Dietary Lectins as Disease Causing Toxicants

Abstract

Lectins are carbohydrate binding proteins present in most plants, especially seeds and tubers like cereals, potatoes and beans. It is now well established that many lectins are toxic, inflammatory, resistant to cooking and digestive enzymes and present in much of our food and sometimes cause "food poisoning." The global pattern of varying prevalence of diseases such as coeliac disease, autoimmune diseases, rheumatoid arthritis, obesity, cardiovascular disease and insulin dependant diabetes mellitus, suggests that some dietary factor specific to plant foods could initiate these diseases. Of the food lectins, grain/cereal lectins, dairy lectins and legume lectins are the most common ones associated with aggravation of inflammatory and digestive diseases in the body and improvement of these diseases and/or symptoms when avoided. 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. With continued exposure of the gut by these toxic food lectins a persistent stimulation of the body’s defense mechanism in a dysfunctional manner occurs, which manifests as an autoimmune disease. If the lectins in diet are causative in initiating all these diseases, it should be possible to identify the responsible constituents and modify or remove them so as to make the diet healthier. Here we present a brief account of lectin toxicity research and show how these proteins have become the focus of intense interest for biologists.