Why Do People Think Lectins Are Toxic to Eat?

Are you one of those people that think lectins — proteins that are found in many fruits, vegetables, whole grains, nuts, beans, and legumes — are actually bad for you?

Sadly, there’s probably one reason you might believe this misinformation, a book titled, The Plant Paradox, by Dr. Steven R. Gundry MD.

In it, Gundry makes a wide variety of unsupported claims that many of the plants we consider to be healthy are actually bad for you.

In fact, Gundry goes as far as to claim, “I believe lectins are the #1 Biggest Danger in the American Diet.”

The #1 biggest danger is making a claim like that, especially when there is a significant lack of science to suggest anything so bold, and very little evidence to even be worried about lectins in the first place. 

Lectins, as they are consumed in a diet, just aren’t an issue. And, unless you’re eating raw kidney beans (why are you eating raw kidney beans!) the alleged poisonous nature just isn’t realistic. 

In other words: “Lectins are far more active in binding to our cells when they’re consumed in high concentrations and in isolation, as they are in experiments, than when they are consumed in food, as they generally are by actual humans,” notes Dr. David Katz, director of the Yale University Prevention Research Center at Griffin Hospital and founder of the True Health Initiative.

In this episode of That’s Healthy, Right?, we’ll look at the problem with taking anecdotal evidence as fact, how some of the healthiest populations in the world live off of lectin-heavy diets, and the only food you actually need to avoid eating (hint: you wouldn’t anyway).

Have a question you want to be considered for the show? To submit a question, email a voice recording that you can do here to info@bornfitness.com.

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Legume Lectins: Proteins with Diverse Applications — International Journal of Molecular Sciences

Lectins as bioactive plant proteins: a potential in cancer treatment — Critical Review of Food Science Nutrition 

Red kidney bean poisoning in the UK: an analysis of 50 suspected incidents between 1976 and 1989 — Epidemiology & Infection 

Effect of Some Processing Methods on Hemagglutinin Activity of Lectin Extracts from Selected Grains (Cereals and Legumes) — International Journal of Advanced Academic Research

Handbook of Foodborne Pathogenic Microorganisms and Natural Toxins — FDA

Reduction in antinutritional and toxic components in plant foods by fermentation — Food Research International 

Does Fruit Really Make You Fat? — That’s Healthy, Right? Podcast  

So Now Kale Is Bad for You? — Born Fitness


Adam Bornstein: 

I absolutely love reading health and fitness books. Probably not much of a surprise, but I love it. It is something that I’ve probably been doing for about 25 years.

And the majority of my books are just filled with little notes that I take in the columns and then transport those notes into documents because I believe that a lot of thoughts that are written in books can oftentimes provide additional clarity around a topic or even help foresee future trends in health and fitness.

So I was incredibly interested when one recent book by a doctor happened to claim that many of the popular plants, popular plants meaning plants that people consider healthy, are actually bad for you.

The book in context here is The Plant Paradox by Dr. Steven Gundry. And the premise is that lectins, which are really these compounds, they’re the proteins that are found in fruits and vegetables, whole grains, nuts, beans, and legumes, are actually toxic for you and that you need to avoid them because they will affect your longevity. They will lead to weight gain. They will cause gastrointestinal issues.

Ah, man, I had trouble recording this episode because I really hate sh*tting on people. I don’t mind giving a hard time for different theories that are not based on science, but I don’t like going at people.

But, I’m going to go at Dr. Gundry here because so many of the claims he makes are just patently false and not based on any real science. He claims that all this is based on his research. But if you look up Dr. Gundry, he hasn’t published anything since 2004, and none of it is about lectins.

This is all based on anecdotal discoveries that he has made in his clinics, which is fine, but you should say that. You should make that clear. And the whole book is really just anecdotal evidence.

So, just to recap, lectins — they’re found in about 30% of the foods that you eat — and really the only food that is dangerous would be found in raw kidney beans. I don’t know about you, but I’ve never eaten a raw kidney bean, nor do I plan on it. Nor do I think I could. It would destroy my teeth.

But this entire theory is based on a toxin, a chemical that is found in a food that no one actually eats, and if you cook kidney beans, it completely denatures the lectins, meaning that they become harmless. So yes, if you are eating raw kidney beans, not canned kidney beans, “raw kidney beans,” be afraid of those lectins.

Otherwise, every single claim in this book is just a hypothetical that has no basis whatsoever. There’s no danger to eating lectins. The Blue Zones, the areas, the regions in the world where people live the longest, live off of a lectin-heavy diet.

People have been eating these foods — things like chickpeas and lentils — for 8,000 plus years. People that have lower incidence of chronic disease also will eat lectin-heavy diets. And when you just look at everything, then there’s a whole section of this book that claims that fruit is more fattening.

You’ve got to be kidding me. Fruit is not more fattening — or fruit is not fattening period — than other foods. It’s not based on anything substantiated. I had to record this episode simply because so many people are now avoiding foods that are so healthy because of this fear, because of this scare tactic that lectins are toxic for you. And they’re just not. It’s just not.

If you want to remove those foods because you feel better, go for it. If you don’t like some of those foods, go for it.

But, if you are avoiding any type of lectin for any type of fear that it is toxic or that there is research that it is damaging to you, unless they’re raw kidney beans, all of the research says you are fine.