NAC, Spirulina, and Antioxidants block the induction of tolerance

Following exhaustive research on food allergies, I’ve accumulated significant findings as to what induces allergies/intolerances and how to get rid of them. Much to my chagrin, a study was published recently detailing how NAC and other antioxidants may block your body’s ability to generate tolerance [R]. NADPH oxidase inhibitors are problematic too, one of which is spirulina. As part of my experimentation to induce food tolerance I stopped taking these. I also stopped taking SAMe, CoQ10, and other antioxidants just in case.

I still think, however, that these are highly useful tools to be utilized in the right situation. For example, take a quick look at the numerous medical uses for NAC [R]. For my own purposes, I can vouch for NAC being very useful for OCD. Spirulina, likewise, has a bunch of very important uses like excreting heavy metals and fluoride from the body.

MCT oil

During my research, I was surprised to come across a study demonstrating how MCT oil – a panacea for the paleo community – creates food allergies, first by blocking antigen absorption and second by stimulating Th2 responses [R]. Blocking the induction of tolerance is one thing, but creating a new allergy is another. Th2 cells produce various messengers or cytokines which aid in the development of allergic inflammation. A Th2 response is tied to inflammatory conditions like asthma and atopic dermatitis [R].

Other kinds of saturated fat don’t have the same effect because MCT oil is absorbed differently by the body. Long chain fatty acids, which include MUFA’s, PUFA’s, DHA, and saturated fat, actually help induce tolerance through “chylomicron formation.” (Note: Lauric acid in coconut oil isn’t a long chain fatty acid.)

Herbs may also increase a Th2 response

I’d like to caution readers that Rhodiola [R], olive leaf extract [R], fulvic, humic acid [R], honokiol [R], Boswellia, garlic [R], and cinnamon (via a metabolite sodium benzoate by converting Th1 to Th2) may also increase a Th2 response, so theoretically these may create a food allergy, too.

Potential benefits of a Th2 response

I don’t like to label things as “good” or “bad” because the reality is always more complex and nuanced. For example, a Th2 cell response helps expel parasites from our gut, so ingesting MCT oil might be a good idea if you have a parasitic infection. Also, Th1 and Th17 cells may convert to Th2 cells, decreasing the Th1 and Th17 response. As you can see, there’s a balance at play.

What should you do?

MCT oil

Concerning MCT oil, I think it should be cut out unless you are using it to get into ketosis. If you’re going to ingest MCT oil in order to induce ketosis, I would suggest that you not take it with other food.


With regard to the herbs, one must realize that there’s likely more we don’t know about all of these substances than what we do know and the body is an extremely complex system. It’s also hard to predict what will actually happen when people take them. I’m assuming I’ll come across many more substances that stimulate a Th2 response as I do more research, but it’s important to realize that these herbs also have many other compensating factors that decrease allergic sensitization and may only stimulate a Th2 response if the body needs it, unlike MCT oil. In addition, these herbs have been safely used for millennia, whereas MCT oil is a novel product.

Note that a Th2 response may be a requirement to induce food allergies, but likely isn’t sufficient and requires other factors (like blocking antigen absorption, etc..) in order to create the allergy. For example, Tregs (which is increased by some of these herbs) have a regulatory role and can suppress Th1 and Th2 cells. Cinnamon is an example of an herb that increases Tregs. Dendritic cells can also decide whether to activate Th cells. A popular cytokine called TNF-alpha might also have to be present for a Th2 response to occur, and most of the listed herbs decrease it [R].

I haven’t seen any animal studies directly tying these herbs/phytochemicals with increased allergic sensitization, as the MCT oil study does. I’ve actually had pretty good results overall from the listed herbs. My autoimmune issue is more tied to a Th1 and Th17 response, so my experience might not be applicable to Th2 dominant people. I’ve come to this conclusion based on my symptoms, I have and how I react to various supplements. There’s also some research that links Th1 abnormalities with food intolerances [R].

Since I haven’t seen any studies directly tying these herbs to allergic sensitization, I think people – especially individuals (like asthmatics) sensitive to a Th2 response – should just be aware that this possible drawback exists and take caution. Interestingly, a few years ago my mother, who has asthma, went on a supplement binge and got into MCT and coconut oil and all of her symptoms flared up. This is probably because many of the herbs and the MCT oil she was taking increase the Th2 response.

If I were to see even an animal study directly tying any of these herbs to allergic sensitization-like the MCT oil study, I would probably give them up or use them sparingly.

The bottom line

  • Many of the substances and supplements I explore and discuss here have a purpose, but knowing which ones are suited for the individual and how to use them is critical.
  • I’d give up the MCT oil unless it’s used for ketosis and also separated from food consumption.
  • I’d keep the herbs, but be extra cautious if you’re someone who is more prone to a Th2 response – ie if you have asthma or IgE-related food allergies (gluten and casein sensitivities are food intolerances, not IgE-related allergies).
  • My guess is the effects from single herbs aren’t strong enough to create a food allergy, but stacking multiple herbs that increase a Th2 response and that don’t also increase compensatory Treg cells may be problematic.

What to know before reading the study:

  • “Allergic sensitization” = creation of a food allergy.
  • An antigen (antibody generators) is anything that stimulates an immune response (e.g. inflammation). This is the thing we are allergic or sensitive to.
  • Intestinal absorption of small amounts of dietary antigen may protect against food allergies by promoting oral tolerance.
  • Anaphylaxis is a severe, whole-body allergic reaction to a chemical that has become an allergen.

Study Synopsis

MCT suppressed antigen absorption into blood…MCT-sensitized mice experienced IgG-dependent anaphylaxis upon systemic challenge and IgE-dependent anaphylaxis upon oral challenge. MCT feeding…promoted Th2 cytokine responses in splenocytes. Moreover, oral challenges of sensitized mice with antigen in MCT significantly aggravated anaphylaxis compared to challenges with LCT……Dietary MCT promote allergic sensitization and anaphylaxis by affecting antigen absorption and availability and by stimulating Th2 responses.

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