Lectins and Autoimmunity

You may have heard about lectins lately. They’ve received more attention in the media for their possible adverse effects on health. For some people, lectins can cause issues, especially with digestion. That’s why some people benefit from reducing or eliminating lectins from their diet.  

What are lectins?

So what exactly are lectins, and what is their link to autoimmunity?  They’re proteins that bind to carbohydrates and are found in almost all organisms, including plants, animals, and microbes. Found in all plant foods, lectins are found at exceptionally high levels in whole grains, legumes, seeds, nuts, and nightshades. The type of lectins in these foods are called agglutinins and prolamins.  

Lectins are considered anti-nutrients because they can interfere with the absorption of other nutrients, including calcium, iron, phosphorus, and zinc.  

Lectins play a part in plant defense, primarily against plant-eating organisms.  In other words, they have a protective mechanism for survival purposes, making them non-digestible to humans and animals.  

What are nightshades?

Nightshades are another lectin-containing group of foods that you should know about. Nightshades are a diverse group of plants including some vegetables and fruits. Common nightshade foods include tomatoes, tomatillos, potatoes, eggplant, peppers, pimentos, goji berries, ground cherries, ashwagandha, paprika, curry, chili powders, and tobacco. 

Nightshades are nutrient-dense foods rich in vitamin C, iron, fiber, protein, potassium, and antioxidants, including lycopene. That’s the good news. The bad news is that they can cause issues in some people. Some of the reasons why include:

• Lectins in nightshades may contribute to leaky gut and inflammatory bowel disease in people with food sensitivities or autoimmune disease. 
• They’re high in a compound called solanine, a chemical that may worsen arthritis pain and inflammation. 
• They contain saponins, compounds which may impair digestion and limit nutrient uptake. 

Why do lectins cause issues for some people?

Most people do not have an issue with lectins. However, some can experience a reaction after eating these proteins. Most types of lectins pass through the digestive system unchanged and aren’t affected by digestive enzymes. They resist being broken down in the gut. The acid in our stomachs also doesn’t break them down very easily. The fact that they’re not easy to destroy is what protects lectin-containing plants in nature.  It’s these very features of lectins that give some people issues. Here are a few reasons why:

• Lectins can become harmful when they block the absorption of nutrients in the body because they bind to carbohydrates like sugar.  
• Some lectins can contain poisonous compounds such as ricin.
• Lectins can bind to your gastrointestinal walls and cause abdominal pain, diarrhea, and vomiting —especially the lectin known as phytohemagglutinin, found in certain legumes.
• They may trigger an autoimmune response.
• Studies show that those with positive rheumatoid factor (RF) may be more sensitive to lectins. A high level of RF is linked to autoimmune disease, especially rheumatoid arthritis.  

Lectins and autoimmune disease

Lectins can play a role in autoimmunity for several reasons. A simple explanation is that for some people, lectins are treated as foreign bodies, which trigger an immune response to attack the “foreign invaders.”  

Lectins can be resistant to digestion. According to research, these proteins can enter our circulation, causing nutrient deficiencies, digestion issues, and severe intestinal damage.

A protein like a lectin shouldn’t get through the gut barrier. However, undigested lectins can penetrate through and provoke the immune response. Results from studies show that we can react to lectin-specific antibodies with 62 different tissue antigens. Studies also showed that IgM anti-lectin antibody levels were linked to RF-positive (positive rheumatoid factors) samples.

Problems with the digestion of lectins can contribute to a leaky gut  and the associated inflammation.  Leaky gut is also known as intestinal permeability. This is when the cells in your gut spread apart, and your gut begins “leaking” larger molecules into your bloodstream. These large molecules may trigger inflammation in the body and brain, causing tissue damage. Leaky gut is linked to autoimmune disorders, food sensitivities, allergies, and inflammation. Unfortunately, lectins can cross the gut barrier and contribute to a leaky gut.  

Other ways that lectins can affect your immune system include:

• Through “molecular mimicry,” when the lectin agglutinin mimics your body proteins  
• Overgrowth of bacteria that live in your gut
• Causing the discharge of histamine from gastric mast cells and stimulating acid secretion
• Triggering increased secretion of mucus

Some of the autoimmune diseases that have been linked to issues with lectins include:

• Celiac disease
• Diabetes
• Hashimoto’s and other thyroid disorders
• Inflammatory bowel disease
• Rheumatoid arthritis

An excellent way to find out if you have issues with lectins is through a nightshade elimination diet or a lectin elimination diet. If your symptoms improve when you omit lectin-rich foods, you are likely lectin sensitive. 

Lectin-containing food

Legumes, whole grains, and nightshades are all foods high in lectins. These include:

• Beans

• Lentils

• Nuts

• Peanuts – A legume especially high in lectins

• Raw or undercooked kidney beans – contain high levels of the lectin phytohemagglutinin, which is undetectable after cooking

• Raw potatoes – nightshades that are particularly high in lectins

• Raw, toasted, or roasted soybeans – only boiling seems to fully break down these legume lectins

• Seeds

• Tomatoes

• Whole grains – Especially, raw whole grains like raw wheat germ

Lectin-free diet

Studies show that some people with autoimmune diseases can benefit from reducing or eliminating lectins from their diet. In these people, a lectin-free diet improved symptoms. Increasing intake of probiotics, prebiotics, and polyphenols also helped.  Based on this research, scientists have concluded that this diet could help treat some autoimmune diseases or put them into remission.  

Lectin-free diets have become very popular due to Kelly Clarkson and The Plant Paradox by Dr. Stephen Gundry. Clarkson has a thyroid-related autoimmune disease and followed a restrictive lectin-free diet to feel better and lose weight. However, many doctors and dietitians are skeptical of elimination diets that are so strict, especially for something like lectins, which only negatively affects a tiny group of people.  

We recommend starting a nightshades-free diet first and then moving on to a lectin-free trial diet.  It’s a good idea to have your functional medicine practitioner monitor you anytime you do an elimination diet. This will help track your progress and your autoimmune disease symptoms. Your functional medicine provider can help determine if your symptoms are caused by lectins or another reason(s).

How to reduce lectins in food

There are a number of ways to reduce your lectin exposure, over and above simply avoiding lectin-containing foods. For example:

• Ferment or sprout grains and beans 

• Pressure cook lectin-rich foods to break down the proteins

• Remove the seeds and skin of foods like tomatoes 

• Soak and boil beans to break down lectin proteins

Remember that cooking, especially pressure cooking and boiling, can break down lectin proteins, making them easier to digest. This is why you may have issues eating tomatoes raw but not as tomato sauce.   

Here’s how to find out if lectins are causing your autoimmune disease

If you are one of the people who have problems with lectins, it could be the root cause of your autoimmune issues. Problems with lectins and other food sensitivities can cause a leaky gut. This can only make your autoimmunity worse. But not every autoimmune patient has lectin sensitivities or a leaky gut. So how do you know if you need to be lectin-leary? It’s simple. I can order the right tests and get to know your unique story and what’s troubling you. Before you go on a lectin-free diet we can chat to see if lectins are the likely culprit or if we should explore other issues.  Schedule a complimentary virtual appointment with us today so we can help you pinpoint the real cause of your autoimmune condition. Autoimmune disease can be reversed with our functional medicine approach. You’ll have more energy, less pain, and you will feel vibrant again.