Many individuals are allergic or experience sensitivity to certain foods such as milk, wheat, and tree nuts. However, there is a chance that some of these side effects are due to a type of lectin poisoning. Lectins are proteins that bind to cell membranes to help immune function, the cell life-cycle, and body fat regulation. They are low-level toxins that also act as a defense mechanism to discourage other animals from eating specific life forms. Lectins essentially help regulate the food chain and assist with survival tactics. If a predator eats a certain plant or animal, the lectins can trigger a negative reaction within the predator, decreasing its likelihood to prey on the life form in the future.
Since lectins are essentially low-level toxins, consuming high amounts can cause multiple negative side effects. These negative effects can include flatulence, bloating, nausea, diarrhea, and other common symptoms that occur when people consume beans. Humans experience these negative reactions from beans because we do not create the enzyme needed to digest them. Since we don’t have this enzyme, the beans ferment in our digestive tract and create the undesirable side effects.
Many health bloggers are promoting a “lectin-free” diet to avoid food sensitivity and negative reactions within their digestive system. However, this diet recommendation is nearly impossible because every life form contains lectins. The science and research behind lectins are still in its early stages, but we do know that avoiding them all together is nearly impossible. However, you can work towards a low-lectin diet, either by eating low-lectin foods or cooking and preparing certain foods in a way that lowers the levels of the binding protein. For example, raw red kidney beans have one of the highest concentration levels of lectins out of any other food, which leads to severe side effects such as nausea and diarrhea. Eaten raw, red kidney beans contain 20,000 to 70,000 hau (hemagglutinating unit). If completely cooked, this amount drastically decreases to only 200 to 400 hau. Cooking these beans automatically switched them to a low-lectin food!
Other ways you can participate in a low-lectin diet include switching to grains made with more refined flours instead of whole grain, such as choosing white rice over brown. The best way to remove lectins in legumes is to soak them overnight along with thoroughly cooking them, like in the previously mentioned red kidney beans. You might remember your mother soaking beans prior to cooking them. Completely eliminating dairy is another option for a low-lectin diet, and instead choosing vegan options such as almond and cashew milk. When eating potatoes and tomatoes, cooking is the best way to lower their lectin contents. Cooking tomatoes actually increases the lycopene content as well, which is the anti-oxidant that is very healthy for you.
For more information and a full list of high-lectin foods, take a look at this article.