Lectins belong to a large family of proteins that can be round in almost all cell types and thus are present in all foods, mainly in legumes and cereals. Lectins can bind carbohydrates without any change in their structure. In this way, they play a very important role in the normal functions of the body. They help cells and molecules to “stick” to each other and perform a variety of functions, which are related to the immune system.
The effects of lectins on human health
Consuming large amounts of lectins can cause long-term health problems. The same properties that lectins use to defend plants in nature can cause problems in the digestion of food in the human body. In this way, when they are consumed, they can cause negative side effects such as nausea, vomiting, diarrhea and other stomach disorders. Lectins can also bind to cells in the digestive tract. This may affect the breakdown and absorption of nutrients as well as the development and function of the intestinal flora.
Repeated and prolonged consumption of foods rich in lectins can damage the intestinal wall, increasing its permeability. As a result, unwanted substances enter the gut more easily, which then end up in the bloodstream. This condition is known as “leaky gut”.
When lectins enter the bloodstream, they interact with glycoproteins on cell surfaces and with antibodies of the immune system. This process can trigger autoimmune reactions, not only against lectins, but also against body tissues. That is, the immune system begins to “wrongly” attack the body itself.
Other side effects that are caused by high levels of lectins in the human body are allergies and fatigue. Studies have even suggested that active lectins can interfere with the absorption of metals, especially calcium, iron, phosphorus and zinc.
Which foods contain lectins?
Lectins are found in all foods. However, they are found in large quantities in legumes, seeds, dairy products, seafood and vegetables. Raw or uncooked legumes are the largest source of lectins. Legumes and cereals do not need to be permanently removed from our diet. The amount of lectins can be removed through specific preparation methods.
Boiling legumes in water and soaking legumes and seeds help eliminate lectin activity. Lectins are water-soluble and are usually found on the external surface of a food, so exposure to water removes them. An example is dried beans. To prepare them, they are boiled for several hours, which inactivates the action of lectins. Furthermore, food fermentation helps a lot, as it allows friendly bacteria to digest lectins.
The benefits of lectin-containing foods
Lectins can protect cells from damage caused by free radicals and posses antioxidant activity. They also slow down the digestion and absorption of carbohydrates, which can prevent a sharp rise in blood sugar and high insulin levels.
According to new scientific findings, foods that contain lectins, such as legumes, whole grains and nuts, are associated with lower rates of cardiovascular disease, weight loss and type II diabetes. These foods are excellent sources of B vitamins, protein and healthy fats. Furthermore, studies have shown that lectins are broken down when they are processed or cooked. Thus, the health benefits of consuming these foods outweigh the adverse effects they cause.
Should lectins finally be avoided?
Excessive consumption of lectins can be harmful to the body. However, people do not usually consume large doses, as foods that are rich in lectins, such as cereals and legumes, are consumed after cooking. Thus, the amount of lectins after cooking is considered negligible and safe for the most people.
Most of the foods, which contain lectins, also contain many vitamins, minerals, fiber and antioxidants. The benefits of consuming them far outweigh the negative effects they cause. However, for people who have an Autoimmune Disease or suffer from digestive problems, a diet that contains low levels of lectin is indicated. With the help of a specialized nutritionist such a diet can be individualized and meet the different needs of the patient.
- https:www.hsph.harvard.edu/nutritionsource/anti-nutrients/lectins/, the nutrition source
- https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-what-are-dietary-lectins-and should-you-avoid-eating-them/