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Beyond Histamine — The Other Food Intolerances that Matter

Updated: Feb 17

If you’ve tried a low-histamine diet but are still experiencing symptoms, you may be experiencing symptoms of other food intolerances that are stalling your progress. Salicylates, oxalates, lectins, gluten, dairy, yeast, and high-FODMAP foods can cause chronic symptoms. They may lead to further inflammation, gut health issues, and leaky gut syndrome. Additional histamine release can be triggered by them, leading to an ongoing cycle of histamine intolerance, food sensitivities, and symptoms.

I know what you’re thinking. “What the heck am I going to eat?” Removing offending foods is one of the steps necessary to feel better and improve leaky gut. Many of these intolerances are not only manageable, but potentially reversible. How to get there is the focus of a good treatment plan in functional medicine. Also important to consider is how the human race got here, with the widespread occurrence of food intolerances among us. There’s no doubt in my mind that the assault on the microbiome the past few generations - indeed since the advent of the “antibiotic era” in medicine and chemicals added to the food supply simultaneously - explains much of it. Some of the intolerance will have a genetic basis, sure, but think about this: there is far more bacterial DNA in the human body than human DNA. Mess with it and problems ensue.

Rehabilitation of your microbiome is essential given how important it is for digestion, enzyme production including DAO, nutrient production, detoxification, dampening inflammation, and preventing leaky gut. It also lessens the risk for and will assist in overcoming food intolerances.

Bear in mind that without addressing these potential underlying food sensitivities that go beyond histamine intolerance, full recovery may not be not possible. Today, I want to talk about other common food intolerances that matter and how to overcome them.


Salicylates are a group of chemicals that are derived from salicylic acid. They can be found in their natural forms in various plant foods, including tomatoes, peppers, chili, avocados, cucumber, broccoli, sweet potatoes, eggplant, dark leafy greens, apples, cherries, melon, and grapefruits. Salicylates may also be found in toothpaste, cosmetic products, aspirin, and other medications, generally in synthetic forms.

Salicylates in their innate form serve as natural pesticides that protect plants from insects, fungus, and other harm. Though this is good for the plants, it may not be good for you. High salicylate foods are not an issue for everyone. However, in some, they can cause salicylate intolerance and related uncomfortable symptoms.

Your body works really hard to remove any excess salicylates. High salicylate load and sluggish liver function may make it difficult to break down all the excess, leading to a build-up. Salicylate build-up can result in the overproduction of leukotrienes by the body, which are chemical mediators that can cause inflammatory issues.

Salicylate intolerance may cause mitochondrial dysfunction, oxidative stress, poor immune system, cellular and tissue damage, and increased histamine release. Salicylate intolerance may result in inflammation, stomach pain, digestive issues, yeast infections, asthma, allergies, respiratory problems, blood sugar imbalances, muscle and joint pain, chronic sweating, poor sleep, insomnia, depression, anxiety, hyperactivity, headaches, migraines, dizziness, and other issues (1, 2, 3). What might I see in clinical practice? A hyperactive child with very aggravated behaviour after eating a bowl of strawberries, coinciding also with red cheeks and red ears, for example. I wrote about salicylate sensitivity in children in this article.


Oxalates are natural molecules found in humans and certain plant foods, including berries, purple grapes, figs, kiwis, beets, spinach, Swiss chards, leeks, celery, potatoes, sweet potatoes, plantains, olives, almonds, cashews, peanuts, soy, quinoa, buckwheat, bran flakes, and tea. Oxalates serve an important function in many plants by allowing them to get rid of any excess calcium. What’s good for these plants is not always good for humans though. Inside your digestive system, oxalates from food bind with calcium, potassium, magnesium, and other excess minerals that will then get removed from your body through urine or stool.

Too many oxalates in your body can cause oxalate “toxicity” and related health issues. Gut microbiome imbalance may also increase oxalate intolerance and related problems. Under normal circumstances, Oxalobacter formigenes, an oxalate-degrading bacteria, is able to take care of any excess. However, if there is a gut microbiome imbalance, there won’t be enough of this bacteria to take care of this job. Combined with a high-oxalate diet, you may end up with a real problem on your hands. Especially if you're not in the habit of drinking enough fluids to help flush oxalates out.

Oxalate intolerance may reduce mineral absorption, increase chronic inflammation, compromise mitochondrial function, increase oxidative stress, lead to poor immunity, cause cellular and tissue damage, contribute to leaky gut and increase histamine release. Kidney stones are one of the most common problems connected to oxalate intolerance. Other issues often caused by oxalate intolerance may include chronic pain, muscle and joint pain, urinary and bladder pain, vulvodynia, headaches, migraines, candida overgrowth, digestive issues, skin problems, poor sleep, and bone loss (4, 5, 6, 7, 8).


Lectins are often referred to as anti-nutrients. They are a type of protein found in plant foods, especially in beans, legumes, squash, bell peppers, nightshades, some nuts including almonds, and wheat. Lectins support cell development and cell communication. They may support immune regulation and immune response. Eating lectins in moderation in well-cooked foods is not an issue for most people. For others, it may turn into a problem.

Lectins may increase the risk of chronic inflammation. They may reduce the absorption of zinc, calcium, iron, and phosphorus. Lectins may cause diarrhea, vomiting, and other digestive issues and may increase the risk of leaky gut syndrome. By increasing the risk of leaky gut syndrome and chronic inflammation, lectins may increase the risk of developing an autoimmune disorder.

High-lectin foods can cause a particular issue when eaten raw. Soaking before cooking helps. Boiling, stewing, and other high-heat cooking methods can significantly decrease lectin levels and make this food safe for most people. However, if you have poor gut health and experience issues from high-lectin foods, you may benefit from a low-lectin or lectin-free diet (9, 10, 11, 12, 13, 14). I wrote more about the low lectin diet in this article.


Gluten is a protein found in wheat, rye, barley, and some oats. Celiac disease is an autoimmune condition characterized by an autoimmune response to gluten. However, many people without celiac disease have issues consuming gluten. Non-celiac gluten sensitivity or gluten intolerance may cause abdominal pain, bloating, diarrhea, cramping, other digestive issues, headaches, migraines, fatigue, eczema, other skin problems, brain fog, depression, anxiety.

Another risk of eating gluten is molecular mimicry. Molecular mimicry happens when a foreign substance or pathogen shares similarities to your own body. Gluten can become this invader. As a defense mechanism, your body memorizes the structure of gluten or another foreign material in order to develop a defense system against it. Because of the similarities between gluten and your body’s own cells, your body may attack its own cells alongside or instead of gluten, causing an autoimmune reaction. Eating gluten may also increase the risk of chronic inflammation, leaky gut syndrome, and autoimmunity. Because of the inflammatory nature of gluten, many of us including myself can benefit from a gluten-free diet (15, 16, 17, 18, 19, 20, 21).


Problems related to consuming dairy are increasingly common. One of these issues is related to casein. Casein is a protein found in dairy. Having a milk allergy means that your body is unable to handle casein. Casein may trigger various allergic reactions, including hives, skin rashes, runny nose, sneezing, watery eyes, swollen lips, digestive issues, blood pressure drop, or even life-threatening anaphylaxis. Casein may cause issues even if you don’t have a casein allergy. It may increase the risk of chronic inflammation and worsen inflammatory symptoms. Just like gluten, casein may also lead to molecular mimicry and increase the risk of autoimmunity.

Beyond casein allergy or casein sensitivity, you may experience other issues with dairy. Lactose intolerance is a common issue caused by a reaction to a natural sugar in dairy. It happens when your body doesn’t produce enough lactase, an enzyme needed for lactose absorption. Lactose intolerance can cause gas, bloating, diarrhea, vomiting, and abdominal pain. Conventional milk and dairy products are also loaded with added hormones and antibiotics that may increase inflammation and symptoms (22, 23, 24, 25, 26). It is important to note that a dairy reaction can either be to the protein (casein) or the sugar (lactose) in milk products. Choosing lactose-free milk will not help with the former.


Yeast is a type of fungus. It is commonly found in baked goods and certain alcoholic beverages, such as beer. In some people, yeast may cause a yeast allergy or yeast sensitivity. If you are sensitive to yeast, you may develop abdominal pain, bloating, diarrhea, and other gastrointestinal symptoms. You may experience hives, skin issues, respiratory problems, or symptoms of asthma. More serious allergic reactions may lead to anaphylaxis.

Eating foods with yeast may also lead to Candida overgrowth and related symptoms, such as yeast and fungal infections, oral thrush, vaginal infections, skin issues, digestive problems, brain fog, headaches, migraines, fatigue, sinus infections, and mood imbalances. Candida overgrowth may contribute to chronic inflammation, leaky gut syndrome, and autoimmunity in the long run. Yeast may also trigger histamine intolerance or mast cell activation syndrome (MCAS). Not to mention that foods in yeast are usually high in sugar and sometimes gluten and casein as well (27, 28, 29, 30, 31, 32, 33, 34, 35). The mast cell literature notes in particular that dairy, gluten and/or yeast products can be problematic for some patients.


FODMAP stands for Fermentable, Oligo, Di-, and Monosaccharides, and Polyols. They are a type of carbohydrate found in legumes, cruciferous veggies, many sweeteners, grains, and many fruits. Though not everyone has problems with FODMAPS, a high FODMAP diet can cause abdominal pain, gas, bloating, constipation, and diarrhea. FODMAPs may increase symptoms of small intestinal bacterial overgrowth (SIBO), irritable bowel syndrome (IBS), and other digestive issues. It’s no wonder that a low-FODMAP diet is often recommended for these gut-related problems.

As I discussed in this article, a low-FODMAP diet can be beneficial for people with histamine intolerance, especially if a low-histamine diet hasn’t provided enough relief. Beyond dietary histamine, histamine intolerance may be caused by excessed endogenous histamine produced by bacteria and caused by a gut issue. As with all cases, addressing the root cause of the problem is necessary for full recovery (36, 37, 38, 39).


If you are dealing with complex symptoms and multiple food intolerances, you may benefit from the FAILSAFE Diet. It stands for Free of Additives, Low in Salicylates, Amines, and Flavor Enhancers. A FAILSAFE Diet is designed to treat food sensitivities.

The FAILSAFE Diet is an elimination diet. During the initial 3- to 4-week elimination phase, you need to remove foods with salicylates, glutamates, amines (including histamine), artificial food additives, food coloring, preservatives, dairy, and gluten from your diet. You have to follow a whole foods diet without these ingredients.

After the elimination phase, you can start reintroducing each food. Keep a food diary to track your symptoms and reactions to food allergens. Try your first ‘challenge food’ for 3 days and watch your symptoms. Maintain an interval of 3 symptom-free days between each challenge food. If you notice any reactions to any offending foods, it means that you may benefit from removing that specific food from your diet.

Next Steps

1. Are you experiencing chronic symptoms of histamine intolerance, oxalate toxicity, salicylate intolerance, gluten sensitivity, casein sensitivity, or other food intolerances? Or don’t know, or where to start? Working with a healthcare practitioner knowledgeable about histamine intolerance, MCAS, and other food intolerances is the best way to get to the root cause of your symptoms and to create an individualized treatment plan. I welcome you to start a personalized functional medicine consultation with me for further guidance to improve your health. You may book your consultation here.

2. Check out my Histamine Intolerance Course here. Learn on your own time, from anywhere. Get an inside look at the most helpful functional medicine tests for pinpointing imbalances, ways to identify and manage the most common (and sometimes surprising) mast cell triggers, and learn what to eat, what to avoid, and why.


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