Published:
September 28, 2020
Last Updated:
February 23, 2022

Lectin Foods: Are These Six Foods Bad for You?

Lectin is a type of protein found in all plant foods. Considered an “anti-nutrient,” lectins prevent the absorption of certain nutrients – and that sounds like the opposite of what we should be doing, right? Anti-nutrients are part of a plant’s survival skills. These compounds help protect plants from being eaten by insects and block potential infections or viruses that could invade and kill plant cells. While these defense mechanisms work well for the plant, they may not bode as well for your gut.

In addition to blocking absorption of important minerals like iron, calcium, and zinc, lectins may disrupt the natural balance of the gut flora, create gut permeability (or leaky gut), and contribute to autoimmune diseases due to this increased permeability. “When prepared properly, lectins actually have many health benefits despite their bad rep,” explains certified nutrition specialist Lauren Chaunt. “It is only when lectins are consumed in their active, or raw state that they can cause digestive upset as they resist being broken down in the gut.”

Though lectins do have their drawbacks, eating whole grains, fruits, and vegetables, many of which contain lectins, has been linked to lower cholesterol and blood sugar levels.

Foods High in Lectins

Legumes

Legumes, lentils, chikpea and beans assortment in different bowls on stone table. Top view.

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Beans and lentils are examples of legumes that contain high amounts of lectin. Raw beans, such as red kidney beans, contain phytohemagglutinin, a lectin which can cause vomiting and diarrhea. Soaking, sprouting, or boiling and stewing can deactivate most lectins as they are soluble in water. Soaking your beans and lentils before cooking them in a stew or making them into veggie burgers can help break down these lectins and make it easier for your gut to digest them.

Peanuts and cashews

Peanuts

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No, these are not nuts! They’re actually part of the legume family. When it comes to peanuts and cashews, heat may not degrade lectins as much as it does beans, so you can also soak and sprout them to eat. Both peanuts and cashews are high in protein and provide a decent amount of vitamins and minerals, such as biotin, vitamin E, and thiamine.

Nightshades

Nightshade vegetables

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Tomatoes, eggplant, peppers, potatoes, and goji berries all contain lectins and are considered part of the nightshade family. Tomatoes and peppers are touted for their abundance of vitamin C, and tomatoes contain the antioxidant lycopene, which protects cells against oxidative stress and contributes to overall disease prevention in the body. Goji berries also have powerful antioxidant properties, eggplants are high in fiber, and potatoes, a starchy vegetable, provide potassium and vitamin B.

However, nightshades contain alkaloids, which can increase inflammation in those who may already experience chronic inflammation, such as those with rheumatoid arthritis or other autoimmune conditions. Just as you would with other lectin-containing foods, avoiding the raw forms of these foods and cooking them instead could help alleviate any potential discomfort.

Wheat and grains

The hands of a farmer close-up holding a handful of wheat grains in a wheat field.

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If you can tolerate them, wheat products are a great source of fiber as well as nutrients such as folate and selenium. Lectins are found in raw wheat, such as wheat germ, and unrefined whole-wheat products. Grains, such as quinoa, are also high in lectins, and it is recommended that quinoa be thoroughly rinsed, soaked, and even fermented or sprouted before cooking and consuming.

Soybeans

Green soybean pods on dry soy bean

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Soybeans are a protein powerhouse, especially for those following a vegetarian or vegan diet. They’re also high in a plant compound called isoflavones, a phytoestrogen that, when eaten in its whole form, such as in organic tofu, may reduce the risk of cancer. While high in lectins, fermenting soybeans can deactivate the lectins in them. Many of the soy products we love to eat are fermented, such as tempeh, miso, and soy sauce.

Corn

Fresh corn on cobs on rustic wooden table, closeup

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Corn is considered a grain, not a vegetable, and consumption is often associated with the processed version – think corn syrup, cornstarch, and popular cereals. Simply cooking corn is one way to make it more palatable as well as lower the lectin content. When it comes to corn products, such as tortillas, treating the corn with lye, a process called nixtamalization, makes it more nutritious and more easily digestible by creating a dough – masa – that is then turned into tortillas and other corn products.

Are Lectins Really Bad for You?

Because foods high in lectins are also high in key nutrients that prevent cardiovascular disease and type 2 diabetes, promote brain health, and keep your gut microbiome flourishing, removing lectins entirely from the diet is controversial. However, for those with autoimmune disease or other conditions marked by chronic low-grade inflammation, removing foods that may aggravate inflammation could be considered. Working with healthcare practitioners, Health Coaches, and nutrition experts can help ensure you are making any diet changes in a healthy and sustainable manner.

Removing Lectins from Your Diet

Your decision to include different types of lectins in your diet or fully adopt a lectin-free diet will depend on your unique body and nutrient needs. If eating lectins causes digestive problems, such as gas and bloating, you may choose to either prepare those foods differently or remove them from your diet entirely.

When making such decisions, working with a nutrition expert, such as a registered dietitian, could help you make sense of your potential nutrition choices, and working with a Health Coach could help you set goals around implementing your food decisions with ease.

How to remove lectins from your diet

Traditional elimination diets do remove some popular foods high in lectins, such as soy and corn. Because of the potential inflammatory nature of foods that contain higher amounts of lectins, doing an elimination diet can help determine which foods are causing adverse reactions and symptoms.

Eating a balanced diet that doesn’t focus too heavily on one food or food group is recommended to ensure your body is getting the essential vitamins and minerals it needs while promoting gut health and overall physical well-being.

What Does a Lectin-Free Diet Look Like?

So what can you eat on a lectin-free diet? A lot, as it turns out. There’s even an official lectin-free diet plan, developed by Dr. Steven Gundry. Although there isn’t much data to support a completely lectin-free diet, Dr. Gundry believes that removing lectins from your diet can relieve symptoms of leaky gut syndrome, promote weight loss, and reduce instances of gastrointestinal upset. These foods have low amounts of lectin in them, and can be included in a lectin-free diet:

  • Avocados 
  • Dark Chocolate 
  • Raspberries 
  • Seafood, including halibut, salmon, and anchovies 
  • Pomegranate seeds 
  • Nutritional yeast 
  • White meat, like chicken, duck, and turkey 
  • Plantains 
  • Sweet Potatoes 
  • Asparagus 

The Bottom Line

Diet is one way to address your health, especially the physical and mental aspects of your well-being, but it’s not the only path to creating great health. Taking a holistic approach allows you to explore different modalities and practices that can foster a healthy body and mind.

Author Biography
Nina Zorfass
,
IIN Content Writer

Nina holds a bachelor’s in dietetics, nutrition, and food sciences from the University of Vermont, is a graduate of IIN’s Health Coach Training Program, and is an NASM-Certified Personal Trainer.

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