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The Truth about Lectins: Villains or Heroes?

September 8, 2025

Lectins may earn the prize for the most misunderstood and controversial plant nutrients.

Depending on who you talk to, these proteins—found abundantly in beans and legumes—will be portrayed as either nutritional villains or heroes.

According to the people who vilify them, high-lectin foods, including beans, can disrupt the gut wall, inflame the wall of blood vessels, and trigger autoimmune diseases.¹ Not good, obviously.

Others argue the opposite, referring to lectins as the heroes of the plant-based kingdom. According to this view, the world’s longest-lived people consume diets rich in beans and other high-lectin foods.

Among the five cultures that make up the world’s Blue Zones, for example, people tend to consume one or more cups of beans a day.

Additionally, numerous large studies have linked the consumption of beans and other lectin-containing foods with increased longevity.²

So…

Are lectins good or bad for you?

As with many nutritional topics, the truth is far more nuanced than the sensational reports that dominate most social media feeds.

For most people, high-lectin foods, when prepared appropriately, can and should be part of a health-promoting dietary strategy. Other people, however, should reduce their exposure.

Get ready to learn how to tell which type of person YOU are.

What are Lectins?

Found in many plants—including beans, lentils, tomatoes, and peppers—lectins are a type of protein. Plants produce lectins as a natural defense mechanism.³

When insects feed on these plants, the lectins bind to molecules in their guts, reducing nutrient absorption, damaging the gut lining, and reducing growth, survival, and, ultimately, the insect’s ability to produce offspring.

This defense mechanism can cause problems for some people, especially if they consume poorly prepared foods that contain active lectins.⁴

Active lectins are resistant to stomach acid, so your gut can’t easily break them down. Once they reach your intestine, they can interfere with mineral absorption and disrupt the intestinal flora.

That can lead to some seriously uncomfortable side effects, including:

Nausea
Vomiting
Stomach upset
Diarrhea
Bloating
Gas

Plus, because active lectins bind to cells, they’re also thought to play a role in some inflammatory conditions such as rheumatoid arthritis.

All of that sounds scary.

However, it’s important to keep two points in mind.

These dangers generally only apply to active lectins, which are avoidable if you take the right steps. A few preparation techniques not only render lectin-rich foods safe to eat, but also health-promoting.
Not everyone reacts to lectins the same way. Some people are lectin-sensitive. For these individuals, even small amounts of deactivated lectins can cause gastrointestinal distress.

So, to determine whether lectins are right for you, you’ll need to consider two questions:

Are you sensitive to lectins?
Are you preparing lectin-rich foods appropriately?

Let’s take them one at a time.

Are You Sensitive to Lectins?

Lectin sensitivity usually stems from underlying gut or immune issues such as irritable bowel syndrome or Crohn’s disease. In individuals with a leaky or inflamed gut, lectins can sneak through the gut lining, enter the bloodstream, and trigger an immune response, resulting in symptoms such as bloating, joint pain, or fatigue.

To find out whether you’re sensitive to lectins, you’ll need to go on an elimination diet. This involves removing high-lectin foods for a few weeks, then reintroducing them while monitoring how your body reacts.

If you experience bloating, joint pain, fatigue, or skin issues after consuming these foods, you may be lectin sensitive.

Here’s how to sort it all out.

Step 1: Remove high-lectin foods

For 21 days, eliminate the following high-lectin foods:

Legumes: Beans, lentils, chickpeas, peas, green beans, and peanuts.
Some vegetables: Nightshades (tomatoes, potatoes, eggplants, and peppers), along with cucumbers, pumpkin, squash, and zucchini.
Grains: Wheat, barley, rye, oats, and corn.
Seeds and nuts: Particularly those with outer shells, like sunflower seeds or cashews.
Dairy: If it’s from grain-fed animals, it may contain lectins indirectly.

During the elimination diet, eat plenty of anti-inflammatory, nutrient-dense foods like non-starchy vegetables (except for nightshades), healthy fats (avocado, olive oil), clean proteins (wild-caught fish, pasture-raised poultry), and low-glycemic fruits (berries, citrus).

These foods help repair your gut lining and reduce inflammation.

Note: Although it’s not a full 21 days, my 10-Day Detox program typically provides enough time to eliminate the effects of high-lectin foods. And by slightly modifying it using the instructions above (for example, you can normally eat nightshades on the program but you’ll want to eliminate them in this case), it can guide and support you through this process.

Step 2: Reintroduce one food at a time over three days.

For example, if you’re testing dairy, have some yogurt or cheese on Day 1, then wait and observe for any symptoms, such as bloating, fatigue, headaches, or skin issues, over the next two days. If you don’t react, move on to the next food.

Are You Preparing Lectin-Rich Foods Correctly?

A handful of preparation techniques will deactivate and remove lectins from beans and other foods.

The problem: Some people use these techniques incorrectly.

Take cooking. It can inactivate most lectins in most foods. However, for certain foods—especially beans—wet high-heat works best.

That rules out using a slow-cooker, one of the biggest time-saving staples in most kitchens. The low heat of a slow cooker just isn’t enough to deactivate the types of lectins found in beans.

For canned beans, that’s not a problem, as they come pre-cooked. Just give them a thorough rinse, and they’re ready to eat.

However, for dry beans, follow these steps.

Step 1: Soak them for at least five hours.

This will break down the lectins. Adding an acidic medium, such as lemon juice or vinegar, to the soaking water can enhance this process.

Step 2: Rinse.

Place the beans in a colander. Rinse under cool, running water for 10-15 seconds.

Step 3: Cook.

Boil the beans for at least 30 minutes, until they’re soft. Instead of boiling, you can also use a pressure cooker, which can break down these proteins far more effectively than boiling.

To reduce lectins in high-lectin vegetables like tomatoes, cucumbers, and peppers, remove the skin and seeds, as these parts tend to contain the highest concentrations of lectins.

Additionally, when shopping for commercially prepared products, look for options that are fermented and sprouted. Fermenting foods like soybeans (to make miso, tempeh, or natto) allows beneficial bacteria to digest lectins, making the food easier on your gut.

Sprouting grains, beans, and seeds reduces lectins by activating enzymes that break them down during the germination process.

Finally, keep in mind that it can take time for your gut bacteria to adapt to any new food. That means, even if you prepare high-lectin foods appropriately, you may still experience gas and bloating if you’re not accustomed to eating them.

Fortunately, for most people, the gut environment returns to normal in roughly one to two weeks. After that, they can eat beans, lentils, and other lectin-rich foods without issue.⁵