Nutrition that heals. Part 2
What are lectins and why should I avoid them?
Lectins are a type of protein that can bind to cell membranes. Lectins offer a way for molecules to stick together without getting the immune system involved, which can influence cell-cell interaction.
Lectins are abundant in raw legumes and grains, and most commonly found in the part of the seed that becomes the leaves when the plant sprouts, aka the cotyledon, but also on the seed coat. They’re also found in dairy products and certain vegetables. While lectin content in food is fairly constant, the genetic altering of plants has created some fluctuations.
Lectins in plants are a defense against microorganisms, pests, and insects. They may also have evolved as a way for seeds to remain intact as they passed through animals’ digestive systems, for later dispersal. Lectins are resistant to human digestion and they enter the blood unchanged.
Why are lectins so important?
Lectins are thought to play a role in immune function, cell growth, cell death, and body fat regulation.
Immune response and toxicity
Because we don’t digest lectins, we often produce antibodies to them. Almost everyone has antibodies to some dietary lectins in their body. This means our responses vary. Certain foods can even become intolerable to someone after an immune system change or the gut is injured from another source. The presence of particular lectins can stimulate an immune system response.
Lectins and the intestinal wall
Lectins can damage the intestinal lining, (…) and the gut can become “leaky,” allowing various molecules (including stuff we don’t want) to pass back and forth amid the gut wall. We may also not absorb other important things, such as vitamins and minerals, properly.
Lectins and immune response
When lectins affect the gut wall, it may also cause a broader immune system response as the body’s defenses move in to attack the invaders.
Symptoms can include skin rashes, joint pain, and general inflammation. Other chronic disorders may be correlated with leaky gut — for example, researchers have even noted that children with autism have very high rates of leaky gut and similar inflammatory GI tract diseases.
Lectins and grains
Unrefined grains are more nutritious than refined versions because they contain more nutrients. However, they also provide more lectins (and other anti-nutrients).
Grain, cereal, dairy, and legume (especially peanut and soybean) lectins are most commonly associated with reports of digestive complaints. Legumes and seafood are the most abundant sources of lectins in most diets.
How can we reduce or neutralize lectins?
Sprouting
Sprouting seeds, grains or beans decreases the lectin content.
Generally, the longer the duration of sprouting, the more lectins are deactivated. In some cases the lectin activity is enhanced by sprouting (like alfalfa sprouts). The lectins in some grains and beans are in the seed coat. As it germinates, the coat is metabolized – eliminating lectins.
Soaking and cooking
If you must have grains and legumes, soak beans and legumes overnight, and change the water often. Drain and rinse again before cooking. Adding sodium bicarbonate (aka baking soda) to the soaking water may help neutralize the lectins further.
Fermenting
Fermentation allows beneficial bacteria to digest and convert many of the harmful substances.
This might be why the healthiest populations stick with fermented soy products like tofu, miso, tempeh, tamari and natto. Even some vegetables, such as cabbage, may have fewer antinutrients when fermented. Cultures with a history of grain eating traditionally have used some form of fermentation to treat grains. If you’ve had sourdough bread or beer, you’ve had fermented grains.
Not all lectins are completely destroyed by these methods, and some particularly stubborn lectins in beans remain no matter how lengthy the treatment. Thus, these techniques don’t totally reduce the negative effects for everyone.
Extra credit
Certain seaweeds and mucilaginous vegetables have the ability to bind lectins in a way that makes them unavailable to the cells of the gut.
The “Blood Type Diet” is based on how our blood cells react with lectins in foods.
Some experts hypothesize that it’s no coincidence the top 8 allergens also contain some of the highest amounts of lectins (including: dairy, egg, wheat, soy, peanuts, tree nuts, fish, shellfish).
by Angela Ingendaay, M.D.