What Are Anti-Nutrients?

There are many uncertainties in the world, but one thing we thought we’d never have to question is whether or not vegetables might be bad for you. Nevertheless, some content creators have raised concerns online about the presence of “anti-nutrients” in plant-based foods such as leafy greens, seeds, grains, and legumes.

Those promoting fear of anti-nutrients (or “antinutrients”) are often adherents of the carnivore diet or something similar—a dietary approach that emphasizes mainly animal products like meat, dairy, and eggs. Medical professionals consistently state that the carnivore diet is unhealthy, which should be your first indication that these influencers aren’t reliable sources.

Anti-nutrients exist, but despite their somewhat ominous name, they don’t pose any significant threat to your health. Here’s what they are, whether you should be concerned about them, and how to reduce their impact in your diet if you are worried.

What are anti-nutrients?

Anti-nutrients are plant compounds that hinder your body’s ability to absorb certain nutrients. (You’ll often hear the term “bioavailability” in relation to anti-nutrients, referring to the amount of a nutrient your body can absorb.) Just as nutrients are naturally found in so many of the plant-based foods we consume, so too are anti-nutrients — they exist as part of a plant’s defense system against threats like insects and diseases.

Different plants contain various anti-nutrients, and they do not all impact nutrient absorption in the same manner. For instance, phytates, which are anti-nutrients present in cereals, pulses, nuts, and seeds, can diminish the body’s ability to absorb minerals such as zinc, iron, magnesium, and calcium. Lectins found in cereals and legumes may reduce the bioavailability of calcium, zinc, phosphorus, or iron. Additionally, oxalates present in spinach, chard, beets, and rhubarb can bind with calcium and hinder its absorption. As these examples illustrate, minerals are particularly affected by anti-nutrients.

Are anti-nutrients bad for you?

Dr. Haleem Mohammed MD MBA and the Medical Director at Gameday Men’s Health explains to Food & Wine that “No, in most cases, avoiding anti-nutrients is unnecessary. Many foods rich in anti-nutrients — like cruciferous vegetables, whole grains, and legumes — are also packed with fiber, vitamins, and phytonutrients that support heart health, metabolic function, and overall longevity.

“Unless a patient has specific concerns, such as a history of kidney stones (where oxalate intake might need monitoring) or iron deficiency anemia, there is no need to eliminate these foods.”

As Mohammed notes, certain anti-nutrients may require monitoring if you have a particular health condition. For instance, tannins are a common type of anti-nutrient that can decrease the bioavailability of iron.

The key word here is decrease—tannins will not completely inhibit your absorption of iron, nor will they permanently prevent you from acquiring iron in future meals. More importantly, tannins possess antioxidant properties that benefit your cardiovascular system and can help fight against cancer.

If you’re someone with iron-deficiency anemia, tannins may be something you need to consider when planning your meals, but for those without iron deficiencies, they aren’t an anti-nutrient you need to eliminate from your diet. As is always the case when making decisions for your health, if you have any specific concerns about how anti-nutrients may interact with your body, it’s best to consult a medical professional.

Can anti-nutrients be good for you?

Here’s the good news: yes! While anti-nutrients may change the bioavailability of some nutrients, they can also provide significant benefits, which is why you don’t want to eliminate them from your diet.

Mohammed provides several examples of which anti-nutrients may benefit you, saying “Phytates (found in whole grains and legumes) have been shown to have antioxidant properties and may help reduce the risk of colon cancer. Glucosinolates (found in cruciferous vegetables like broccoli and kale) support liver detoxification and have been linked to lower cancer risk. 

“Tannins (found in tea, coffee, and some fruits) have anti-inflammatory and antimicrobial properties. Instead of being purely harmful, anti-nutrients often contribute to long-term disease prevention and overall well-being.” 

How can you reduce the anti-nutrients you’re eating?

There are several strategies you can employ to reduce the anti-nutrients in your nutrient-rich foods without having to cut ingredients out of your diet entirely. Mohammed also emphasizes that “Rather than avoiding anti-nutrients, optimizing food preparation and maintaining a varied diet will provide the best balance for nutrient intake and long-term health.”

Vitamin C aids iron absorption, so try pairing iron-rich plants with those high in vitamin C, like citrus fruits and bell peppers. Soaking beans and legumes overnight before cooking them is an easy method to reduce their anti-nutrient content, which is mainly found in their skin and dissolves in water. (Additionally, soaking your dried beans overnight makes them easier to cook.)

For those with thyroid problems, Mohammed explains that “Cooking cruciferous vegetables reduces goitrogens, which may affect thyroid function in those with pre-existing thyroid disease.”

Additionally, the doctor says, “Fermentation (e.g., yogurt, sourdough, pickled vegetables) enhances beneficial bacteria and lowers anti-nutrient content.” If pickling more of my vegetables means absorbing even more nutrients from them, I won’t be mad about that.