You might have noticed (if you’re a nerd like me) in the past few weeks anti-nutrients have made some headlines… And you may well have been wondering what these are…
Anti-nutrients are substances in food that reduce the absorption of essential vitamins and minerals.
In this post, we will discuss what anti-nutrients are, the effects of excessive consumption, and ways to reduce or neutralise their effects.
What are Anti-Nutrients?
We know that all foods contain nutrients – however what’s less known is that some plant foods including grains, seeds, nuts, and legumes, contain compounds which are known as anti-nutrients. They are the compounds that act as a form of defence mechanism in the plant, helping to protect it from infections or consumption by animals and insects.
When you consume these anti-nutrients, they can potentially interfere with the body’s ability to absorb essential vitamins and minerals. Examples of anti-nutrients include:
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Phytate:
The most common anti-nutrient, most common in grains and legumes. It’s found in the hulls of nuts, seeds, and grains, and has a strong binding affinity for several minerals (such as zinc, calcium and magnesium, iron, and copper) which may potentially limit their absorption.
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Lectins:
All plant foods contain these to a differing degrees, but they are present in greater quantities in grains and legumes and have the potential to interfere with the absorption of minerals such as iron, calcium, zinc and phosphorus.
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Oxalates:
Commonly found in cocoa, dark leafy greens, nuts, and seeds, and bind to calcium, therefore being particularly problematic in those who struggle with kidney stones.
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Tannins:
These polyphenols are found in food and beverages, most commonly tea and coffee, as well as some fruits, and can impair digestive enzyme activation, protein digestibility, and iron absorption – which is why we recommend taking iron supplements two hours apart from your hot drinks.
These substances can cause digestive discomfort and can have harmful effects on health if consumed in large amounts.
Effects of Excessive Consumption
Consuming high levels of anti-nutrients can lead to various health issues such as reduced nutrient absorption, gastrointestinal issues, inflammation, and toxicity. It’s important to note that excessive consumption can vary based on the type of anti-nutrient and individual factors such as age, gender, and health status.
To be sure though, these compounds aren’t all bad! Some anti-nutrients have actually been shown to provide health benefits. We know that saponins have been shown to reduce blood glucose and insulin responses to starchy foods, phytic acid has been related to reduced cancer risks, as well as lower cholesterol and slow digestion.
Ways to Neutralise the Effects of Anti-Nutrients:
There are ways to reduce or neutralise the effects of anti-nutrients, such as soaking, sprouting, fermenting, cooking, and processing. These methods can help improve the digestibility and nutrient availability of foods that contain anti-nutrients.
Soaking:
Hydrating legumes, grains, and lentils prior to cooking is a basic yet powerful technique to deactivate enzyme inhibitors. These inhibitors contain anti-nutrients that are found in the outer layer, and are water-soluble, which causes them to dissolve in water. Soaking the whole grains in water overnight or in water combined with acidic ingredients such as lemon juice or cider vinegar is an effective method to counterbalance phytic acid. This process is often used in conjunction with sprouting, fermenting, or boiling.
Sprouting:
Germinating, also known as sprouting, is one of the most effective methods for neutralising anti-nutrients, particularly phytates and lectins. Most anti-nutrients serve as protective mechanisms for seeds, inhibiting sprouting until the ideal conditions are present. Sprouting grains, legumes, and seeds, however, helps to lower their phytate content, decrease tannins and enhance their nutrient availability.
Fermentation:
Fermentation is a time-honoured method for food preservation and preparation, that has been widely utilised across different cultures. The fermentation process serves to reduce phytate and lectin levels, as well as augment beneficial bacteria and nutrient density simultaneously. For example, fermenting soy into tempeh or miso, cabbage into sauerkraut or kimchi, and whole grains into sourdough bread improves digestion and nutrient absorption. Additionally, fermented foods are rich in probiotic bacteria, which have been proven to sustain a balanced gut microbiome and provide a multitude of health benefits.
Boiling:
High-heat cooking has been demonstrated to decrease the presence of lectins, tannins, and protease inhibitors. Boiling whole grains, legumes, as well as boiling or steaming Brussels sprouts, cauliflower, and leafy greens, in particular, has been found to significantly reduce oxalates levels.
It’s also important to remember that eating a varied diet full of fruit and vegetables, legumes and nuts and seeds is ultimately key to good health – so don’t let a couple of headlines scare you away.
Anti-nutrients can have negative effects on health if consumed in excessive amounts. However, by including a variety of foods in your diet and using methods to reduce or neutralise the effects of anti-nutrients, you can ensure adequate nutrient intake and avoid excessive consumption.
If you have specific health concerns, it’s best to consult with a naturopath for personalised advice.
