When it comes to a healthy diet, you’ll usually see beans, grains and vegetables at the top of the list. But these foods may contain lectins, which you may have heard could affect your digestive system. If you’re concerned about lectins and gut health, here are a few things to know.
What are lectins?
Lectins naturally occur in many plant foods. They help protect plants against pests and diseases. “Lectins are proteins that are found in most plants,” said Lillian Swatek, a dietitian with Banner Health.
“These plant foods also contain other ingredients such as protein, healthy fats, fiber, vitamins, minerals, phytochemicals and antioxidants that can help reduce risk for a variety of diseases, including cancer,” Swatek said. In fact, since lectins may fight tumors, some are being studied as possible treatments for cancer.
“Scientists are also investigating the possible antibacterial and antifungal properties of lectins. This may lead to new drugs for fighting infections,” Swatek said.
What foods contain lectins?
You’ll find lectins in:
- Beans: Kidney beans, black beans and chickpeas
- Grains: Wheat, barley and rye
- Vegetables: Nightshades like tomatoes, potatoes and eggplants
- Fruits: Melons
- Nuts: Peanuts
- Seeds: Chia, pumpkin and sunflower seeds
Why do lectins have a bad reputation?
Swatek said the main reason you hear so much about lectins is likely from a book and ads by Dr. Stephen Gundry. “His book ‘The Plant Paradox’ contains claims that are not backed by science,” she said.
There are some problems with the research linking lectins to gut problems:
- Lectins can bind to carbohydrates that live on the surface of your gut. Some studies have found that this interaction can disrupt the gut lining and cause health problems. However, they often study animals and focus on specific types of lectins or uncooked lectins. More research is needed to understand the effects of lectins on humans.
- Some studies show that a high lectin intake causes inflammation or issues with immune function, but other studies find little impact.
- Research that shows lectins can make it harder for your body to absorb some nutrients often doesn’t take cooking into account. Cooking breaks down lectins and lowers the amount the food contains. Most high-lectin foods, like beans and grains, are cooked before they’re eaten.
How do lectins affect the gut?
High levels of lectins can cause digestive issues. “If we were to eat even a small amount of raw beans, it would likely cause gas, bloating, nausea, diarrhea or worse in some people. But who eats raw beans? We eat grains and beans after cooking, which eliminates most of this risk,” Swatek said.
How should I manage my lectin intake?
Many people don’t need to worry about lectins. “For most people, eating raw fruits and vegetables, nuts, seeds, beans and grains that contain lectins is perfectly safe. Just make sure beans are cooked well,” Swatek said. You may also want to soak raw beans overnight.
If you think that some raw fruits or vegetables cause digestive problems, try them cooked or peeled. Fermenting foods also reduces the lectin content, so foods like sauerkraut and kimchi can be good choices.
In general, a balanced diet that contains a lot of nutrients is good for your gut health. Don’t eliminate food categories like lectins without talking to a health care provider about managing lectin intake.
“Please don’t stop eating fruits, vegetables, nuts, seeds, whole grains and cooked beans unless you have a very specific allergy or intolerance to any of these,” Swatek said. “You could be avoiding foods that help keep you healthy!”
If you would like to include some lower-lectin foods, you may want to choose:
- Low-lectin vegetables: Leafy greens like spinach and kale, cruciferous vegetables like broccoli and cauliflower and root vegetables like carrots and sweet potatoes are naturally low in lectins.
- Fruits: Most fruits are low in lectins.
- Whole grains: Options like rice and quinoa have lower lectin levels.
Can everyone eat lectins?
Some people may need to avoid lectins. Talk to your provider about your diet if you have:
- Existing gut issues: If you have irritable bowel syndrome, Crohn’s disease, leaky gut syndrome or chronic inflammation, your gut may be more sensitive to lectins. Eating high-lectin foods could make symptoms like bloating, gas, pain or fatigue worse.
- Autoimmune diseases: Foods high in lectin may cause flare-ups or inflammations if you have conditions like rheumatoid arthritis or lupus.
- Food allergies: Avoid eating any foods you’re allergic to, including those that contain lectins.
When should I get medical care?
See a health care provider if you often have nausea, vomiting, diarrhea, pain or bloating. It’s important to find out what’s causing your symptoms, whether it’s lectins or something else. Your provider may recommend tests or adjustments to your diet.
You should also talk to a provider if you’re considering making any major changes to your diet, whether that’s limiting lectins or another change. Your provider can talk to you about your needs and goals, provide gut health tips and recommend a plan that’s right for you.
The bottom line
Lectins are proteins found in some beans, grains and vegetables. If you don’t have any digestive issues, you can probably eat lectins safely and you don’t need to worry about following a low-lectin diet. Just remember to cook beans and grains thoroughly to avoid any issues.
If you have gut health problems or other concerns, you may want to talk to a health care provider to find out whether lectins might make your symptoms worse. You can reach out to Banner Health to find a dietitian or gastroenterologist who can help.
