There are many foods that have crept into the human diet in recent times (post-agriculture period) that contain what are termed ‘anti-nutrients’.
In essence, an anti-nutrient is a compound naturally found in certain plants, most often the seed portion, that enable the plant to be resistant to predators (microbes, fungi, bugs, birds, etc.). The most common anti-nutrients are gliadin and glutenin which are found in wheat, saponins which are found in potatoes (along with harmful glykoalkaloids), and lectins which are found in legumes (legumes contain saponins also). Legumes include peanuts, beans, peas, lentils, alfalfa, carob, and soybeans.
How Anti-Nutrients Harm Us
Upon entering our digestive tract, anti-nutrients irritate the intestinal tract resulting in intestinal permeability – in other words, wheat (breads, pasta, pizza, cereal) containing gliadin and glutenin, potatoes containing glycoalkaloids and saponins, and legumes containing saponins and lectins – all of those foods irritate the lining of the gastrointestinal tract, breaking down the the natural barrier of the intestinal wall. This breakdown of the intestinal wall is sometimes referred to as ‘leaky gut syndrome’. Intestinal permeability is associated with chronic low-grade inflammation (resulting in diverticulitis), inappropriate immune responses (allergies), and autoimmune diseases (such as celiac disease, inflammatory bowel disease (IBS), rheumatoid arthritis, Type 1 diabetes, and Multiple Sclerosis).
For the record, sweet potatoes and yams do not contain saponins or glycoalkaloids.