What are Lectins?
Lectins are large proteins produced by plants. Plants have evolved over millennia to create these proteins as a defense mechanism to defend themselves against the animals that prey upon them. You see, unlike animals, plants can’t run away from, bite, or scratch predators. Instead, they use toxic chemicals as a defense mechanism. Lectins are present in the seeds, leaves, rinds, skin, and grain of most plants. Unfortunately for us, the same chemical toxins that have evolved over millions of years to kill/immobilize animals like insects, also wreak havoc on our own health.
Lectin Mechanism of Harm
One of the main reasons why lectins are so harmful to us is because they tear apart the lining of our gut. You see, your gut lining is only one cell thick and therefore it doesn’t take much to harm it and make it less functional. Your intestines are responsible for absorbing the vitamins and minerals from the food you eat. If you cannot absorb nutrients well, your health will be adversely affected.
Lectins attack your gut lining and pry apart the one-cell thick gut wall. When this happens, lectins pass through your intestinal wall and get into the bloodstream. Once they are in your bloodstream, your immune system attacks these foreign invaders as if they were lethal pathogens. Your gut becomes red, swollen, inflamed and full of white blood cells after being inundated with lectins in the same fashion your skin gets after getting stuck with a splinter.
Another lectin mechanism of harm is their ability to disrupt hormonal signals within the body. For example one nasty lectin, wheat germ agglutinin (WGA), has a similar chemical structure to insulin. Insulin’s main function is to activate cells to store energy from glucose and fats. When insulin binds to its corresponding insulin receptor, the cell functions normally. But when WGA binds to the insulin receptor, it does not release. This causes muscle loss and increased fat gain! What’s even more disturbing is WGA is the lectin that is found in whole wheat/whole grains. This is the stuff that is usually touted as being healthier than refined white grains, but actually this is not the case.
In addition to disrupting hormonal signalling, lectins also disrupt the communication between cells by binding to the polysaccharide complexes located on our cell membranes. Our cells attach a variety of complex molecules to their membranes. These molecules act like mailing addresses so that when the necessary compounds need to enter the cell, they can go to the right place. When lectins bind to these complexes on the cell membrane, it renders them useless by altering the “mailing address”. Communication between neighboring cells now becomes disrupted.
Lectins and Hormesis
If plants contain lectins, and lectins are so bad, why does every dietitian out there recommend eating a bunch of plants then? To understand why plants are actually good for us, even though they are filled with different toxins, we must understand the concept of hormesis.
According to wikipedia, “Hormesis is any process in a cell or organism that exhibits a biphasic response to exposure to increasing amounts of a substance or condition.”
Basically, hormesis is a process where a living organism is exposed to a stressor like a toxin, and instead of causing permanent harm, the organism adapts to the stressor and grows stronger because of it.
If you lift weights you have experienced this. When you lift a heavy amount of weight you are actually tearing muscle fibers. The next day you can feel the damage that has occurred because you can feel the soreness in your muscles. But what happens after? A few days later you are able to lift even more weight! This is because your body repairs the damage and when it does this, it becomes even stronger. This is the magic of hormesis.
The hormesis phenomenon applies to the toxins in plants as well. Lectins in plants provide a mild stressor to our immune system when we consume them. This immune stimulation allows us to, overtime, grow stronger and more resistant to pathogens and disease.
Lectins and Fruit
Fruit is usually touted as being one of the healthiest forms of food one can eat. This isn’t quite the case. The plants that grow and bear fruit have developed some advanced evolutionary “tricks” that in many ways harm us when we eat their fruit.
Different plants have different evolutionary strategies. For example, a strawberry has hundreds of tiny little seeds that are meant to be consumed by animals, pass through their digestive tract unharmed, and excreted out in the feces. The evolutionary trick that is happening here is the plant is using the animals to help spread its seeds all over the place to give the seeds a better chance of survival.
If the seeds aren’t fully mature in the fruit, plants increase the amount of lectins in them. Why? This deters animals from eating the seeds of the plants before they are fully formed and mature. The plant “wants” the seeds to remain uneaten until they are ready to be planted and have the ability to grow into another plant.
Today fruits are artificially ripened. When a fruit is artificially ripened the flesh of the fruit matures, but the seeds within the fruit do not. Therefore, fruits that are artificially ripened contain higher amounts of lectins. This means if you eat a strawberry from Peru, that strawberry was most likely picked when it wasn’t ripe. Since the strawberry wasn’t ripe, each seed within the fruit will have extra high levels of lectins. When you consume the strawberry, it will cause your body to inflame in response to the excess detrimental chemicals.
Plants have evolved another interesting evolutionary tactic. Fruits contain the sugar fructose. This is different from glucose which is found in the majority of other carbohydrate sources. Both fructose and glucose raise your insulin levels when you consume them, but glucose also raises your leptin levels. Fructose on the other hand, does not raise leptin levels.
If you know anything about leptin, you know that it is the hormone that sends satiety signals to your brain to let you know that you are full. Thus, fruit isn’t very filling. Fruits have been designed by plants for them to not be filling so you can eat more of them. When you eat more of them you spread out more of their seeds. Plants essentially hijack animals to carry out the hard work of spreading their seeds. We suffer from this because we end up eating a lot of fruit and put on excess fat.
Fruits and Vegetables that Contain Lectins
You want to stay away from any fruit or vegetable that contains seeds. Cucumbers, zucchinis, and tomatoes all contain seeds and skin that are filled with lectins. Peas, snap peas, green beans, lentils, beans, edamame all contain high levels of lectins.
I’m not saying you can’t have these every once in a while, but it’s important to be aware of the possible side effects some of this food has.
Vegetables Lacking Lectins
Vegetables that lack lectins are mainly cruciferous vegetables and vegetables that are leafy greens. Vegetables like broccoli, brussel sprouts, cabbage, cauliflower, spinach, artichokes, kale, collard greens, watercress, most herbs, scallion, arugula, asparagus, swiss chard, onion, carrot, celery are lectin free.
You are what you eat, eats
Most of the livestock that we eat gets fed a diet that consists of mainly corn and soy. Corn and soy are filled with lectins. When you eat beef that was fed a diet loaded with this stuff it’s entire life you essentially eat what the beef was eating before it was killed. Therefore, by eating grain-fed meat, you are essentially eating a bunch of lectins. This doesn’t only include the flesh, for example, milk and eggs are also filled with lectins.
Why is Corn and Soy bad for us?
The fat content of corn and soy is mostly made up of omega 6 fats. In large amounts, omega-6 fats tend to be very inflammatory. What you want are foods with higher amounts of omega 3 fatty acids to help lower the omega 6/omega 3 fatty acid ratio you consume. This results in less inflammation in the body.
There you have it. That’s some general information about lectins and how it affects us. I personally have made a few changes to my diet based on this information and have seen benefits from it.