High Lectin Foods

Lectins have become a hot topic in the world of nutrition, often sparking debates about their role in food. Some argue they’re natural anti-nutrients, while others claim they’re misunderstood plant compounds. Regardless of which camp you’re in, lectins are widespread in the foods we eat every day. So, let’s break it down—where are they found and why does it matter?

Foods High In Lectins

While lectins are found in a variety of foods, some contain particularly high amounts. Here’s a rundown of the highest lectin foods, to the best of our current knowledge.

1. Legumes

Legumes by and large have more lectins than any other type of food that has had research on it. For example, in one study, green lentils were shown to contain 3,407,872 ± 722,469 units/g when raw. Brown and yellow chickpeas contained 13,312 ± 2822 units/g and black beans contained 26,429 ± 5603 units/g.

a) beans such as black beans, fava beans, green beans, borlotti beans, edamame beans, kidney beans, lima beans, pinto beans, rashti beans, and white beans

When consumed raw, some legumes can be dangerous to consume. Others, such as green beans and edamame can be eaten raw, and contain substantially lower lectins than other types of beans and legumes.

Haricot vert green beans, for example, were shown to contain 6656 ± 1411 units/g when raw and edamame contained only 416 ± 88 units/g when raw. As you’ll notice, both have substantially less lectins when raw than the other legumes mentioned above. Both had no detected lectins after some boiling (5 minutes for edamame and 10 minutes for the green beans).

Cooking legumes can significantly reduce their lectin content, such as in the case of beans, which then become edible upon proper cooking. Soaking and sprouting, as well as pressure cooking, can also help.

2. Nightshade Vegetables

Another type of food that’s been shown to contain lectins is nightshades. These vegetables are common staples in many cultures, and while they don’t have nearly as many lectins as shown in research, they do contain some.

These vegetables seem to mostly contain lectins in the seeds and skins. As such, some people remove the seeds and peel the skins. Cooking them can also help to neutralize lectins.

The highest quantitative number of lectins we’ve seen in research on nightshades was the potato with 826 ± 175 units/g. Note that even though this is lower than the green beans mentioned above, green beans can be eaten raw whereas potatoes should be cooked prior to eating.

After cooking the potatoes, no lectins were detected. For tomatoes, there still were some lectins detected after cooking. That being said, these lectins are generally found in the seeds and skins, so removing them should help to reduce any lectins in tomatoes present. (There are several low lectin sauces available that are made without seeds or skins.)

Bell peppers measured in at only 26 ± 6 units/g for red and yellow, with none detected for green, and none detected in any after cooking.

Black pepper (table pepper) is generally considered to not contain lectins.

3. Whole Grains

Whole grains are another common type of food that often contains lectins. Examples include:

a) Wheat

b) Barley

c) Corn

d) Rice

e) Oats

Many whole grains contain lectins, it seems especially in the bran and germ layers. This is why for example, generally speaking, white rice has less lectins than brown rice and white bread has less lectins than whole wheat bread.

Rice has had mixed results in terms of lectin quantity. For example, in one study, rice was found to have 208 ± 44 units/g, with none detected after cooking. In another study however, 20 different variations of rice were tested. 14 of them were found to contain lectins and 6 of the 20 were not.

Strangely enough, in one study, wheat was found to have no lectins detected, even before cooking. Even so, there could still be lectins in the wheat, and this could be as a result of the testing or some sort of impurities. The wheat was from Denmark, and it’s also worth considering that the variation of wheat could be why. That being said, wheat is generally thought to contain gluten 100% of the time, and gluten is a lectin.

While some oats contain gluten, and gluten is a lectin, we are uncertain of the lectin quantity of gluten-free oats, though curious.

Cooking, soaking, and sprouting can all help to reduce lectins in grains.

4. Dairy Products

While we haven’t seen much research on lectins in dairy or the exact quantities, it seems that lectins in dairy could come from what the cows eat.

Examples of dairy include:

a) Milk

b) Cheese

c) Yogurt

d) Ice cream

For example, grain-fed cows would have more exposure to lectins than grass-fed ones. Therefore, choosing dairy or milk from grass-fed cows could be better in terms of lectins.

Additionally, the fermentation process can neutralize lectins, so fermented dairy products like some cheeses may contain less lectins.

5. Nuts & Seeds

Some nuts and seeds have also been found to contain lectins. Examples include:

a) Almonds

b) Cashews

c) Nigella seeds

d) Tomato seeds

e) Quinoa

Additionally, there are plenty of “seeds” that are not typically considered seeds, such as rice, beans, and peas.

In almonds, lectins have been found in the skins.

Black, white, and red quinoa were found to contain lectins in the quantity of 26 ± 6 units/g in one study, with none detected after 15-20 minutes of boiling.

Cooking, soaking, and sprouting can all help to reduce lectins in nuts and seeds.

The Dangers Of Eating High Lectin Foods

The highest lectin foods that are currently commonly eaten by humans are only safe to eat when cooked. The cooking process reduces the number of lectins in foods, thereby making them safe to eat.

For example, in one instance published in the British Medical Journal, it’s noted that in a hospital when a dish with red kidney beans was served, that 11 people suffered “profuse vomiting” and some diarrhea, and all had recovered by the next day. While no pathogens were found, the beans “contained an abnormally high concentration of the lectin” known as PHA. Likely, this is a result of undercooked beans.

That being said, there have been other concerns raised, including that lectins have been found to be able to bypass the gut barrier. It’s theorized that because of this, the body may react to the lectin with a food sensitivity reaction, and “healing and sealing” the gut may help to reduce lectin food sensitivities.

Best Methods to Reduce Lectins

There are many ways to reduce lectins in foods. For example:

1. Boiling & Soaking: Soaking beans, grains, and nuts before cooking can reduce lectins significantly.
2. Pressure Cooking: This is one of the most effective ways to destroy lectins, especially in beans and legumes.
3. Fermentation: This process helps naturally break down lectins, making foods more digestible and nutrient-rich.
4. Peeling & De-seeding: Removing the skins and seeds can reduce lectin content, for example in nightshades.
5. Sprouting: Sprouting can decrease lectin levels and improve nutrient bio-availability, for example in grains and legumes.

Conclusion

There are many different types of foods that contain lectins. We’ve outlined some of the highest lectin foods here. There are many ways to reduce your lectin intake which you’ll find on this page.

Resources

1. http://medicinalplants-kr.org/

2. https://pmc.ncbi.nlm.nih.gov/articles/PMC8618113/