Are Lectins Safe to Eat?

More Americans than ever are suffering from chronic inflammation, obesity, and autoimmune disorders. While there is no singular cause for any one of these epidemics, some recent publications and media have made the argument that “you are what you eat.”

Specifically, what we are eating are called “lectins.” These proteins, which bind to carbohydrates in plants, are thought by some nutritionists and health experts to be the cause of what ails so many people in our country and around the world. Perhaps most notably, Dr. Steven Gundry, author of the controversial best-seller The Plant Paradox, makes the argument in his book that “healthy” foods are responsible for our “disease and weight gain.” 

Professionals are not in full agreement about whether lectins, these plant-based proteins, are really to blame for so many of our chronic conditions. Indeed, the Mayo Clinic states that “No scientific evidence exists to show that eliminating dietary lectins will cure any medical disorders or conditions.” However, given the rise of books and media by Gundry and similar peers, there is apparently a growing amount of circumstantial evidence suggesting that lectins may at least play a moderate role in the development of health problems for certain people. (Either that, or they play a major role in the development of yet another health fad.) 

In this article, we’ll take a broad look at lectins. We’ll learn which foods they reside in, what conditions they are thought to be linked to, and whether you need to make any immediate changes to your dietary lifestyle.

So, What Are Lectins?

According to the Harvard School of Public Health, lectins are “defined as proteins that bind to plants.” They’re found in all plants, but appear in higher concentrations in certain fruits, vegetables, and grains. Although lectins occur naturally in plants and work as a defense mechanism, the human digestive system can find them difficult to process. 

There have been some accounts of serious reactions to lectins; the Harvard article cites publicized stories concerning the link between the consumption of slightly raw kidney beans and phytohaemagglutinin, a lectin responsible for the excessive accumulation of red blood cells. 

For the most part, however, there isn’t too much evidence connecting lectins to chronic disease other than empirical data. Word-of-mouth stories form the basis for the anti-lectin argument, rather than peer-reviewed studies and consensus in the scientific community. 

What Foods Contain Lectins?

Although most plants contain at least some traces of lectins, certain foods have higher levels than others. These include legumes (beans, peanuts), tomatoes, wheat, and most fruits. From what the research shows, lectins do not offer any nutritional advantage to humans and serve primarily to protect plants from being damaged or eaten while they are still in the processes of growing and ripening. 

What Might Lectins Be Linked To?

There is some speculation that lectins may be responsible for certain chronic and autoimmune conditions, including diabetes and rheumatoid arthritis This is because lectins have the tendency to bind to cells in the human body for extended periods of time, and since they elicit an inflammatory response, over time their presence can cause issues with mineral absorption, nutrient processing, gut microbiota, and even insulin resistance. 

Then again, the most frequently cited studies asserting these claims were conducted between the years of 1994 and 2004. Almost twenty years after the fact, few if any equally conclusive results concerning linkages between lectins and illness have been reproduced in other studies. Nevertheless, these plant-based proteins continue to be a point of interest for researchers today, either for medical reasons, marketing potential, or some combination of both.


As more research is conducted, only time will tell if lectins should be further pursued. So don’t worry too much about cutting out specific foods from your diet. If you’re experiencing negative symptoms and believe it might be linked to your diet, work with a professional nutritionist to experiment with removing specific types of food, one at a time, rather than cutting out many of the fruits and vegetables that most every professional agrees is essential to a balanced and nutritious diet.

At the moment, the verdict is still out as to whether lectins are a plausible or a preposterous explanation for some of our most compelling conditions.

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