Lectins: Are These Food-Based Proteins Friend or Foe?

John Watson; Reviewed by Anya Romanowski, MS, RD


August 17, 2018

In This Article

Debunking the Lectin-Free Diet

Unlike other dietary interventions with hard-to-pin-down origins, the lectin-free diet craze can be sourced to one person: Steven Gundry, MD, a California-based cardiologist and heart surgeon who attributes going lectin-free to his own improved health. Gundry has outlined what he sees as the hazards of lectins in the 2017 book The Plant Paradox: The Hidden Dangers in "Healthy" Foods That Cause Disease and Weight Gain. It advances Gundry's thesis that the ingestion of lectins incites an inflammatory process that can cause weight gain and serious health conditions, such as autoimmune disease.

Gundry has been pilloried by some for his alarmist language comparing ingested lectins to initiating chemical warfare on your body and for extending his influence into the commercial realm, offering a nutraceutical product called Lectin Shield on his website at nearly $80 a bottle. But the book is nonetheless a best seller, and his narrative about lectins is trickling down through various media outlets and vocal proponents.

Critics argue that the trouble with this is that it doesn't seem to be backed up with any convincing clinical research, and doesn't even pass the test of basic logic. As many have pointed out, the global populations with the longest, healthiest lifespans avail themselves of diets rich in lectins, whereas the United States famously does not. They ask quite rightly, if lectins were truly the source of our dietary struggles, shouldn't we be in better shape from avoiding them in relatively higher proportions than other societies?

Again, it's important to remember that lectins are far from monolithic and vary in qualities from food to food, from the benign to the toxic.[9] Furthermore, and quite crucially, they are rendered safe for consumption upon cooking. So if you find yourself with a hankering to eat raw kidney beans, you will probably experience some gastric distress; however, if you instead place those same beans in a pot and let it simmer, the prevailing science shows you will be at no risk. That's because the toxic lectin content in raw red kidney beans drops by 99% after cooking them (from 20,000-70,000 to 200-400 hemagglutinating units).[3]

It is this disconnect between common sense and hype that has led high-profile publications, such as The Atlantic [1] and the Washington Post,[10] to label the lectin-free diet as "pseudoscience" and promoting "insidious misinformation."


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