The Pros and Cons of Lectins

What is a lectin? A lectin is a type of protein that is attracted to certain types of sugars or carbohydrates in our diets. It binds to cell membranes in a sticky manner and becomes the “glyco” of glycoproteins. Lectins offer a way for molecules to stick together without involving the immune system, which can influence cell-cell interaction. However, lectins are involved in the immune response.

Where are lectins found?
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Lectins are found mostly in starchy foods, except for seeds, dairy and nightshade vegetables. They are high in foods such as the following:
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• Raw grains (including grain-based flours such as soy flour)
• Legumes, including peanut butter and peas
• Dairy products
• Soy, edame
• Seeds and seed coats (including hemp and flax)
• Raw or undercooked kidney beans
• Nightshade vegetables (tomatoes, pepper, white potatoes, eggplant, cayenne pepper, pepper)
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What is the function of a lectin?

Lectins serve as a natural pesticide for plants. They ward off bugs, diseases, fungi, and microorganisms. It has even been hypothesized that lectins allow a plant to evolve and seeds to pass through a gastrointestinal tract unchanged and, thus, subject to further propagation. The curious part is that they end up in the bloodstream of humans unchanged since they are resistant to our digestive process.

Lectins are thought to play a role in immune function, cell growth, cell death, and body fat regulation. They can also be powerful allergens.

Are there any benefits to lectin use?

Surprisingly, lectins and their application in medicine have benefits. In general, a wide range of biological applications has been attributed to plant lectins, such as mediators of inflammatory and immune response, antiviral, antibacterial, antifungal, and anthelminthic agents, healing effect, drug delivery, histochemical markers, biosensing of diseases, and antitumoral activities.

One of the most well-documented uses of lectins is in anticancer activities. In addition, lectins may interact with receptors and other molecules present in the cell surface and/or cytosol to reduce cell proliferation, activating cell death pathways.
A recent 2022 study linked lectins to antiviral uses, including COVID. Anti-viral lectins bind to glycans on the viral surface and interfere with the binding of the virus to an infected cell.

What are the dangers of lectins?

Although lectins do play a role in human physiology, care in the selection and cooking process of many lectin-containing foods can render the dangers harmless. In other cases, lectins may need to be avoided. Systemically, they can disrupt lipid, carbohydrate, and protein metabolism, promote enlargement and/or atrophy of key internal organs and tissues, and alter the hormonal and immunological status of the body. 

Lectin-free diets exist; some integrative physicians use them with their patients to alleviate systemic complaints.
Lectins and the intestinal wall: Despite popular literature, not all lectins are bad, as we discussed in our discussion of their applications in medicine. It is essential to take a balanced view of the topic of lectins and realize that while lectins may cause some problems when used correctly and for the right therapeutic reasons, they can also be a medicinal aid.

Final thought

Lectin-free diets have again become popular since Dr. Gundry published his book The Plant Paradox in 2017. Remember that a lectin-free diet is very restrictive and fosters an unhealthy relationship with food. It may make getting all your nutrients from the food groups difficult. It may not be accessible or affordable.

 Despite being on the NY Times bestseller list, this book has problems. His views on lectins may just be one of them.