What are Lectins?

Proteins that bind carbohydrates

Do not confuse lectins with leptin, lactose or pectin.

Lectins are proteins that bind to carbohydrates or glycoproteins (carbohydrate-protein mixture) [1].

Proteins called lectins (from the Latin legere, "select") have the ability to bind to specific carbohydrate molecules.

They are found in every living organism, including viruses, bacteria and most foods, to varying degrees, but most are harmless. Scientists have been studying lectins since 1884.

Some scientists believe that lectins are part of plants' protective mechanisms [2].

Plants also use lectins to communicate with their environment, for cell organization and as reserve proteins, among other functions [3].

Lectins are carbohydrate-binding proteins found in all living organisms. They protect plants and help them communicate with their environment.

Different types of lectins for plants

In plants, lectins are concentrated in seeds, early leaves and roots. Leaves usually contain fewer lectins, although this may vary from plant to plant. A good example of a leaf is romaine lettuce.

The types of food lectins that can cause sensitivity are [4, 5, 5]:

• Legumes lectins, such as white kidney beans. On average, 15% of a bean's protein is lectins.
• Cucurbitaceae lectins, found in the juice of cucumber, melon and squash.
• Prolamins, like gluten and gliadin, are the alcohol-soluble lectins found in cereal grains.
• Agglutinin or hemagglutinin in soy and wheat germ, which can cause blood agglutination (clumping).

Plant agglutinins have the ability to clump together blood cells of certain blood types, suggesting that people with certain blood types may be more susceptible to lectin-induced health problems than others [6].

Some plant lectins, such as ricin from castor beans and agglutinins from white kidney beans, are highly toxic to humans and rats. Ricin can cause blood agglutination and could be used in chemical warfare and genetically engineered herbicides [4].

White kidney bean hemagglutinins can cause acute nausea followed by vomiting and diarrhea.

Other plant lectins are less toxic but can cause damage in other ways.

Lectins are concentrated in the seeds and roots of plants. Lectins in kidney beans, cucumbers, melons, pumpkins, grains and soy can cause food sensitivities. Some plant lectins are extremely toxic, while others are less harmful.

Harmful effects of dietary lektins

1) Resistant to digestion

Lectins are resistant to heat and digestion in both rats and humans. They can be easily transported through the intestinal wall into the blood [7, 8, 9].

In the blood, lectins can stimulate the immune system and alter hormone functions, or precipitate in blood and lymph walls [9, 10].

Lectins are not digested or broken down by heat. They can enter the bloodstream, overactivate the immune system and disrupt hormones.

2) Damage intestinal lining, causing leaky gut.

Lectins bind to intestinal mucosal cells, cause cell damage and increase the absorption of intestinal contents [11].

Some dietary sources of lectins, such as wheat, can directly break tight junctions in intestinal cells [12].

Lectins can cause leaky gut, increasing the exposure of both nutritional and bacterial antigens (inflammatory substances) to the immune system [13].

They can also interfere with nutrient absorption [14].

Lectins can bind to the intestinal mucosa and damage it, causing a leaky gut and hindering the absorption of nutrients.

3) Boosting the immune system

When lectins reach the bloodstream, most people develop antibodies against dietary lectins [15, 16].

These antibodies do not necessarily protect you from harmful lectins. Whether this causes disease depends on individual susceptibility.

In mice, nasal or dietary administration of lectins stimulates the production of IgG and IgA, similar to that of the cholera toxin [17].

Lectins can enhance the immune response to antigens that are not inflammatory in themselves. For example, mice fed wheat germ agglutinin and egg white develop a much stronger antibody response to egg white than when fed egg white alone [18, 19].

Therefore, consumption of lectin-containing foods in combination may increase the risk of developing sensitivity to other foods.

Since lectins can enhance the immune response to other antigens, they could be used in conjunction with oral vaccines [20].

Lectins can induce mast cell reactions, suggesting that they may exacerbate allergies and histamine intolerance.

By being absorbed into the bloodstream, lectins can overstimulate your immune response, increase your sensitivity to other foods and exacerbate allergies and histamine intolerance.

4) Cause autoimmunity

Since lectins can trigger the immune system, they can cause autoimmunity in susceptible people [21].

Lectins cause autoimmunity by binding to glycoproteins and glycolipids (sugar molecules attached to proteins and fat), such as sialic acid, on the surface of cells. Interestingly, the brain and intestines are rich in sialic acid.

In humans, sialic acid is present in almost all body fluids and tissues. In the blood, it is found in fibrinogen, haptoglobin, ceruloplasmin, α1 -antitrypsin, complement proteins and transferrin [22].

Lectins also increase inflammation by stimulating the production of IFN-gamma, IL-1 and TNF-alpha [11].

Lectins bind to healthy cells and tissues, which can cause autoimmunity and increase inflammation.

5) Influencing the gut microbiota

Lectins affect the composition of gut bacteria and can cause dysbiosis (microbial imbalance), making you susceptible to autoimmune diseases. However, the mechanism by which lectins affect gut bacteria is not fully understood.

Lectins lower levels of intestinal heat shock protein (iHSPs), an anti-inflammatory protein important for healthy interaction with gut bacteria and defense against oxidative stress [23].

In rats, dietary lectins increase intestinal levels of E. coli and Lactobacillus lactis, both of which are associated with autoimmune diseases such as rheumatoid arthritis [24].

Kidney bean lectins can cause overgrowth of E. coli in the gut, while snowdrop lectins and mannose-specific lectins can block this effect [25].

Lectins can disrupt the gut microbiome and feed harmful bacteria associated with autoimmune diseases.

6) Causing abnormal cell growth

Lectins can cause expansion and overgrowth of cells in many tissues, including the intestines, pancreas and liver [26, 3].

In cell studies, lectins have elicited the growth and activation of lymphocytes [5].

Insulin

In low doses, wheat germ agglutinin can mimic insulin function in fat cells. However, at higher doses, wheat germ agglutinin can cause insulin resistance (in a cellular study) [27].

Enlargement of the pancreas due to dietary lectins can reduce insulin levels in rats [5].

Obesity

In a cellular study, wheat germ agglutinin and ricin from castor oil can increase fat synthesis in fat cells [28].

Brain functions

In roundworms, lectins can be transported from the gut to dopamine neurons and disrupt neuronal and dopamine functions, suggesting that it may contribute to Parkinson's disease [29].

Certain types of lectins can cause insulin resistance, obesity and neurotransmitter imbalance.

The lectin-avoidance diet

Diet Formula

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.

However, allowed are all seafood, meat, eggs (if not allergic) and most fruits and vegetables.

Romaine lettuce, cruciferous vegetables, cucumbers and celery are the best vegetables. 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 is probably better if they are pressure-cooked. Other sweet potatoes, nightshade vegetables (such as tomatoes), and squash can be consumed when pressure-cooked.

But even if you get rid of lectins, you will not get rid of all anti-nutrients. Tannins, for example, are found in many plants and are considered anti-nutrients because they can alter the digestion and absorption of nutrients [30].

The lectin-avoidance diet includes all types of meat and seafood and most fruits and vegetables. Cereals, beans, nuts, seeds and dairy are excluded. Some vegetables must be pressure-cooked to reduce their lectin content.

Curing autoimmune disease

A study of 800 autoimmune patients evaluated a diet devoid of grains, sprouted grains, pseudo-grains, beans and legumes, soy, peanuts, cashews, nightshades, melons and pumpkins, non-southern European cow's milk products (Casein A1), and grain/bean-fed animals.

Most of these patients got their TNF-alpha (an inflammatory molecule) levels back to normal after 6 months on this diet.

The study concluded that elevated 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 [31].

Dr. Steven Gundry, the study's author, disapproves of foods originating in America.

The Lectin Avoidance Diet can help with:

• Chronic fatigue and fibromyalgia
• Brain Fog
• Histamine intolerance
• Irritable bowel syndrome
• Irritable bowel disease
• Other autoimmune diseases

 

Allowed foods in the diet (low in lectins)

Protein

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 suffer from an autoimmune disease or chronic inflammatory disease.

• Fish - My top five include frozen wild-caught salmon, fresh wild sardines, roe (fish eggs), oysters and anchovies (all seafood with low toxicity is good).
• Meat Products
• Beef - preferably grass-fed
• Chicken - I eat the whole chicken except for the sharp bone fragments, which I chew on to extract the marrow.
• Pork
• Cricket flour
• Hemp protein
• Liver - Beef or chicken (without additives)
• Bone broth - best to make yourself
• Brewer's yeast or nutritional yeast (without synthetic folic acid)
• Glycine
• Cooked tempeh (some people cannot stand this and it is not allowed on Dr. Gundry's diet)

 

Eggs are fine from a lectin standpoint, but people with chronic intestinal inflammation easily develop an egg allergy.

Start your day with a high-protein breakfast. Suitable foods are meat, fish, hemp protein and nutritional yeast. Eggs are fine unless you are allergic.

Carbohydrates

My favorite source of safe carbohydrates is raw honey.

Fruit is not rich in lectins, but it does contain tannins. I eat fruit occasionally, although it affects my immune system. My favorites are pineapple and citrus fruits. Dr. Gundry and I view melons unfavorably.

• Starch - I find purple sweet potatoes to be the least inflammatory starch out of whole foods. Japanese sweet potatoes are not bad either. Any sweet potato is fine as long as they have been pressure cooked.
• Fruit - Blueberries, pineapple, citrus fruits, golden berries, papaya, mulberries and mango.
• Fiber - resistant starch is my main source of fiber.
• Trehalose
• Carob

 

Raw honey and resistant starch for all my carbs.

My main carbohydrate sources are raw honey and resistant starch. You can also eat pressure cooked sweet potatoes, some berries, pineapple and citrus fruits.

Fats

Use caprylic acid, black cumin seed oil, extra virgin olive oil and ghee for your oils.

Delete omega-6 oils (except black seed oil and olive oil).

Try taking a few tablespoons of caprylic oil daily. Give them the right amount, and you should have no gastrointestinal problems. Use 1 tablespoon of black cumin seed oil and extra virgin olive oil daily.

• Caprylic acid - The best oil. Try to take 3 to 5 tablespoons daily (1 to 1.5 with each meal). Reduce the dosage if you experience gastrointestinal symptoms and work up.
• MCT oil
• Black cumin seed oil - Anti-inflammatory oil with thymochinone
• Avocados or avocado oil
• Extra virgin olive oil
• Ghee - in moderation for frying and stir-frying and using for sleeping
• Hemp seed - This is the only seed I tolerate.

 

For some people, seeds cause problems, but they are better than nuts. Stick to the ones mentioned above at first and eventually try seeds. I don't eat seeds because they give me a certain amount of inflammation.

Use caprylic acid, black cumin oil and extra virgin olive oil. Some people also tolerate seeds, but it is better to avoid them at first.

Vegetables

• romaine lettuce
• Cruciferous vegetables: broccoli, cauliflower, kale, Brussels sprouts (steamed, boiled or stir-fried)
• Cucumber
• Celery
• Sprouts - broccoli, alfalfa, etc.

 

Other nightshade vegetables are fine.

Spices/Others

• Dulse powder or Nori for iodine
• Sunflower lecithin - after meals for PS and PC
• Mustard
• Italian herbs
• Stevia
• Xylitol
• Nutritional yeast (no folic acid)

 

Other spices are generally good.

Chili, bell bell pepper and cayenne pepper belong to the nightshade family, so some people may react to them.

Excluded foods in the diet (high in lectins)

• All grains
• Nightshades, including tomatoes, peppers, potatoes and eggplant
• Gluten from wheat, rye, barley, malt and perhaps oats
• Legumes and all beans, including soy and peanuts; cashews belong to the bean family and are not allowed
• Dairy, including milk and milk products such as cheese, cottage cheese, yogurt and kefir
• Yeast (except brewer's yeast and nutritional yeast)
• Fruit (during the trial period)

 

Watch for symptoms of intolerance: bowel, sleep or mood changes, memory disturbances or other significant changes that you can associate with the intake of the food group. Symptoms may take a week to appear.

Avoid all grains, nightshade vegetables, legumes and dairy. During the trial period, also avoid fruits.

Food groups that deserve special attention

Seafood
Seafood is an important dietary component for lectin-sensitive people. Like any food, it can cause health problems in a minority of people. However, the DHA from fish oil is crucial for modulating the immune system and reducing lectin sensitivity.

I do well with mildly cooked wild-caught salmon (less well with fully cooked), fresh mildly cooked wild sardines (not canned) and fresh oysters. Other types of seafood are also good.

To reduce the risk of parasites, I buy frozen wild salmon, let it thaw for 24 hours in my refrigerator, and warm or lightly boil it. Industrial freezers should kill all parasites, and if that fails, a temperature of 145 degrees for 5 to 10 minutes can do it. I also use a lot of herbs. The immune system also protects against parasites, so personally I don't worry about that.

I have experimented with wild salmon a day with no problem. Currently, I eat 6 oz. a day.

If you are concerned about mercury, you can take NAC or R-lipoic acid to prevent accumulation of heavy metals and activate detox pathways.

The purpose of the diet is to get good quality DHA, iodine, protein and less omega-6.

Fish and seafood are crucial: they are rich in anti-inflammatory DHA, iodine and protein. I prefer wild-caught salmon, sardines and oysters.

Raw honey
Raw honey has some great benefits that starch does not. It is the healthiest carbohydrate source for people sensitive to lectin. Honey:

- Cares for the stomach

- Is a very potent antimicrobial, which means it should help SIBO

- Has beneficial prebiotics, such as FOS and GOS

- Contains few lectins

- Has both immune-boosting and anti-inflammatory properties

- Combats fungal toxins

- Contains fructose, which helps increase energy by increasing orexins

Raw honey is a better carbohydrate source than starch because of its anti-inflammatory, immune-boosting and antimicrobial properties.

Eggs
Eggs are extremely nutritious and are considered a superfood. However, eggs can cause other health problems in some people due to egg intolerance if you have been on a heavy lectin diet for some time, or if you suffer from excessive stress.

I developed an allergy to eggs when I was in my early 20s, but most people can handle them just fine. If it makes you feel good, feel free to eat because eggs are super healthy. If you can handle eggs, you will need fewer supplements.

How do you reduce lectin levels in food?

- Soaking and cooking for more than 2 hours destroys lectins in beans. In common beans, the lectin content drops from 820 to 3.2, while in fava beans it drops from 51.3 to 6.4 [32].

- Pressure cooking destroys lectins in some foods, such as beans, sweet potatoes and some pumpkins.

Nutrients to be added

- Calcium

- Magnesium

- Potassium