Are Anti-Nutrients Robbing You of the Vitamins and Minerals You Need?

Anti-nutrients sound scary, and they're in every plant-based food. But are they worth worrying about? STACK investigates.


That word alone is enough to inspire fear in any person who cares about what they put inside their body. Nutrients are defined as "substances that provide nourishment essential for growth and the maintenance of life." Anti-nutrients sound like the creation of a deranged super-villain hell-bent on wiping out an entire population. But here's the thing—anti-nutrients are in tons of foods. In fact, every plant-based food contains them in some form or another. But don't think that gives you license to live a life fueled solely by Cheetos. Here's why anti-nutrients aren't quite as scary as they sound.

What Are Anti-Nutrients?


Anti-nutrients are defined as "naturally occurring substances found in plant-derived foods that interfere with absorption or proper functioning of nutrients in the body."

Several substances fall under the category of anti-nutrients. Let's run down some of the big ones.

RELATED: The 6 Worst Foods For Athletes 

Lectins are proteins that can bind to cell membranes and aren't capable of being digested by the human body. In large quantities, they can cause gastrointestinal issues. Foods high in lectins include grains, legumes, nightshade vegetables, nuts and dairy.

Tannins are a class of antioxidant polyphenols that may impair digestion of various nutrients, hence their classification as an anti-nutrient. Foods high in tannins include berries, nuts, chocolate, rhubarb, legumes, chickpeas, beans and unripened fruit.

Protease inhibitors are a type of anti-nutrient that can hinder protein digestion due to their effect on digestive enzymes. Foods high in protease inhibitors include soybeans, legumes, tubers and green tea.

Calcium oxalate is the primary form of calcium found in most types of vegetables. It can cause nutrient absorption issues, and large amounts have been shown to contribute to kidney stones. Foods high in calcium oxalate include spinach, rhubarb, almonds and baked potatoes.

Phytic acid reduces the absorption of minerals, including zinc, magnesium and iron. Phytic acid is abundant in many nuts, edible seeds, grains, beans and legumes.

RELATED: What is Gluten and Why Would Someone Avoid It?

Hold On, I Thought Those Foods Were Healthy?

You're probably pretty confused right now. Fruits, vegetables, nuts, beans, legumes, whole grains—these are foods that you've long known to be healthy. Heck, we've even told you they're healthy. And they are.

Anti-nutrients exist in plant-based foods for a variety of reasons, almost all of them relating to self-preservation. Plants are living things, and like other living things, they try to stay alive. Calcium oxalate crystals in plants, for example, often serve as a type of natural pesticide that repels bugs. Tannins are thought to protect against freezing and reduce palatability to protect against predators.

So, there's a good reason why plants contain anti-nutrients. It's simply self-preservation.

Now that you know why they exist, let's break down why anti-nutrients probably aren't worth losing sleep over.

Though anti-nutrients have effects that might sound undesirable at first, they're not quite as simple as you might think. Like many substances, their effects within the body are complex. In fact, most anti-nutrients also do quite a lot of good. Lectins aid in functions like inflammation control and might even reduce tumor growth. Protease inhibitors are thought to have anti-inflammatory and anti-cancer properties. Phytic acid is believed to help lower cholesterol and reduce the risk of heart disease.

"[Anti-nutrients] are the very same components that are thought to give beans, lentils, whole grains, vegetables, and fruits their well-documented disease-fighting powers. In fact, you may know these 'anti-nutrients' by another name – 'phytonutrients,' the highly-prized, health-boosting compounds that we celebrate in whole foods," writes registered dietitian Johannah Sakimura on

If you're eating a well-balanced and varied diet, anti-nutrients shouldn't be of much concern to you. People with gastrointestinal issues or certain diseases might have to pay closer attention to anti-nutrients than others, but the bottom line is that anti-nutrients are just natural parts of plant-based foods.

RELATED: The High-Protein Food You Need to Stop Ignoring

"All plants contains anti-nutrients. Broccoli, spinach, and other green leafy veggies. Red wine. Dark chocolate. Nuts. Seeds. Green tea. Heck, fiber itself is an anti-nutrient. Not eating plant foods because they have compounds designed to resist their digestion would be like not eating a lobster because it has a shell and claws. All living things try to avoid being eaten. It's simply not a tenable argument," writes sports dietitian Brian St. Pierre for Precision Nutrition.

However, if it's something you'd like to pursue, there are steps you can take to reduce a food's anti-nutrient content.

Sprouting and Soaking


Many foods are subject to processes that reduce their anti-nutrient content. Sprouting and soaking are two of the most effective methods. Foods such as nuts, seeds and legumes can be sprouted.

Both soaking and sprouting can dramatically reduce a food's anti-nutrient content and increase its amount of healthy enzymes.

Sprouting and soaking are fairly simple. If you've got water, you can sprout and soak certain foods. This guide from the Vegetarian Times is a good resource if you're interested in giving it a try.

RELATED: Tom Brady Wants to Sell You Cacao Goji Energy Squares 


Photo Credit: Getty Images // Thinkstock