Food With Lectins To Avoid


Lectins are a type of protein that can be found in our favorite foods. They can have negative side-effects on your body if they are not digested properly. Many lectins are found in foods like soybeans, spinach, kidney beans and peanuts, where they act as natural pesticides to protect them from being eaten by insects. You may wonder why we should even care about lectins as they don’t make us sick at all times so you’re probably wondering why you should try to avoid them in your diet.

Food With Lectins To Avoid

These six foods are some of the worst sources of lectins in the American diet when consumed raw.

1. Raw Kidney Beans

Red kidney beans are a great source of plant-based protein and they are a low-glycemic-index food. However, it’s critical that you boil them thoroughly before you eat them. Eating raw or undercooked kidney beans exposes you to an incredibly high level of phytohemagglutinin. Cooking beans thoroughly reduces the activity of this lectin to undetectable levels.

2. Peanuts

Peanuts are another form of legume, and like kidney beans, they contain lectins. Peanut lectins can be detected in the blood after eating peanuts in large amounts. While no studies have been done to determine whether this has health effects, it does show that peanut lectins are absorbed by the body.

3. Whole Grains

Raw wheat and other whole grains are high in lectins. Raw wheat germ, which is often sold as a source of fiber, can contain as much as 300 mcg of wheat lectins per gram. If you’re trying to avoid lectins, do not eat raw whole grains.

4. Raw Soybeans

Soybeans are another legume that’s full of lectins. However, unlike some other legumes, soybeans are often eaten toasted or roasted. This type of dry heat does not appear to be as effective at breaking down lectins as boiling. Be cautious when eating raw or toasted soybeans if you are avoiding lectins.

5. Raw Potatoes

Potatoes are part of the nightshade family and contain high levels of lectins. Raw potatoes, in particular the skin, appear to contain potentially harmful lectins that may affect your health.

More studies need to be done to see whether these lectins are the cause of health problems after eating raw potatoes in humans.

Lectin-Free Alternatives

All of the above foods have associated health benefits as well as lectins. In most cases, cooking these foods with “wet” heat, such as stewing, boiling, cooking in sauce, or mixing into dough and baking, breaks down lectins to negligible levels. Simply avoid eating raw legumes, grains, or potatoes, and eat these foods cooked instead.

Why You Should Avoid Lectins

Lectins are sometimes dangerous because of how they bind to carbohydrates like sugar. You should avoid certain types of lectins due to a risk of:


Certain types of lectins can prevent your body from absorbing other substances that have nutritional value. This can eventually lead to serious problems such as malnutrition.


Some sources of lectins are considered seriously poisonous. Castor beans, for example, contain a potent lectin poison called ricin.

Damage to the Digestive System

Certain types of lectin may bind with the walls of your digestive system which can lead to serious problems. Eating one particular lectin, phytohemagglutinin, can lead to severe abdominal pain, vomiting, and diarrhea.

Potential Risk of Auto-immune Response

Some proponents of lectin-free diets claim that lectins can cause symptoms of auto-immune disorders. However, studies are still being done to confirm or deny this idea. Currently, there is no scientific consensus backing up the idea that lectins are connected to any health conditions outside of acute lectin poisoning.

The Truth About Lectins—Why Beans Have Gotten a Bad Rap

The longest-lived people in the world eat a mainly plant-based diet that, at its foundation, is centered on beans, legumes, greens, nuts, whole grains, and fruits. In the blue zones, they eat seasonally, they cook at home, and they often celebrate and dine with friends around the table. Hailing from all parts of the globe, the healthiest people in the world share a common pantry staple—beans

Some recent fad diets and media headlines have made beans a controversial (and often eliminated) food due to their high lectin content and the claim that lectins cause inflammation and indigestion. So, what are lectins and are they safe to consume?

What are Lectins?

Lectins are proteins that are found in all plants that bind to carbohydrates. They are a protective measure that helps the plant thrive and survive in nature. The same characteristics that protect them in nature can lead to digestive discomfort if consumed by humans—but there’s a catch. Lectins are in ALL plants. Plants that we’ve been eating for thousands of years, like rice, wheat, potatoes, tomatoes, seeds, nuts, but the highest amounts are found in raw legumes (beans, lentils, soybeans, peas, and peanuts included) and whole grains. 

What about Lectin Poisoning?

If you eat raw beans, you will almost certainly have nausea, vomiting, upset stomachs, and diarrhea. At the very least, you’ll probably have uncomfortable bloating and gas. Some nonhuman studies have found that active lectins can interfere with the absorption of minerals like calcium, iron, phosphorus, and zinc. 

The good news is that cooking or soaking beans destroys active lectins. Dried beans have to be soaked and then boiled for at least ten minutes. But it takes about an hour to cook most beans so that they are edible. Dr. Greger of NutritionFacts notes, “Without presoaking, it takes 45 minutes in a pressure cooker to get rid of all lectins, but an hour to make kidney beans edible. So basically… cooking beans to the point where they are considered edible is more than sufficient to destroy virtually all lectin activity.” 

“…cooking beans to the point where they are considered edible is more than sufficient to destroy virtually all lectin activity.” 

What about canned beans? Dr. Greger says that’s even simpler: “Canned beans are cooked beans; the canning process is a cooking process.”

What the Research Says

If prepared correctly (i.e. soaked, canned, fully cooked), then lectin-containing foods are safe to consume. Studies show that boiling legumes, soybeans, and even kidney beans (which have extremely high lectin levels when raw), greatly reduces and often completely eliminates lectin activity. 

Lectins have health benefits, as well, and can act as antioxidants, protecting human cells from damage caused by free radicals. They are slow digesting and could prevent sharp rises in blood sugar. And in cases of population studies, and research from the blue zones, lectin-containing foods like whole grains and beans are associated with lower rates of cardiovascular disease, type 2 diabetes, and better health overall. Rich in B vitamins, protein, fiber, and minerals, the health benefits of lectin-containing foods outweigh any extremely small potential risks.

Dietary recommendations that promote the elimination of foods containing lectins are not supported by any major health organizations. Dr. Robert Eckel, a professor of medicine at the University of Colorado and a past president of the American Heart Association says, “This is against every dietary recommendation represented by the American Cancer Society, American Heart Association, American Diabetes Association and so on.” 

Preparing Plants for Your Plate 

It is rare to actually eat food with a high amount of active lectins, as many of the lectin-containing foods we eat (whole grains & beans) are never consumed raw, so there should be no fear when choosing to consume these centenarian favorites. Many lectin-containing foods are also high in fiber, which is essential for a healthy metabolism and good digestion, as well as a strong immune system.  

Cooking with wet, high-heat methods like boiling, stewing, or soaking can deactivate most lectins. When it comes to the lectins in nuts and seeds, these are water-soluble and found on the outer surface so exposure to water removes them. If these foods have given you digestive discomfort in the past, look for “sprouted” varieties or soak your own nuts and seeds to deactivate the enzyme inhibitors and ease the digestive process. 

Canned beans are cooked and then packaged in liquid, making them low in lectins. Dried beans must be soaked for several hours and then boiled for several more to soften and cook completely, which effectively disables and deactivates the lectins. However, undercooked or raw beans simmered at low heat or cooked in a slow cooker will not remove all lectins because the heat is not high enough to help break down the enzymes. If beans have caused digestive issues in the past, try using canned beans for slow cooker recipes or soak and boil them before use in a slow cooker. 

In addition to proper cooking methods, consuming beans on a regular basis can actually improve your body’s ability to digest them. According to a study published in the BMC Medical Journal, people who ate beans every day for three weeks reported less intestinal gas and discomfort by the end of the study. Try working a small serving of beans into your daily diet and slowly increasing your portion sizes over time.

Avoiding lectins altogether would mean avoiding almost all plant foods, which would mean avoiding a majority of the foods that the longest-lived people in the world consumed every day of their lives as well as the foods shown to reduce risk of chronic diseases like heart disease and diabetes. Cooking properly, soaking, or buying canned beans protect you from digestive discomfort and potential harm. 

Don’t Eat Enough Whole Grains? This is One Everyone Loves


If you’re having a hard time getting enough whole grains into your diet, corn might be the easy fix you need.

Both a vegetable and a whole grain, corn has been unfairly dismissed in recent decades as little more than a vehicle for butter and salt, and a source of starchy, empty calories. The skepticism comes in part from negative health outcomes associated with high-fructose corn syrup, a ubiquitous ingredient in processed foods.

But fresh corn—and popcorn, too—can play a key role in a healthy diet, supplying you with fiber, plenty of vitamins and minerals, and phytochemicals that can improve vision. Corn has long been a staple ingredient in Costa Rica’s Nicoya Peninsula, where centenarians have traditionally leaned on their agricultural “three sisters”: corn, squash, and beans.

[Related: Fresh Corn, Avocado, and Cilantro Tacos with Pinto Beans]But fresh corn—and popcorn, too—can play a key role in a healthy diet, supplying you with fiber, plenty of vitamins and minerals, and phytochemicals that can improve vision.

nicoyan centenarian holding corn

Corn has long been a staple ingredient in Costa Rica’s Nicoya Peninsula, where centenarians have traditionally leaned on their agricultural three sisters…

With sweet corn season fast approaching, now’s the time to work fresh corn into your daily meal planning.

Packed with antioxidants

Despite its name, sweet corn only carries about 6 grams of sugar per medium ear, making it considerably lower in sugar than a comparable amount of banana or beet. Sweet fresh corn also provides about 3 grams of insoluble fiber per cup and is also rich in resistant starch, helping you feel full longer. Because of its fiber volume that helps it digest slowly, corn is a low- to medium-glycemic index food, so it won’t cause blood sugar to spike.Despite its name, sweet corn only carries about 6 grams of sugar per medium ear, making it considerably lower in sugar than a comparable amount of banana or beet.

Corn is a good source of vitamin C and some B vitamins. One cup of fresh corn contains about 5 grams protein, more than a cup of broccoli, with more magnesium, phosphorous, and potassium than in broccoli as well. Popcorn delivers these same minerals, plus zinc and copper.

Sweet corn is also packed with antioxidants like lutein and zeaxanthin, which can improve vision. And although cooking corn does decrease its vitamin C content, researchers at Cornell University found that the heating process actually increases its antioxidant activity. When cooked over low heat for 10 minutes or more, corn releases increasingly larger amounts of a cancer-fighting phytochemical compound known as ferulic acid.

Try some of our easy recipes like Heirloom Bean Salad with Smoky Sun Dried Tomato Vinaigrette, ‘Ulu Curry Corn Chowder, or Nicoyan Corn Tortillas that spotlight the versatility of fresh corn, or get started with these quick and simple dish ideas:

  • Make elotes, or Mexican street corn. Grill sweet corn ears, then mix in ancho chile powder, lime juice, and chopped cilantro. Sprinkle with some nutritional yeast and enjoy.
  • Work fresh corn into your favorite salsas and guacamole.
  • Cut corn kernels off the ear and sprinkle onto flatbread or over nachos to add fun texture and delightful sweetness.
  • Add corn to potato salads for more color and flavor.
  • Add fresh corn to corn muffins or cornbread.

8 Foods High in Lectin That Are Actually Good for You

Lectin-rich pizza eggplant with tomatoes and basil

Foods like tomatoes and eggplant are high in lectins, but that doesn’t necessarily mean you should eliminate them from your diet.

Image Credit: nata_vkusidey/iStock/GettyImages

Lectins are naturally occurring proteins are found in most plants — with beans, peanuts, lentils, tomatoes, potatoes, eggplant, wheat and other grains containing higher amounts, according to the Mayo Clinic.

Lectins work to protect plants as they grow. Lectins could be bad for you in really high amounts, but most diets do not contain the levels of lectins that would cause concern, per the Mayo Clinic. Plus, foods containing lectins actually have numerous health benefits — so the fact that they should always be avoided is one big lectins myth.

For starters, lectins may help stabilize blood sugar by slowing down digestion and the absorption of carbohydrates, per the Harvard T.H. Chan School of Public Health. Large population studies also show that lectin-rich foods like legumes, nuts and whole grains may help to control weight and cut the risk of heart disease and type 2 diabetes.

Lectins have also been researched in anticancer treatments, according to an August 2013 study in the journal ​Cell Proliferation​, and there’s some evidence that lectins may cause cancer cell death. Lectins also show potential as both diagnostic and treatment tools in digestive system cancers, per a July 2017 study in the ​International Journal of Molecular Sciences​.

Still, some people who are at high risk for diseases related to mineral deficiencies (like osteoporosis with calcium deficiency or anemia with iron deficiency) may want to keep an eye on their diet for anti-nutrients like lectins, per the Harvard T.H. Chan School of Public Health.

Lectins are considered anti-nutrients because they can interfere with the absorption of calcium, iron, phosphorus and zinc. But, cutting out lectins altogether is not recommended, as they also have health benefits.

Is There a Daily Limit for Lectins?

Because it’s not widely believed that lectins can cause harm when eaten in normal amounts, there is no established Daily Value (DV) for lectins. It’s rare to eat foods with a high amount of active lectins, according to the Harvard T.H. Chan School of Public Health.

Find the top foods high in lectins below.

1. Beans

Lectin-rich beans and rice in bowls

Raw beans are high in lectins, but most of them are removed through the cooking process.

Image Credit: Rawf8/iStock/GettyImages

Although beans are considered a food high in lectins, you probably won’t eat them in a way that will cause harm.

Dried beans, such as kidney beans, are typically soaked and then boiled for hours. This inactivates most lectins, which are largely found on the exterior of a food and are water-soluble, meaning they’re removed when they come in contact with water, per the Harvard T.H. Chan School of Public Health. Your body also produces enzymes during digestion that break down some lectins.

Raw kidney beans contain 20,000 to 70,000 hemagglutinating units (hau), a measure of lectins, while fully cooked beans contain only 200 to 400 hau, per the FDA. Try them in these deliciously easy recipes using canned beans.

2. Peanuts

Although peanuts are legumes that are high in lectins, they also provide a wide range of other health benefits. One ounce of dry-roasted peanuts contains 7 grams of protein and important minerals like magnesium and zinc.

Dry-roasted or oil-roasted peanuts contain 0.4 to 144.7 micrograms of lectins per gram — in other words, a very small amount.

3. Lentils

Lentils are sometimes considered one of the many foods high in lectins to avoid, but you really shouldn’t cut them out of your diet.

Several studies have shown that eating lentils is connected to a lower risk of diseases such as diabetes, obesity, cancers and heart diseases, due to the bioactive compounds in lentils, per a November 2017 review in the ​International Journal of Molecular Sciences​.

4. Tomatoes

Tomatoes are high in lectins and part of the nightshade family, along with eggplant, potatoes and other healthy foods. Some diets shun tomatoes because of their lectin content, but the fruit provides a whole host of healthy nutrients: Just one tomato offers nearly 20 percent of your DV of vitamin C, plus vitamin A and B vitamins.

What’s more, tomatoes contain lycopene, a natural compound that research has shown may be linked to a lower risk of certain cancers and stroke, per Harvard Health Publishing. Try them in these tomato recipes that aren’t salads.

5. Potatoes

Lectin-rich Potato halves baked with thyme, top view

Potatoes’ lectins are removed during the cooking process.

Image Credit: YelenaYemchuk/iStock/GettyImages

Although potatoes are typically shunned on lectin-free diets, they provide a number of health benefits. Just one baked potato contains 3.6 grams of fiber (13 percent of the daily value), along with 24 percent of the DV for vitamin C and 20 percent of the DV for potassium.

Plus, lectins in general can act as antioxidants that protect cells from free radicals, per the Harvard T.H. Chan School of Public Health. Try them in these creative potato recipes under 300 calories.

6. Eggplant

Another member of the nightshade family, lectin-rich eggplant is a healthy vegetable that’s filled with beneficial compounds. Not only does eggplant provide volume that fills you up, but it also offers protective antioxidants like phenols and flavonoids (including anthocyanins), per the Cleveland Clinic.

Anthocyanins are responsible for eggplant’s purple hue and are linked to lower rates of chronic diseases like heart disease, cancer and diabetes, per an August 2017 study in the journal ​Food & Nutrition Research​​.​ Try eggplant in these delicious recipes that aren’t eggplant parm.

7. Wheat

Wheat is high in lectins, but you likely don’t need to avoid it for that reason alone. In fact, people without celiac disease who avoid gluten (a protein in wheat) might have an increased risk of heart disease because they don’t eat enough whole grains, per a May 2017 study in ​BMJ​.

If you’re experiencing digestive distress from wheat products, there can be a variety of causes: Although lectin toxicity or sensitivity is one possible explanation, you may also have a food allergy or intolerance — or another gastrointestinal issue. Work with your doctor or a registered dietitian to determine the root cause before deciding to eliminate lectin from your diet (or any food group or ingredient, for that matter).

Raw wheat germ has around 300 micrograms of wheat lectins per gram, but those are nearly completely removed by cooking. Cooked pasta, for instance, has less than 0.4 micrograms per gram.

8. Sunflower Seeds

Lectin-rich sunflower seeds in a bowl with a spoon

Lectin-rich seeds help provide nutrients like magnesium that Americans don’t get enough of.

Image Credit: Julio Ricco/iStock/GettyImages

Lectins have been founds in the seeds of about 500 plant species, including oilseeds such as sunflower seeds, according to Tufts University.

Although seeds are one of the several foods high in lectins, they provide several perks. They contain iron (which helps make proteins that transport oxygen-rich blood throughout your body), calcium (important for bone health), magnesium (helps with hydration, bowel and brain health) and phosphorus (important for repairing cells), according to the Cleveland Clinic.

Americans don’t tend to get enough magnesium — but lectin-rich seeds are one good way to squeeze it into your diet.

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