You’ve cleaned up your diet. You removed refined sugar, gluten, and refined foods. There is no junk food near your kitchen. You started following a low-histamine diet. Yet, you are still having symptoms. You might’ve noticed some symptoms subsiding, but others are sticking around. What can be the issue?
If you are still experiencing symptoms, such as digestive issues, joint pain, fatigue, skin problems, and so on, you may be reacting to another food. Lectins may be the culprit and the missing piece. Lectins can trigger mast cell activation, histamine intolerance, and chronic inflammation. High-lectin foods can cause and worsen unwanted chronic symptoms. So let’s talk about lectins for a moment.
In this article, you will learn about lectins. You will learn what lectins are. I will discuss potential problems with lectins and the symptoms of lectin intolerance. I will go over the list of foods that are high in lectin. You will learn about histamine intolerance and mast cell activation syndrome (MCAS) and the difference between the two. I will discuss the connection between lectins, mast cell activation, and histamine intolerance. Finally, I will offer some natural solutions for lectin intolerance and histamine intolerance.
What Are Lectins
Lectins are a form of carbohydrate-binding proteins. They are found in various plant foods. They are particularly high in beans, legumes, wheat, bell peppers, squash, and nightshades.
Though lectins are commonly referred to as anti-nutrients, they are not completely bad. Lectins offer support for cell communication and cell development. They may also support your immune health by helping immune regulation and immune response (1, 2, 3).
For most people, consuming lectin in moderation in well-cooked foods doesn’t cause any health issues. For other people, however, eating lectin-rich foods, especially in moderate or higher quantities, can turn into a problem. Since lection may increase the risk of chronic inflammation, it can lead to digestion issues, leaky gut syndrome, nutrient deficiencies, and related health issues. If you have histamine intolerance and have already removed all high-histamine foods yet, still struggling with symptoms, you may also be dealing with lectin intolerance.
Problems with Lectins
According to a 2020 study published in Foods, lectins can act as dietary allergens that may lead to allergic reactions (4). Lectins may increase the risk of chronic inflammation and immune reactions. Since lectins may decrease the absorption of zinc, iron, calcium, and phosphorus, it may lead to nutrient deficiencies and related health issues.
Lectins can lead to vomiting, diarrhea, and other digestive issues. They may increase your risk of gut microbiome imbalance and leaky gut syndrome. Microbiome imbalances and leaky gut syndrome may further increase chronic inflammation, gut health issues, chronic symptoms, and the increased risk of autoimmunity.
A 2015 review published in Alternative Therapies has found that lectins may increase autoimmune reactions (5). A 2000 review published in the British Journal of Nutrition has found that lectins may increase symptoms of rheumatoid arthritis (6). However, eliminating lectins and other problematic foods can reduce symptoms.
Symptoms of Lectin Intolerance
Symptoms of lectin intolerance may include:
- Gas, bloating, and abdominal cramps
- Nausea, vomiting, and upset stomach
- Fatigue, tiredness, and sleep issues
- Painful and swollen joints
- Skin rashes and other skin problems
- Allergy-like complaints
- Hormonal fluctuations
- Neurological symptoms
Foods High in Lectin
Foods high in lectin include:
- Beans, including kidney beans, fava beans, mung beans, garbanzo beans, and lima beans
- Peas, including green peas and yellow peas
- Other legumes, including lentils, peanuts, and carob
- Nuts, including ground nuts
- Wheat, oats, buckwheat
- Nightshades, including peppers, tomatoes, peppers, and potatoes
- Conventionally raised meat when raised on corn and soy
- Vegetable oils, including corn, soybean, and sunflower oil
- Dairy (cow milk), as most cows produce A1 dairy casein protein beta-casomorphin-7, which is a protein similar to lectin
Risk Factors for Lectin Intolerance
You may develop lectin intolerance for a variety of reasons. The main risk factors for lectin intolerance and risk factors for increased symptoms of lectin intolerance may include:
- Frequent use of antibiotics
- Gut microbiome imbalances
- Leaky gut syndrome
- Following a vegan or vegetarian diet high in high-lectin foods, especially legumes and/or grains
- Autoimmune disorders or family history of autoimmune disorders
- Joint problems of rheumatoid arthritis
- Poor sleep and fatigue
- Neurological issues
- Mental health issues
- Skin conditions
Lectins and Histamine Intolerance
Lectins may be a problem if you have histamine intolerance or mast cell activation syndrome (MCAS) in a variety of ways.
What Is Histamine Intolerance?
When you think about histamine, I’m positive that anti-histamines for allergies come to mind first. Because of the ‘anti’ part of anti-histamine, histamine often gets a bad rap. Yet, histamine is absolutely essential for your immune health and overall well-being.
Histamine is an important chemical that helps to remove allergens as part of your immune response. It also aids digestion by releasing hydrochloric acid to break down food and bacteria and supports your brain and mental health by serving as a chemical messenger between your brain and the rest of your body.
At healthy levels, histamine is a good guy that supports your health. Too much histamine, on the other hand, can turn into a serious health issue. If your body is releasing too much histamine and cannot break down excess histamine, it will cause a histamine buildup. This histamine buildup is called histamine intolerance. Histamine intolerance can affect your entire body, including your gut, brain, lungs, and cardiovascular system, causing widespread symptoms (7).
Symptoms of Histamine Intolerance
Symptoms of histamine intolerance can affect your entire body. They can be widespread, affecting many areas of your body at the same time. Some people may only experience a couple of random symptoms, others may experience every histamine intolerance symptom possible. Some may only experience mild symptoms, while others experience severe symptoms that seriously interfere with their lives.
As you will notice, many symptoms of histamine intolerance are similar to lectin intolerance. This overlap may not be a coincidence. Lectin intolerance may also worsen your histamine intolerance symptoms, and histamine intolerance may worsen lectin intolerance. Unless you address both, it may turn into a never-ending vicious cycle.
Symptoms of histamine intolerance include the following:
- Itchy skin, eyes, ears, and nose
- Eczema or other types of dermatitis
- Red eyes
- Facial swelling
- Crawling sensation on the skin or the scalp
- Tightness in the throat
- Difficulty regulating body temperature
- Sudden drop in blood pressure when standing up
- Low blood pressure
- Fast heart rate
- Heart palpitations
- Dizziness or vertigo
- Difficulty falling asleep or sleep issues
- Brain fog
- Anxiety or panic attacks
- Congestion or runny nose
- Seasonal allergies
- Migraines and headaches
- Acid reflux
- Abnormal menstrual cycle
- Premenstrual syndrome (PMS)
What Is Mast Cell Activation Syndrome
Your mast cells are white blood cells. They are located in tissues throughout your body, including your digestive tract, respiratory tracts, skin, reproductive organs, surrounding nerves, and blood. Since your mast cells store inflammatory mediators, including histamine, they play an important role in your immune health. When your body encounters allergens, toxins, or other foreign invaders, it will have an allergic reaction. Your mast cells will trigger an allergic response causing the release of histamine and other chemicals.
Though the activation of your mast cells is important, overactivation and other mast cell activation issues can become a problem. Mast cell activation syndrome (MCAS) is a complex health issue that involves a number of different systems in your body leading to an array of symptoms. MCAS may develop due to a variety of triggers, including mold, chemicals, toxins, heavy metals, allergens, medications, infections, viruses, food, and alcohol. If you have MCAS, some or all of these triggers can cause your mast cells to release inflammatory mediators, including histamine resulting in unwanted symptoms (8, 9, 10, 11).
Symptoms of Mast Cell Activation Syndrome (MCAS)
Symptoms of MCAS will impact more than one part or system of your body. Symptoms may vary from person to person. Symptoms of MCAS may include:
- Heart palpitations
- Low blood pressure
- Chest pain
- Weight changes, including rapid weight loss or weight gain
- Digestive trouble, including diarrhea, nausea, and vomiting
- Loss of appetite or low appetite
- Vision changes
Are MCAS and Histamine Intolerance the Same?
MCAS and histamine intolerance are not the same. If you have histamine intolerance, you have a build-up of histamine from high-histamine foods, stress, environmental toxins, and other histamine-promoting factors that your body cannot break down properly. If you have MCAS, your mast cells get triggered by allergens, mold, toxins, medications, infections, pain, stress, and other triggers, causing an immune response and mast cell histamine release.
MCAS can cause histamine intolerance. In fact, I’ve found that MCAS is one of the most common driving factors for histamine intolerance. However, you can develop histamine intolerance without MCAS. You may also have MCAS without symptoms of histamine intolerance. Though you may have both conditions, it is absolutely possible to only have one.
Lectins, Mast Cell Activation, and Histamine Intolerance
Now that you understand what histamine intolerance is, let’s talk about the connection between lectins and histamine.
Gut Microbiome Imbalance and Leaky Gut Syndrome
I have already talked about how lectins may increase gut microbiome imbalance, gut inflammation, intestinal permeability, or leaky gut syndrome. According to a 1999 review published in the BMJ, lectins may be able to pass through the gut wall and open the gut barrier (12). Lectins may also be able to bind to the gut mucosa causing further gut health problems. As I broke down in this article, leaky gut syndrome, gut microbiome imbalances, and gut infections are some of the main underlying causes of histamine intolerance that can further trigger your symptoms.
Triggering Mast Cell Activation and Histamine Release
A 2020 study published in Foods has found that lectins may act as dietary allergens that may lead to allergic reactions (4). They can aggravate allergies, allergic reactions, histamine release, histamine intolerance, and further sensitivities to other foods.
Your mast cells are home to hundreds of different kinds of receptors. These receptors on the outside of your mast cells help your body notice anything foreign, pathogenic, toxic, or harmful coming their way. A toll-like receptor is a specific receptor on your mast cells that helps to recognize mold, bacteria, viruses, lectins, and other problematic substances.
Coming into contact with lectins, your mast cell toll-like receptors may set off mast cell activation, especially if you have lectin intolerance, lectin sensitivity, or mast cell activation problems. An overactivation of your toll-like receptors will lead to the release of histamine and other inflammatory mast cell mediators to protect you from harm. However, if you are consuming high-lectin foods regularly, it will lead to increased mast cell activation and histamine release, which can lead to chronic inflammation and chronic symptoms.
Furthermore, if you have leaky gut syndrome, lectins can pass into your bloodstream, where they can further activate your mast cells and other immune cells. This can lead to a further release of histamine and increase histamine intolerance symptoms.
Immunoglobulin E (IgE) is an antibody that allows your body to recognize allergens. IgE also plays a role in lectin sensitivities and lectin allergens. If you have pre-existing mast cell activation or allergies, lectins may make your symptoms worse when IgEs recognize lectins. A 2007 study published in Clinical and Experimental Immunology has found that foods high in lectins, such as potatoes, may activate mast cells and basophils in those with allergies tendencies and food sensitivities (13). Researchers found that removing high-lectin foods helped to reduce symptoms.
Furthermore, there may be a link between autoimmune conditions and lectins. Lectins may increase the risk of autoimmunity and may further trigger existing autoimmune conditions. According to a 2015 review published in Alternative Therapies and 2000 review published in the British Journal of Nutrition, lectins may increase autoimmune reactions (5, 6).
Many people with histamine intolerance and MCAS also have an autoimmune condition. For example, I see patients all the time with Hashimoto’s disease (an autoimmune thyroid condition) and histamine intolerance. You can learn more about this connection between your thyroid and histamine intolerance here. Irritable bowel diseases (IBDs), such as ulcerative colitis and Crohn’s disease are common underlying issues behind histamine intolerance as well.
Solutions for Lectin Intolerance
Lectin intolerance can come with uncomfortable chronic symptoms. Fortunately, you can reduce lectin intolerance with the help of some simple dietary and lifestyle strategies. Here is what I recommend:
Learn a Better Way to Cook Lectins
High-lectin foods generally cause the most issues when you are eating them raw. The good news is that most high-lectin foods are rarely or never eaten raw. However, not preparing them carefully or undercooking them can cause problems too.
Soaking high-lectin foods, especially beans and legumes, before cooking them is important. Boiling, stewing, or using other high-heat cooking methods may also help to reduce lectin levels significantly, making them safe to consume for most people.
However, this may not be enough. If you have poor gut health, chronic inflammation, or other chronic health issues, you may not tolerate lectin well even when prepared and cooked properly.
Some high-lectin foods may have other problems besides lectin too. Beans and legumes are high-histamine foods that can also cause histamine intolerance. Wheat is high in gluten which can increase the risk of gluten-related chronic inflammation, food sensitivities and intolerance, gut symptoms, leaky gut syndrome, and other health problems. Many high-heat cooking methods can increase histamine in your food, increasing histamine intolerance. If you have problems with high-lectin foods despite preparation and cooking, you may benefit from a low-lectin or lectin-free diet.
Try a Low-Lectin or Lectin-Free Diet
If cooking high-lectin foods appropriately and only eating them at moderate amounts doesn’t help, you may benefit from a low-lectin or lectin-free diet. Remove high-lectin foods from your diet, such as beans, legumes, and nightshades. Consume only low-lectin and/or lectin-free foods. Try a low-lectin or lectin-free diet for about a month and see if your symptoms improve.
If your symptoms improve, you may choose to stay on a low-lectin diet completely. However, once you repair your gut health and reduce chronic inflammation, you may be able to reintroduce well-cooked high-lectin foods in moderate amounts. If you are ready to reintroduce them after 2 to 3 months, begin with a small amount and watch your body’s reactions. If you are reacting to certain high-lectin foods, remove them from your diet. If you are still reacting to all high-lectin foods, stay on a low-lectin diet.
Improve Your Gut Health
Your gut health affects your entire body. Poor gut microbiome imbalance and leaky gut syndrome may increase chronic inflammation, histamine intolerance, lectin intolerance, and related symptoms. Along with a gut-friendly anti-inflammatory diet, I recommend that you take a high-quality probiotics supplement, such as ProBiota HistaminX probiotics, to support your gut microbiome balance.
Follow a Low-Histamine Diet
If you have both histamine intolerance and lectin intolerance, you may benefit from a low-lectin AND low-histamine diet. I recommend following a low-histamine, anti-inflammatory, nutrient-dense, whole foods diet. Remove inflammatory foods, including refined sugar, refined oils, canned and processed meat, artificial ingredients, junk food, and highly processed foods. Remove high-histamine foods. Follow a nutrient-dense, anti-inflammatory, and low-histamine diet rich in greens, vegetables, herbs, spices, fruits, healthy fats, and organic meat. Try new recipes. I recommend all the low-histamine recipes in The 4-Phase Histamine Reset Plan and Low Histamine Cooking in Your Instant Pot. If you want to go a step further, you should join my Histamine Reset Online Program.
Lower Your Histamine
Reducing your histamine levels is more than just diet. Following a low-histamine nutrition plan is key to your recovery. However, poor sleep, stress, environmental toxins, and other factors can also increase your histamine load. Improving your sleep, reducing stress, reducing environmental toxins, supporting your liver and gut, and other strategies can all play a role in lowering your histamine bucket and improving your health and well-being. You may also benefit from certain supplements for histamine intolerance.
I recommend that you work with a functional health practitioner (hint: my team and I) to check for histamine intolerance. If you are dealing with symptoms of histamine intolerance, I recommend that you follow my Histamine Reset Plan outlined in my Histamine Online Program.
Look Into Salicylate and Oxalate Issues
If you are following a low-histamine and low-oxalate diet and still noticing issues with certain foods and have some of the same symptoms, it may be time to look further. Oxalates and salicylates are two other food compounds that can cause similar symptoms to histamine intolerance and lectin intolerance. Histamine intolerance can come hand in hand with problems with oxalates and salicylates. You can learn about the connection between oxalates, salicylates, and histamine intolerance by reading this article.
Lectins are a form of carbohydrate-binding proteins found in various plant foods, such as beans, legumes, wheat, bell peppers, squash, and nightshades. Lectin intolerance, histamine intolerance, and mast cell activation often come hand in hand. Without addressing all, you cannot eliminate all your symptoms. You may benefit from a low-histamine and low-lectin diet.
If you are dealing with symptoms of lectin intolerance histamine intolerance or MCAS, I invite you to schedule a consultation with us. We can help identify the root cause of your condition and recommend a personalized treatment plan to repair your body and regain your health and well-being. Schedule your consultation here. You can also get started on your own with my Histamine Online Program.
1. Lagarda-Diaz I, Guzman-Partida AM, Vazquez-Moreno L. Legume Lectins: Proteins with Diverse Applications. Int J Mol Sci. 2017 Jun 12;18(6):1242. doi: 10.3390/ijms18061242. PMID: 28604616
2. Jiang QL, Zhang S, Tian M, Zhang SY, Xie T, Chen DY, Chen YJ, He J, Liu J, Ouyang L, Jiang X. Plant lectins, from ancient sugar-binding proteins to emerging anti-cancer drugs in apoptosis and autophagy. Cell Prolif. 2015 Feb;48(1):17-28. doi: 10.1111/cpr.12155. Epub 2014 Dec 9. PMID: 25488051
3. Lepenies B, Lang R. Editorial: Lectins and Their Ligands in Shaping Immune Responses. Front Immunol. 2019 Oct 9;10:2379. doi: 10.3389/fimmu.2019.02379. PMID: 31649680
4. Barre A, Damme EJMV, Simplicien M, Benoist H, Rougé P. Are Dietary Lectins Relevant Allergens in Plant Food Allergy? Foods. 2020 Nov 24;9(12):1724. doi: 10.3390/foods9121724. PMID: 33255208
5. Cordain L, Toohey L, Smith MJ, Hickey MS. Modulation of immune function by dietary lectins in rheumatoid arthritis. Br J Nutr. 2000 Mar;83(3):207-17. doi: 10.1017/s0007114500000271. PMID: 10884708
6. Food Immune Reaction and Autoimmunity. Alternative therapies. 2015. Link Here
7. Maintz L, Novak N. Histamine and histamine intolerance. Am J Clin Nutr. 2007 May;85(5):1185-96. doi: 10.1093/ajcn/85.5.1185. PMID: 17490952
8. Afrin LB, Self S, Menk J, Lazarchick J. Characterization of Mast Cell Activation Syndrome. Am J Med Sci. 2017;353(3):207-215. Link Here
9. Frieri M, Patel R, Celestin J. Mast cell activation syndrome: a review. Curr Allergy Asthma Rep. 2013;13(1):27-32. Link Here
10 Akin C, Valent P, Metcalfe DD. Mast cell activation syndrome: Proposed diagnostic criteria. J Allergy Clin Immunol. 2010 Dec;126(6):1099-104.e4. doi: 10.1016/j.jaci.2010.08.035. Epub 2010 Oct 28. PMID: 21035176
11. Petra AI, Panagiotidou S, Stewart JM, Conti P, Theoharides TC. Spectrum of mast cell activation disorders. Expert Rev Clin Immunol. 2014;10(6):729-739. Link Here
12. Freed DL. Do dietary lectins cause disease? BMJ. 1999 Apr 17;318(7190):1023-4. doi: 10.1136/bmj.318.7190.1023. PMID: 10205084
13. Pramod, S. N., Venkatesh, Y. P., & Mahesh, P. A. (2007). Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin E. Clinical and Experimental Immunology, 148(3), 391–401. Link Here