“Don’t you lectin me” (Lectins danger)


Needing sustenance for an anti-GMO rally, the activist stops by Whole Foods and checks all the pedantic blocks: Organic, of course, but also nothing pasteurized or containing gluten, aspartame, sodium,  hormones, antibiotics, rBST, or MSG.

But our ever-vigilant shopper now has to take it one ostentatious step further. The latest food fear to exorcise, as of about 3 p.m. last Tuesday, are lectins. These are proteins that bind to carbohydrates and are found in many grains and beans, among other foods. When they are isolated, lectins can have both positive and negative impacts.  

In the same way that some people (let’s call them Dr. Oz and Food Babe) equate gluten as bad for everyone because it aggravates celiac symptoms, a few enterprising types are lumping all lectins in all their forms into one frightful category. This is as nonsensical as avoiding Jolly Green Giant sliced mushrooms because consuming their distant cousins that grow in the wild would cause hallucinations, sickness, and possibly death.

Such composition fallacies, in the form of assigning guilt to any product that has a seeming similarity to one that is harmful, is a staple of many self-styled heath gurus. But there’s more than one type of lectin, each has its own properties, and according to Washington Post reporter Cara Rosenbloom, “Scientists are still trying to map out all of the lectins and what they are capable of.” This unknown quantity give Oz, Babe, and their ilk another fear to prey upon.

Investigative reporter Georgi Markov was killed when a modified umbrella was used to inject a microscopic dose of ricin into his leg. Ricin is a lectin, so these can be dangerous and even deadly, but form and context are what matter. An assassin injecting concentrated ricin into a victim subcutaneously is much different than sitting down to a bowl of beans and rice.  

While there have been studies on lectins, these have been done on their isolated form, not on foods that contain them. Additionally, they have been performed in test tubes or on lab animals. Health implications, whether negative or positive, don’t always translate from rat to person, so we are unsure what health impacts might be attributable to lectins. The lack of clinical trials on the impact of lectin-containing foods on humans is not keeping alarmists from being, well, alarming. In The Plant Paradox, author Steven Gundry warns readers that to consume tomatoes is to “incite chemical warfare in our bodies.”

While some lectins become toxic at low doses, no one is eating those, especially in their isolated forms. Lectins in raw kidney beans could cause diarrhea and vomiting, so this is a sound reason to avoid consuming uncooked kidney beans. The taste and the way they grate on your throat would be two more. But this is no justification to avoid all beans no matter how prepared. There is no empirical evidence to suggest lectins in grocery store foods pose an inherent danger.

Boiling raw beans or grains make them fit for consumption. One minor concern, Rosenbloom writes, is that using slow cookers to prepare beans from scratch would not get them hot enough to zap any potentially harmful lectins. Other than that, engage in all the legume love you want.

Proponents of going lectin-free claim this dietary change could cure arthritis, multiple sclerosis, acne, irritable bowel syndrome, headaches, and cancer. Such broad, exaggerated pronouncements, backed by no studies, is a pseudoscience giveaway.

There’s also the issue of what going lectin-free would mean. There would be a substantial nutrition price to pay for cutting out grains, legumes, peas, lentils, nuts, seeds, oils, tomatoes, potatoes, peppers, dairy, and eggs. If I followed this, the only thing left in my cart would be Ho Hos.

3 thoughts on ““Don’t you lectin me” (Lectins danger)

  1. I was suspicious as soon as I started reading Grundy’s book, and he depicts all plants as being in a war with animals that want to eat them. In fact, many if not most plants benefit from animals (and humans) eating their fruits and seeds (or even require it), in order for their seeds to spread and germinate. That’s why many fruits are tasty, sweet and attractive colors. Moreover, many of Gundy’s claims are not backed up by scientific references, unlike authors like Joel Fuhrman of Eat to Live, who cite studies supporting virtually everything he says. Grundy admits in places that animals have developed a number of digestive and metabolic processes to minimize damage from lectins. He seems to downplay this, but it largely undermines the main thesis of his book. He cites many supposed patients who got “cured” on his diet, but such anecdotal evidence is subject to confirmation bias and many uncontrolled variables, which is why it’s considered weak and unreliable by most scientists. Finally, studies of long-lived people in “blue zones” and other demographic data suggest that for the most part eating beans, nuts, seeds, and tomatoes is quite healthy, and any negative effects are more than offset by their many benefits (vitamins, minerals, proteins, anti-oxidant properties, etc)–unless you have a specific food sensitivity to one or more of them.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s