Anti-nutrients- understanding their role in food and health

When it comes to human nutrition, the focus is often put on the positive aspects of food, such as macronutrients, vitamins and minerals. However, there is another side to the story—the presence of anti-nutrients in certain foods.

Anti-nutrients are naturally occurring compounds found in different plant and animal foods that can interfere with the absorption or utilisation of nutrients in the body.

In this article, I will give an overview of anti-nutrients, their possible effects on human health, and how to minimise their impact through food preparation techniques.

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What are anti-nutrients?

Anti-nutrients are substances found naturally in foods that may reduce the bioavailability or utilisation of certain nutrients. They are produced by plants, animals, or microorganisms as a defence mechanism against predators (like humans, animals), pests, or environmental stressors. This is how plants protect themselves from humans, how they survive as they don't have feet to run away. While these compounds can have negative effects on nutrient absorption in the body depending on the person, their gut microbiota, their variety in diet, they also serve important ecological functions as well as have many health benefits, like lowering cholesterol levels, helping with detoxification, lowering inflammation etc.

Most common anti-nutrients (below list is not a complete list of anti-nutrients) and their possible negative effects on health include:

1. Phytates: Phytates, also known as phytic acid, are present in many plant-based foods, particularly grains (wheat, rye, barley, quinoa, wild rice etc), legumes (beans, lentils, peanuts), and nuts (almonds, walnuts, Brazil nuts). They bind to minerals like iron, zinc, calcium, copper, phosphorus and magnesium, forming insoluble complexes that are poorly absorbed by the body. Phytates also inhibit certain essential digestive enzymes, amylase, pepsin, trypsin- amylase is needed for braking down starch and pepsin and trypsin is required to break down protein.

2. Gluten: found in wheat, barley, rye, it's known to be one of the most difficult-to-digest plant proteins. Gluten can cause digestive problems, contribute to leaky gut, autoimmune illnesses, allergic reactions, cognitive issues, joint pains, fatigue etc. You can learn more about gluten here.

3. Oxalates: Oxalates are found in foods like spinach, beets, potatoes, rhubarb, rice bran, buckwheat groats, certain nuts (almonds), navy beans, raspberries, dates. They can form crystals in the body and contribute to the development of kidney stones. Oxalates can also bind to minerals (like magnesium, iron, zinc etc), impairing their absorption.

4. Tannins: Tannins are a group of compounds found in tea, coffee, cacao, wine, fruits (grapes), and legumes. They can inhibit the absorption of iron and other minerals by forming complexes that are resistant to digestion (causing digestive issues) as well as cause protein deficiency.

5. Lectins: Lectins are proteins found in many plant foods, including legumes (beans, peanuts, whole grains, and some vegetables (raw potatoes). They can interfere with nutrient absorption by binding to the lining of the gut and disrupting the integrity of the intestinal barrier.

6. Saponins: Saponins are proteins found in chickpeas, soya beans, navy beans, kidney beans, alfalfa sprouts etc. They affect the gastrointestinal lining and can contribute to leaky gut syndrome and autoimmune disorders.

7. Solanines: Solanine is found in nightshade vegetables and berries (tomatoes, potatoes, eggplants, peppers, goji berries). In high quantities and with people sensitive to nightshades, solanine can cause nausea, vomiting, diarrhoea, stomach cramps, dizziness, headaches.

8. Goitrogens: Goitrogens are found in kale, cabbage, Brussels sprouts, broccoli, cauliflower, Chinese cabbage, cassava. They prevent the absorption of iodine, and affect the under-functioning of the thyroid gland.

How can you minimise anti-nutrient effects on health?

While complete elimination of anti-nutrients from the diet is neither practical nor desirable as many of the mentioned foods have health benefits, there are several methods to reduce their impact on health:

1. Soaking, Sprouting and Fermentation: Soaking grains, legumes (beans and lentils), and nuts overnight or for a few hours before cooking can help reduce anti-nutrient levels. Fermentation of foods, such as in the case of sourdough bread or fermented soy products like tempeh, can also decrease anti-nutrient content. I have written an article in the past on how to soak nuts and seeds.

2. Cooking, Steaming and Boiling: Cooking, steaming and boiling foods can help break down anti-nutrients and improve nutrient availability. Heat treatment can reduce the activity of enzymes responsible for anti-nutrient effects.

3. Diversifying the Diet: Consuming a varied diet with a wide range of foods and avoiding consuming large amounts if a single food at one meal can minimise the potential negative effects of anti-nutrients by spreading their intake across different meals.

4. Pairing with Nutrient-Rich Foods: Combining anti-nutrient-rich foods with sources of nutrients that counteract their effects can enhance overall nutrient absorption. For example, consuming vitamin C-rich foods alongside iron-rich plant foods can improve iron absorption. So while eating steamed or cooked spinach, squeeze some lemon on top of it.

Anti-nutrients are naturally occurring compounds found in various foods that can affect nutrient absorption and utilisation in our bodies. While they can pose challenges to nutrient bioavailability, their negative effects can be minimised through appropriate food preparation techniques. A varied diet, coupled with soaking, fermenting, cooking, and pairing with nutrient-rich foods, can help ensure a balanced and nutrient-dense intake, while managing the potential impact of anti-nutrients on health.

If you have health goals you want to reach, whether it's around improving your body composition, improving your nutrition, having better digestive health, skin health, don't hesitate to reach out to me for nutrition counseling and health coaching at info@katrinpeo.com.