Lectins are one of the most significant sources of food sensitivity. This post covers low-lectin and high-lectin foods, as well as other plant substances that may cause inflammation. The Lectin Avoidance Diet is an elimination diet that helps you figure out which foods are inflammatory, and which are less inflammatory for you.
What Are Lectins?
Do not confuse lectins with leptin, lactose, or pectin.
Lectins are proteins that bind to carbohydrates or glycoproteins (proteins that contain carbohydrate chains) .
Proteins termed lectins (from the Latin legere, “to select”) have the ability to bind to specific carbohydrate molecules.
Lectins allow cells to bind or communicate with each other.
They are found in every living organism, including viruses, bacteria, and most foods, to one degree or another, but most of them are harmless. Scientists have been studying lectins since 1884.
Some scientists believe that lectins are part of a plant’s protection mechanisms .
Plants also use lectins to communicate with their environment, for cell organization, and as reserve proteins, among other functions .
Different Types of Plant Lectins
In plants, lectins are concentrated in seeds, early stage leaves, and roots. Leaves typically contain fewer lectins, although this may vary from plant to plant. A great example of a leaf is romaine lettuce.
- Legume lectins, such as white kidney beans. On average, 15% percent of a bean’s proteins are lectins.
- Cucurbitaceae lectins, found in the sap or juice of cucumber, melon, and squash.
- Prolamins, such as gluten and gliadin, are the alcohol-soluble lectins found in cereal grains.
- Agglutinin or hemagglutinin is so-called as it can cause blood agglutination (clumping of blood cells). Examples include wheat germ and soybean agglutinins .
Plant agglutinins have been characterized by testing their ability to clump blood cells of certain blood types, which suggests that people with certain blood types may be more susceptible to health problems due to lectins than others .
Some plant lectins, such as castor bean ricin and white kidney bean agglutinins, are very toxic to humans and rats. Ricin can cause blood agglutination and might be used in chemical warfare and genetically engineered herbicides .
White kidney bean hemagglutinins can cause acute nausea, followed by vomiting and diarrhea.
Other plant lectins are less toxic, but they can cause damage in other ways.
Harmful Effects of Dietary Lectins
1) Lectins Are Resistant to Digestion and Are Absorbed Into the Bloodstream
They can be readily transported through the gut wall into the blood .
2) Lectins Damage the Gut Lining, Causing Leaky Gut
Lectins bind to surface glycoproteins and gut lining cells, causing damage to the villi, increasing the uptake of intestinal content by the cells, and shortening the microvilli .
Some dietary sources of lectins, such as wheat, can directly break tight junctions in gut cells .
Lectins cause leaky gut, allowing increased exposure of both dietary and bacterial antigens (inflammatory agents) to the immune system .
Lectins can also interfere with nutrient absorption .
3) Lectins Stimulate the Immune System
These antibodies don’t necessarily protect you from harmful lectins. Whether this causes disease depends on individual susceptibility.
In mice, administration of lectins through the nose or by feeding stimulates IgG and IgA production, similar to that of the cholera toxin .
Lectins can potentiate the immune response to antigens that wouldn’t be inflammatory by themselves. For example, mice fed with wheat germ agglutinin and egg white protein develop much stronger antibody responses to egg white protein than if they are fed egg white protein alone [18, 19].
Therefore, consumption of lectin-containing foods concomitantly with other products can increase the likelihood of developing sensitivity to other food products.
As lectins can potentiate the immune response to other antigens, it is proposed that lectins might be used along with oral vaccines .
Lectins can induce mast cell reactions, suggesting that they can aggravate allergies and histamine intolerance.
4) Lectins Cause Autoimmunity
As lectins can act as triggers to the immune system and leaky gut, lectins can cause autoimmunity in susceptible people .
Lectins trigger autoimmunity by binding to glycoproteins and glycolipids (sugar molecules attached to proteins and fat), such as sialic acid, on the surface of the cells. Interestingly, the brain and gut are rich in sialic acid.
In humans, sialic acid is present in body fluids (blood, breast milk, gallbladder excretions, synovial fluid, sweat, gastric juices, and urine) and tissues (red and white blood cells, platelets, salivary glands, throat, stomach, cervix, colon, cartilage, etc.). In the blood, it’s found in fibrinogen, haptoglobin, ceruloplasmin, α1 -antitrypsin, complement proteins, and transferrin .
5) Lectins Affect the Gut Microbiota
The presence of lectins affects the composition of the gut bacteria and may cause dysbiosis (microbial imbalance) predisposing you to autoimmune diseases. However, the mechanism by which lectins affect gut bacteria is not fully understood.
Lectins reduce levels of intestinal heat shock protein (iHSPs), an anti-inflammatory protein that is important for healthy interaction with the gut bacteria. Also, lectins interfere with iHSP functions, thus reducing the gut lining’s sensitivity to oxidation and inflammation .
In rats, dietary lectins increase gut levels of E. coli and Lactobacillus lactis, both of which have proteins similar to HLA and are associated with autoimmune diseases such as rheumatoid arthritis .
Kidney bean lectins can cause E. coli overgrowth in the gut, while snowdrop lectins and mannose-specific lectins can block this effect .
6) Lectins Cause Abnormal Cell Growth
In cell-based studies, lectins triggered lymphocyte growth and activation .
7) Other Links Between Lectins and Health
In addition to autoimmunity, there are also other links between lectins and health.
However, most of these studies are cell-based or model organism-based, so additional animal or human studies are necessary to confirm these findings.
Lectins and Insulin
At low doses, wheat germ agglutinin can mimic the insulin function in fat cells. However, at higher doses, wheat germ agglutinin can cause insulin resistance (in a cell-based study) .
Enlargement of the pancreas due to dietary lectins may reduce insulin levels in rats .
Lectins and Obesity
Lectins and Brain Functions
In roundworms, lectins can be transported from the gut to dopamine neurons, and interfere with neuronal and dopamine functions, suggesting that it may contribute to Parkinson’s disease in humans .
The Lectin Avoidance Diet
The Lectin Avoidance Diet has a simple formula: eat meat and seafood, as much as you want, mainly during the day.
The Lectin Avoidance Diet excludes grains, beans, nuts, seeds, most potatoes, and all dairy.
Allowed foods include all seafood, meat, chicken/turkey (all fowl), eggs (if not allergic), and most fruits and vegetables.
Romaine lettuce, cruciferous veggies, cucumbers, and celery are the best vegetables to include. Raw honey, citrus fruits, berries, and pineapple are the recommended fructose-containing foods.
Japanese and purple sweet potatoes are the best starch to include in your diet, but it’s probably better if they’re pressure cooked. Other sweet potatoes, nightshade vegetables (like tomatoes), and squash could be consumed if pressure cooked.
However, even if you get rid of lectins, you won’t get rid of all anti-nutrients. For example, tannins are found in many plants and are considered anti-nutritional because they can alter nutrient digestion and absorption .
Cures Autoimmune Disease
A study of 800 autoimmune patients evaluated a diet that avoided grains, sprouted grains, pseudo-grains, beans and legumes, soy, peanuts, cashews, nightshades, melons and squashes, non-Southern European cow milk products (Casein A1), and grain/bean-fed animals.
Most of these patients started with elevated levels of TNF-alpha (an inflammatory molecule), which were reduced to normal after 6 months on this diet.
The study concluded that increased adiponectin is a marker for lectin and gluten sensitivity, while TNF-alpha can be used as a marker for gluten/lectin exposure in sensitive individuals .
Dr. Steven Gundry, the author of the study, frowns upon foods that originated from America.
Feel Better By Eliminating Harmful Food Compounds
I see myself as a canary in a coal mine as I’m sensitive to many foods.
Over time, I’ve built up a list of food products that cause an insignificant level or no inflammation.
At some point, I realized that many of my health problems resulted from lectins.
I understand that not everyone is the same, but I’ve noticed that others who are very sensitive to foods struggle with similar issues.
This doesn’t mean you won’t be able to eat anything else for the rest of your life.
This diet is just to inform you about the foods that are relatively safe. Personally, I live off of these foods and try not to stray.
The Lectin Avoidance Cookbook
Due to frequent queries about how to implement this diet, I have released the Lectin Avoidance Cookbook. If you have chronic inflammation and suspect that some of it may come from food, doing an elimination diet may help you manage your health issues.
The Lectin Avoidance Diet may help with:
- Chronic fatigue and Fibromyalgia
- Brain fog
- Histamine intolerance
- Irritable Bowel Syndrome
- Irritable Bowel Disease
- Other autoimmune diseases
In the Lectin Avoidance Cookbook, we have 93 recipes and counting. We’ve also added the Lectin Avoidance Diet Companion Guide, which explains:
- How to know if you are sensitive to lectins
- Ways to mitigate the health effects of eating a high-meat diet in order to ensure that you live a long and healthy life
- The scientific rationale that led me to use resistant starch Hi-Maize as a healing food
- Ways to hack your metabolism if you are too thin or cannot lose weight due to inflammation
After you pay for the book, you will be redirected to a link where you can download it. The redirect takes about 5-10 seconds, so be patient. If you have any issues, email [email protected]
Try the cookbook. If you don’t start feeling better within 30 days, I will give you 100% of your money back!
Foods Allowed In The Diet (Low In Lectins)
You should get a good amount of protein in the morning – about 30 grams.
Your diet should consist of 20 to 30% protein if you are suffering from an autoimmune or chronic inflammatory disease.
- Fish – My top 5 are frozen wild-caught salmon, fresh wild sardines, roe (fish eggs), oysters, and anchovies (any low-toxicity seafood is ok)
- Meat products
- Beef – Preferably grass-fed
- Chicken – I eat the whole chicken except for the sharp bone fragments, which I chew to get the marrow out
- Cricket flour
- Hemp protein
- Liver – Beef or chicken (without additives)
- Bone broth – Best to make your own
- Brewer’s yeast or nutritional yeast (without synthetic folate)
- Cooked tempeh (Some people can’t handle this and it is not allowed on Dr. Gundry’s diet)
Eggs are fine from a lectin standpoint, but people easily develop egg allergies in stages of chronic gut inflammation.
My favorite source of safe carbs is raw honey.
Fruits aren’t rich in lectins, but they do have tannins. I eat fruit occasionally, even though they spike my immune system. My favorites are pineapple and citrus. Dr. Gundry and I look at melons unfavorably.
- Starch – I find purple sweet potatoes the least inflammatory whole food starch. Japanese sweet potatoes aren’t too bad either. Any sweet potato is fine, as long as they are pressure cooked. I would still pressure cook the purple sweet potatoes.
- Fruits – Blueberries, pineapple, citrus, golden berries, papaya, mulberries, and mango
- Fiber – resistant starch is my main source of fiber
- I use raw honey and resistant starch for all of my carbs.
Cut omega-6 oils out (except black seed oil).
Try to have a couple of tablespoons of caprylic oil daily. Space it right, and you shouldn’t have gastrointestinal effects. Use 1 tbsp black cumin seed oil and extra virgin olive oil daily.
- Caprylic acid – The best oil. Try to have 3 to 5 tablespoons daily (1 to 1.5 with each meal). Reduce dosage if you get gastrointestinal problems and work up. MCT oil is also good.
- Black cumin seed oil – Anti-inflammatory oil with thymoquinone
- Avocados or avocado oil
- Extra virgin olive oil
- Ghee – In moderation for sauteing, stir-frying, and using for sleep
- Hemp seeds – This is the only seed that I tolerate
To some people seeds cause problems, but they are better than nuts. In the beginning, stick with the above mentioned and eventually try the seeds. I don’t eat seeds since I get some degree of inflammation from them.
- Romaine lettuce
- Steamed, boiled, or stir-fried cruciferous vegetables (broccoli, cauliflower, kale, or Brussels sprouts)
- Sprouts – broccoli, alfalfa, etc.
Other non-nightshade vegetables are fine.
- Dulse powder or Nori for iodine
- Sunflower lecithin – After meals for PS and PC
- Italian seasoning
- Nutritional yeast (no folic acid)
Other spices are okay in general.
Chili, paprika, and cayenne pepper are part of the nightshade family, so some people might react to them.
Foods Excluded From The Diet (High In Lectins)
- All grains
- Nightshades, including tomatoes, peppers, potatoes, and eggplant
- Gluten from wheat, rye, barley, malt, and maybe oat
- Legumes and all beans including soy and peanut. Cashews are part of the bean family and are not allowed. People with an enzyme deficiency that increases oxidative stress can’t eat certain beans such as broad beans
- Dairy, including milk and milk products as cheese, cottage cheese, yogurt, and kefir
- Yeast (except brewer and nutritional)
- Fruits should be avoided during the trial period but can be added back in later
Look for symptoms of intolerance: Bowel, sleep, or mood changes, memory impairment, or any other significant changes you can relate to the ingestion of the food group. It may take a week or so for the symptoms to appear.
To download a full list of foods to eat or avoid on the Lectin Avoidance Diet, click on the button below.
Food Groups to Pay Special Attention To
Seafood is an important dietary component for lectin-sensitive people. Like any food, it may cause health issues in a minority of people. However, the DHA from fish oil is critical in the modulation of the immune system and the decrease of lectin sensitivity.
I do well with very mildly cooked wild-caught salmon (less well with fully cooked), fresh very mildly cooked wild sardines (not canned), and fresh oysters. Other kinds of seafood are good as well.
To reduce the risk of parasites, I buy frozen wild salmon, defrost it in my fridge for 24 hours, and warm it up or cook it lightly. Industrial freezers should kill all the parasites, and if they don’t, 145 degrees for 5 to 10 minutes will. I also use a lot of spices. The immune system protects against parasites as well, so I’m personally not concerned about them.
I’ve experimented with having up to 18 oz. of wild salmon a day without any problem. I currently eat 6 oz. a day.
The point of the diet is to get good quality DHA, iodine, less omega-6, adequate protein quantity, and nutrition.
Raw honey has some great benefits that starch doesn’t have. It’s the healthiest carb source for lectin-sensitive people. Honey:
- Is a mucilage, which means it coats the stomach
- Is a very powerful anti-microbial, which means it should help SIBO
- Has beneficial prebiotics, such as FOS and GOS
- Has low glycemic index
- Contains few lectins
- Has both immune boosting and anti-inflammatory properties
- Combats mold toxins
- Contains fructose, which helps increase energy by increasing orexins
Eggs are extremely nutritious and are considered a superfood. However, in some people, eggs can cause other health issues – not from lectins, but because of the proteins, you can easily become intolerant to if you’ve been on a heavy lectin diet for a while, or if you suffer from excessive stress.
I developed an allergy to eggs in my early 20s, but most people are fine with them. If you feel fine, then indulge, because eggs are a truly healthy food. If you can include eggs, you can reduce your need for supplements.
How to Reduce the Lectin Levels in Food
- Soaking for 2 hours and cooking destroys bean lectins. In common beans, the lectin content declines from 820 to 3.2 (hemagglutinating activity), while in fava beans it declines from 51.3 to 6.4 .
- Pressure-cooking destroys lectins in some foods, such as beans, sweet potatoes, and some squashes.
Nutrients to Add
Additional Lectin Sensitivity Resources
Genetic Factors That Predispose You
To learn if you are genetically susceptible to lectins, sequence your genes with 23andme ($99) and use SelfDecode. SelfDecode is the best genetics app out there and is the market leader in giving you recommendations based on your genes, symptoms, and (soon) blood tests.
With our new system in place, we can tell you which systems in your physiology are not working and how to fix them.
You can see how substances interact with your problematic genes, which genes you should be careful about, and which substances best fit you.
Most importantly, you can see if you have the lectin sensitive gene, and if you do, find out ways to reduce lectin sensitivity.
By using SelfDecode, I’ve been able to figure out that the cannabinoid gene is the most important for lectin sensitivity. I drew on multiple lines of evidence to figure this out. After seeing the gene in all of my clients with this food sensitivity (I personally also have 2 bad alleles), I was able to confirm the important role of this gene.
It’s the perfect fit when it comes to the evidence implicating this gene.
Table: Genetic SNPs that Contribute to Lectin Sensitivity
Read this post to learn more about other markers and symptoms of lectin sensitivity.
Get Started Reducing Lectins and Inflammation With These Tools
If you are suffering from inflammation, it is important to figure out which foods you are reacting to. You may or may not be sensitive to lectins.
Therefore, avoiding lectins permanently might not be the best solution. The best way to find out is to do an elimination diet. You remove most common food sensitivities until your symptoms subside, then you bring them back one at a time to determine if you react to each food. At the end of the diet, you should be able to eat a diverse diet comprising of foods that do not cause you any inflammation.
- The Lectin Avoidance Diet cookbook provides recipes, instructions, and resource list to help you figure out foods that cause you inflammation
- The SelfHacked Elimination Diet course provides both the science and practical step-by-step instruction to figure out your food sensitivities, and to overcome them
- The All About Inflammation course provides background info about inflammation and layperson-friendly science behind it
Note: SelfHacked is, in part, supported by purchases of these products. All proceeds get reinvested back into the company to help serve you better and improve the quality of our products, so we thank you for supporting us!