The Problem with the Antinutrients in Vegetables

3 years ago
The Problem with the Antinutrients in Vegetables

Generally, it is believed that plant-based foods are healthy and are rich in nutrients. But do you know plants contain anti-nutrients that may have harmful effects on your health? 

Antinutrients are natural or synthetic plant compounds found in a variety of plant-based foods such as grains, legumes, beans, and nuts. These antinutrients interfere with the absorption of vitamins, minerals, and other nutrients by inhibiting the digestive enzymes.  

All the antinutrients may not cause adverse effects. In this article, we will discuss what these antinutrients are, what science says about them, and how you can avoid their harmful effects on your health. 

What are Antinutrients? 

Antinutrients are plant compounds, which inhibit the absorption of most of the nutrients in your body. They are found in legumes, seeds, and nuts at higher levels and vegetables, fruits, and green leaves at a lower level.

Generally, seed food contains major antinutrients. The most common antinutrients are phytic acid, lectins, and saponins. These antinutrients bind to vitamins and minerals, making them unabsorbable. They are the plant’s defense mechanism to repel pests, bugs, and other predators, protecting seeds to live and reproduce. 

Not all the antinutrients are harmful; few are considered beneficial too. Anti Nutrients such as polyphenols are beneficial when consumed in appropriate doses. They are packed with antioxidants and help to treat digestive problems, control diabetes, and treat neurodegenerative disorders. Flavonoids in tea, coffee, and wine also have a lot of health benefits when consumed in limited amounts. 

Even these positive antinutrients can inhibit the absorption of some essential minerals such as copper, iron, zinc, and vitamin B1. When these anti-nutrients are over-consumed, they can inhibit some crucial enzymes like proteins and starch, found in plant food. 

Common Anti Nutrients You Should Avoid

Phytate (Phytic acid)

Phytate or phytic acid is present naturally in plant seeds, especially in legumes, peanuts, cereals, oilseeds, and other plant-based food. Studies say that phytate hinders the activity of enzymes in the small intestine and stomach affecting the digestion of protein. 

It is believed that phytates are negatively charged structures that bind with positively charged metal ions like calcium, copper, zinc, and magnesium. This complex compound lowers the absorption and bioavailability of these metal ions. This increases the risk of health problems like anemia and bone loss. However, eating foods like meat, leafy green vegetables can counteract the effects of phytate and increase iron absorption.

Iron deficiency is one of the major leading health problems; studies suggest that increased levels of flavonoids, polyphenols from consumption of tea, coffee, etc., decreases the iron absorption in your body. Hence, including meat, poultry, and fish in your diet can help to restore the iron content.


Gluten is one of the hardest plant proteins to digest; it inhibits the digestive enzymes and causes gastrointestinal(GI) distress. It is a well-known fact that gluten leads to leaky gut syndrome (autoimmune diseases), cognitive problems, and allergic reactions as well. Gluten is commonly found in wheat, rye, and barley plants. 

Gluten sensitivity has been classified under the symptoms related to adverse reactions to the gluten protein. It might lead to celiac disease, a severe form of gluten allergy. It also causes joint pains, headaches, tiredness, and poor memory.


Tannins are commonly found in tea, coffee, wine, and chocolates. Tannins isolated from the plants have been shown to inhibit several digestive enzymes, including trypsin, alpha-amylase, and lipase. This can lead to protein deficiency and gastrointestinal problems. 

You need an adequate amount of enzymes for proper digestion, to metabolize food, and provide nutrients to the cells. Tannins inhibit these enzymes, leading to digestive problems like diarrhea, constipation, bloating, and other GI issues. 


Oxalates are found in high quantities in soybeans, black /brown millets, and sesame seeds. Due to oxalates in food sources such as legumes, it is known as a poor protein source. 

They also inhibit the enzymes essential for digestion and cause health issues such as constipation, kidney stone, mineral imbalance, inflammation, UTI issues, GI problems, mitochondrial dysfunction, and autoimmunity. 


Lectins are present in higher quantities in food sources such as beans and wheat. They reduce nutrient absorption and affect digestion, causing bloating and gas for many people. Lectins have the ability to sustain digestion by the GI tract, which means they can penetrate the cell lining and can even damage the membranes of the epithelium lining, inhibit nutrient digestion and absorption, and stimulate shifts in the gut bacterial flora. 

Lectins can also cause food poisoning and immune responses, such as joint pain and rashes. Generally, lectins are at high levels in raw grains, dairy foods, and legumes like peanuts and soybean. 

Soaking and cooking thoroughly can reduce all the lectins present in your food. Even fermenting your food is one of the best ways to reduce the lectin content. 


Saponins are commonly found in legumes and quinoa. They also affect your gastrointestinal lining leading to a leaky gut and autoimmune syndrome. Saponins bind to iron and reduce its absorption, which can affect iron status in your body. 

Saponins are resistant to digestion by humans, but it has the ability to enter the bloodstream and affect your immune response. 

Trypsin Inhibitors

Trypsin inhibitors are commonly found in grain-containing products such as cereals, porridge, baby food, and bread. Also, trypsin inhibitors contribute to the antinutritional property of raw soybean. It inhibits pancreatic proteinases in the small intestine.

Although trypsin can get degraded by heat processing and cooking, it can still cause several health problems, such as mineral deficiencies in young infants, children, and anyone who has reduced pancreatic function. 


Isoflavones are a type polyphenolic and are commonly found in soybeans. Studies suggest that it can cause a hormonal change and also contribute to digestive issues. Isoflavones are believed to interfere with estrogen. Studies say soya can impact reproductive function in women by altering the hormone levels. 


Solanine is toxic with fungicidal and pesticidal properties. It is one of the plant’s natural defenses. Solanine can not be removed by boiling; however, it can be destroyed by frying. Solanine is commonly present in nightshade plants such as potato, eggplant, bell peppers, and tomatoes. Though these vegetables have beneficial antioxidants, their overconsumption can cause various side effects. Acute toxicity can lead to drowsiness, itchiness in the neck region, increased sensitivity, stressful breathing, and gastrointestinal symptoms such as abdominal pain, nausea, vomiting, and diarrhea.


Chaconine is commonly found in corn and potatoes. It is generally present in low levels in plants but can accumulate to high levels in greened, stored, damaged potatoes. This may cause acute poisoning leading to gastro-intestinal and neurological disturbances

How to Reduce Antinutrients in Your Diet 

Antinutrients don’t just affect the absorption of certain minerals, but they can also cause toxicity when present in higher levels in your diet. We can use some traditional methods and technological processes to reduce these antinutrient components in food. Let us discuss some of these methods:

1. Soaking 

Soaking is a great way to reduce antinutrient content. When soaked in water overnight, legumes, beans, and other grains have shown better nutritional value. Antinutrients are generally water-soluble; they simply dissolve when food is soaked overnight. A study indicated that 6 h soaking could reduce 27.9%, and 24 h of soaking reduced 36.0% of phytic acid at room temperature. Soaking results in a substantial decrease in phytate, protease inhibitors, lectins, tannins, and calcium oxalate. 

2. Sprouting 

Sprouting or germination is the most suitable method of reducing the anti-nutrients from plant food. Sprouting results in the activation of the enzyme phytase, which reduces phytic acid. As gemination changes the nutritional content and biochemical properties of the plant, it is highly recommended for reducing antinutrients. According to studies, germination decreases the phytic acid content of chickpea seeds and pigeon pea by 60% and that of urad bean, mung bean, and soybean by 40%.

3. Fermentation 

In fermentation, sugars are oxidized to generate energy. It is a metabolic process that improves mineral absorption from plant foods. It significantly lowers anti-nutrients such as tannins, phytic acid, and polyphenols. 

4. Boiling 

Generally, many legumes are cooked by boiling before consumption. Some studies have reported that boiling or cooking enhances the nutritional value of foods by reducing their antinutrients. 

Boiling at high heat can degrade any antinutrients such as lectins, tannins and protease inhibitors, and calcium oxalate. It is one of the most effective and best ways to reduce antinutrients in your food. 

Final Words

Antinutrients reduce the nutritional value of plant foods and may even cause adverse effects on your health.

Though we always consider plant foods a healthy option, there is this side of the theory that talks about antinutrients. With all the evidence-based information, you can choose to follow steps to reduce antinutrients from your plant food or choose an alternative diet, a carnivore diet.

To know more on the carnivore diet and its health benefits read – Top-10-benefits-of-the-carnivore-diet

Dr. Rashmi Byakodi is a health and wellness writer who aims to spread awareness about health through her words. With her medical background and a passion for writing, she has been creating health content on various platforms. Dr. Rashmi believes that with the right knowledge and a healthy lifestyle, we can combat many health issues, and she strives to spread the same through her blog posts. 

Find her on LinkedIn, Quora, and Pinterest.

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