What Are Antinutrients, and Why Are They Harmful?

by BiohackMD Staff July 18, 2018 4 min read

What Are Antinutrients, and Why Are They Harmful?

Everyone knows nutrients are compounds in our food that we need to stay healthy, but you may not have heard of antinutrients. As the name suggests, antinutrients are compounds that work in opposition to nutrients, interfering with the body’s ability to absorb beneficial nutrients and minerals. Beyond limiting the nutritional value of foods you eat, they can cause or contribute to a wide range of problems, including leaky gut syndrome, inflammation, abdominal pain, headaches, nausea, diarrhea, kidney stones, and allergy like symptoms such as rashes and itchiness.

The highest concentrations of antinutrients are typically found in legumes, beans, grains, and nuts, but are also found in the leaves, roots, and fruits of certain types of plants. Antinutrients aren’t entirely bad, and it’s neither healthy nor possible to avoid them completely. Rather than trying to avoid them altogether, it’s best to identify the ones that cause problems for you, and do your best to limit those in your diet. The most reliable way to do this is an elimination diet.  Basically you remove foods from your diet until you find your problems reduced or eliminated, then slowly reintroduce foods to see which cause your symptoms to come back. Once you’ve figured out which foods cause problems for you, avoid them going forward.

There are four primary antinutrients found commonly in many foods: gluten, lectins, oxalates, and phytates.


Gluten, the most famous (or infamous) antinutrient of the bunch, is a protein found in wheat, rye, barley, and oats. Gluten can’t be digested by the human GI system, and causes some amount of trouble for almost all people. Individuals with celiac disease deal with immediate and severe reactions to consuming any gluten at all, but many other people have some amount of gluten sensitivity. When an indigestible material like gluten passes through the digestive system, it causes an inflammatory immune response. This inflammatory response can interfere with the body’s ability to properly absorb nutrients, and cause cramping, bloating, abdominal pain, brain fog, and eventually leaky gut syndrome.

Foods containing gluten can be particularly difficult to remove from your diet, because grains containing gluten are thought to be broken down in the digestive system into compounds called gluteomorphins. These compounds are related to opioids, and bind to the same receptors in the brain, causing cravings and addictive tendencies in similar ways. Gluten is also found in a huge number of processed and packaged food, including many products you wouldn’t expect to find it in, making avoiding it a challenge.


Lectins are a type of protein found in most species of plants, and certain varieties of lectins can cause problems in the digestive system. Different people can have widely varying sensitivity to lectins, and for some people they don’t cause any problems. For those that are sensitive, they can cause problems in the intestines by sticking to intestinal walls leading to intestinal permeability. As you digest food, the process can cause small traumas to the intestinal lining, which your body normally heals without any trouble. Lectins stuck to the intestinal walls interfere with this process, preventing the healing. Over time this unrepaired damage may lead to holes in the lining of the intestinal walls, leading to leaky gut syndrome.

Because lectins are found so commonly in plants, they are essentially impossible to avoid entirely. But certain sources of lectins, particularly nightshades, wheat, and beans tend to be particularly problematic. If you are sensitive to lectins, you may have noticed headaches, stomach pain, joint pain, or brain fog when eating these foods.


Oxalates, or oxalic acids, are found in many plants such as beans, black pepper, chocolate, beets, and many cruciferous vegetables. In the bloodstream, oxalates bind to calcium, forming small sharp oxalic acid crystals. These crystal can be deposited in muscles through the body, causing muscle pain, or deposited in the kidneys, eventually leading to kidney stones.

Like other antinutrients different people will have a different sensitivities to oxalates, but they do have a cumulative effect, meaning frequent consumption over time can increase negative reactions and effects. For those particularly sensitive to oxalates, small amounts can cause allergic-like reactions including pain or burning in the eyes, mouth, and throat. Stomach pain, nausea, and diarrhea can result from consuming large amounts of oxalates.


Phytates, or phytic acids, are found in many common foods, including whole grains, seeds, and soybeans. They block absorption of valuable minerals like calcium, zinc, and magnesium, by binding to these minerals, preventing your body from using them. Phytates also interfere with certain enzymes in the digestive system, including amylase, pepsin, and trypsin. Your body uses amylase to break down starches, and pepsin and trypsin to break down proteins. When phytates interfere with these enzymes, your body can’t process such foods correctly, and you don’t get the full nutritional value.

The body can deal with phytates in small quantities without trouble, and they are so common you won’t be able to eliminate them completely. But minimizing your consumption of foods with high concentrations of phytates will ensure your digestive system is operating optimally, leading to more effective fat burning and muscle building.

If you want to learn more about how to avoid antinutrients in your diet, check out our post Tips for Avoiding Antinutrients.

[source: https://blog.bulletproof.com/4-top-antinutrients-to-avoid-and-why/ ]


BiohackMD Staff
BiohackMD Staff