The Truth About Antinutrients: Myths, Facts, and What You Need to Know

Ever heard that spinach, beans, or nuts might harm your health because of ‘antinutrients’?

It’s a buzzword that’s been making the rounds, leaving many people wondering if these healthy foods are secretly bad for them.

The term antinutrient can sound intimidating, but don’t worry, there’s no need to panic. These naturally occurring compounds have gotten a bad rap lately, thanks to social media and wellness influencers. But the truth? It’s far less scary than it seems.

While antinutrients do play a role in how your body absorbs certain nutrients, they’re not the health destroyers some claim them to be. In fact, they’re just a small piece of the bigger nutrition picture.

From your morning cup of coffee to the nutrient-packed avocado, many plant-based foods contain anti-nutrients.

In this article, we’ll break down what antinutrients really are, where they’re found, and how they affect your health.

Spoiler alert: they’re not the villains they’re made out to be! Plus, I’ll share simple, practical tips to help you enjoy these foods confidently. Let’s dive in.

What Are Antinutrients?

So, what exactly are antinutrients, besides a word that might sound a little scary?

Technically, an antinutrient is a compound in food that can reduce your body’s absorption of certain nutrients. At first glance, that might make you think, “Should I avoid these altogether?”

While the definition sounds concerning, the reality is more nuanced.

Antinutrients are naturally found in many plant-based foods and even have important roles, like protecting plants as they grow. And when it comes to nutrition, nothing is ever as simple as “good” or “bad.”

You might be surprised to learn that foods like almonds, oats, soybeans, and asparagus—some of the healthiest options around—contain anti-nutrients.

What are the different types of anti-nutrients?

There are many types of antinutrients, some more common in our diets than others. You’ve probably seen a few of them called out on social media, in fad diets, or even in pseudoscientific claims.

So, what are the different types of antinutrients, and where are they?

• Lectins – Found in legumes, cereal grains, nuts, seeds, fruits, and vegetables, lectins are probably the most well-known and frequently misunderstood antinutrient. (Yes, they’re in a lot of nutritious foods!)
• Oxalates – Commonly found in greens like spinach, nuts, legumes, cereal grains, sweet potatoes, and regular potatoes, oxalates are another hot topic in antinutrient discussions.
• Phytates – Present in legumes, cereal grains, nuts, and seeds, phytates are often linked to concerns about mineral absorption.
• Goitrogens/Glucosinolates – These are found in cruciferous vegetables like cabbage, broccoli, kale, and some greens, as well as in millets and cassava.
• Phytoestrogen – Found in soy and flaxseeds, phytoestrogens are often a focus of hormone-related health debates.
• Tannins – Present in tea, cocoa, coffee, berries, stone fruits, nuts, beans, and whole grains, tannins are another misunderstood compound.

These compounds are naturally found in many healthy, plant-based foods, which are packed with nutrients your body needs.

Should we really be concerned about anti-nutrients?

Not at all! While the term “antinutrient” might sound concerning, these compounds aren’t as scary as they’re sometimes made out to be.

In fact, many of them come with surprising health benefits that you won’t hear about in alarmist social media posts.

In the next section, we’ll take a closer look at each type of antinutrient, addressing common claims, the actual research behind those claims, and the potential benefits these compounds bring to the table.

By the end, you’ll see why there’s no need to avoid these nutritious foods!

Lectins

Lectins are storage proteins found in plants, protecting plant cells from microbial invaders like bacteria, viruses, and fungi. But they are also found in nearly all life forms—including animals, fungi, and even algae—produce lectins.

If you wanted to eat a truly lectin-free diet, well… you’d have to stop eating altogether.

If you remember nothing else, remember this: Lectins are proteins, which means they’re completely destroyed when cooked or canned. So unless you’re snacking on raw beans (please don’t), you’re in the clear.

And speaking of beans, they’re the biggest source of lectins in our diet—so go ahead and enjoy that chili or hummus!

The Problem with Dr. Gundry:

Steven Gundry, MD, a cardiothoracic surgeon turned diet alarmist, has stirred up most of the fear around lectins. In his book, he claims that vegetables are to blame for America’s health woes—a bold and baffling claim that conveniently ignores basic nutrition science.

Instead, we’ll briefly mention how little nutrition education physicians receive.

In his book, Gundry promotes a lectin-free diet that’s both restrictive and nutritionally inadequate, then profits by selling the supplements you’d need to compensate for the diet’s deficiencies.

This approach checks all the nutrition red-flag boxes: elitism, fatphobia, fearmongering, and a sales pitch. It’s hard not to draw comparisons to other dubious health “experts” (cough, Dr. Oz, cough).

Now that that’s off my chest, we’ll move on to the claims.

Claim #1: Lectins bind with minerals, reducing their absorption in our intestinal tract.

This is technically true. However, foods containing lectins are often rich in the very minerals they supposedly “bind,” making the risk of deficiencies negligible at best. Furthermore, cooking inactivates 94–100% of lectins.

In other words, while this hypothesis is interesting for a lab experiment, it has virtually no impact on real life.

Claim #2: Lectins cause leaky gut

Let’s start with this: “leaky gut” is not a recognized medical term. Intestinal permeability can change for various reasons, but one of the most common is not eating enough fiber—the kind of fiber found in foods containing antinutrients like lectins.

This claim comes from findings that active lectin binds to cells lining the intestinal tract. But again, little, if any, active lectins are left in food after the cooking process, so this problem is moot.

Claim #3: Lectins cause inflammation.

This claim builds on the false assumption that lectins cause “leaky gut.” If claim #2 were true, this would make sense—but it’s not, so here we are.

The gut indeed plays a huge role in immune function, and an unhealthy gut can contribute to inflammation throughout the body. But since there’s no evidence that lectins harm the gut, this claim doesn’t hold up.

This is actually well-documented. (Also here, and here. There’s more, but you get the picture.)

I spent days scouring the internet for anything that could substantiate these claims. Even using an incognito browser and intentionally trying to get Google to support this, I could not find any evidence that lectin-containing foods are harmful.

Claim #4: Lectins are toxic.

Ricin, a well-known poison, is technically a lectin—but before you worry, know this: ricin comes from castor bean “mash” and is not present in any food you’d typically eat. Most cases of ricin ingestion are due to intentional poisoning.

Just because ricin is toxic doesn’t mean all lectins are dangerous. It’s like saying all mushrooms are deadly because one species is poisonous—completely unfair and inaccurate.

Claim #5 billion: just kidding

By this point, you’ve probably noticed a pattern. I’ve spent hours (okay, days) researching lectin claims, from human studies to animal models to the ever-dramatic in vitro experiments (cells in a petri dish). Nothing supports the idea that lectin-containing foods are harmful.

If you’re curious to read about this more, Wikipedia has a pretty good overview to get you started.

Even in animal studies, researchers used pure, active lectins injected directly into the gut—something that has zero relevance to your actual diet. So unless you’re planning to inject raw lectins into your stomach (please don’t), there’s no real-world risk.

So lectin isn’t bad for you, but are there benefits?

Benefits of Lectins and Lectin-Containing Foods

First, let’s address the obvious: lectins are everywhere. They’re in legumes (beans, chickpeas, soy, peanuts), nightshades (like tomatoes, potatoes, and eggplant), nuts, seeds, and grains (such as wheat, quinoa, and oats).

Heck, even meat contains lectins—so don’t come at me, Carnivore Bros.

Just look at that list. These foods are packed with fiber, vitamins, minerals, and polyphenols that have proven health benefits. The idea of a lectin-free diet starts to sound, well, pretty absurd, doesn’t it?

The Benefits of Lectin-Containing Foods:

• Chronic Disease Prevention: Foods high in lectins are linked to a lower risk of diabetes and colon cancer. They’re also associated with better glucose management for people with diabetes.
• Gut Health: Their variety of fibers supports a diverse gut microbiome. Why does that matter? A healthy microbiome influences everything from immunity to mental health.

But What About Lectins Themselves?

The research on lectins specifically is less robust than the evidence for the foods they’re in. That said, some studies suggest lectins might:

• Help reduce the risk or growth of certain tumors.
• Improve blood sugar levels in individuals with diabetes.
• Play a role in supporting the immune system.

However, it’s worth noting that this research has its limitations. Much of it relies on in vitro or animal studies, which don’t necessarily translate to real-life human benefits.

What to Take Away:
Let’s call lectins neutral and the foods they’re in healthful. Instead of worrying about lectins, focus on eating a wide variety of nutrient-rich, minimally processed, and affordable plant-based foods—your body (and gut) will thank you.

Oxalates

Oxalates and oxalic acid are compounds found in plants. They play essential roles in plant growth and development, helping them respond to environmental stress and ward off herbivores.

Interestingly, humans also produce oxalates as a byproduct of vitamin C metabolism and certain amino acids.

How Do Oxalates Affect Humans?

When consumed, oxalates bind with calcium in the body. This can reduce calcium absorption and, for some individuals, contribute to the formation of kidney stones.

However, it’s important to remember that not everyone is susceptible to this, and oxalates are just one of many factors influencing kidney stone risk.

Other Potential Concerns of Oxalates

While oxalates can pose risks under specific circumstances, most concerns about their toxicity are overstated. Let’s break it down:

Toxicity Risks
Oxalates can become toxic, but only at extremely high doses. Many reports of oxalate-related toxicity often involve individuals consuming other toxins, such as the theobromine in chocolate, which reaches harmful levels well before oxalates do.

Irritation from Sharp Crystals
Some foods, like kiwi, contain sharp oxalate crystals that can cause irritation in the mouth or throat. However, this irritation is temporary, and no long-term adverse effects have been documented.

Diet and Calcium

The real health risk arises when someone consistently eats a low-calcium, high-oxalate diet, which increases the chance of calcium-oxalate kidney stone formation.

However, this is primarily a concern for those predisposed to kidney stones, not the general population.

Cooking and Oxalates

Oxalates are poorly absorbed during digestion, and cooking can further reduce their levels.

Cooking with water, such as boiling or steaming, helps leach oxalates out of foods. Additionally, germinating grains and seeds can significantly lower oxalate content, making them even safer to enjoy.

High Oxalate foods and their Health Benefits

Many nutrient-dense foods are naturally high in oxalates, offering significant health benefits despite their oxalate content. Here’s a closer look:

Notice that many of these foods are not only rich in vitamins, minerals, and phytochemicals but also serve as important vegetarian protein sources. Their benefits far outweigh any concerns about oxalates for most people.

How to reduce the effects of oxalate

For most people, oxalates in food aren’t a concern. However, if you’re prone to calcium oxalate kidney stones, here are some practical steps to reduce their impact:

Pair Oxalates with Calcium

When consumed together, calcium and oxalates bind in the gut, reducing absorption and lowering the risk of kidney stones. However, this also means you’ll need to ensure you’re getting calcium from other parts of your diet to meet your needs.

Stay Hydrated

Drinking plenty of water helps dilute oxalates in your urine, minimizing the chance of stone formation.

Cook Oxalate-Rich Foods

Steaming or boiling oxalate-rich foods can reduce their oxalate content by leeching it into the cooking water. This simple step can make a difference without requiring major dietary changes.

Verdict: For individuals prone to kidney stones, moderation—not elimination—of high-oxalate foods is key. For everyone else, these foods are safe and provide significant health benefits.

Phytates

This class of antinutrients don’t get as much attention by the pseudo-science crowd, luckily.

Phytates, sometimes referred to as phytic acid, are naturally occurring molecules found in plant seeds like nuts, seeds, grains, and beans. They serve as storage for phosphorus and other minerals, helping plants grow.

Phytates can bind to minerals such as iron, calcium, manganese, and zinc, potentially reducing their absorption in the gut. This has led to concerns about whether phytates could contribute to nutrient deficiencies.

But the effect of phytates as an antinutrient is only significant when:

1. They’re consumed in extremely large quantities.
2. The individual is already malnourished or has very low mineral stores.

For most people, phytates in a balanced diet are not an issue.

How to Reduce Phytates

Traditional preparation methods such as soaking, sprouting, and fermenting significantly reduce the phytate content of foods. Many cultures naturally incorporate these techniques, making the potential risk of mineral deficiencies even smaller.

Health Benefits of Phytates

Phytates bring a surprising number of health benefits to the table:

• Antioxidant Properties: Phytates help combat oxidative stress, which can protect cells from damage and reduce the risk of chronic diseases.
• Protection Against Insulin Resistance: They may play a role in improving insulin sensitivity, supporting better blood sugar regulation.
• Heart Health: Phytates are linked to reducing calcified plaque buildup in arteries, potentially lowering the risk of heart disease.
• Cancer Prevention: Some studies suggest that phytic acid contributes significantly to the protective effects of whole grains against colon cancer.

I talk sometimes about the synergy of food, and this is the exact reason why.

Phytates are a great example of how the whole is often greater than the sum of its parts when it comes to nutrition.

Sure, you could take supplements to meet your fiber, vitamin, and mineral needs. But you’ll miss out on the synergistic effects of whole foods—how the various components in food interact to boost health in ways that isolated nutrients can’t replicate.

Verdict: no risk

While phytates can impair mineral absorption under certain conditions, this typically only occurs with extremely high intake or in cases of malnutrition.

For the vast majority of people, the health benefits of phytate-containing foods—like whole grains, beans, nuts, and seeds—far outweigh any potential drawbacks.

With simple preparation methods like soaking, sprouting, and fermenting, you can reduce phytate levels if needed, but most people can enjoy these nutrient-packed foods as they are without concern.

Goitrogens

Goitrogens are compounds that can interfere with thyroid function by limiting the thyroid’s ability to use iodine. Examples include goitrogens include goitrins, thiocyanates, and flavonoids

They are naturally occurring compounds that help repair damage and defend against stress.

Sources of Goitrogens:

• Non-dietary sources: Certain medications (e.g., phenobarbital, rifampin, lithium), smoking, and environmental pollutants like nitrates and PCB/PBB.
• Dietary sources: Found in cruciferous vegetables (broccoli, kale, cabbage, cauliflower), cassava, peaches, Lima beans, corn, sweet potatoes, and soy products (tofu, tempeh).

These usually only cause a problem in individuals with low iodine intake. Paradoxically, excessive iodine intake can act as a goitrogen, though this is highly unlikely.

There are a few things you can do to reduce your risk of problems with goitrogens.

• Cook your veggies: Cooking significantly reduces goitrogen levels. Any form of heat works—boiling, steaming, roasting, or sautéing.
• Vary your vegetable choices: Eating a wide variety of vegetables reduces the chance of consuming high amounts of goitrogens and improves gut health.
• Quit smoking: Smoking introduces goitrogens into your system while harming your overall health.
• Eat enough iodine: Reliable sources include iodized salt and sea vegetables. Most people can meet their needs by choosing iodized salt at the grocery store. There’s really no health benefit to those “fancier” salts anyway.
• Eat more selenium. Selenium protects the thyroid and supports overall health. Vegetarian sources include Brazil nuts, sunflower seeds, tofu, beans, whole grains, and cheese.

Health benefits of Goitrogens and Goitrogen-Containing foods

For most people, the benefits of eating goitrogen-containing foods far outweigh any risks of thyroid disease.

Cruciferous vegetables, soy, and other sources are rich in fiber, vitamins, antioxidants, and anti-inflammatory compounds that lower the risk of heart disease and cancer.

Flavonoids, for example, are powerful antioxidants that reduce chronic inflammation and support overall health. These compounds make these foods nutritional powerhouses, especially as part of a balanced diet.

Verdict: Goitrogens are not a concern unless you have a thyroid condition or an iodine deficiency.

And if you do, simple steps like cooking your veggies and eating a variety of foods make it easy to enjoy their health benefits safely.

Phytoestrogen

Phytoestrogens are plant-based compounds that mimic the structure and function of estrogen in the body. While soy is the most well-known source, phytoestrogens are also found in a variety of other foods.

There are four main groups of phytoestrogens:

• Isoflavones – soy, flaxseed, nuts
  • These phytoestrogens help mimic estrogen in the body and are particularly effective in reducing symptoms of menopause, such as hot flashes.
• Lignans – many fruits, vegetables, nuts, seeds (particularly flaxseeds), and grains
  • Lignans support estrogen balance and promote heart health.
• Coumestans – red clover, bean sprouts, sunflower seeds
  • These compounds are linked to improved bone health and may help reduce osteoporosis risk.
• Stilbene – grapes, berries, peanuts
  • Stilbenes are powerful antioxidants that may protect against cognitive decline and support brain health.

There is a lot of misinformation out there about phytoestrogens, with claims that they interfere with estrogen production or “feminize” men.

However, there is no evidence to support these fears.

In fact, research has shown that phytoestrogens can have numerous health benefits, such as reducing menopause symptoms, decreasing the risk of heart disease, improving bone density, and supporting cognitive function.

I talk about this a lot in my article, “The Health Effects of Soy,” so I’ll avoid going into more detail here.

Verdict: Incorporating phytoestrogen-rich foods like soy, flaxseeds, and fruits into a balanced diet is not only safe but beneficial.

Tannins

Tannins are bitter compounds found in foods like tea, coffee, chocolate, wine, and some legumes and grains.

Tannins bind with iron, reducing its absorption. This is why, in my previous discussion of iron, I suggested not having tea with your meals if you have problems with iron deficiency.

Tannins have shown promise as anti-microbial agents, with the ability to fight off harmful bacteria, and may even help with blood pressure, cholesterol levels, and immune system modulation.

Their anti-cancer properties are still being explored, but early research looks promising.

For those concerned about iron absorption, simply spacing out tannin-rich foods from iron-rich meals is a practical solution.

Research on tannins is a bit mixed, but currently, the negative effects seem to mostly be attributed to other compounds found in the food.

While that seems to clear tannins themselves, those compounds are still in the foods we eat that have them.

Nutrition research can be hard, guys…

Verdict: Overall, tannins can be enjoyed as part of a healthy, balanced diet without significant concern for most people.

Great News for Vegetarians

Some studies suggest that vegetarians actually adapt to their diet by increasing the absorption of nutrients from their food, even though they tend to consume more anti-nutrients than their omnivorous counterparts.

This means that your body becomes more efficient at absorbing essential vitamins and minerals, like iron and zinc, over time—helping to counteract some of the effects of anti-nutrients like phytates and tannins.

So, if you’re a vegetarian, there’s little need to worry too much about the anti-nutrient talk—your body’s got your back, making the most out of what you eat!

What can we do about the anti-nutrients in our food?

If I haven’t convinced you not to stress over anti-nutrients, don’t worry—there are definitely ways to reduce the anti-nutrients in your food. 

For example, soaking almonds and oats before consuming them can help reduce anti-nutrient levels. Similarly, fermenting soybeans into tempeh or tofu can make them even more digestible while maintaining all their nutritional benefits

Here’s what you can do:

• Switch to Sprouted Grains: Sprouting grains can significantly reduce their anti-nutrient content, making them easier to digest and increasing nutrient absorption.
• Use Cooking Methods Like Boiling: While boiling might not be the most exciting cooking method, it’s effective at reducing certain anti-nutrients. If you can handle it, it can be a helpful step.
• Soak Beans and Nuts: Soaking beans, nuts, and seeds and discarding the water can reduce anti-nutrient levels, making them a better choice for your diet.

Ultimately, the best thing you can do is vary your diet.

We’ve discussed many of these anti-nutrients before, by another name: phytochemicals. If you don’t remember that discussion, the conclusion was to always strive for variety in your diet to ensure you get as many phytochemicals as possible.

Here, we can look at it from another angle but arrive at the same conclusion: By incorporating a wide range of plant-based foods, you ensure a good balance of nutrients and minimize the risks of consuming too much of any one antinutrient.

So, mix it up, keep it colorful, and enjoy a diverse, nutrient-packed diet!

Myth-Busting

How do these “problems” become so blown up?!?

Let’s be honest, it’s pretty simple—fear sells

It’s much easier to get you to click when they scare you and then imply they are the only ones who can fix you!

Anti-nutrients become a hot topic because it’s an easy way to scare people into clicking on articles, buying fad diet books, or signing up for YouTube channels and social media accounts that promise to “fix” the issue. When people are worried, they’re more likely to believe someone has the answer.

Many of these exaggerated claims stem from diet trends that promote eliminating so-called “harmful” anti-nutrients, like Paleo, Whole30, and the Bulletproof Diet.

Keto is also low in anti-nutrients, but that’s more because it eliminates most carbohydrate sources rather than specifically targeting anti-nutrients.

There’s a reason that U.S. News and World Report consistently ranks plant-packed diets like the Mediterranean, DASH, and Flexitarian consistently rank as some of the healthiest.

These diets are high in vegetables, fruits, and whole grains, and they support long-term health and wellness.

So, here’s the bottom line: Anti-nutrients, when consumed in normal amounts, won’t hurt anyone. In fact, plant foods are full of beneficial nutrients that our bodies thrive on, and it’s important to eat a variety of them to get the full spectrum of health benefits.

On the flip side, diets that restrict plant foods—like Keto or the Carnivore Diet—are consistently ranked poorly for health. In fact, the carnivore diet wasn’t even considered for evaluation.

An anti-nutrient never hurt anyone, when consumed in normal amounts.

Final Thoughts

Antinutrients may sound a bit intimidating, but they’re really just a small part of the bigger nutrition picture. While they can have a minor effect on nutrient absorption, they’re hardly harmful when you’re eating a balanced diet.

In fact, the foods that contain antinutrients—like whole grains, nuts, beans, and vegetables—are some of the healthiest options you can choose.

With simple strategies like soaking, cooking, or combining foods thoughtfully, you can easily minimize any potential downsides while still enjoying all the health benefits. So, don’t worry about that hearty bean stew or leafy green salad—you’re doing your body a huge favor!

Have questions or concerns about antinutrients? Drop a comment or reach out—I’d love to hear your thoughts.

Would you like to take this information on the go? Download my free PDF guide on antinutrients all in 1 simple page!

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About the Author

Jennifer Hanes MS, RDN, LD

Jennifer Hanes MS, RDN, LD is a registered dietitian, mom, wife, and vegetarian in North Texas. She has dedicated Dietitian Jenn to be a source of information, ideas, and inspiration for people like her, vegetarians that live with people with different dietary beliefs and/or needs in a multivore household.

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