When it comes to nutrition, there’s always a new bad guy. First, we avoided fat. Then, carbs got the boot. It seems the more we dissect the foods we eat, the more likely we are to find something to worry about.
Take the gluten-free craze, for example: Life-changing for people with Celiac’s disease or gluten sensitivities—but pretty darn confusing for the rest of us. Ask two different experts about whether or not you should avoid gluten and you’ll get two different answers.
Adding to the confusion, lectins—a protein found in plants—are on the chopping block now, too.
You’ll find some type of lectin in all sorts of fruits, vegetables, whole grains, legumes, nuts, seeds, and dairy—with grains, legumes, and nightshade vegetables often at the center of the controversy. Cut out chick peas? Say it ain’t so!
First, a little background: Lectins are basically a defense mechanism, protecting plants from harmful pathogens—like fungi, insects, molds, and diseases—in their environment by binding to the cell membranes of certain sugar and carb molecules. Lectins also help seeds travel through animals’ (humans included) digestive systems unscathed, so they can make it back to the soil and grow.
Since we don’t digest lectins, they may cause GI issues like gas and bloating (you know what they say about beans, after all) and even trigger our immune system’s inflammatory response as they pass through our systems, according to Precision Nutrition. And since lectins bind to sugars and carbs, they can interfere with our absorption of vitamins and minerals.
While some experts suggest issues are more pronounced in people who already have compromised guts or immune systems, others go as far as to label lectins as straight-up toxic. According to the best-selling book, The Plant Paradox, one of the leading works on the anti-lectin train, lectins “incite a kind of chemical warfare in our bodies, causing inflammatory reactions that can lead to weight gain and serious health conditions.” The author, Steven Gundry, M.D., suggests lectins are implicated in everything from autoimmune diseases, cancer, heart disease, mental health issues, and dementia.
But don’t freak out just yet. Some lectins can be toxic (which is why we don’t eat castor beans, for example), but others can have powerful beneficial effects, such as modulating inflammation and grabbing onto harmful molecules associated with disease. (After all, oxygen is technically a toxin, but that doesn’t mean you should stop breathing!)
You don’t need to stop eating foods that are otherwise healthy just because they contain lectins, confirms David L. Katz, M.D., M.P.H., director of the Yale-Griffin Prevention Research Center. Most of the research on lectins out there is done on small animals or cell cultures, not humans, and while some do suggest the potential toxic effects of certain lectins, the results are very preliminary and don’t necessarily translate to humans, Katz says.
And even then, “the research suggests this tends to be the case only if lectin foods are consumed raw—and when’s the last time you ate a raw chickpea?” says Abbey Sharp, R.D. When you cook your food, lectins often bind to compounds in whatever you’re eating instead of molecules in your body, so cooked beans are completely safe and healthy.
It’s also possible that the culprit behind the stomach issues often associated with legumes is actually a type of carbs called ‘oligosaccharides,’ which humans also don’t digest well, Sharp adds.
Ultimately, most people have more to gain by eating lectin-containing foods than they have to lose. Research overwhelmingly supports that people who eat more fruits, vegetables, nuts, and whole grains have a lower risk of obesity and chronic disease, and one study published in the International Journal of Epidemiology estimates that up to 7.8 million deaths could have been prevented in 2013 if everyone ate 10-plus servings of fruits and vegetables a day. How? Higher consumption of these whole foods is associated with lower risks of heart disease, stroke, and cancer.
What’s more, eating just one serving of fiber– and protein-loaded beans, peas, chickpeas, or lentils a day can help keep your weight in check, according a review published in The American Journal of Clincal Nutrition.
The bottom line: There’s really no reason to lose sleep over lectins just yet. Until larger, human studies show that lectin-rich foods offer more risk than reward, eating a diverse diet loaded with whole plant foods—whether they contain lectins or not—should be your number-one nutritional priority. If you have any immune or gastrointestinal issues (like an autoimmune condition or Crohn’s disease), talk to a dietitian about trying an elimination diet to identify any food sensitivities that might be involved.