Research on Lectins and Health Risks
Research indicates that lectins may pose risks for certain individuals, potentially leading to systemic inflammation, digestive issues, increased fat storage, and even autoimmune conditions like celiac disease and Crohn’s disease. Lectins can elevate histamine levels, causing reactions in some people.
While there’s extensive research on the harmful effects of lectins, opinions vary. Some experts believe the concerns are overstated since many lectin-containing foods are typically cooked, which reduces their lectin content.
What Are Lectins?
Lectins are a broad class of proteins found abundantly in plants. They serve as a defense mechanism for plants against microorganisms, insect pests, and animals. Scientifically, lectins are “glycoproteins that bind carbohydrates and agglutinate cells,” meaning they cause cells to clump together. This clumping can affect red blood cells, gut mucosal cells, and even probiotic bacteria.
Lectins are proteins that protect plants from harm. Unlike other proteins, lectins survive the mammalian digestive system, allowing seeds to pass through a mammal’s gut and still germinate. However, this can lead to gastrointestinal distress in humans. Since we do not digest lectins, our bodies see them as foreign objects and produce antibodies to attack them, triggering an immune response.
Are Lectins Bad for You?
Research suggests that consuming high amounts of lectins can cause health issues in people with a genetic sensitivity to them. Most people are unaware of their genetic makeup and only know they experience health problems. Symptoms like gut issues, low energy, or brain fog might be linked to lectin sensitivity, but doctors often don’t test for histamine intolerance.
After consuming lectins, they bind to cell membranes, particularly those lining the digestive tract. This binding can cause gut cells to die or lose function and disrupt a healthy gut biota by clumping gut microbes together. Lectins also affect lipid, carbohydrate, and protein metabolism. While small amounts of lectins may have health benefits, higher amounts can cause health concerns.
Not all lectins are harmful, but many people in the Western world consume too many high-lectin foods, such as grains, beans, and tomatoes. If you regularly experience inflammation, disease, or gastrointestinal distress, try eliminating lectins to see if it helps. Healing from damaged gut mucosa takes time, so immediate results may not be evident.
Reasons to Avoid Lectins
Lectins Are Antinutrients
Lectins can block the absorption of essential minerals, earning them the label “antinutrients.” They interfere with the body’s ability to digest and use other nutrients, particularly calcium, iron, phosphorus, and zinc. If you consume lectin-rich beans along with foods containing these minerals or with a multivitamin, your gut may not absorb the minerals properly. To avoid this, consume these minerals or your multivitamin during a meal that does not contain lectins.
Lectins May Cause Inflammation
Studies show that lectins can cause inflammation by activating pro-inflammatory pathways, affecting immune system functioning. The body creates antibodies in response to lectins as if they were foreign invaders like viruses. This inflammation can lead to autoimmune diseases such as rheumatoid arthritis and celiac disease, especially in individuals with dysfunctional digestive enzymes. Long-term inflammation increases the risk of heart disease and cancer. Lectins may also stimulate biochemical reactions affecting the pancreas and islet cells, making the body vulnerable to autoimmune attacks and diabetes. Gluten contains lectin, so those with gluten sensitivity should minimize lectin intake.
Lectins May Permeate the Gut Barrier
Consuming lectins can damage the intestinal wall or epithelium. While a healthy gut can repair itself from small amounts of damage, high quantities of lectins can lead to a leaky gut. A leaky gut allows toxins, food molecules, pathogens, and lectins to pass through, leading to chronic inflammatory conditions such as inflammatory bowel disease, Crohn’s disease, autoimmunity, neurological disorders, and allergies.
Raw Lectins May Be Toxic
Consuming undercooked or raw legumes can be toxic. For example, red kidney beans contain high levels of phytohaemagglutinin, a lectin that can cause severe vomiting and diarrhea. Cooking beans in a pressure cooker or boiling them for at least 10 minutes can denature lectins, making them safer to eat. However, slow cookers may not reach a high enough temperature to break down lectins.
Lectins May Cause Digestive Distress
Lectins can cause gastrointestinal distress by clumping cells, including helpful microbes and gut mucosal cells. This can lead to symptoms like diarrhea, bloating, gas, or constipation. In some people, lectins may silently damage the gut and body systems without noticeable symptoms.
Foods High in Lectins
About 30% of the foods we eat contain lectins. While some high-lectin foods also contain antioxidants, nutrients, and fiber, some experts advise limiting their intake. High-lectin foods include red kidney beans, navy beans, chickpeas, soybeans, black beans, lima beans, lentils, black-eyed peas, peanuts, wheat, white potatoes, nuts, nightshade vegetables (tomatoes, eggplant, peppers), corn, and dairy.
Popular Low-Lectin Foods
If you’re concerned about lectin consumption, there are plenty of healthy, low-lectin foods to choose from. These include celery, garlic, onion, broccoli, cauliflower, Brussels sprouts, dark leafy greens, asparagus, mushrooms, avocado, artichokes, beets, kimchee, sweet potatoes, olives, olive oil, and citrus fruits.
Should You Try a Lectin-Free Diet?
Choosing to avoid high-lectin foods is a personal choice. Dr. Steven Gundry popularized the lectin-free diet with his book, “The Plant Paradox.” If foods like beans and grains cause digestive issues, eliminating them may alleviate symptoms. A lectin-free diet may not directly cause weight loss, but eliminating processed grain products could help shed pounds. Some benefits of reducing lectin intake may work quietly inside your cells and tissues.
If you want to know whether you have a genetic susceptibility to lectins, you can order a DNA kit online. If you can’t live without high-lectin foods but experience digestive distress, try taking turmeric and a high-quality probiotic to reduce systemic inflammation.
Other Natural Ways to Reduce Lectin Intake
If you choose to cut back on lectins, eliminating high-lectin foods isn’t your only option. Properly cooking foods reduces lectin levels, but they are surprisingly resistant to temperature. Moist heat is more effective than dry heat in denaturing lectins. Cooking beans at over 100 degrees C (212 F) for 10 minutes or at 95 degrees C (203 F) for one hour can break down lectins.
Fermenting foods also reduces lectin content. Fermented foods like kimchee, sauerkraut, and natto have significantly lower lectin levels. Soaking legumes and grains can deactivate about 50% of the lectins. Adding baking soda to the soaking water and soaking for 16 hours can further reduce antinutrients. Sprouting beans and grains can also reduce lectins substantially.
Points to Remember
Consuming lectin-containing foods can cause digestive symptoms like nausea and diarrhea. Lectins are carbohydrate-binding proteins found in many plant foods. High quantities of lectins can prevent the absorption of essential nutrients and cause inflammation and digestive concerns. Cooking, soaking, sprouting, and fermenting can lower lectin levels in foods.
