Lectins are plant-based proteins that bind to carbohydrates and are found in many foods, including grains, legumes, fruits, vegetables, and dairy products. These molecules have been studied for their potential effect on human health, particularly in relation to intestinal inflammation and nutrient absorption. The lectin-free diet, popularized by cardiologist Steven Gundry in his book “The Plant Paradox,” is based on the idea that reducing or eliminating lectins can improve gastrointestinal health, reduce inflammation, and promote weight loss. However, the scientific debate is ongoing and evidence supporting this diet is limited. Foods high in lectins include legumes such as beans, lentils and soybeans; whole grains such as wheat and corn; and certain vegetables such as tomatoes, eggplant, and peppers (nightshades).
The lectin-free diet eliminates lectins and instead favors animal proteins, fish, healthy fats, lectin-free vegetables, and low-sugar fruits. Proponents of the diet believe that lectins can contribute to leaky gut, interfere with nutrient absorption, and trigger a harmful immune response. Some studies suggest that eliminating lectins may alleviate symptoms in individuals with autoimmune diseases, irritable bowel syndrome and chronic inflammation. However, many experts point out that lectins are largely neutralized through cooking, fermentation and other culinary processes, reducing their potential harmful effect. Additionally, eliminating entire categories of lectin-rich foods could lead to nutritional deficiencies, as many of them provide essential fibers, vitamins and antioxidants.
The lectin-free diet may not be necessary for most people, and its long-term effectiveness has not been demonstrated in controlled clinical trials. Experts recommend carefully evaluating the diet with the help of a nutritionist, rather than relying on claims that are not fully supported by the scientific community. In conclusion, while the lectin-free diet may offer benefits to individuals with specific food sensitivities, its general application requires further research. It is important, on the other hand to see if there is a real sensitivity or allergy to nightshades proteins (allergens rather than lectins) or grains proteins or legume proteins as well. Rather than completely eliminating foods containing lectins, it may be more helpful to adopt preparation methods that reduce their concentration and monitor the individual body’s response.
- Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Scientific references
Vojdani A, Vojdani C. (2019). Lectins, agglutinins, and autoimmunity. Immunologic Research, 67(1), 20-34.
Smirnov AN, Shashkov AS. (2018). The role of lectins in human nutrition and health. Biochemistry (Moscow), 83(5), 579-594.
Gundry, S. R. (2017). The Plant Paradox: The Hidden Dangers in “Healthy” Foods That Cause Disease and Weight Gain. Harper Wave.
Cordain L. (2000). Cereal grains: humanity’s double-edged sword. World Review of Nutrition and Dietetics, 84, 19-73.
Freed DLJ. (1999). Lectins in food: their importance in health and disease. The British Journal of Nutrition, 81(5), 363-364.
