What vegetables have lectins? A guide to plant proteins

November 10, 2025 •

4 min read

Estimates suggest that around 30% of foods commonly consumed contain lectins, a family of proteins that bind to carbohydrates. Knowing what vegetables have lectins is important for people with sensitivities and those seeking to reduce their intake through proper food preparation.

Quick Summary

Many vegetables contain lectins, particularly legumes and nightshades, although the amount and type vary. Cooking, soaking, and other preparation methods significantly reduce or deactivate lectins, making these nutritious foods safe to eat for most people.

Key Points

Legumes: The highest concentration of active lectins is found in raw legumes like kidney beans, which must be thoroughly cooked to be safe.
Nightshades: Vegetables like tomatoes, potatoes, and peppers contain lectins, primarily in the skin and seeds, but the concentration is lower than in raw legumes.
Cooking Reduces Lectins: High-heat cooking methods such as boiling and pressure cooking are highly effective at deactivating lectins in foods.
Low-Lectin Options: Many vegetables like leafy greens, broccoli, and asparagus have naturally low lectin content and are safe to eat raw or cooked.
The Controversy: While some diets advocate avoiding lectins, most health experts agree that the nutritional benefits of lectin-containing foods, when properly prepared, far outweigh any potential risks.
Listen to Your Body: Individuals with certain digestive sensitivities or autoimmune conditions may be more sensitive to lectins and should consult a doctor or dietitian.

The Basics: What Exactly Are Lectins?

Lectins are a type of protein found in almost all living organisms, including plants, animals, and fungi. In plants, they serve as a natural defense mechanism against pests, insects, and other predators. When consumed in their highly active, raw form, certain lectins can cause digestive distress, as they are resistant to digestion and can bind to the carbohydrates on the surface of cells lining the digestive tract.

It is important to note that not all lectins are harmful. Many are harmless, and research suggests some may even offer beneficial effects, such as antioxidant properties. However, concerns often arise with the potent lectins found in certain raw vegetables and legumes, which is why proper cooking is crucial.

High-Lectin Vegetable Categories

When considering what vegetables have lectins, two groups are most commonly highlighted: legumes and the nightshade family. Both are highly nutritious but require specific preparation to minimize lectin content.

Legumes

This large family of plants, which includes beans, peas, and lentils, is known for its high concentration of lectins in the raw state. The best-known example is the red kidney bean, which contains a potent lectin called phytohemagglutinin. Eating just a few raw or undercooked beans can cause severe nausea, vomiting, and diarrhea. However, thorough cooking completely deactivates these toxic lectins, making the beans safe and healthy to eat.

Common High-Lectin Legumes:

Red kidney beans
Soybeans (edamame)
Black beans
Lentils
Chickpeas
Peas
Peanuts (technically a legume)

Nightshade Vegetables

The nightshade family, scientifically known as Solanaceae, includes several popular vegetables. While they contain lectins, the levels are generally lower than in legumes and concentrated primarily in the skin and seeds.

Common Nightshade Vegetables with Lectins:

Tomatoes
Potatoes (especially the skin)
Eggplants
Bell peppers
Goji berries

How to Reduce Lectin Content in Vegetables

The good news is that reducing lectins is a straightforward process that is already part of many traditional cooking methods. Here are some effective techniques:

Soaking: For dried beans and legumes, soaking them overnight in water helps to dissolve and remove water-soluble lectins. The soaking water should always be discarded and the legumes rinsed thoroughly before cooking.
Boiling and Pressure Cooking: Heat is the most effective way to deactivate most lectins. Boiling high-lectin foods like kidney beans for at least 10 minutes is essential. Pressure cooking is considered the most potent method for neutralizing lectins effectively and quickly. Avoid using slow cookers for beans, as the low temperature may not be sufficient to destroy all lectins.
Removing Skins and Seeds: For nightshade vegetables like tomatoes and cucumbers, the majority of lectins are located in the skin and seeds. Peeling and deseeding can significantly reduce lectin intake.
Sprouting and Fermenting: These processes can break down lectins, making foods more digestible. Examples include fermented soy products like tempeh and miso.

The Lectin Controversy and Balanced Perspective

Much of the concern surrounding lectins was popularized by books like The Plant Paradox, but many nutritionists argue that these claims are largely exaggerated and not supported by conclusive human research. The vast majority of studies highlighting negative effects used high concentrations of raw lectins, which do not reflect typical dietary consumption.

The established health benefits of eating whole, plant-based foods, including those with lectins, far outweigh any potential risks for most people. These foods are rich in fiber, vitamins, minerals, and antioxidants that protect against chronic diseases. Excluding these foods unnecessarily can lead to nutritional deficiencies.

Comparison Table: High-Lectin vs. Low-Lectin Vegetables


High-Lectin Vegetables (Require Cooking)	Low-Lectin Vegetables (Generally Safe Raw or Cooked)
Beans (kidney, black, pinto)	Leafy greens (spinach, kale, arugula)
Soybeans (edamame, tofu)	Cruciferous vegetables (broccoli, cauliflower)
Lentils and chickpeas	Asparagus
Tomatoes (skin and seeds)	Garlic and onions
Potatoes (especially skins)	Avocados
Peppers (bell, chili)	Sweet potatoes
Squash (pumpkin, zucchini)	Mushrooms

Conclusion

In summary, the question of what vegetables have lectins is straightforward: many do, particularly legumes and nightshades. However, for the average person, this is not a cause for alarm. The key is proper preparation. By using simple, time-tested methods like soaking, boiling, and pressure cooking, you can safely enjoy the immense nutritional benefits of these foods while deactivating most of their lectin content. Unless you have a specific sensitivity or autoimmune condition, there is little evidence to suggest a restrictive, lectin-free diet is necessary or even beneficial. A varied, balanced diet rich in properly prepared plant foods remains the best approach to overall health. For those with specific health concerns, consulting a healthcare provider or registered dietitian is always the best course of action.

What are the benefits of eating lectin-rich foods? The science of legume lectins reveals their potential for cancer treatment and other positive health effects. Read more on the National Institutes of Health website.

Frequently Asked Questions

Almost all plant foods contain at least some amount of lectins, but the concentration varies widely. High-lectin vegetables include legumes and nightshades, while many leafy greens and cruciferous vegetables are naturally low in lectins.

Yes, cooking is one of the most effective ways to deactivate lectins. High-heat methods like boiling and pressure cooking are especially good at destroying active lectins, making foods like beans and lentils safe for consumption.

Lectins in tomatoes are mainly found in the skin and seeds and are less potent than those in raw legumes. For most people, consuming cooked tomatoes is not harmful, but those with sensitivities can peel and deseed them to reduce lectin intake further.

A lectin-free diet involves excluding all foods containing significant amounts of lectins, such as legumes, grains, and certain vegetables. It was popularized by Dr. Steven Gundry, but many health experts do not endorse it for the general population due to its restrictive nature and lack of strong scientific evidence.

Vegetables generally considered low in lectins include leafy greens like spinach and kale, cruciferous vegetables such as broccoli and cauliflower, asparagus, and sweet potatoes. These are often recommended for those seeking to minimize their lectin intake.

In their raw, active form, lectins can cause digestive issues like nausea, bloating, and vomiting. However, these symptoms are most often associated with improperly prepared foods and are rare with standard cooking practices.

While all plants contain some lectins, the types and concentrations in raw salad greens are typically very low and not considered a health concern for most people. The potent, harmful lectins are primarily concentrated in uncooked legumes and grains.