Lectins in raw or undercooked kidney beans can cause symptoms that mimic food poisoning. But that doesn’t mean no one should eat any beans — it just means we can’t eat raw kidney beans. (iStock)

In the diet world, a new buzzword is emerging: lectins. Have you heard of lectins? Ten years ago, you probably hadn’t heard of gluten, either. Going “lectin-free” is primed to become the next big thing in dieting, but this diet seems more fad than fact.

Lectins are a type of protein found in many foods including grains and beans. As isolated compounds, they have been researched for many years and can have positive and negative health effects. While some lectins are highly toxic, others are benign.

The problem is that online health gurus are painting all lectins with the same brush, and playing up the negative effects without the evidence to back it up. Saying all lectins are poison is akin to saying that you shouldn’t eat button mushrooms because some foraged mushrooms are toxic. It makes no sense.

What the online rhetoric doesn’t mention is that North Americans actually don’t ingest a lot of lectins, so the problems they cite — linking lectins to obesity, irritable bowel syndrome and inflammation — may be way overblown. Before you fall for any pseudo-advice, here are the facts.

Lectins 101

There’s more than one type of lectin, and different ones can do different things. Scientists are still trying to map out all of the lectins and what they are capable of. And unlike handy lists of how much iron or vitamin C is found in certain foods, there aren’t easy-to-access lists of the amount of lectins in food, and what each one does.

Without getting too technical, lectins help cells stick together. Research shows that lectins may have some benefits — they are antimicrobial, help the immune system and have anti-cancer potential. But the same stickiness also makes them act as “anti-nutrients,” which hinder the body’s absorption of certain vitamins. High intake of lectins may damage the lining of the intestine, which lets proteins cross into the bloodstream undigested. This could cause an allergic reaction or increase risk of developing autoimmune diseases.

It’s critical to note that the majority of lectin studies have been done with isolated lectins, not actual foods, and have been conducted in test tubes or in animals, not in people. So how can these online health gurus conclusively link lectin-containing foods to certain health issues when clinical trials in humans have not even been conducted yet?

Many rely on what we know for sure: Some lectins are toxic. But no one eats those ! For example, lectins in raw or undercooked kidney beans can cause symptoms that mimic food poisoning, such as vomiting and diarrhea. But that doesn’t mean no one should eat any beans— it just means we can’t eat raw kidney beans.

Cook your beans

Have you ever crunched into a raw kidney bean? I didn’t think so. Hard as rocks, all beans and lentils would be inedible in their raw form. Boiling beans for 30 minutes eradicates most, if not all, of the lectins. Note that soaking beans overnight does not remove enough lectin, and don’t rely on slow cookers when cooking beans from scratch — the machine doesn’t get hot enough to destroy lectins. Prepared properly, beans have low lectin levels and are safe to eat.

Grains can also be boiled to reduce lectin content. Think about quinoa, rice and barley — boiled first, then eaten, right? Fermenting and sprouting foods can also help reduce lectin content. Friendly bacteria in the fermentation process digests the anti-nutrients, and can reduce lectins by up to 95 percent.

It’s a fad

Articles that promote the lectin-free diet cite it as a miraculous cure-all for arthritis, multiple sclerosis and even cancer. That’s the first sign it’s a fad — overblown promises of astonishing health benefits before any clinical proof exists.

The next sign of a fad is a long list of foods to eliminate. What’s not allowed on the lectin-free diet? Whole grains, beans, peas, lentils, nuts, seeds, tomatoes, potatoes, peppers, dairy, eggs and fruit — they’re all out. That’s pretty much my entire grocery list. Obviously this diet is not sustainable, and it unnecessarily cuts out a wide range of nutritious ingredients.

It’s also a likely fad when everyone — regardless of age, health status or medical needs — is advised to follow the same diet. How can one diet work for everyone? Finally, it’s a fad when scare tactics persuade you to spend money on supplements. Of course, anti-lectin advocates sell expensive pills (just $79.95 a month) that claim to neutralize or reduce the negative effect of lectins.

If you have digestive issues and are particularity sensitive to beans or grains, avoid them. But please, don’t suddenly eliminate all lectin-containing foods from your diet because an online article told you that they are bad for you. The amount of lectins found in the normal food supply is too low to be a real health concern.

Registered dietitian Cara Rosenbloom is president of Words to Eat By, a nutrition communications company specializing in writing, nutrition education and recipe development. She is the co-author of “Nourish: Whole Food Recipes Featuring Seeds, Nuts and Beans.”