Health Dangers of Lectins

Health Dangers of Lectins

Health Dangers of Lectins

health dangers of lectinsOne of the hidden “Dangers of a Plant Based-Diet” are proteins called lectins. The health dangers of lectins can be numerous and insidious.

Seeds like grains, beans, and nuts house the plant’s embryo.

Naturally, the plant wants to protect these offspring and uses lectins as a means to do so. [r]

Health Dangers of Lectins: What are Lectins?

Lectins are one of the most insidious chemical weapons plants have in their arsenal to fight back against predators. Heavy concentrations of lectins can be found in the plant’s seeds. Why? Plants are serious about protecting their offspring. But they can be found in other parts of the plant as well.

As part of a plant’s immune system, lectins go on the attack when a plant is stressed or damaged.

They are natural insecticides.

So when a grasshopper starts chewing away at a leaf, the plant can stop it in its track with its lectins.

Lectins are so effective that crops are genetically modified to express higher concentrations to better ward of pests. Unfortunately this scientific marvel that protects crops doesn’t protect us from lectins attack.

While lectins are ancient molecules that surely evolved as a defense to insects and various pathogens, it turns out humans aren’t immune to their damaging effects.

Health Dangers of Lectins: How Lectins Attack

Many lectins are resistant to human digestion. So if I were foolish enough to eat a piece of whole wheat bread, the lectins could access my gut completely intact.

leaky gutA helpful way to think of the gut is to think of it as a tubing system made of bricks. The bricks (cells called enterocytes) are attached by mortar (tight-junctions). This brick wall is very selective of what it lets in. In fact, it’s job is to only let “good guys” pass through while keeping the “bad guys” out.

Lectin proteins are big, bad guys. Way too big to squeeze through the mortar of the brick wall (i.e. tight-junctions between enterocytes). But lectins are “sticky,” and they connect to the wall. Once connected they tell the wall to open up (release zonulin which then causes the “mortar” between the “bricks” to open). [r]

While sticking to the wall, these big lectin proteins start doing damage by blocking vitamins and nutrients from getting access through the wall to the inside. [r]

But that’s just the beginning.

Leaky Gut

After the message (zonulin) is sent, the mortar (tight-junctions) between the bricks (enterocytes) pry apart. This creates a breach in the wall and the big lectin proteins can get in. [r]

And not only the lectins, but other dietary and bacterial compounds that aren’t supposed to be allowed in, can get through the brick wall.

For example, parts of bacteria called lipopolysaccharides (LPSs), which are “bad guys” (endotoxins), can slide on through to the inside.

We now have a situation where foreign invaders have gained access to the inside and can invade in to the lymph nodes, glands, and blood stream.

Just like any break in – the body’s alarm goes off and an immune response mounts and inflammatory cytokines stimulate battle.

This breach in the wall of the gut is often referred to as “leaky gut.”

And the attack is on.

Health Dangers of Lectins: The Lectin Attack

Once the border is breached, the sirens go off, and the war begins.


After the lectins cause a breach in the brick wall, the foreign invaders slide in, like LPSs. And like any war, the body calls in the troops – i.e. white blood cells release inflammatory cytokines like IFN-gamma, IL-1, and TNF-alpha. [r] These signaling molecules promote inflammation to identify, destroy and remove the enemy.

But lectins don’t do down without a fight.


Our immune system tags lectins as foreign invaders and creates antibodies against them. [r, r] But these foreign invaders can latch on to healthy cells. In fact, lectins are called “sticky proteins” because they bind to carbohydrates or glycolipids and glycoproteins that stick off the membranes of our cells. So we have a situation where a “bad guy” lectin hooks on to a “good guy” normal cell, and “friendly fire” results. The body attacks healthy cells. [r, r]

For example, lectin binds sialic acid which is a molecule that is prevalent in our brain and gut cells, and triggers autoimmune responses to these vital cells.

Inflammation is often a double-edge sword. It can save the day destroying enemies, but can leave many unintentional casualties.

Autoimmunity is a disorder of our time.

Joint pain, heart palpitations, severe fatigue, autoimmunity can be disabling. It takes an average 5 years and 5 doctors to get a diagnosis. And it’s estimated that 50 million Americans suffer from one. Thus, it’s more common than cancer or heart disease. And the frequency of diagnosis in increasing. (r)

  • Type 1 diabetes rose 23% from 2001 to 2009 in the US. (r)
  • Crohn’s increased more than 300% between 1994 and 2014 in the UK. (r)
  • Pediatric IBS increased 7.2% every year between 1999 and 2010 in Canada. (r)
  • Global instances of rheumatologic disease rose over 7% per year for 30 years, endocrine diseases 6.3%, GI diseases 6.2%, and neurological diseases 3.7%. (r)

Lupus, Type 1 diabetes, Celiac’s, multiple sclerosis (MS), Crohn’s disease, rheumatoid arthritis. There’s over a 100 recognized disorders.

Perhaps some of the increase in autoimmune diseases can be attributed to more reporting and more sensitive diagnoses, but most researchers in the field believe these factors alone cannot account for the drastic rises in autoimmunity.

It’s still largely a mystery, even to immunologists, why the body turns on itself and attacks its own cells and tissues.

Most of the blame is put on our environment. The “hygiene hypothesis” theorizes that our modern, sterile environments prevent the immune system from getting the early and regular exposure to microbes it needs in order to learn how to react to threats. Additionally C-Sections, downtick in breastfeeding, less exposure to nature, overuse of antibiotics, and modern sanitation “over-protect” us.

Others blame environmental toxins and chemicals that interfere with the immune system’s ability to distinguish self from non-self

Others put the blame on genetics. But the rate at which these autoimmune conditions have risen over the last 30 years far outpace the rate at which genes can pass them on.

While I’m all for more time in nature and less antibiotic use, I’d argue our plant-based, lectin-loaded diet is just as responsible.

Cellular Disruption

Cellular Communication

health dangers of lectins cellular disruptionLectins are known for disrupting communication between cells. When one neuron is trying to relay a message to another neuron, lectins can block the transmission.

The main reason I stopped eating plant lectins was because of this blocking mechanism which can result in symptoms like brain fog and decreases mental performance.

Endocrine Disruption

Another way lectins disrupt communication is via interacting and modifying hormone functions. Lectins can interact with endocrine receptors, disrupting and modifying hormone function.

Hormones are like managers whose job is to tell employees (cells and tissues) what to do. They keep everything and everyone working together in a coordinated effort. Lectins can silence these managers, they can camouflage and mimic them, or even change the messages that the manger would otherwise direct to employees.

This confuses the employees, has them doing the wrong work, doing too much or too little or not doing any work at all.
Translation = The coordinated work and communication between cells and tissues gets thrown out of whack.


Lectins are also known for their ability to clump cells together. For example, when lectins are swimming in the bloodstream they can clump blood cells together. The body then has no choice but to dispose of these which can result in adverse effects like anemia.

They can also agglutinate immune cells thereby activating or inactivating them, which can lead to allergies and autoimmune issues.


A mitogen is a compound that helps induce mitosis, or cell division. Lectins can encourage this inappropriately and cause cells to replicate in cancerous ways. [r, r]

Health Dangers of Lectins: Lectin Diversity

There are many different types of lectins with different carbohydrate targets, different attack strategies, and variable potencies.

Some plant lectins, like the castor bean ricin, are serious plant weapons against humans. So much so that humans turned them into weapons against humans. Ricin has been used in chemical warfare to cause blood agglutination. [r] Other lectins damaging effects are more subtle.

Health Dangers of Lectins: Gluten

Perhaps the most notorious lectin is gluten. It’s a seed storage protein found in wheat, barley and rye. And like other seeds, gluten is meant to nourish the plant embryo when it sprouts.

People with Celiac’s disease have an autoimmune attack when they eat gluten.

“Full blown” Celiac’s disease is fairly uncommon, however, reports of gluten sensitivity are quite common. In fact, gluten intolerance is now commonly looked at on a spectrum that goes from full blown Celiac’s at one end to a low-grade gluten sensitivity on the other.[r]

The problem with the gluten lectin is that they are very difficult for our enzymes to digest. So they get partially digested creating toxic gliadin peptides as well as gluteomorphins.

The gliadin peptides can stimulate an immune response and inflammation while gluteomorphins act like opiate drugs, which can explain some of glutens addictive properties.

I don’t recommend eating gluten too often but there are other lectins that I think are even worse…

Health Dangers of Lectins: Wheat Germ Agglutinin (WGA)

Not all lectins are created equal. They have different structures which target different carbohydrates to attack and latch on to. Some are harmless. Some aren’t.

wheat germ agglutininWheat Germ Agglutinin (WGA) is an exceptional bad guy. [r, r]

It is also a prime example demonstrating many of the tricks and attacks lectins can have on humans.

WGA Hormone Mimicry [r]

Insulin plays a major role in directing how our bodies use energy. For example, when insulin connects with a cell, it tells that cell to allow energy to enter. But WGA camouflages itself to look like insulin. [r] And it can steal insulin’s spots (receptors) on cells. It then horribly disrupts the message that insulin would normally send.

When WGA connects with a fat cell, it can blocking out insulin. It then can tell that cell to store fat, just as insulin would do. But, unlike insulin which binds to the cell, delivers its message and then leaves, WGA binds indefinitely. It keeps the floodgates open for fat storage. [r]

To make matter worse, WGA also binds to the insulin receptors on muscle cells and brain cells. Typically, insulin would bind to these cells and tell them to allow in energy. This energy is needed for building muscle and fueling brain cell activity. But WGA, instead of opening the energy gates for these muscle cells and neurons, acts as a blocker preventing the cells from allowing energy entry. Since these muscle and brain cells don’t get the message to let energy in, the cells starve. Muscle cells waste. Brain cells panic.

Neurons, in an attempt to survive, send hunger signals and cravings for sugar.

Because I’m likely no match to these cravings, I’ll fill another bowl of ice cream. My pancreas then gets to work and releases more insulin into the blood. This insulin is shuttled to the starving brain cells. However, because WGA is blocking insulin receptors and not letting go, insulin cannot send its message to the brain cells to allow in energy.

So we have a situation where the neuron is starving, there is food all around, but it’s blind from seeing the food because it’s being blocked. Eventually these brain cells and peripheral nerves die. And this is thought to contribute to dementia, Parkinson’s and peripheral neuropathy. [r]

WGA – Entry and 4 “B’s” Attack


Although most lectins are rather larger, WGA is smaller, and because of this can sneak through the gut more easily than other lectins. [r]

And because the vagus nerve connects the gut to the brain, WGA can hop on this highway and go straight to the brain. To make matters worse, WGA can cross the blood-brain barrier. And because it’s a “sticky” protein, it can connect with many other substances that have no business in the brain, and transport them right on in. Naturally, this can result in neurological problems. [r]


In addition to invading the brain, WGA can invade the body too. Like other lectins WGA can cross-react with good proteins forming a good guy-bad guy connection. The body’s immune system sees WGA as a bad guy, creates antibodies to combat it, and ends up taking out the good guy and bad guy. Again, we have a “friendly fire” autoimmune response.

Blood Vessels

WGA can also bind to cells that line the blood vessels. The body then attacks the WGA and the blood vessels get hit by the attack leading to a hardening of arteries which may play a role in the progression of atherosclerosis.

Bad Guys

Just like WGA can drag along other substances across the blood-brain-barrier, its “stickiness” also enables it to bind with influenzas and other pathogens and transport them across the gut into the body.

When I hear of someone that gets sick all the time, I immediate think “leaky gut,” “wheat leaks,” and “WGA tag-along.”

Health Dangers of Lectins: Our Defense Against Lectins

Plants evolved lectins to deter predation. But humans also evolved protective and adaptive mechanisms to deal with lectins.


Our first line of defense against lectins is mucus. We have mucus that lines our nose and our mouth to trap lectins as well as provide a protective coating. This mucus continues down in our intestines. The intestinal mucosal wall functions to keep lectins in the gut and out of the body.

Gastric Acid

While many lectins are resistant to digestion, gastric acid can disarm some lectin proteins.


Our third line of defense is the vast microbiome residing in the gut. There are many bacteria that will eat up a lectin before it has a chance to invade.

Good but Not Good Enough

Although these defenses are good and likely more than adequate pre-Agricultural Revolution, they are often insufficient to deal with the onslaught of lectins that now make up a modern diet.

We are exposed to more lectins than ever.

Eating plant-based foods that didn’t even exist until modern human history now make up the majority of our diets. Further, we’ve genetically modified crops to express even more lectins.

For example, because lectins are so effective against pathogens like fungi and insects, biotech companies engineer crops to express WGA. So now our corn and tomatoes come with a big dose of WGA.

Suffice it to say – our human defenses are not enough…

Health Dangers of Lectins: What to do?

What I do is I don’t eat plant-based lectins. Problem solved.

But if I were forced to eat plant-based foods, here are some precautions I’d take.

1. Use a pressure cooker

Some lectins are temperature sensitive. So tossing beans and potatoes into the Instant Pot can destroy some lectins. Though not all. Grains are quite resistant. Beans have more lectins than anything else though, so they and all legumes go in the pressure cooker. Boiling, while less effective than the pressure cooker, is a good alternative. Dry heat, like baking, tends to be less effective.

2. Soak

Before you put the beans in the pressure cooker, soak them. Change the water several times. Let them soak overnight. Add baking soda with each new soak. Yes this is a pain, but less than the pain resulting from eating them improperly prepared. Easiest just not to eat them.

3. Ferment

I don’t think anyone should ever eat soy. But if one had to, they should ferment it first.

4. Sprout

Sprouting seeds will often help decrease the lectin load (although there are exceptions like alfalfa which actually increases lectin load when sprouted). As the seed sprouts the lectin gets broken down to feed the growing seedling.

5. Peel and Deseed

The seeds and peels are where lectins tend to concentrate. Not eating seeds is a good start. And remember seeds include grains, nuts and beans. Peeling and deseeding also go a long way to reduce lectin exposure. This includes fruits like squash and pumpkin and nightshades like peppers and tomatoes.

6. Choose Wisely

Choosing wisely, to me, means not choosing to eat foods inherently high in lectins. But what if you must eat some grains? Choose white versions over the whole grain version. I’d pick white rice over brown, white bread over whole wheat. Yes this is contrary to everything we’ve been told, and eating the more refined versions of these aren’t good either, but with the hull stripped away, some lectins get stripped out as well.

Health Dangers of Lectins: Conclusion

A lectin-free diet would basically eliminate all plant-based foods. In this light, it’s not surprising that the Carnivore Diet is so effective.

There are many very smart doctors and researchers who believe and convincingly argue that this intestinal permeability is a root cause of so many of our modern diseases. And lectins play a large role in creating these breaches in the gut.

A damage gut is often the first domino to fall in a cascade of detrimental effects. Lectins can be the inflammatory, immunotoxic, neurotoxic, and cytotoxic domino.

Some plants and “plant parts” contain more lectins than others. Seeds (grains, beans, and nuts) as well as legumes and nightshades are lectin loaded. It’s why people have intolerances and reactions to wheat, beans, peanuts, potatoes and tomatoes.

As mentioned, some preparation methods can be used to reduce lectins toxic impact. Consequently, these methods can also destroy the healthy vitamins – perhaps the reason why someone is eating them in the first place.

Instead of trying to manipulate plants to make them edible and somehow satisfy our nutritional needs, it may be easier to focus on an animal-based diet, congruent with how we are designed to eat.

[NOTE: You can now access the complete “Health Dangers of a Plant-Based Diet” series here]:

Resources and Additional Reading

[r] = Reference

I initially fell down the lectin rabbit hole with the help of “Self Hacking” and the “Lectin Avoidance Diet” – I don’t recommend doing it per se as you may remove lectins but not other plant antinutrients, but it’s a good place to start. If you are interested in this method, I would suggest checking out the “3 Levels” in the 30-Day Guide to going Full Carnivore, which is essentially a lectin avoidance diet to the max 🙂

Dr. Steven Gundry has really brought awareness to the destructive nature of lectins in his book, The Plant Paradox. It’s an enlightening read.

Some of the research into lectins is truly fascinating.

Besides the above [r]’s, here’s where I’d start:

  1. Plant lectins and animal lectins aren’t the same (and here)
  2. The nitty gritty details of what lectins are and how they function (excellent pdf for the science-inclined)
  3. Yep lectins can be toxic to livestock as well

7 Replies to “Health Dangers of Lectins”

  1. As a chemist who taught evolution, it stands out as important to express that (Ex:) “plants that have ‘x’, result in their survival to reproduce” opposed to “plants produce ‘x’ in order to survive”. There is no “will to survive” per se, as survival is driven by random chemical mutation that best fits the environment (of pests, etc). I find it important that people adopt this scientific perspective, rather than the subtle “religious” assumption that individuals will their survival. It’s almost hilarious to believe in ego-driven intention.

  2. hello. i have struggled to gain weight for years. a few months ago i switched to a gluten free whole grain bread, pistachios and almonds (for vitamin e) and also started eating a big serving of hash browns with extra virgin olive oil every night. i gained weight (eating healthy all around) but my stomach started getting weird, brain fog, then headaches and stomach pain after eating carbs. i realized it’s the potatos, and stopped. but this article, your saying the whole grain bread has lectins too… i am sensitive to high FODMAP… now i’m going to have to limit grains and seeds… i’ll never gain weight : / anyways, i cut out potatos 2 weeks ago and have limited carbs. i’m hungry all the time waiting to recover so i can eat more with my high metabolism but my stomach is still wrecked (feels like a minor hangover stomach) and i’m worried permanant damage may have been done? do you think this will return to normal? i’m in the navy and honestly over the last 7 years, medical has always been shitty, i’m going to go through a lot of red tape and not get any help (like when i herniated my L5 disc ect.) can you tell me your thoughts and also recommendation of how to proceed because i’m pretty depressed about it and feeling hopeless for help. thank you.

  3. Has any of this helped those with Sjogrens?? I know it helps inflammation and all, but what about the dry mouth, dryness, getting off the dangerous meds that are supposed to help. Any insight into this??

    1. I understand that a gluten free diet is helpful to decrease gut and systemic inflammation for all autoimmune conditions.

      Comment: The word celiac comes from a Greek word meaning abdomen. It is not named after anyone, so it is not spelled celiac’s disease.

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