According to Steven Gundry, MD, a heart surgeon based in California who is credited with the development of the lectin-free diet, lectins disrupt cell communication and increase inflammation, causing poor gut health that leads to a host of ills, including digestive problems (bloating, gas, diarrhea), and weight gain, per Dr. Gundry’s website. (1) Yet many nutrition experts do not agree that you should actively avoid foods that contain lectins. Gundry has written several books on the lectin-free approach, and The Plant Paradox, published in 2017, was a New York Times bestseller. In the book, he reveals what he believes is responsible for health problems and obesity: lectins found in plants. Because of the book’s success, he went on to produce iterations, including The Plant Paradox Cookbook, The Plant Paradox Family Cookbook, and The Plant Paradox Quick and Easy. He also has a podcast called The Dr. Gundry Podcast. There’s no proof of these claims, though. Specifically, Derocha says there’s no evidence that eliminating a certain food can “clean” your gut, though avoiding lectins has the potential to benefit certain groups. “Lectins are proteins that can stick to cell membranes of the digestive tract, so people with GI issues or chronic conditions like colitis or Crohn’s disease may benefit from avoiding them,” says Derocha. “When eaten in large quantities, lectins can also disrupt the digestive process, due to the sticky nature of the proteins and their impact.” Remember though, there are many caveats. First, it’s unclear what dose of lectins could potentially be harmful. Not to mention, many of the foods potent in lectins (think: beans, lentils) are rarely eaten raw, when lectin levels are highest. (4) Also realize that many foods that contain lectins are packed with prebiotics — a type of fiber that can feed healthy gut flora. (5) Therefore, avoiding these can lead to constipation and poor gut health, says Derocha. In reality, there are many unknowns about lectins, and it’s not the open-and-shut case that’s presented in Gundry’s book. “While there is not enough research to fully show the pros or cons of a lectin-free diet or the amount of lectin that could make a difference, there is some concern about lectins due to the potential impact of how it affects absorption of some nutrients,” says Derocha. “[High levels of] lectins are known to cluster red blood cells, which carry oxygen throughout the body. If red blood cells cluster due to excess lectin — again, the amount of lectin that’s considered harmful is unknown — we may be at risk of organs and muscles not getting enough oxygen to work as efficiently as they could,” she says. The authors of a 2019 medical journal article raise these same concerns, but they note that more studies are needed. (6) Lectins may specifically affect how your body absorbs minerals like calcium, iron, phosphorous, and zinc, Derocha says. This means that lectins are considered “anti-nutrients,” though it’s noted that this may be more of a concern in developing countries where people are at risk for malnutrition or have limited food available to them. (4) “Carbohydrates are essential for the body to function — they are good for us. It’s the amount and type that’s typically the problem,” says Julie Lanford, RD, MPH, the creator of CancerDietitian.com. “I don’t think most people eat enough beans. Cutting out refined carbohydrates and eating more beans would be a good switch,” she says. Consider what you’re missing out on if you forgo foods like whole grains, beans, and certain vegetables entirely, that are supported by research for their disease-preventing properties. “We know people need to eat a lot of plant foods for their best health, and that includes beans and whole grains,” says Lanford. For instance, beans have both soluble and insoluble fiber, a combination that promotes gastrointestinal health and cholesterol management, she says. Take the case for whole grains. A report from 2015 found that a higher consumption of whole grains was associated with a lower risk of total mortality and death from cardiovascular disease. (7) Overall, omitting foods with lectins can make it more difficult to get the nutrients your body needs to thrive. Foods with lectins provide protein, fiber, healthy fats, minerals, and B vitamins. (4) What’s more, there are inherent risks to following a diet that restricts many foods — and labels them as downright harmful or toxic. “If you’re constantly anxious about your food choices and how they will affect your body or operate under a lot of food rules, it can weigh on your mental health,” says Lanford. This can trigger disordered eating habits or a full-blown eating disorder. “Having a good relationship with food is important for your health,” she says.
Foods You Can’t Eat
Lectins are found in these foods, according to Gundry: (1,2)
WheatQuinoaWheat germBrown riceOatsBarleyPastaBreadFlourCrackersCookiesCerealArtificial sweetenersDiet drinksTomatoesWhite potatoesEggplantBell peppersHot peppers*SquashCucumbersBeansPeanutsSoyLentilsSplit peasSeedsMilkNon-pasture-raised meats
*These are nightshades, and are allowed if you peel the skin and remove the seeds. In general, peeling vegetables and removing seeds is recommended on a lectin-free diet.
Foods You Can Eat
These are a sampling of foods that are allowed on the lectin-free diet: (1,2)
Pasture-raised meatsPasture-raised eggsKimchiSauerkrautItalian or French cheeseItalian or French butterIn-season fruits (berries, cherries, apples, nectarines, peaches, and others)Green bananasSweet potatoesMilletWhite riceJicamaSorghumVegetables (leafy greens, broccoli, celery, onions)Pressure-cooked beans and legumesOlive oilAvocadosAlmond milk (unsweetened, organic)
Most likely, the focus on lectins is misplaced. “Most people who like to think that there’s one thing that’s causing their problem(s) don’t realize that when you cut out that one thing, it forces you to cut out a variety of eating behaviors,” says Lanford. For instance, you may now not be eating processed carbohydrates, and are replacing foods like cookies and crackers with alternatives like fruits or veggies. Certainly, that’s a good change, but you didn’t need to avoid lectins to get there. Ultimately though, it’s an unnecessary stress and complication to make the effort to cut those foods out of your diet.
