Lectins are plant proteins that bind to polysaccharides (complex carbohydrates), lining the cells of other organisms—particularly fungi, insects and us[60]. These molecules line your blood vessels, your nerves, your joints, and basically every cell in your body. This is part of the glycobiome. These proteins do a few things when they’ve infiltrated. First, they pry apart the tight junctions between the cells of your gut lining[61] (which is one cell thick[62]), by attaching themselves to certain cell receptors, creating zonulin. Zonulin opens up these tight junctions, allowing lectins to enter the bloodstream, which normally should not happen[63]. Once this happens, they confuse the immune system with a strategy called molecular mimicry[64]. This is a process by which lectins, after binding with the sugar molecules in your body after being leaked out of the gut, will mimic the surrounding proteins. What does this do? Well, your immune system will recognize that there are foreign proteins (the lectins) that have infiltrated the body, and will launch an immune response on them to kill them. However, the immune system cannot distinguish between the lectins and the cells the lectins are mimicking, and therefore have the tendency to kill them too in the process. Again, this can happen to nerve cells, in your joints, and the sugar cells on the lining of blood vessels. Neuropathy, anyone? Arthritis, anyone[65]? Heart disease, anyone[66]?
Lectins also have the propensity to mimic and/or block hormones as well, which, of course, will cause imbalances. WGA, or wheat germ agglutinin, a lectin found in wheat, for example, tends to mimic insulin, and therefore attaches to docking ports that insulin is supposed to insert itself into, which is not indicated, as this is activating cellular
mechanisms at inappropriate times and for inappropriate periods of time, but they also tend to never let go either[67]. Excessively elevated insulin causes you to be in an excessive anabolic state, that being a fat-storing mode, as aforementioned, and therefore this lectin in particular (but others as well) will tend to cause hormonal imbalances on top of an autoimmune response.
There’s also some fairly compelling evidence to suggest that lectins are one cause of Parkinson’s disease and forms of dementia due to their inclination to travel up the vagus nerve into the brain[68]. That’s probably not a good thing. Ricin, a lectin in castor beans, also touted as the most dangerous lectin known to man, kills people within a matter of hours by inhibiting your cells’ abilities to form proteins[69]. People who have eaten undercooked kidney beans, which have lectins in them that haven’t quite been killed by the cooking process (PHA, or phytohemagglutinin, in particular) have reported nausea, vomiting, and diarrhea, and had, in effect, succumbed to food poisoning from this occurrence[70].
Celiac disease is a disease characterized by extreme gluten intolerance. Take a guess at what gluten is. Yes, it’s a lectin. If you still had any doubt about lectins being a problem, understand that gluten intolerance is a very real thing, and it doesn’t seem to be a very astute assertion to assume that
gluten is the only lectin causing problems within human beings, even if you yourself don’t feel pain or too much discomfort after you eat. Type 1 diabetes is a disease characterized by the inability of the beta cells on your pancreas to secrete sufficient insulin into the bloodstream at the appropriate or indicated times. There are many theories as to why this happens, but one quite compelling one posits that it seems to be caused by leaky gut, which lectins have been shown to lead to. The theory states that these lectins will attach to these beta cells, and engage in molecular mimicry, and launch an immune response on the beta cells, over time leading to type 1 diabetes. Other lectins such as PNA, or peanut agglutinin, seem to damage the mucus lining in the rectum, potentially leading to pre-cancerous lesions, and a lectin found in potatoes, called Solanum Tuberosum (STA), seems to inappropriately cause a histamine response and activate the immune system.
Unfortunately, you can even get lectins in animal foods if the animals ate foods with lectins in them, such as corn and soy and other grains. This is more probable if you are eating monogastric animals like pigs, any birds like chicken, etc, because the compounds in the food they eat (if it’s of a species inappropriate and unspecific nature) will end up in their tissues and fat cells, but not ruminant animals, like cows, as they have 4 stomachs that help them ferment and digest and filter out any harmful compounds in those plants. However, if you are drinking their milk, this could still cause some problems.
It turns out, just a few thousand years ago, a genetic mutation occurred that caused some cows to start producing milk with the protein casein A1, instead of casein A2, which all throughout time, they had produced. These are slightly different from each other, as casein A1, when metabolized, is turned into beta-casomorphin-7[71], which can function as a lectin that initiates an immune attack on the beta cells on the pancreas, which typically trends—once again—to type 1 diabetes[72]. It turns out that a lot of people actually are not lactose intolerant, but A1 intolerant, and can actually tolerate milk produced by an A2 cow, which they do, in fact, sell in stores, albeit at a far more expensive price, as these cows are harder to come by now, as it’s cheaper to raise A1 producing cows, and they supply more milk.
To avoid the lectins in animal meat, you need to find pasture raised/pastured meat. However, if you’re in a commercial grocery store, you will not find pastured pork or chicken, but you can find pastured eggs and grass-fed and grass-finished (GFGF) beef (grass-fed is the term used for pastured beef, as cows eat grass, and the other animals like chickens do not). It is important to note, however, that grass-fed does not always mean grass-finished, meaning the cow could’ve eaten grass for less than half their life, and still legally be referred to as grass-fed. Also, avoid the terms “free-range” and “organic” on meat products, which are not even close to being better. “Organic” simply means that the animals were fed “organic” corn and soy, and “free-range” means they had access to the outdoors, but, often times, for less than 10 minutes a day, and the rest of the time is spent in a cage getting fattened up on corn and soy again (spoiler—corn and soy do the same thing to us too).
Bottom line—you do not want to be eating lectins, or anything that behaves like them either. These are very harmful plant compounds, which, again, in one particular study, have even been shown to be a probable cause of heart disease[66]. It’s best to stay away from these.
Related Health Issues
- Leaky Gut
- Neuropathy
- Arthritis
- Heart Disease
- Parkinson’s Disease
- Histamine Response
- Immune System Acitvation
Goeke, Edward. Contraindicated: A Closer Look and Revision of Mainstream Health Axioms That Have Perpetuated Illness, Disorder, and Disease For Over a Century (pp. 70-74). Edward A Goeke. Kindle Edition.