Lectins

Lectins are most commonly found in grains, legumes, and nightshade vegetables, such as tomatoes, potatoes, and eggplant. They are proteins that bind to certain sugar molecules in the intestinal wall than can hinder digestion and nutrient uptake. When consumed in ordinary amounts, lectin can have certain health benefits, such as regulating the immune system by keeping protein levels normal in the blood fighting off viral and fungal infections. Problems begin to arise when too many lectins are consumed. Inflammation, vomiting, diarrhea, and leaky gut can result from too many lectins being ingested. Lectins can also interfere with the digestion and absorption of other foods when the intake is too high. Because they are difficult to digest, those who have GI problems should reduce intake of lectins. When consumed in large amounts, lectin intake can lead to damage of the gut wall resulting in leaky gut syndrome. Substances are then able to enter the bloodstream through the intestines and cause inflammation throughout the entire body. A good example of the effect that lectins can have on an individual is consuming uncooked beans. This would cause lectin poisoning and the individual would experience symptoms, such as nausea, vomiting, and diarrhea. 

Foods with the highest lectin content are potatoes, eggplant, soybeans, lentils, peppers, wheat germ, red kidney beans, peas, tomatoes, and peanuts. In order to reduce the lectin content in these foods, they can be treated in different ways prior to consuming them. Before eating legumes, they should be soaked and then cooked. This will reduce the lectin content and enhance the nutritional value while also reducing the antinutrient content of the legume. When soybeans are cooked, their lectin content is reduced from 10-20g of lectin per kilogram to 2-4g per kilogram. At this level, lectins can improve gut microbiota rather than causing negative effects. Red kidney beans and other beans should always be cooked prior to consuming them. Raw beans can cause nausea, vomiting, and other side effects. By peeling and deseeding foods such as squash, peppers, and tomatoes, this can reduce the lectin levels as well. Pressure cooking after peeling and deseeding can further reduce the lectin content. Soaking and sprouting grains and seeds can also help reduce the lectin content. Sprouting involves soaking the seeds for up to 24 hours and then rinsing and draining the seeds every few hours for the next few days. Fermenting foods is another great way to reduce the lectin content. Not only can fermentation reduce lectin content, but it allows for beneficial bacteria to digest the lectins and increase the nutritional profile of the food being fermented. Not to mention it is a great way to add in probiotics to a diet to promote gut health. With proper preparation, these foods do not have to be eliminated from your diet if reducing lectin content is the main goal.