My Food Sensitivies Were Due to Iodine Post Flox

Prior to being floxed, I ate a fairly high iodine diet, especially in my younger years.    I estimated I grew up ingesting 1-3 mg (yes, that’s MILLIgrams) per day via milk, eggs, and bread products alone.    Dairy products often have very high iodine contents because of fish meal/byproducts fed to cows, iodine used as disinfectant for the milking machines, tanks, lines, and equipment, and teat dip for cows (teats are dipped in iodine disinfectant after every milking).    When I worked with dairy cows and was milking, I got plenty of teat dip on my hands twice a day – probably getting at least a 100 mg or more of iodine per day via absorption through the skin alone.   Eggs also tend to be high in iodine, most likely due to ingestion via feed.   Back when I was growing up, iodination was used as a form of preservative for breads, so there was another source of constant iodine (today, this is not the case; bromine is often used instead).   Obviously, sea foods, shellfish, Kombu and kelp are high in iodine.   Soybeans, some omega oils such as fish oils, and vitamins and supplements containing iodine also will have higher iodine content.   Fast food, processed food, Asian food, and restaurant food are typically heavily salted, and if this salt is iodinated, then these foods will also be considered high iodine foods.

A person with a healthy functioning thyroid axis can handle a wide variety in amounts of daily iodine, as I did pre-flox.    There were probably days when I ingested very little iodine, perhaps the 150 ug US RDA requirement or less.   On the other hand, I might easily have eaten my favorite meal of a 6 egg omelet, ¾ of a gallon of milk, and 6 pieces of toast with lots of butter (and pancakes on the side) without a problem, and that was just for breakfast.   The motto of the thyroid axis is:   Take what iodine you need and leave (excrete) the rest.   And for 50 years, up to the day I was floxed, that occurred without a problem and without me even being aware of it.

In my particular case, I believe many of my “food sensitivities” were as a result of “iodine sensitivity” post flox.    My staples of dairy, eggs, and bread were now out, simply because of the iodine content in them.   Any seafood, soy, heavily salted processed food, and multivitamin supplements or fish oils with iodine were now out.   I could feel and react to as little as 5 ug (micrograms) of ingested iodine once I became aware of the symptoms.   This could easily be a residual amount in canned food, for example, if iodine was being used as a disinfectant during the manufacturing process, or as a preservative.   Because I had experimented with and was very familiar with how iodine alone made me feel, I could then experiment with eating eggs, or drinking some milk, and feeling the same symptoms.    Indeed, I felt like I could pretty much tell which foods had iodine in them simply by my body’s response.    Research “low iodine diets” to learn which foods are considered to be low and high in iodine, and remember that iodine may be used for disinfectants and preservatives anywhere along the food manufacturing chain, which means it’s ubiquitous in our food (even if in tiny amounts).   The raw food diet, or Paleo diet will naturally be lower in iodine, and this may be one reason why many people with treatment-resistant thyroid disorders feel much better on this type of diet.   Many people with other autoimmune disorders are also eventually diagnosed with thyroid disorders as well, which is why I believe the “autoimmune” diet (Paleo type diet) often helps them as well.

Not all flox victims will have or develop this iodine sensitivity, as I did.   Iodine is phenomenally important to our well being and functioning, and for people who can tolerate iodine, I would definitely recommend getting enough through a healthy diet, to support thyroid gland health as well as total body health.   This could be through organic eggs and dairy, or seafood such as sardines, for example.   A healthier ratio of iodine to selenium and other nutrients such as the amino acids will occur via the diet instead of supplementation.   Knowing what I know now, I would recommend against any heavy duty supplementation of iodine or selenium for flox victims until you 1) know how it will affect your symptoms, and 2) test thyroid gland status before hand, in particular, the autoimmune component.   Be aware that the effects of iodine are two fold:  1) effects on non-thyroid cells of the body, and 2) effects on the thyroid gland cells.   If, after reading this document, you think that your acute flox reaction may have included a “TH/Iodine Toxicosis” reaction as well, be aware that there are potentially long term consequences to that.   A “thyrotoxic hyperthyroid flare” such as the one I experienced in my March 2010 reaction, is like a fourth of July firework that explodes brightly high in the sky during the acute phase, with several smaller bursts over time as the embers fall from the sky, and then finally “burning out” to Hypothyroidism when all is said and done.   This process could take weeks, months, or years, depending on how healthy the thyroid gland is to begin with, nutritional status, and the thyroid gland’s capacity for recovery.

If you’ve had a flox reaction, I would recommend doing everything you can to “support thyroid health”, which includes a healthy diet with iodine, selenium, zinc, Vitamin E and other anti-oxidants, healthy fats, at least 100 gm carbs per day, and protein.   I would also continue to monitor my thyroid health with labs twice a year for the first couple of years at least, and learn and be aware of thyroid symptoms and disorders in general.   This is what I wish I had known and done when I was floxed.   As to whether or not this would have helped me, we’ll never know.   I believe I already had Hashi’s, due to a number of factors such as my first FQ exposure in Jan 2009, and probably genetics are coming into play in my situation as well.   Knowing what I know now, I would have addressed the Hashi’s much earlier and with any luck, perhaps prevented the progression of symptoms I experienced while floundering around waiting for a diagnosis, and treated more effectively.   With luck, a flox victim’s thyroid gland and axis will recover over time, but in my opinion, a flox victim is always at risk for “thyroid issues” after being floxed.   For people already on thyroid medication or considering medication, recognize that getting a TSH as close to zero is the goal, and then experimenting with how much iodine you can tolerate will guide you as to your dietary choices.

On the other hand, if you experiment with iodine and selenium and find out you are already very sensitive to either or both, it may be that you already have a “TH/Iodine metabolism problem” going on, as I now do.   Or, you may have already been diagnosed with either hyper or hypothyroidism.  This makes your journey much harder, in my opinion, in trying to decide how to handle iodine in a way that’s best for your metabolism.   There is an incredible amount of information of the internet available, which is both helpful and confusing.   Helpful, because there is a lot of knowledge and there are a lot of options, but confusing, because there are a lot of options and knowing which one will work for you is anybody’s guess.   I think all I can say at this point in time is to be aware that throwing iodine into the mix is every bit as important as using T3 and T4, for example, and trying to sort out where you’re at on the “iodine metabolism scale” can take a while.

Having said all the above about Iodine being my main food sensitivity, I also came to believe that other food sensitivities may have existed as well, especially when I was OFF thyroid hormone medication.   Many foods which are safe for healthy thyroid glands can potentially negatively affect or aggravate existing thyroid pathology.  Some of these include soy (genistein inhibits TPO), gluten (association between AITD and Celiac), lactoperoxidase (LPO) and myeloperoxidase (MPO) –peroxidases in the same family with functional and structural homology to thyroid peroxidase (TPO) are in dairy products and could be potential additional antigenic targets.   In addition, many flox victims report a sensitivity to glutamate/glutamic acid, and I strongly suspected this to be true within myself as well.   In Year 4 and 5 post March 2010 Cipro, I was OFF thyroid hormone medication, and my food sensitivities increased greatly, to the point I felt like I was on the “everything free” diet.   I could hardly eat anything without feeling my symptoms, in particular the CNS symptoms, worsen almost immediately.   I attributed most of this to iodine due to my thyroid pathologies, and maybe glutamic acid and/or other amino acids, as I was dairy free and gluten free.   See the next section, Anatomy of an Iodine-Induced Flare for a more detailed discussion on how I try to ferret out how the role of iodine, as well as potentially other antigenic proteins such as lectins, may be playing into my food sensitivities.

As I mentioned elsewhere, I did not feel like I had “leaky gut”.   Topical iodine, along with other topical steroid hormones and even topical magnesium, seemed to have equal effects on me, basically ruling out a strictly gut oriented reaction for these substances.   Many of the receptors, transporters, enzymes, and signal transductions processes that I focused on as potential underlying mechanisms in FQ toxicity are located systemically throughout the body.   Examples of underlying commonalities to thyroid hormones and steroid receptors include substances such as acetylcholine, glutamate, adenosine, phospholipase C, cAMP, G-protein receptors, and probably a thousand other potential substances and targets.   These will probably all be active to some extent throughout the GI tract along with other organ systems, with some being more active than others in the “gut”.

In Year 5 Post, as my food sensitivities continued to worsen after yet another flare, I did start suspecting Mast Cell Activation Syndrome or an extreme IgG4 hypersensitivity going on.  This developed in earnest when the severe pain and swelling in my thyroid and thymus gland developed after the flares.  The symptoms seemed to fit:  the “on/off” nature of the attacks, the pain and “tightness” in my chest, the sweating and flushing, the dry, burning “inflammation” like feeling in my lungs, which also now occurred in my stomach (possibly pancreas if IgG4 in nature?), along with nausea, the dry, gritty eyes, painful eyes, and of course, extreme CNS symptoms.  I also noticed how I would feel good in mood before a major flare; indeed, this is yet another way that I started recognizing that a flare was coming.  A “serotonin burst” with mast cell degranulation could conceivably fit with my “feel good before the crash” syndrome.  Both nicotinic and muscarinic receptors are present on mast cells, indicating a cholinergic connection.  Mast cells are widely distributed throughout the body, including connective tissue in the walls of the stomach.  The sight, smell, thought, or taste of food results in vagal stimulation that releases Ach and gastrin, which act directly on the parietal cells and mast cells.   The mast cells in turn release histamine and other substances.  Mast cells are present in and around tendons, and have been found to be increased in density in tendinopathies; in vitro studies have verified that mast cell proteases are capable of activating collagenase.   Mast cells are also increased in cases of Subacute Thyroiditis, and in the thymus of some Myasthenia Gravis patients.  Risk factors for developing Mast Cell Activation Syndrome include, among other things, hypothyroidism and sensitivity to neuromuscular blocking agents (which therefore include FQ’s).   I did test for tryptase/histamine once about 2.5 hours after eating some “semi-stimulating” food for me, but was unable to be fully symptomatic during the test, because I was unable to drive when I was fully symptomatic.   My results were well within normal limits that time, but given my symptoms, I wouldn’t rule out MCA in me.  Given my iodine sensitivities, I would suspect that iodinated proteins or their intermediates, would be on the target list for me.  This would include not only exogenous iodine ingested, but endogenous metabolites produced during metabolism of iodine, including thyroid hormone, as well.


There are numerous sources on the internet which discuss high and low iodine foods.  Here is one of them:   Database of the Iodine Content of Food and Diets Populated with Data From Published Literature

Below are some excerpts from this document that I cut and pasted directly.  Iodine content of food, whether natural or processed, varies greatly depending on a large number of factors, some of which are discussed in this document.  I’m including these excerpts here simply to demonstrate this:

“As expected iodised products such as mineral tablets, salt and bread contain an order of magnitude higher average contents than most other foodstuffs (Figure 3.3). Concentrations in other salt products including cooking salt are also high but these values could include salt that was iodised but not reported as such in some studies. Of the natural food products, highest iodine contents are reported in seaweed, up to 4500000 μg/kg, fish oils and marine fish (geometric means 4066.4 and 1294.6 μg/kg respectively), which contain 10 times (namely 0.45 %) the amount in freshwater fish (geometric mean 102.8 μg/kg) and are an excellent dietary source of iodine (Table 3.3).

The results also highlight the importance of food processing as this can provide sources of “adventitious” iodine in the diet. This is iodine added to food but not for the purpose of supplementation, which Dunn (1996) describes as the “silent prophylaxis”. Koutras (1980) outlines the following adventitious sources of iodine:

  • iodine content of poultry and eggs increased by the use of fish flour as chicken food
  • iodoform used in water as a disinfectant
  • iodates used as oxidants and sanitising agent in the bread making process
  • use of iodophors as antiseptic cleansing agent in the dairy industry
  • iodine-rich red food colouring erythrosine (2,4,5,7-tetraiodofluorescein) (e.g. in red glazed cherries)


The two key aspects in this respect are the use of iodophors as antiseptic cleansing agent in the dairy industry and iodine-containing red food colouring (erythrosine) in meat and other products. Although milk is naturally enriched in iodine (see the data in Chilean Iodine Educational Bureau, 1952) the use of iodophors has significantly increased the iodine levels to such an extent that there has been concern about the toxic effects. The use of red food colouring probably accounts for the very high iodine concentration reported in canned cherries (113000 μg/kg) and the broad range in average meat iodine values (0 – 1500 μg/kg) recorded during the present review (Figure 3.3). Average iodine concentrations in dairy products vary widely (0 – 1500 μg/kg or μg/l) (Figure 3.3), however, cows milk specifically ranks only 18th out of 44 food types in terms of geometric mean iodine concentrations (Table 3.3) whereas eggs rank 10th which may indicate the widespread use of fish meal and seaweed as chicken feed. Cows milk has a higher geometric mean concentration (95.0 μg/l) than cheese (33.1 μg/kg) or butter (32.0 μg/kg) which ranks 34th out of 44 in Table 3.3, but iodine concentrations in butter are higher than those reported in margarine (average 0.7 – 9.4 μg/kg) (Appendix 2).

Baby-food and infant formula have relatively high average iodine concentrations probably reflecting the dairy component of many of these products (Figure 3.3). Human milk shows a very broad range in average concentrations (0 – 1750 μg/l) (Figure 3.3) and ranks 19th out of 44 food types in terms of geometric mean values (Table 3.3) containing similar iodine contents to dairy milk products.

The results show that all cereals (wheat, barley, oats and rice), bread and flour products have very low iodine concentrations as expected and these basic foodstuffs are likely to be poor sources of dietary intake (Figure 3.3 and Table 3.3). The exception is maize, which has a similar geometric mean iodine concentration (92.6 μg/kg) to cows milk (Table 3.3).

Vegetables have higher concentrations than cereal crops, however, there is a broad overlap in the range of average values reported for leafy vegetables (0.4 – 1636 μg/kg) and other vegetables (0.2 – 1102 μg/kg) (Figure 3.3). Some leafy vegetables such as spinach and lettuce have quite high geometric mean iodine concentrations ranking 7th and 12th out of 44 food types respectively (Table 3.3) whereas other leafy vegetables such as cabbage rank much lower (31st). Interestingly root vegetables such as turnip and beetroot also rank quite highly (8th and 11th) but some of these results are for the whole plant including the leaves. Beans, peas and pulses (legumes) are not noticeably higher in iodine than other vegetable types whereas tomatoes contain low iodine concentrations (geometric mean 25.3μg/kg) commensurate with the poor transfer ratio of iodine from soils to plants indicated above. In general, the geometric mean iodine content of leafy vegetables (88.8 μg/kg) is slightly higher than other vegetables (80.1 μg/kg) (Table 3.4) therefore, on this basis, there is some evidence that the iodine content of leafy vegetables is greater than other vegetables but the results are equivocal.

Average iodine concentrations in herbs and spices and in nuts show a similar range to vegetables (Figure 3.3) whereas fruits and sweets are low in iodine (Figure 3.3 and Table 3.3). In general drinking water contains very low iodine concentrations (geometric mean 6.4 μg/l, Table 3.3) and in most developed countries water will not form an important dietary source of iodine. However, in undeveloped subsistence level economies, the present study has shown that drinking water can contribute significant quantities to the diet (see Johnson et al., 2003).”



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