While lectins might be a relatively new word to mainstream diet conversations, the history of lectins research dates back to the early 19th century.
Perhaps, at some point, you’ve considered a diet that’s gluten-free, or paleo, or keto, or vegetarian, or dairy-free… But, have you considered a lectin-free diet?
What are Lectins?
Simply defined, a lectin is a specific kind of protein found in most plants. And this protein helps plants ward off attacks from would-be predators like you!1
Now, when you consume lectin-rich foods, the proteins bind to the sugar residue on the outside of your cell membranes. Specifically, these “barnacles” attach themselves to your red blood cells. Some scientists feel this process can harm to your body, leading to digestive issues and gut irritation. This is most prominent in lectin-rich foods like beans and nightshade vegetables.2
The Early History of Lectins
The word lectin comes from the Latin word legere, meaning to “pick out or choose.” As far as scientific discovery is concerned, the history of lectins began in the early 1900s. In the 1940s scientists began studying the differences between blood types and the presence of glucose on a cell’s surface. During these studies, the involvement of lectins became better understood. Lectins were officially named in 1954 for the way they bond to a cell’s surface.3
During the 1970s and 1980s, the history of lectins deepened, as scientists began learning more about the connection between carbohydrates, nutrient absorption, and how lectins affect the nature of cells.
Because lectins are resistant to breaking down or being absorbed in your gut, they can interfere with the flora and the nutrient absorption in your small intestine.
As research on lectins continued and the history of lectins unfolded, that lack of absorption was linked to some major digestive issues.4,5
Where Do You Find Lectins?
There are some facts about lectins that scientists and dieticians agree on: higher levels of lectins are present in many foods, and these foods can be fermented, deseeded, or thoroughly cooked in order to be digestible. Consuming fewer lectins in your diet can be a good thing.
So, what foods are loaded with lectins? According to Dr. Gundry, this list includes:
- Legumes: beans, lentils, chickpeas, and peanuts
- Squash and their seeds: pumpkin, butternut, zucchini
- Nightshade vegetables: tomatoes, eggplant, potatoes, and peppers
- Grains: in particular, wheat
Beans Are Particularly Toxic
You’ve probably heard that beans are high in plant-based protein and fiber, and they contain plenty of helpful vitamins and minerals your body needs… and it’s true. By that definition, they are nutritious. But they also contain high levels of a particular lectin called phytohaemagglutinin, which is considered toxic to humans in large quantities. Yikes!
Pressure Cooking Beans
Here’s the good news: phytohaemagglutinin levels can be reduced in beans by soaking and pressure cooking them at high temperatures. Pressure cooking and soaking beans and legumes in multiple changes of water may help to safely lower harmful lectin levels – enough that you can eat them and reap their nutritional benefits.
A hemagglutinating unit (hau) is how lectin levels are measured in food. In their raw form, red kidney beans (one of the most popular beans in our American diet) contain 20,000–70,000 hau. Once they’re soaked and thoroughly pressure cooked, however, this level is much lower. Cooked red kidney beans contain only 200–400 hau, which is considered a safe level.6
Here’s a tip:
Stick to using your pressure cooker, not your slow cooker, when cooking dried kidney beans to be sure you lower phytohaemagglutinin levels. A slow cooker doesn’t create the necessary pressure to remove lectins! When red kidney beans are consumed raw, or not fully cooked, they can cause symptoms similar to food poisoning.7,8
Lectins: The Story Can End Happily
While the history of lectins is still unfolding, researchers now know they can be dangerous to your health. So do your best to avoid them as much as you can. Also, find out which diet suits your body and health needs best by talking to your doctor. Your healthcare professional will know how to get you started.
And always remember: An effective diet means that you are consuming beneficial nutrients and lots of vegetables, wild-caught meats, in-season fruits, and low-lectin grains like millet and sorghum – so consider moderation and balance when you embark on a new approach to your diet.
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