Lectins, not to be confused with leptin, the hunger/fullness hormone, are carbohydrate binding proteins that have been implicated in destroying the gut wall, and also in the treatment of cancer and HIV. What are lectins, and do we want to eat them or avoid them? Let’s take a look at the research that has been compiled on these proteins.
WHERE ARE LECTINS FOUND?
Lectins are found in plant foods, and are thought to have evolved as a natural defense by plants deterring animals to eat the leaves. Lectins are found in most plant foods and especially seeds, nightshades (potatoes, tomatoes, eggplant and pepper) and beans. In fact, the high lectin content in uncooked kidney beans can cause major gastrointestinal distress.
WHAT HAPPENS WHEN WE EAT LECTINS?
Lectins are known as anti-nutrients because they block the absorption of some nutrients. When humans eat those plants raw, the lectin content is high, and this can cause distress in the GI system – bloating, nausea, diarrhea. Lectins pass through the digestive tract undigested – we cannot digest these proteins. However, cooking breaks down most of the lectins so that they are removed from the body reducing negative affects. Lectins are thought to be related to Type I diabetes by stimulating class II HLA antigens on cells that do not normally display them causing pancreas islet cells to express both foreign antigens and class II HLA antigens causing an auto-immune attack. Lectins are also thought to be involved in Rheumatoid Arthritis in a similar way, and peptic ulcers. It is thought that prophylactic oligosaccharides can prevent the effects of lectins.
SHOULD WE AVOID LECTINS?
In small amounts, lectins can actually have positive affects, such as helping with cell growth and immune function. Removing lectins completely from the diet will most likely result in nutrition deficiencies, and consumption of beans has been shown to improve blood lipid levels and inflammatory markers. Additionally, lectins have been tested as a cure for HIV and cancer. Whether or not to consume lectins should be an individual decision based on health. For those with autoimmune disease and gastrointestinal imbalances, studies have shown avoiding lectins would be very beneficial due to the effects of lectins on the cellular level. For healthy individuals, being aware of reactivity when eating foods with lectins is helpful. If you suspect that you might be sensitive to lectins, an elimination diet is the best way to test for lectin sensitivity. Remove all sources of lectins for 2 weeks, and then reintroduce lectins.
REDUCING LECTIN CONTENT IN THE DIET
If you are looking to reduce lectins in your diet, sprouting grains, beans, legymes and seeds reduces enzymes that help to reduce the total amount of lectins. White bread is a better choice than wheat bread since wheat is high in lectins. The fermentation process in making sourdough bread makes this a better choice than traditional bread. If you find that you need to avoid lectins due to sensitivity, the top foods with high lectin content are red kidney beans, soybeans, wheat, wheat germ, peanuts and tomatoes. The diet will become restrictive quickly as you will also want to avoid beans, peas, lentils, peanuts, out of season fruit, squash, nightshades, grains, corn and wheat flour. If you have lectin sensitivity, you’ll also want to consider the diet of animal products that you are eating. For instance, meat from corn fed animals should be avoided, along with casein protein A1 milk.
Do you limit lectins in your diet?