Carnivore diet

Are Lectins Bad For You? 10 Dangers of Eating Them

10 Dangers of Eating Lectins

“Make sure to eat your plants and veggies”.

This is nonsense. Plants and vegetables are not put on this earth to serve humans.

They don’t want to be eaten. Over millions of years evolving with animals, they developed defense mechanisms.

Instead of fleeing or attacking, plants have chemical booby traps that poison their predators. They’re like Kevin McCallister in Home Alone.

One of them, lectins, causes countless issues such as:

  • Autoimmune diseases
  • Insulin resistance
  • Obesity
  • Leaky Gut

Here’s what lectins are, 8 reasons why they are bad for you and 5 high lectin foods.

Are Lectins Bad For You?

Are Lectins bad for you? First we need to discuss what they are.

It turns out plants aren’t so innocent after all. They’re loaded with chemical weapons to attack their predators.

We tend to think of only refined sugar and carbohydrates as unhealthy. But these chemicals in plants can also be as damaging.

One of the most damaging plant chemicals are lectins. They are carbohydrate binding proteins designed to damage cellular communication.

What is their function? Lectins are designed (by evolution) to cause a severe immune response in the insects that eat them, which ultimately results in paralysis.

Lectins and their roles in pest control

But the same mechanisms are detrimental to your health.

Lectins are like sugar seeking drones. And because sugar is on almost every cell in your body, lectins seek them out and latch on.

They also bind to something called Sialic acid, which is found in the gut, brain and nerve endings. Brain fog is often the result of your brain literally getting clogged with these lectins, which disrupt normal cellular communication.

Lectins are in both plants and animals, however the most damaging ones are in plants.


Lectins Are a Plant Defense Mechanism

Unlike animals who can run away, plants need extra protection for their seeds <*>.

Remember, evolution was about maximizing genetic fitness. That is, increasing the chance genes are passed down to the next generation. If a vegetable’s seeds are eaten, its genes ceased to exist.

So plants tend to concentrate their defenses in seeds to protect the family jewels. Over time through evolution, the plants that were best able to protect their offspring survived. Thus, the plants and vegetables that exist today are hyper optimized machines to protect their seeds.

Lectins are highly inflammatory, and resistant to cooking and digestion. Thus, they pass right through the gut where they wreak havoc.

Yet humans continue to try to eat them…

When an insect eats lectin containing seeds and has an adverse reaction, its intuition dissuades it from ever doing so again. Whereas humans just paper over the symptoms and take antacids, instead of avoiding the foods that caused discomfort in the first place.

How much smarter are we really?

Two Lectins to Watch Out For

There are many different lectins. The most infamous ones and damaging ones are Gluten and Wheat Germ Agglutinin.


Gluten is the most renown lectin.

I get it the fear is annoying. To many today, gluten is scarier than nuclear weapons.

What is it? Gluten is actually a complex of 100s of different proteins mainly consisting of two: gliadin and glutenin. It is the main protein in wheat and comprises approximately 80% of the protein in wheat.

Gluten can cause a whole spectrum of reactions. It can even kill people that are highly allergic. This alone should make you skeptical of all the health claims around gluten containing foods.

Gluten is technically what is called a prolamin. The real danger stems from the fact that you do not have the enzymes to break down their amino acid structure. They are incapable of being digested and anything that cannot be digested or expelled causes harm.

Celiac disease -- a severe gluten allergy -- is on the rise.

However, gluten is not just a concern for people that have celiac disease. It damages everybody.

The picture below shows the gut of two people: one with celiac and one without. For both groups of people, gluten their increases intestinal permeability.

When you eat gluten, it stimulates the release of zonulin, which prys the gut open. This is why gluten has been linked to so many autoimmune disorders (I will discuss more below).

However, gluten is not the only damaging lectin. In fact, gluten free products tend to have more of other lectins that are even more damaging.

Wheat Germ Agglutinin (WGA)

The other lectin that’s especially pernicious is Wheat Germ Agglutinin. An agglutinin is a protein that is in seeds to protect against insects. Crops today are modified to contain higher levels of agglutinin to make them even more resistant to insects.

Wheat Germ Agglutinin is an especially small lectin. So even if the gut wall isn’t compromised, it can still pass through the walls of the intestine easier.

Wheat has a dark side and it shows with WGA.

Some of the damaging effects of WGA include <*>:

  • Disrupting endocrine dysfunction by binding to insulin receptors
  • Blocking sugar from getting into muscle cells
  • Interfering with protein digestion
  • Increasing inflammation
  • Crossing blood brain barrier
  • Stimulating weight gain.

One of the biggest reasons the damage from WGA is so insidious is because it is in the bran. So from this perspective, whole wheat grains are worse for you.

10 Dangers of Eating Lectins

Lectins are especially damaging to humans because we haven’t adapted to handle them.

For instance, in 1988 a hospital launched a healthy eating day for staff. One dish had red kidney beans. Over the next 4 hours, over 10 people vomited profusely and had diarrhea. It was not a pretty sight in the hospital. No pathogens were found.

The culprit: the lectin phytohaemagglutinin <*>.

Who would think it’s riskier to eat a plant than an animal thats’ alive? How does something that’s supposedly so innocent cause so much damage?

The challenge is that lectins are not acutely toxic. Unlike chloroform, if you consume lectins in low doses you’re not going to die immediately. The damage occurs over years..

Because of this, it’s hard to link these diseases directly to lectin consumption. But if you cut them out, you’ll notice the fog starts to clear.

There are a number of health issues directly caused by lectin consumption:

1. Insulin Resistance

Insulin resistance is associated with almost every chronic disease <*>. Persistently high levels of insulin both causes disease and signals that your body is chronically inflamed.

Various mechanisms cause insulin resistance.

One such mechanism is lectins. When they reach the bloodstream they bind to insulin receptors and interfere with insulin’s action <*>.

This causes your pancreas to secrete more insulin than necessary. Ultimately this can lead to insulin resistance and chronic hyperinsulinemia.

2. Obesity

Lectins and wheat were prized by our ancestors to gain weight. In advance of a cold winter, people used them to fatten up <*>.

The problem is most people are now fattening up all year round.

There are a number of ways lectins make you gain weight. One such mechanism is via insulin. Persistently high insulin signals that you’re in the anabolic or fed state: that you should be building up and storing fat instead of burning fat. As discussed above, lectins are linked to insulin resistance and hyperinsulinemia.

This study shows that when added to insulin, lectins stimulate the insulin receptor more than insulin alone.

Lectins stimulate the insulin receptors

Lectins also exert their weight gain effect via leptin. Leptin is a hormone that regulates satiety.

Lectins can bind to the leptin receptor and cause leptin resistance. <*> When you’re leptin resistant, your body doesn’t signal that you’re full.

This may be why bread is served at the beginning of a meal: to block hunger receptors and make you even more hungry.

3. Leaky Gut & Digestive Problems

If you have digestive issues, lectins are a likely culprit. Digestive issues are the most direct symptom of lectin consumption.


Your gut has evolved over millions of years to recognize and expel one thing: infectious microorganisms. The problem is that it hasn’t yet adapted to the flood of lectins and antinutrients added to your diet.

As a result, lectins are indigestible to humans and the gut is the first site where they wreak havoc.

After passing through your gut undigested, Lectins attach directly to the intestinal lining. There they cause digestive discomfort and can even pry your gut lining open. Additionally, lectins like gluten also stimulate the release of zonulin which opens up a space in the lining, causing leaky gut.

Once a gap is open, anything you consume can find its way into your bloodstream. Similar to a splinter, your body recognizes the foreign invader and tries to expel it. Usually, it's quite successful. However, there are major externalities and side effects including chronic inflammation.

difference between an impaired barrier from a normal barrier in our intestinal lining

Last but not least: harmful bacteria love lectins. A healthy gut microbiome is vital to your health <*>.

4. Inflammation

Once you have leaky gut, food you consume can pass into the bloodstream. This effectively hacks your immune system and makes it go haywire.

This study pictured below, for instance, showed a spike in lectin concentration in the blood after peanut digestion.

Spike in lectin concentration right after eating peanuts

Foreign bloodstream invaders activate the immune system and cause inflammation.

As a result, lectin intake is associated with proinflammatory cytokine production -- a signal that the immune system is on alert.

Chronic inflammation is associated with a range of conditions, such as cancer, cardiovascular diseases, insulin resistance and again, autoimmune diseases <*>.

5. Autoimmune Disorders

Autoimmune disorders are on the rise. One of the biggest causes in my opinion are lectins.

Your immune system uses antibodies to identify pathogens. But in the case of autoimmune disorders they bind to healthy cells.

One of the reasons why is because lectins can mimic healthy cells. Once lectins enter the bloodstream, they play dress up. They are able to mimic your healthy proteins and confuse your immune system <*>. This is why lectins cause insects to become paralyzed.

I have to give it to lectins, this is a heck of an attack maneuver. Instead of plants exerting the energy to attack you, they cause you to turn on yourself.

Your immune system needs time to rest and if you’re eating 6+ meals a day or constantly bombarding your gut with lectins it will break.

Many autoimmune diseases such as celiac disease, type 1 diabetes, rheumatoid arthritis are associated with leaky gut, suggesting that the gut damage from lectins plays a big role in the etiology of these diseases <*>.

Over a third of autoimmune diseases linked to leaky gut

6. Atherosclerosis and Cardiovascular Disease

Lectins have been implicated in the development of cardiovascular disease.

The first mechanism is via platelets. Platelets are blood cells that form clots to stop bleeding. However, aggregation of platelets can block blood flow through vessels leading to a coronary event. Lectins can aggravate this effect. Endothelial function has been shown to improve on a low lectin diet <*>.

Additionally, The Diet and Reinfarction Trial (DART) showed that a group that consumed more fiber had a higher cardiovascular mortality rate. Lectins, amongst other things, may have played a role in the negative consequences of fiber <*>.

Is it finally time to rethink the suggestion to replace red meat with lectin rich legumes and grains?

7. Depression

Depression is on the rise. One of the biggest reasons why: the evolutionary mismatch.

Society has transitioned from real food to junk food. Real relationships to junk relationships. Sun daily to a sedentary, indoor lifestyle. All of these are major factors in the rise of depression.

But when it comes to diet, one of the so called “healthy” foods may be a culprit: vegetables.

How? A study in yeast showed that lectins are transported directly from the gut across the brain barrier into the brain <*>.

Once in the brain, they bind to dopamine receptors damaging their function. Dopamine is a neurotransmitter that signals pleasure. Dopamine dysregulation is linked to depression <*>.

Additionally chronic inflammation exerts many of its most pernicious effects on the brain where it’s been implicated in both depression and neurodegenerative disorders.

8. Neurodegenerative Disorders

Low dopamine production is also associated with Parkinson’s disease.

This could explain why vegetarians have a higher rate of Parkinson’s <*>.

This study showed that when scientists severed the vagas nerve -- the nerve that connects the gut and brain -- in c elegans, it reduced their risk of parkinson’s by 40% <*>.

Quite the draconian treatment. However, it begins to elucidate one of the mechanisms by which diet may cause neurodegenerative disorder.

9. Type 1 Diabetes

Type 1 diabetes is on the rise. However, the medical institution views it as a result of losing the genetic lottery.

What if it was also connected to our poor diet?

Lectins may play a role. This study showed that maternal gluten consumption increased the risk of type 1 diabetes by 2x between the lowest and highest intake group <*>.

Association between maternal gluten intake and offspring type 1 diabetes

Why? One explanation is because lectins damage insulin receptors.

Another explanation is because of the autoimmune component of type 1 diabetes. One of the causes of type 1 diabetes is because your immune system attacks your pancreas cells, damaging insulin production <*>

10. Nutrient Deficiencies

Lastly, lectins also exhibit anti nutrient effects and can lead to nutrient deficiencies. Antinutrients are a big problem with plant based foods and why vegetables are a lot less nutritious than you think.

Just because a vegetable has a nutrient, doesn’t mean you absorb it.

Lectins, for instance, can actually block protein absorption by interfering with digestive enzymes and binding to sugar molecules that disrupt physiological processes.

This study showed that lectins reduce protein absorption, for instance. This is by inhibiting trypsin, a digestive enzyme <*>

List of High Lectin Foods

Foods highest in lectins

There are 5 main categories of foods highest in lectins

  1. Beans and legumes
  2. Squash: pumpkin, butternut, zucchini
  3. Grains: new food to us. Lectin bombs. Even gluten free
  4. Nightshades: tomatoes, potatoes, peppers
  5. Fruit: out of season. If it has a seed it’s a fruit. Peppers and cucumbers.

If you’re having health issues, try cutting these lectins out for 30 days.

However, there are ways to lower the lectin content in food. If you want to learn about some ways to do so read this awesome post about lectins from Kevin Stock.


You can see that a diet that is rich in lectin increases the risk of many western chronic diseases.

These conditions are linked with each other: if you have one, you have a high chance to have more from the list. This suggests that they all have a common cause, one of which may be high lectin intake.

Lectins are a plant defense mechanism and serve as protection from being eaten. So, it’s not surprising that eating large amounts of lectins is indeed a threat to our health.

The more we follow our natural diets and cut out the toxic junk, the healthier we will be.

If you want to continue this journey and start improving your health, check out the getting started with the carnivore diet guide I prepared for you by clicking the button below.

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