Lectins are a family of proteins found in nearly all the foods, but they are especially high in legumes and grains. Most plants don’t ‘want’ to be eaten and develop defense mechanisms. Lectins are thought to be one such mechanism.
When consumed in large quantities, lectins are toxic, even deathly. While most of the research is highly preliminary, they have been shown to cause intestinal permeability in animal studies (nobody has studied whether the same happens in living humans). Once in the blood, lectins stimulate the immune system and have been linked to various autoimmune diseases.
Recent research has suggested that these lectins may effectively serve as a vehicle allowing foreign proteins to invade our natural gut defenses and cause damage well beyond the gut, commonly in joints, brain, skin and various body glands…
When consumed in excess by sensitive individuals, they can cause 3 primary physiological reactions: they can cause severe intestinal damage disrupting digestion and causing nutrient deficiencies; they can provoke IgG and IgM antibodies causing food allergies and other immune responses and they can bind to erythrocytes, simultaneously with immune factors, causing hemagglutination and anemia.
Hamid, R & Masood, A. Dietary lectins as disease causing toxicants. Pakistan Journal of Nutrition (2009). https://www.pjbs.org/pjnonline/ab1120.htm
All of which sounds very worrying, and were I to leave it here, you might be tempted to ditch all legumes from your diet. But before you do that, let’s take a moment to reflect.
Plants and animals are in a constant arms race, of sorts. Plants develop defense mechanisms, and animals evolve ways to get arount them. While lectins are theoretically dangerous, most people have no problems eating moderate amounts of lectin-containing foods. Mainly because:
- Humans don’t normally consume large quantities of lectins. We simply can’t eat most lectin-rich foods raw. Have you tried eating raw beans? Soaking and cooking eliminate most, but not all, lectins.
- The small amounts left in cooked foods simply aren’t a problem for most people. The digestive system can easily cope with, and recover from, whatever minor, if any, damage small quantities of lectins do. Remember that the vast majority of people eat lectins every single day without any real health problems. In fact, legumes are concidered as health foods.
So why am I mentioning lectins if most people can eat them without any problems? Because they can be an issue for people who, for whatever reason, are more sensitive to them. For individuals who struggle with allergies, autoimmune issues, or just seem sensitive to almost everything, eliminating lectins can be a big help. It might be the key to stopping the rampant inflammation and put them back on the road to health and clear skin.
At least one study has shown that diet that eliminates gluten and lectins normalizes inflammation levels in people with auto-immune problems.
Lectins are mainly found in these food families:
- Legumes; all beans, including soybeans and peanuts
- Grains, especially wheat; white rice is unlikely to be a problem
- Nightshades (potatoes, tomatoes, eggplants, bell peppers, hot peppers); but unlikely to be an issue for most people
- Dairy products
Elimination diet and challenge
If you suspect you are lectin sensitive, complete the following elimination and re-challenge diet (adapted from Krispin.com).
- Eliminate all suspected food families from your diet (see the above list). Check the labels to make sure you aren’t consuming hidden lectins. Stay on this diet for at least 7 days. In proper elimination diets, you normally avoid the suspect foods for 21 days. If that’s too much or too difficult, do at least seven days. It should be enough to at least get some idea.
- On day 8, introduce several foods from one eliminated family (test one family at a time). For example, consume soy, kidney beans, and peanut butter. If eliminating dairy, have milk, yogurt, and cheese. Eat some at every meal.
- Go back to step #1 for two days. You are on the elimination diet for seven days, consume legumes on day 8, and days 9 and 10 you are back on the elimination diet.
- Check your symptoms on the day of testing and the following two days. Pay attention to changes in energy, mood, appetite, bowel function, skin, sleep, or anything else that seems off. It may take a day or two for symptoms to appear.
During the 7-day elimination diet phase, you can follow the paleo meal plan here. This 14-day paleo meal is another good source of ideas and recipes for the elimination diet phase. Just substitute the breakfast eggs with something else, and prepare the salads and vegetable dishes without nightshades. These meal plans also eliminate gluten, which is handy for combined gluten and lectin elimination diet.
Soak and cook to reduce legumes
Even if you are sensitive to lectins, you may still be able to eat lectin-rich foods if you prepare them correctly. This applies mainly to grains and legumes.
If you decide to eat these foods, soak and cook them thoroughly to get rid of most lectins. I recommend soaking for 24 hours, rinse, and then cook thoroughly.
I should point out that dry heat doesn’t do as good a job as wet heat in neutralizing lectins. So dry roasted peanuts can still have a not-insignificant amount of lectins and therefore most likely to cause problems. Similarly, be careful bread and baked products as they often contain some lectins.
For more information, please see these articles about dietary lectins: