Lectins? What are lectins and how do they make me fat? Good questions.
Lectins are carbohydrates that are bound to proteins. Plants make them to protect themselves from insects and diseases. They are found in high, potentially “toxic”, concentrations in wheat, rye, barley, wheat germ, quinoa, rice, oats, millet and corn. Also legumes, all dried beans, soy and peanuts. Dairy, especially from grain-fed cows as opposed to grass-fed cows. Nightshades like potato, tomato, eggplant and pepper contain them as well.
Lectins have been documented to cause “food poisoning” in people without any bacteria or pathogen being found. Lectins are toxic, inflammatory, or both. They are resistant to cooking and digestive enzymes so they aren’t easily broken down.
Lectins in wheat, kidney beans, soybeans and peanuts are known to increase intestinal permeability (a leaky gut). This allows proteins, bacteria, amino acids, undigested food, and viruses to crossover into the body. Usually the immune system is quick to attack and eliminate these foreign invaders. However, lectins also impair the immune systems ability to fight off these fragments that leak into the body. Some intestinal bacteria, immune system proteins, food proteins, and body tissues, have the same protein sequences, further confusing the immune system. This causes the immune system to attack itself and the body’s tissues as if they are invaders! Enter, autoimmune diseases! Also, wheat contains gluten, which compounds the lectin problem!
Current estimates of gluten sensitivity in the US are 30-40% of the population with the majority of these people not even being aware that they have the problem. People who are the most sensitive end up with Celiac’s Disease. Gluten causes inflammation in the gut lining and pain. It can cause severe symptoms (Ciliac’s) or be subclinical and exhibit almost no symptoms. With time though, people will begin to exhibit clinical symptoms: abdominal cramping, dry skin, dry hair, diarrhea, nausea, constipation, and low energy to name just a few.
So how do lectins cause me to gain weight and not be able to lose it? Lectins interfere with leptin. Leptin tells us to stop eating, stores excess calories in fat, supports the growth of blood vessels, bone, the immune system, glucose- and fat-metabolism, and the reproductive system. In mice, the administration of leptin causes satiation and weight loss. In overweight humans it does not. Overweight humans often have high levels of leptin already. This points to Leptin Resistance as a cause of their obesity. Lectins appear to interfere with leptin receptors, blocking leptin’s effect of controlling appetite/satiation. This may lead to an increase in glucose in the blood and start insulin resistance (Type II Diabetes) in some people. Lectins may also contribute strongly to the metabolic syndrome.
So, where do you think you would be if you followed the old USDA food pyramid? It recommended 6-11 servings of grain a day! Consider how much the obesity rate in the US has gone up and you might just see a connection.
How do you reverse the process? The first step is to get off of the foods that have potentially toxic lectins in them. Hunter-Gatherer diets, the Paleo diet, the Atkins diet, and other similar diets will reduce your exposure to lectins. However, you should consult with your physician/nutritionist before starting any dietary program to make sure that it is right for you and your problems.