Lectins: To Eat or Not to Eat?

Being on a mission to help others with autoimmune disease and inflammation, I thought about lectins as I was cranking up a batch of lentil soup requested by my son-in-law. So, lectins…to eat or not to eat…that is the question. Lectin-containing foods have been a source of debate, especially for those who have an autoimmune disease. 

Just because a particular food may be considered healthy, doesn’t mean it is good for you. Many studies show that plant foods, for example, contain anti-nutrients that prevent us from absorbing certain nutrients and can even get into our bloodstream and trigger immune responses. Lectins are one example. Wheat, vegetables (particularly nightshades), seeds, beans, legumes (soy, peanuts, lentils, etc.), traditional dairy products, grain-fed and farm-raised animal proteins contain lectins, which can increase inflammation in some people.

Dr. Steven Gundry in his book, The Plant Paradox, sees lectins as a cause of autoimmune disease, believes lectin-rich foods should be limited in the diet and provides a “yes” and “no” list for lectin-containing foods, especially for those testing positive for lectin sensitivity. [i] However, a recent research study looking at the reaction of lectin antibodies with human tissues indicated that some people may develop antibodies and autoimmune reactions to lectins, but disagreed with this as a blanket concept.[ii]

So, exactly what are lectins? Lectins are contained both in animal and plant proteins. They basically are a protein and act as a natural toxin to prevent themselves from being eaten or destroyed. In fact, even the acid environment of the stomach cannot digest them, so they travel on to the small intestine where they can bind to cells in the intestine, destroy them, and then enter into the bloodstream. From there, lectins may travel to other tissues and cause inflammation, which is why people with autoimmune diseases such as thyroid, arthritis, diabetes as well as heart disease, or obesity may need to restrict or even eliminate them.

Wheat germ agglutin (WGA) is a lectin found in wheat, and even though it’s a food staple across the world, is known for its direct ability to damage gut tissue even without sensitivity or allergy. WGA is such a powerful insecticide that it has been used in developing GMO wheat. [iii] It also is highly inflammatory and known to cause a leaky gut, which can allow food particles to get into the circulation and potentially set up an autoimmune disease in susceptible individuals. This is why the very first action of many functional medicine practitioners is to put individuals with autoimmune disease on an anti-inflammatory diet that excludes gluten and dairy as well as other lectin-containing foods. This can often help to put out the fire of inflammation.

While eliminating WGA may help some, it may not be the total solution for everyone with lectin sensitivity. Unfortunately, other lectins such as chitin-binding lectins are found in tomatoes, potatoes, barley, rye, and rice.

What foods contain the greatest amounts of lectins? Raw legumes contain the greatest amounts of lectin (beans, lentils, peas, soybeans, peanuts) and whole grains like wheat contain the highest amounts of lectins. While it’s true that you could experience severe food poisoning if you eat even a small handful of raw red kidney beans, cultures have prepared lectin-containing legumes safely for centuries. Improperly prepared lectins, however, can cause a range of symptoms, ranging from dangerous ones like clumping of red blood cells to more moderate ones (nausea, vomiting, stomach upset, and diarrhea) or milder ones (bloating and gas).[iv]

People with autoimmune disease may be more likely to feel symptoms after eating lectins. For example, in people with inflammatory arthritis, lectins, especially wheat lectins, can bind with glucosamine, a carbohydrate that surrounds joints, and cause inflammation and joint pain. Nightshades are also very high in lectins and contain alkaloids such as solanine (white potatoes), nicotine, capsaicin (peppers) which can also trigger autoimmune inflammation. [v]

Personally, I limit lectins in my diet but don’t totally avoid them. While some health experts insist that they should be totally avoided, they can be nutritious. They are often high in antioxidants and are great sources of B vitamins, protein, fiber, minerals, and healthy fats, so for many people, eliminating all lectins may be too restrictive. A recent review of suggests that some individuals may be more susceptible than others to the negative effects of foods referred to as anti-nutrients, but notes that in some cases they may be even therapeutic.[vi] In, The Blue Zones, beans, particularly fava, black, soy, and lentils were found to be the cornerstone of most Blue Zone culture diets, linked to long and happy lives.[vii]       

Specific food lectins should be avoided if you have sensitivity to them. I actually tested positive for lentil sensitivity and found that I had some leaky gut and gut pathogen issues. While I healed my gut, given my autoimmune disease, would not choose to eat them on a regular basis and definitely not until I fixed my gut and unless I removed the lectins. So, why should you limit or avoid foods containing them? Glad you asked.

Why avoid Lectin-containing foods? Reasons to consider moderating or eliminating lectins:

• Lectins are high in carbohydrates, which contributes to weight gain.
• Some individuals have sensitivities to them (this can be investigated by a food sensitivity test, as not all people develop celiac or true allergies).
• They can be inflammatory, causing substances called cytokines to be released especially for people with autoimmune disease.

Ways to reduce/avoid lectins or lectin reactions:

• Eat a lower carb, higher fat diet
• Soak lectin-containing beans prior to cooking
• Boil lectin-containing legumes
• Ferment legumes
• Use a pressure cooker, which destroys the lectins.
•  Keep a food journal or use an app to monitor what types of foods you are eating and track how you feel after eating lectin-containing foods. If you have increased symptoms, you may want to avoid the specific food and/or monitor your reactions and how you are preparing the food.
• Try an elimination diet. When re-introducing foods that contain lectins, pay attention to symptoms that start of increase after eating certain foods
• Try an autoimmune protocol diet (AIP) diet which may work best for people with autoimmune disease.
• If you need even a more lectin restrictive diet, refer to Dr. Gundry’s diet plan. The Wahl’s Protocol is also an option for those with autoimmune disease.
• Get tested for lectin food sensitivity.
• Please note that if you are gluten sensitive, none of the cooking methods will destroy or remove wheat gluten from foods.

It’s important to know that microwaving does not remove lectins from beans. So, yes, while I made lentil soup, I removed the lectins through soaking the raw lentils and cooked them in a pressure cooker, which is the best way to neutralize them.

As to the answer of whether to eat or not to eat lectins, that depends on the individual. It can be challenging to know what the right foods for your body are and which ones to avoid. Everyone reacts differently to foods. So, my suggestion is if you find that you have symptoms after eating lectins, see if the symptoms only happen when you eat them (making sure you know how they were prepared) and totally go away when you eliminate them from your diet. To truly find out whether you have lectin sensitivity, you can get tested with a lab test such as a Lectin Zoomer by Vibrant Wellness. A functional diagnostic nutrition practitioner or another functional medicine practitioner can help you to identify these food sensitivities and assist with the right food plan to support your individual situation.

---

[i] https://drgundry.com/dr-gundrys-print-friendly-yes-no-lists/

[ii] Vojdani, A., Afar, D., & Vojdani, E. (2020). Reaction of Lectin-Specific Antibody with Human Tissue: Possible Contributions to Autoimmunity. Journal of immunology research, 2020, 1438957. https://doi.org/10.1155/2020/1438957—

[iii] https://www.greenmedinfo.com/page/opening-pandoras-bread-box-critical-role-wheat-lectin-human-disease

[iv] https://www.hsph.harvard.edu/nutritionsource/anti-nutrients/lectins/

[v] https://shawnwells.com/wp-content/uploads/2020/11/Your-Guide-To-Lectins-Phytates-Oxalates.pdf

[vi] Petroski, W., & Minich, D. M. (2020). Is There Such a Thing as “Anti-Nutrients”? A Narrative Review of Perceived Problematic Plant Compounds. Nutrients, 12(10), 2929. https://doi.org/10.3390/nu12102929

[vii] Buettner, Dan. The Blue Zones of Happiness: Lessons From the World’s Happiest People. National Geographic Partners, 2017.