Not All Superfoods Are Super for You

Michelle Shyam
9 hours ago
9 min read

Nuts, seeds, grains, and greens are hailed as superfoods. But what if some of them are silently sabotaging your digestion, minerals, hormones, and energy? This isn’t about fear. It’s about awareness. Because many “healthy” plant foods contain natural defense chemicals called anti-nutrients — compounds that can block mineral absorption, irritate the gut, and quietly drain your system over time.

If you’ve been eating clean but still feel bloated, fatigued, inflamed, or stuck — this might be the missing link. Let’s talk about the plant compounds nobody warns you about.

What are anti-nutrients?

Plant anti-nutrients are compounds present in plants that may interfere with the absorption of nutrients in the human body's digestive tract.

Why do they exist?

These anti-nutrients are part of the natural defense mechanism of plants against predators, and they can also help regulate the release of nutrients in the soil.

Six of the most known anti-nutrients (that this post will cover) are:

Phytates or phytic acid
Oxalates or oxalic acid
Lectins
Goitrogens
Tannins
Saponins

Other lesser known ones are: Enzyme inhibitors, Amylase inhibitors and Protease inhibitors.

Phytic Acid:

Phytic acid, also known as inositol hexaphosphate (IP6), is a naturally-occurring compound found in many plant-based foods, such as grains, legumes, and nuts.

It acts as a storage form of phosphorus and is considered an anti-nutrient because it can bind to minerals like iron, zinc, and calcium, making them less available for absorption by the body.
However, phytic acid also has potential health benefits, such as reducing the risk of certain types of cancer and improving bone health. So, moderation in intake of phytic acid-rich foods is recommended for a balanced and healthy diet.

Here are some of the potential side effects of phytic acid:

Reduced Nutrient Absorption: Phytic acid can bind to minerals like iron, zinc, and calcium, reducing their absorption in the gut. This can lead to nutrient deficiencies if dietary intake is not sufficient.
Digestive Issues: Consuming large amounts of phytic acid can lead to digestive issues like bloating, gas, and diarrhea. This is because phytic acid can bind to starches and other carbohydrates in the gut, slowing their digestion and causing fermentation.
Reduced Protein Digestion: Phytic acid can also bind to proteins in the gut, reducing their digestibility and potentially leading to amino acid deficiencies.
Impact on Beneficial Gut Bacteria: Phytic acid can impact the balance of beneficial gut bacteria, potentially leading to imbalances in the gut microbiome.
Risk of Dental Decay: Phytic acid can bind to minerals in the mouth, potentially leading to dental decay and cavities. This is why some oral health experts recommend limiting phytic acid intake to protect oral health.

Here are five common sources of phytic acid:

Whole Grains: Phytic acid is commonly found in the bran of whole grains such as wheat, oats, rye, and barley.
Legumes: Beans, peas, lentils, and soybeans all contain significant amounts of phytic acid.
Nuts and Seeds: Phytic acid is found in high amounts in nuts such as almonds, cashews, and hazelnuts, as well as seeds like sesame, sunflower, and flaxseed.
Certain Vegetables: Vegetables like spinach, beet greens, and Swiss chard contain moderate amounts of phytic acid.
Some Fruits: Berries like raspberries, blackberries, and cranberries contain moderate levels of phytic acid, as well as kiwi fruit and pomegranates.

Oxalates:

Oxalates are naturally occurring substances found in many plant-based foods, such as spinach, kale, and rhubarb. It's important to note that oxalates are not a concern for most people and a varied diet is key for overall health.

Consuming foods that are high in oxalates can lead to several potential side effects in some individuals, particularly those who are susceptible to kidney stones or have kidney disease. Here are some of the possible side effects of oxalates:

Kidney Stones: Oxalates can bind with calcium to form crystals that can accumulate in the kidneys and form kidney stones. People who are prone to kidney stones or have a history of kidney stones should be cautious with their oxalate intake.
Gastrointestinal Issues: Oxalates can bind with minerals in the gut and interfere with their absorption, potentially leading to digestive issues like bloating, diarrhea, and abdominal pain.
Nutrient Deficiencies: As oxalates bind with minerals, they can prevent their absorption, which can lead to deficiencies in nutrients like calcium and iron.
Joint Pain: Some studies have suggested that high oxalate intake may contribute to joint pain in some individuals, although more research is needed to confirm this link.
Nerve Damage: In rare cases, oxalate accumulation in the body can lead to nerve damage and other health problems. However, this is typically only a concern in people with certain genetic conditions that affect oxalate metabolism.

Here are five common sources of oxalic acid:

Spinach: Spinach is one of the highest sources of oxalic acid, with levels ranging from 700 to 1500 milligrams per 100 grams.
Rhubarb: Rhubarb is another high-oxalate food, with levels ranging from 400 to 900 milligrams per 100 grams.
Beet Greens: Beet greens are high in oxalic acid, with levels ranging from 300 to 600 milligrams per 100 grams.
Swiss Chard: Swiss chard is another leafy green vegetable that contains high levels of oxalic acid, with levels ranging from 200 to 600 milligrams per 100 grams.
Nuts and Seeds: Some nuts and seeds contain significant amounts of oxalic acid, such as almonds, cashews, peanuts, sesame seeds, and poppy seeds. However, the amounts are generally lower than in leafy greens and rhubarb.

Lectins:

Lectins are a type of protein that can bind to carbohydrates. They are found in a variety of plant-based foods have been associated with negative health effects, such as digestive issues and inflammation. It is important to note that not all lectins are harmful and some may even have potential health benefits. As with any food, it's best to consume lectin-containing foods in moderation and to listen to your body's individual needs and reactions.

Here are some potential side effects of lectins:

Digestive Issues: Lectins can bind to the lining of the gut and interfere with nutrient absorption, which can lead to digestive issues like bloating, gas, and diarrhea.
Allergic Reactions: Some people may be allergic to specific types of lectins, which can cause symptoms like hives, swelling, and difficulty breathing.
Inflammation: Some studies have suggested that lectins may promote inflammation in the body, which can contribute to a range of health problems.
Joint Pain: Like oxalates, some studies have suggested that lectins may contribute to joint pain in some individuals.
Impact on Beneficial Gut Bacteria: Lectins can bind to certain types of beneficial gut bacteria, potentially leading to imbalances in the gut microbiome. This can impact overall health and may contribute to a range of health problems.

Here are five common sources of lectins:

Legumes: Beans, peas, lentils, and soybeans are all high in lectins, with kidney beans being particularly rich.
Grains: Wheat, rice, and other grains contain lectins, with wheat germ agglutinin (WGA) being a particularly potent type.
Nightshade Vegetables: Certain vegetables from the nightshade family, such as tomatoes, potatoes, okra, bellpeppers and eggplants, contain lectins.
Dairy: Some dairy products, such as cheese and milk, contain small amounts of lectins.
Seeds and Nuts: Lectins can also be found in seeds and nuts, such as peanuts, sunflower seeds, and pumpkin seeds.

Goitrogens:

Goitrogens are substances that can interfere with the function of the thyroid gland by blocking the uptake of iodine. This can lead to the formation of goiters and potentially impact thyroid hormone production. It's important to note that while goitrogens can interfere with thyroid function, most people can safely consume goitrogenic foods in moderation without any adverse effects on their thyroid function. However, individuals with thyroid conditions, such as hypothyroidism or Hashimoto's thyroiditis, may need to limit their intake of goitrogenic foods.

Here are some common sources of goitrogens:

Cruciferous vegetables: Cruciferous vegetables such as broccoli, cauliflower, kale, and cabbage are high in goitrogens.
Soy-based foods: Soy products such as tofu, soy milk, and edamame contain goitrogens.
Millet: Millet is a type of grain that contains goitrogens.
Cassava: Cassava, a starchy root vegetable, contains goitrogens and can also release cyanide if not prepared properly.
Peanuts: Peanuts are a source of goitrogens, especially when consumed in large amounts.
Flaxseeds: Flaxseeds are high in goitrogens, but they are also a good source of omega-3 fatty acids and fiber.

How do Goitrogens work?

Goitrogens work in different ways, depending on the type of substance involved.

Thiocyanates and isothiocyanates, interfere with iodine uptake by competing with iodine for transport into the thyroid gland.
Perchlorate and nitrate, block the uptake of iodine by inhibiting the sodium-iodide symporter, which is a protein responsible for transporting iodine into the thyroid gland.
Glucosinolates found in cruciferous vegetables such as broccoli, cabbage, and kale, can interfere with the production of thyroid hormones by inhibiting the activity of thyroid peroxidase, an enzyme that is required for the synthesis of thyroid hormones.

Tannins:

Tannins are naturally occurring compounds found in various plant-based foods and beverages, such as wine, tea, and nuts. Tannins have antioxidant and anti-inflammatory properties and are believed to have potential health benefits, such as reducing the risk of heart disease and certain types of cancer. However, excessive consumption of tannins may cause negative effects.

Some common side effects of tannins include:

Dry mouth: Tannins can cause a dry, puckered feeling in the mouth due to their astringent properties.
Nausea and vomiting: Consuming large amounts of tannins may irritate the digestive system and cause nausea and vomiting.
Stomach upset: Tannins may also cause stomach pain, cramping, and diarrhea in some people.
Interference with nutrient absorption: Tannins can bind to certain nutrients, such as iron, and make them less available for absorption by the body.
Allergic reactions: Some people may have an allergic reaction to tannins, which can cause hives, itching, and difficulty breathing.

It's worth noting that the severity of these side effects can vary depending on the individual and the amount of tannins consumed.

Here are the top 5 sources of tannins:

Tea: Black tea, green tea, and other varieties of tea are rich sources of tannins. The tannin content of tea depends on the brewing method and the type of tea leaves used.
Coffee: Coffee beans also contain tannins, which contribute to the bitter taste of coffee. The tannin content of coffee can vary depending on the roast level and brewing method.
Wine: Red wine is a significant source of tannins, as the tannins are extracted from the grape skins during the winemaking process. White wine and other alcoholic beverages also contain tannins, although in lower amounts.
Nuts: Some nuts, such as walnuts, pecans, and almonds, contain significant amounts of tannins.
Fruits: Many fruits, especially berries, contain tannins. Examples include pomegranates, grapes, blueberries, and cranberries. The tannin content in fruits can vary depending on the ripeness and processing methods.

Saponins:

Saponins are a type of chemical compound found in various plants, particularly those used for medicinal purposes. They are known for their soapy texture and have been used in traditional medicine to treat a variety of ailments, including inflammation, coughs, and skin conditions. Saponins are also commonly used in the food industry as emulsifiers, helping to stabilize and thicken products such as beverages and sauces.

It's important to note that saponins can have both beneficial and harmful effects on the body. While some studies suggest that saponins may have anti-inflammatory and cholesterol-lowering properties, they can also interfere with the absorption of certain nutrients and may cause gastrointestinal discomfort in some individuals. It's always best to consume saponin-rich foods in moderation.

Here are some common food sources of saponins:

Legumes: Saponins are commonly found in legumes such as lentils, chickpeas, and beans. The levels of saponins can vary depending on the type and preparation of the legumes.
Quinoa: Quinoa is a popular gluten-free grain (from Maize) that contains high levels of saponins, which can give it a slightly bitter taste.
Nuts and seeds: Certain nuts and seeds, such as almonds, peanuts, and sesame seeds, also contain saponins.
Berries: Some berries, including goji berries, sea buckthorn berries, and soapberries, are rich in saponins.
Herbs and spices: Many herbs and spices contain saponins, including turmeric, ginseng, fenugreek and licorice root.
Vegetables: Some vegetables, including asparagus, spinach, and broccoli, contain saponins, but the levels are generally lower than in legumes and grains.

Here are some possible side effects of saponins when consumed in large amounts:

Gastrointestinal discomfort: Saponins can irritate the digestive system and cause symptoms such as nausea, vomiting, diarrhea, and abdominal pain.
Interference with nutrient absorption: They can bind to certain nutrients such as vitamins and minerals, making them less available for absorption by the body.
Hemolysis: Saponins can cause the breakdown of red blood cells, leading to anemia in some cases.
Allergic reactions: Some people may have an allergic reaction to saponins, causing symptoms such as itching, hives, or difficulty breathing (in the case of peanut allergy)
Toxicity: In high doses, some types of saponins can be toxic and may cause serious health problems such as liver or kidney damage. It is still not clear what amount constitutes 'toxic levels'.

In conclusion...

Plants defend themselves. That’s nature. Your job isn’t to avoid food. It’s to understand it.

Because “healthy” isn’t about trends. It’s about how your body responds.

Eat smarter — not blindly.