Are Lectins Good or Bad?

With all the talk about lectins and nightshades, they are getting a bad reputation. Are they good or bad? Should you eat them or avoid them? The answer depends on you.

What are Lectins?

Lectins are a large class of sugar-binding proteins that can be found in all forms of life. In plants, lectins are part of the natural defense against microorganisms, pests, and insects. You can think of them as a natural pesticide. It is in every living plant to varying degrees.

One recent diet suggests lectins are bad for humans. People have tried to avoid lectins, but unless you specifically have a sensitivity to lectins or particular lectins, eliminating them entirely from your diet is ill advised.

Lectins not only contain a number of nutritional benefits, some lectins are even being used in cancer therapy. And because foods highest in lectins come from grains, greens, and beans, vegans and vegetarians would be seriously depleted of their main protein sources.

When you look at the diets of the oldest living people who live in the healthiest areas on the planet (Blue Zones), you find a staple ingredient in all of them - legumes.

The question you should be asking isn’t, “Are lectins good or bad?” The right question is “Are lectins good or bad for me?” That’s a much different question because everyone is different.

Associated Problems with Lectins

Lectins are not inherently evil; however, some people have a sensitivity to lectins. Whenever you have a sensitivity to any food, you should actively avoid it.

Many members of the lectin protein family can agglutinate (clump together) and become a serious problem, such as blood clotting. Lectins may contribute to the development of autoimmune diseases, obesity, cardiovascular disease, and type 2 diabetes through autoimmune mechanisms involving leaky gut and the activation of your adaptive immune system. The adaptive immune system is the big guys that are called in when the innate immune system was unable to eliminate the threat.

Should You Avoid Foods High in Lectins?

Lectins are in most foods, but if you have a problem with lectins, you should limit them. However, if you do not have a problem with lectins, there are a lot of foods loaded with nutrients that also contain lectins. Just remember the old mantra, “Everything in moderation.”

Foods high in lectins tend to be high in fiber and rich in B vitamins and protein. Ironically, these foods are often associated with a reduced risk of cardiovascular disease, healthy weight management, and a reduced risk of type 2 diabetes, contrary to someone who has a sensitivity.

If you do have a problem with lectins, keep in mind that you need to make up the nutritional deficits that come with removing those foods from your diet.

Lectins are in many different foods. The foods that are highest in lectins are grains and legumes. Those are the biggest trigger points. Nightshades would also be up there. So when we work with somebody on a low lectin diet, we typically have them take out all grains, all legumes and all nightshades.

Foods High in Lectins:

Legumes - Legumes are the bean family. Peanuts, although it may not sound or look like it, are also a legume - not a nut. Beans, such as lentils, kidney beans, and soybeans, are very high in lectins, particularly when in their raw, uncooked state. Just as you want meats to be cooked to a certain temperature, you also want to properly cook beans. This reduces the number of lectins. This is advisable even for people without a sensitivity. Thankfully, they taste a lot better cooked than raw! People with a sensitivity should avoid or limit consumption of beans.

Nightshade Vegetables - Nightshades are a family of foods, including white potatoes, peppers, eggplant, okra, tomatoes, and cayenne pepper, just to name a few. It's a common family that some people have a sensitivity to. The symptoms that people get with nightshade could be anywhere, but it often is joint-related.

Arthridity, stiffness, soreness. The mechanism for that is called molecular mimicry, that you actually create an autoimmune mechanism out of nightshades.

Nightshade vegetables contain chemicals called saponins that can increase intestinal permeability and inflammation. In my book, The Autoimmune Fix, I share a Transition Protocol with two phases. During Phase 2, you should eliminate these vegetables temporarily from your diet. Once you have completed Phase 2 of your diet, you should add each one back one at a time to see if any of them trigger inflammation for you. If not, you can safely resume eating them.

Wheat - Not everything in wheat is bad for you. There are some good things in wheat, but the bad does outweigh the good, which is why everyone needs to get wheat out of there. There are different compounds in wheat. One of the families of compounds in wheat are the lectin family. Lectins are only bad if you have a sensitivity to them.

In wheat, they're called wheat germ agglutinin. They're in the wheat germ part of the wheat kernel. And the lectins are much more difficult for the body to digest and breakdown. If your enzymes aren't in top shape in terms of making enough enzymes that act as scissors to break down the chain, then you can develop a sensitivity to lectins.

How Do You Know If You Have a Problem With Lectins? Test!

And the Zoomers are the tests to find out. Remember that lectins are a class of proteins. The lectin in wheat (wheat germ agglutinin) is different than the lectin in kidney beans (phytohaemagglutinin).The Lectin Zoomer detects IgA and IgG antibodies to lectins and aquaporins in the most comprehensive panel of foods available on the market.

The Lectin Zoomer looks at lectins in the following foods:


      Bell pepper




      Kidney bean


      Lima Bean

      Mung Bean








In my practice, when you do a comprehensive test of wheat sensitivity, one of the things we look for is if there is a sensitivity to wheat germ agglutinins. If wheat germ agglutinins is one of the markers that's elevated, then you know, “Mrs. Patient for a while we're talking you off all lectins because you have a lectin sensitivity here.”

Guess what. Mrs. Patient may never have felt anything after eating those foods. She most likely only knows through testing. That's one of the ways we know to consider lectins as a potential family of proteins that people may be having a problem with.

The Wheat Zoomer is only available in the United States. If you are overseas (or also available in the US), there is also another test called Cyrex Array 3.

On the Wheat Zoomer and on Cyrex Array 3, there's a marker called "wheat germ agglutinin." That's the left-in portion of wheat. If you are reacting, if you have elevated antibodies to wheat germ agglutinin, it is probably best for you to go grain-free because all grains are high in lectins. At least for a period of time it could really expedite your healing. The tests are a great way to check to see if lectins should be removed from your diet.                                                                                      

If you have a restricted diet including no grains and nightshades but did food sensitivities for legumes with nothing coming up, where could LPS be coming from?

When you remove inflammatory foods, that's one thing off the checklist that may cause the intestinal permeability. But a primary mechanism in creating leaky gut is the environment of the intestines, which for years has been with these foods that aren't really good for you.

It's called your microbiome. It's that whole community of bacteria. 39% of celiac children have bacteria in their gut never identified in humans. Even after two years on a gluten-free diet, 19% of them still have this bacteria in their gut. This is important to recognize. The environment you've created in your gut doesn't just disappear as soon as you stop throwing gasoline on the fire. You still have this accumulative result of a microbiome, and when it's out of balance it's called dysbiosis.                             

Most people today have dysbiosis, which is why you have to repopulate with the prebiotic foods, root vegetables, applesauce with cinnamon, and probiotic foods. You have to change your microbiome. Get rid of the bad. Make way for the good.

If you’ve removed triggers like wheat, dairy, sugar. grains and nightshades, and you have elevated levels of LPS in your bloodstream, the permeability is probably still there. A primary trigger to tearing the cheesecloth, to the permeability, is that the environment needs to be rebuilt. Removing offending foods is only one part of the equation. You need to also rebuild the diversity of flora in your microbiome to help heal that gut and support your health.

If you see LPS in the bloodstream, it indicates a leaky gut. If you have a leaky gut, you can see an increase in the number of foods that you are sensitive to because the foods you are eating will also enter the bloodstream. Anything not supposed to be there will trigger an immune response. Soon it isn’t only lectins you have a sensitivity to - it’s everything you are eating.

That's why we find testing for these infections in the gut so beneficial to find out if you have adequate digestive enzymes, if you have any of these inflammatory markers. These show up on tests, and it's great when we test it and catch it before you have the symptoms or a diagnosis. Prevention is easier than trying to undo the damage that you’ve already incurred.

Food Sensitivities and Leaky Gut

When you have a number of foods that come back that you're sensitive to, there's one mechanism that almost has to be there. And that is pathogenic intestinal permeability or the leaky gut because the leaky gut is the gateway where all these molecules get through. Permeability can create a sensitivity to a lot of different foods.

So when we eat for example gluten, but really any food, the protein should be fully broken down in our stomach. The hydrochloric acid is very helpful in doing this into individual amino acids. Then those pass through to the small intestines, where they're absorbed and utilized throughout the body. Every tissue and organ is made up of amino acids.                                      

But if we have compromised hydrochloric acid or if we're eating things like gluten that just don't break down, then the peptides or these chains of amino acids pass through to the small intestines where they cause inflammation, and then they cause permeability.  They leak out, and your body does not recognize it. So it mounts a response. That’s how you develop sensitivities. We develop antibodies to these amino acid peptides, and we also then start attacking any tissue or organ in our body that matches that same amino acid sequencing.

Then comes the autoimmune mechanism from there. An ounce of prevention is worth a pound of cure. Test to see if you have any food sensitivities or a leaky gut. If you have a leaky gut, heal it! If you have a food sensitivity avoid the food.

Conclusions on Lectins

There is no one perfect diet for everyone. Anyone can be sensitive to anything. Some people, although rare, are sensitive to water. If you're sensitive to a food, don’t eat the food. Don’t remove lectins from your diet thinking it will help unless you know that lectins are a problem for you. These foods offer a ton of nutritional benefits.

To find out if lectins are causing issues in your health, take a test. The bloodwork doesn’t lie. Meanwhile, restore your gut in order to minimize future food sensitivities and improve your overall immune health.

Dr. Tom O’Bryan, founder of, is an internationally recognized speaker, best-selling author, and autoimmune expert. Bringing insight with compassion and common sense to the complexities of immune health, he is the modern day Sherlock Holmes for chronic diseases.

Having trained tens of thousands of practitioners around the world, his work around wheat-related conditions, identifying triggers for autoimmunity, and eliminating toxins for health have taken center stage.

His empowering message of healing echoes throughout his best selling book The Autoimmune Fix, his latest best seller How to Fix Your Brain, his 9-part Betrayal docuseries, and his podcast event The Gluten Summit - A Grain of Truth.

He demonstrates that changing the microbiome (regenerating a healthy environment in the body), and changing the microbiome within our soil (regenerative agriculture) creates incremental and powerful changes to our health. In fact, these changes are vital to the health of both the patient and the planet.