be reading this wrong, but it seems that indicates that frying and nixtamalization pretty much eliminate the mycotoxins. I don't have access to the full article to validate this from the abstract.

        - I do not think anyone can be totally confident in the reported B vitamin content of snack foods, since it is not required to be analyzed or reported per regulations unless it is added (


        - That said, I think it's safe to say it's not merely the niacin content, but what happens to my body (and perhaps others) when running after consuming this particular niacin. Maybe there is something special about the way some bodies process niacin, or that which is released from nixtamalization? That's why I would love other runners to try it out. Of course, so far, nobody seems to want to try it :(

        - Having had a niacin flush in my life, the resemblance that "Tortilla Chip Flush" has to it is uncanny. The feeling is not anything like what is reported for the mycotoxin reaction.

        - I have pretty much done control tests to the best of my ability. I don't know how much more I can do. Recommendations are appreciated!

        Thanks for your thoughts - any additional ones are also welcome!


        1. re: Drew_S

          Were it me, I wouldn't focus on the niacin, since there's so little of it in corn chips.

          Here are some possible offenders:
          the flavor enhancers (look up "ribo rash" -- flavor enhancer 635 or ribonucleotides E635, 627, 631).
          The oil (allergy) used to fry to chips (try baked chips and see what happens).
          The preservatives (try organic chips).
          The GMO-corn (try non-GMO corn chips). Dunno if this will make a diff.
          Corn allergy. Pulverized corn may hit you harder than fresh corn. Been checked?

          Dunno how much nixtamaliation occurs in chip manufacturing since nutrition is not a manufacturing priority, but you're right, the fumonisins are lowered during nixtamalization.

          Just did a google search for corn chips rash. Some interesting stuff.

          1. re: maria lorraine


            Well, I think you are onto something:


            So, (select foods + running = rash), although rare, is EIA. I will have to mention this to my doctor the next time I go!

            Strictly speaking, I never would have used the term anaphylaxis, since I only ever get a flush - never swelling or breathing issues. Apparently, anaphylaxis can manifest merely as a rash. Who knew?

            In reality, it seems like I am quite lucky that my symptoms are limited, and I know which food triggers it.



            1. re: Drew_S

              Drew, I know there's a tendency to seize onto a thing, and think, yes, aha, that's it, but until it's confirmed, you're still guessing. Sorry.

              There are still lots of other potential causes worth looking into. Especially if you only get this after eating tortilla chips.

              If your EIA guess is correct above -- and I'm not at all sure you're right, as you aren't either -- then you need to get checked **now**, if for no other reason than if you are right, you need to always carry an epi pen when you run. Today's EIA hives are tomorrow's throat closing.


              1. re: maria lorraine


                Yes, understood. As I mentioned in my earlier post, I will definitely mention this to my doctor.

                The good news is that I haven't been able to make this happen any other way, and I actually haven't experienced it in a couple of years since I identified the pattern. It just took a long time to get around to writing about it!



      2. The corn chips could be a red herring-- could also be some variant of exercise induced urticaria, although that usually presents as a more hive-y rash than a flush, but something to consider nevertheless?

        3 Replies
        1. re: chococat


          I've fairly scientifically identified that it's tortilla chips and running. I can eat anything else and run, and I don't get the flush, and I can eat tortilla chips and not run, and be just fine!

          And of course it's completely reproducible for me. Just have a bunch of chips of any brand - no condiments - and run, and if I don't wait an hour or two, I get the flush, every time.


          1. re: Drew_S

            Perhaps it's the lime in the chips?

            I do know the niacin flush and I do know the running flush aka tortilla chip flush that you speak of, however, I've never kept a food diary to know what I've eaten the night before to attribute to the running flush.

            I've always blamed it on the laundry detergent on my running clothes (or lack of cleaning said running clothes. Ha Ha!) but I never run the miles that you do either.

            1. re: JerryMe

              Well, it's been interesting for me to learn about exercise induced anaphylaxis. I can't say if that is what you have experienced as well, but it'c possible.

              I think it would be helpful for runners if someone like Runner's World wrote an article about it!