What are antinutrients?

Plant-based foods are rich in nutrients and deliver amazing health benefits for surprisingly few calories. However, “antinutrients” are also found in the same fruits, vegetables, and grains that are so nutritious. This leaves us with a puzzle—what do we do when our supposedly healthy foods contain the less-than-healthy antinutrients, and is there anything we can do to reduce their impact?

Antinutrients are naturally occurring organic compounds found in plant-based foods that may partially impair the body’s ability to absorb or use certain nutrients. Antinutrients are neither toxins nor impurities, but they may prevent us from deriving the full benefits of some foods.

What are antinutrients?

The name says it all: antinutrients work against the action and effectiveness of nutrients. Nutrients provide the body with the complex substances and chemicals it needs to grow, heal, and thrive in a state of optimum good health. Antinutrients reduce the effectiveness of those substances.

In a natural environment, antinutrients serve as protectors for the plants from which they come. In nature, antinutrients prevent insects from devouring their host plants, and may kill those insects if they consume those plants in large amounts.

Antinutrients work in a variety of ways. When we consume them, they often work by reducing the availability of healthy compounds to tissues, or they may prevent nutrients from being completely absorbed in the digestive tract. Other antinutrients join chemically to nutrients and cause them to pass out of the body more rapidly than they need to.

Common antinutrients

Below are the most common antinutrients and where they’re found. Some of these antinutrients may also have positive effects on health.

Fiber: You might be surprised to find fiber on the list, as it’s recommended for good health, but fiber is a great example of what antinutrients are and what they can do. Fiber slows the absorption of carbohydrates and may prevent some from being digested at all. While this might sound bad, it’s helpful because the slow absorption of carbohydrates keeps blood sugar and insulin levels in a healthy balance. Without fiber, carbohydrate digestion takes place too rapidly, causing a person’s blood glucose and insulin levels to spike, then fall abruptly. Fiber is best consumed as-is, although it’s important to start off slowly with high-fiber foods.

Tannins. If you like teas, coffee, or chocolate, you’ll get plenty of tannins. They’re also found in berries, grapes, and some beans. Wine owes its astringent taste to tannins. Tannins slow the working of several enzymes, including chymotrypsin, amylase, and lipase. Tannins also reduce the digestion and absorption of iron. People who have frequent headaches or migraines may need to avoid tannins, as they prompt the release of the neurochemical serotonin, which can sometimes cause headaches.

Soaking or boiling tannin-containing foods is an effective way to reduce their impact. That’s great given that tea and coffee, two of the biggest sources of tannins, are typically boiled during preparation.

Oxalates. Oxalates are compounds found in spinach, as well as other dark green leafy vegetables. Oxalates bind to calcium and prevent it from being well-absorbed. For people who are calcium deficient, this can be problematic. As well, when eaten in excess, oxalates can form kidney stones. For people who are prone to kidney stones or gout, oxalate-containing foods should be eaten in moderation. Soaking or boiling foods containing oxalates is a good way to reduce their impact or remove them completely.

Lectins. Lectins are ubiquitous proteins found in plants, especially food plants. Legumes, grains, and seeds tend to concentrate lectins. Excessive intake of lectins can lead to problems in the absorption of some nutrients, but it’s difficult to get such a large amount of lectin in one meal that would result in this type of problem.

Phytates: Phytates bond easily with iron, zinc, copper, magnesium, and calcium, reducing their availability to tissues needing minerals. People with a zinc deficiency need to take care when consuming seeds, legumes, and grains, as phytates can make mineral deficiencies worse. Conversely, phytates may lower cholesterol levels and reduce spikes in blood sugar. You’ll find phytates in potatoes, whole wheat, turnips, walnuts, chia seeds, almonds, and most beans. Soaking these foods in cold water for two to three hours will significantly reduce levels of phytic acid.

Glucosinolates. Glucosinolates interfere with the absorption of iodine. Found in mustard, broccoli, and cabbage, as well as other cruciferous vegetables, glucosinolates are sulfur-rich compounds that can cause problems for people who have thyroid disorders, like hypothyroidism. As is sometimes the case with antinutrients, glucosinolates also have some nutritional benefits and have been investigated for their anti-cancer properties.

Preparing foods with antinutrients

In many cases, antinutrients can be removed or reduced by the way foods containing them are prepared. For example, soaking beans and legumes in water overnight significantly reduces phytates and tannins. Fermentation is another effective way to reduce antinutrients, as is boiling. Microwaving foods tends to be less effective at reducing antinutrients than cooking or boiling.

Balancing out antinutrients

The effects of antinutrients can be minimized by eating a varied and balanced diet. It may sound very simple but eating a wide variety of colorful fruits and veggies effectively negates many antinutrients.

The Takeaway

Plant-based foods including fruits, vegetables, grains, seeds, and nuts have far too many health benefits to be shunned because of antinutrients. Remember, for antinutrients to cause problems, they must be consumed in unrealistically large amounts in a single meal. However, if you have specific health issues such as migraines, kidney stones, or hypothyroidism, it’s a good idea to consult a physician or dietician before you add a particular food to your daily diet.

Works Cited

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