Kale is no longer a superfood—it causes digestive problems, kidney stones, and more

Kale is no longer a superfood—it causes digestive problems, kidney stones, and more

In recent years, kale has become extremely popular and is being hailed as a superfood due to its impressive nutritional profile. Kale is rich in essential vitamins and minerals such as vitamins A, K, B6 and C, calcium, potassium, copper and manganese and seemed to be a perfect addition to a healthy diet. However, recent discoveries have shed light on a worrisome component of kale that is causing health problems in a significant portion of the population. Oxalic acid, a type of antinutrient found in kale, poses risks to women's digestive health, kidney function, and even sexual well-being. In this article, we look at the history of kale, the concept of antinutrients, the effects of oxalic acid on health, and how to consume kale in a way that minimizes its negative effects.

The story of kale

Kale has an interesting history dating back to the early 1990s. Surprisingly, it was primarily used as a decorative greenery in pizza and salad bars. In fact, Pizza Hut was the largest buyer of kale in the country, using it to surround its pizzas as a visual garnish. However, the perception of kale changed when its nutritional value was discovered. Recognizing its richness in essential nutrients, people began consuming kale as food and not just as a decorative element.

Understanding antinutrients

Antinutrients are substances that hinder the absorption of nutrients in the body. They are found in foods that are otherwise considered healthy and can have adverse health effects. Common antinutrients include protease inhibitors, phytic acid, lectins, gluten, and oxalates or oxalic acid. Unfortunately, kale is high in oxalates, which can interfere with nutrient absorption.

The influence of oxalic acid on health

The oxalic acid found in kale affects the body in several ways, most notably by interfering with calcium absorption. When consumed, oxalates bind to calcium in the blood and form small, sharp oxalic acid crystals. These crystals can lodge in certain parts of the body, such as the kidneys, and cause kidney stones to form. In addition, oxalates can cause vulvodynia in women, a condition characterized by painful sex due to the presence of oxalic acid crystals in the labia.

Additionally, oxalic acid interferes with calcium absorption, resulting in excessive calcium buildup in places where it shouldn't be. This can impact the cardiovascular system, heart health, joint and bone health, dental health, muscle contraction, nerve function, and more.

Foods high in oxalates may increase the risk of kidney stones in susceptible individuals. Normally, calcium and small amounts of oxalate are present in the urinary tract at the same time, but remain dissolved and do not cause problems. However, sometimes they combine and form crystals. In some people, these crystals can lead to stone formation, especially if oxalate levels are high and urine volume is low.

Digestive health can also be affected by oxalates. Many people experience bloating after eating kale or other oxalate-rich foods. Because our bodies cannot fully digest oxalates, consuming excessive amounts of these compounds can cause problems as they build up in our system.

Is kale still nutritious?

While kale contains essential nutrients, it also contains antinutrients, including oxalic acid. Therefore, people with a family history of calcium-related problems should be cautious when taking oxalic acid. Cooking kale by steaming or boiling can help reduce oxalate levels. Eating raw kale may not be advisable because the antinutrients can interfere with the absorption of nutrients. Sprouting kale is another way to reduce its oxalate content.

A balanced approach that includes both cooked and raw foods is often the safest option

. Certain foods, such as tomatoes, have improved nutrient absorption when cooked. For example, cooking tomatoes increases the absorption of lycopene, an essential antioxidant for heart and skin health, while decreasing the absorption of vitamin C. Therefore, it is important to monitor and moderate oxalic acid intake over time to prevent accumulation in the body. If you choose to consume kale, it is recommended to steam or boil it to reduce the oxalic acid content. Click here for a detailed list of foods high in oxalic acid.

Health Benefits of Kale

Despite concerns about oxalic acid, kale still offers numerous health benefits when consumed in moderation. Here are some of the top health benefits of kale:

1. Reich an Nährstoffen: Grünkohl ist reich an Vitamin A, K, B6 und C, die zu verschiedenen Aspekten der Gesundheit beitragen, darunter Immunfunktion, Sehkraft, Knochengesundheit und Kollagenproduktion.
2. Reich an Antioxidantien: Grünkohl enthält starke Antioxidantien wie Beta-Carotin, Lutein und Zeaxanthin, die dazu beitragen, den Körper vor oxidativem Stress zu schützen und das Risiko chronischer Krankheiten zu verringern.
3. Entzündungshemmende Eigenschaften: Die im Grünkohl enthaltenen Antioxidantien und Phytonährstoffe wirken entzündungshemmend und können dazu beitragen, das Risiko chronischer entzündungsbedingter Erkrankungen wie Herzerkrankungen und Arthritis zu verringern.
4. Unterstützt die Verdauungsgesundheit: Grünkohl ist eine ausgezeichnete Quelle für Ballaststoffe, fördert eine gesunde Verdauung, beugt Verstopfung vor und unterstützt ein gesundes Darmmikrobiom.
5. Herz-Kreislauf-Gesundheit: Grünkohl enthält Verbindungen, die nachweislich den Cholesterinspiegel senken und das Risiko von Herzerkrankungen senken.
6. Knochengesundheit: Grünkohl ist reich an Kalzium, das für die Erhaltung starker und gesunder Knochen unerlässlich ist. Es enthält außerdem Vitamin K, das eine entscheidende Rolle im Knochenstoffwechsel spielt.
7. Gewichtskontrolle: Grünkohl ist kalorienarm und reich an Ballaststoffen, was ihn zu einer wertvollen Ergänzung zu einer Diät zur Gewichtsreduktion oder Gewichtskontrolle macht. Der Ballaststoffgehalt fördert das Sättigungsgefühl und beugt übermäßigem Essen vor.

Kidney stones | 10 foods with high…

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Kidney stones | 10 foods high in oxalates

Studies and sources

To add even more credence to the above health benefits, here are some relevant studies:

1. Eine im Journal of the Academy of Nutrition and Dietetics veröffentlichte Studie ergab, dass der Verzehr von Grünkohl und anderen Blattgemüsen mit einem verringerten Risiko für koronare Herzkrankheiten verbunden ist. Verweis zu den Lerninhalten
2. Im Journal of the American Dietetic Association veröffentlichte Forschungsergebnisse zeigten, dass eine höhere Aufnahme von Vitamin-K-reichen Lebensmitteln, einschließlich Grünkohl, bei Frauen mit einem geringeren Risiko für Hüftfrakturen verbunden war. Verweis zu den Lerninhalten
3. Eine in der Fachzeitschrift „Oxidative Medicine and Cellular Longevity“ veröffentlichte Studie betonte die antioxidativen und entzündungshemmenden Eigenschaften von Grünkohl und seine potenziellen Vorteile bei der Vorbeugung chronischer Krankheiten. Verweis zu den Lerninhalten
4. Im Journal of Medicinal Food veröffentlichte Forschungsergebnisse zeigten die cholesterinsenkende Wirkung von Grünkohl und anderen Blattgemüsen bei Personen mit hohem Cholesterinspiegel. Verweis zu den Lerninhalten

While kale has long been hailed as a superfood due to its impressive nutrient profile, it's important to be aware of its oxalic acid content. Oxalic acid, an antinutrient found in kale, can interfere with calcium absorption and potentially lead to health problems like kidney stones and vulvodynia. However, this does not mean that kale should be completely eliminated from the diet.

Cooking kale can reduce its oxalate content, making it safer to consume. Additionally, a balanced diet that combines cooked and raw foods can help minimize the negative effects of antinutrients. Kale continues to provide numerous health benefits, including being rich in nutrients, antioxidants, and fiber, and supporting digestive, cardiovascular, and bone health, among other benefits.

As with any nutritional decision, it's important to listen to your body and make choices that meet your individual health needs and considerations.

By consulting a doctor or registered dietitian, you can get personalized advice on incorporating kale and other nutritious foods into your diet while managing specific health concerns.

It's worth noting that kale is just one of many healthy foods out there. If you find that kale doesn't suit your body or are concerned about its oxalic acid content, there are plenty of other nutrient-dense greens and vegetables to choose from. Spinach, chard, kale, and broccoli are examples of vegetables that offer similar health benefits with lower oxalic acid levels.

In summary, while kale is known for its nutritional value, it is important to be aware of the presence of oxalic acid in this leafy vegetable. Oxalic acid can interfere with nutrient absorption and potentially cause health problems in susceptible individuals. By cooking kale and maintaining a balanced diet with a variety of foods, you can continue to enjoy the health benefits of kale while minimizing the potential negative effects of oxalic acid. As always, it's important to listen to your body and make decisions that meet your individual health needs.

Cooked Kale Recipe: Sautéed Garlic Kale with Lemon

Ingredients:

• 1 Bund Grünkohl
• 2 Esslöffel Olivenöl
• 4 Knoblauchzehen, gehackt
• Saft von 1 Zitrone
• Salz und Pfeffer nach Geschmack

Instructions:

1. Beginnen Sie mit der Zubereitung des Grünkohls. Spülen Sie die Grünkohlblätter gründlich unter kaltem Wasser ab, um Schmutz und Ablagerungen zu entfernen. Entfernen Sie die harten Stängel, indem Sie mit einer Hand die Unterseite des Stängels festhalten und mit der anderen Hand die Blätter abziehen. Die Grünkohlblätter in mundgerechte Stücke zupfen oder hacken.
2. In einer großen Bratpfanne oder Bratpfanne das Olivenöl bei mittlerer Hitze erhitzen. Fügen Sie den gehackten Knoblauch hinzu und braten Sie ihn etwa 1–2 Minuten lang an, bis er duftet und leicht golden ist.
3. Geben Sie den vorbereiteten Grünkohl in die Pfanne und vermengen Sie ihn mit der Knoblauch-Öl-Mischung. Verwenden Sie eine Zange oder einen Spatel, um sicherzustellen, dass der Grünkohl gleichmäßig bedeckt ist.
4. Reduzieren Sie die Hitze auf eine niedrige Stufe und decken Sie die Pfanne ab. Lassen Sie den Grünkohl etwa 5–7 Minuten kochen, bis er zusammengefallen und zart ist. Gelegentlich umrühren, um ein Anbrennen zu verhindern.
5. Nehmen Sie den Deckel ab und drücken Sie den Saft einer Zitrone über den gekochten Grünkohl. Mit Salz und Pfeffer abschmecken. Den Grünkohl vorsichtig umrühren, um den Zitronensaft und die Gewürze zu verteilen.
6. Weitere 1–2 Minuten kochen lassen, damit sich die Aromen vermischen.
7. Vom Herd nehmen und den sautierten Knoblauchkohl in eine Servierschüssel geben. Als Beilage oder als nahrhafte Ergänzung zu jeder Mahlzeit servieren.

By lightly cooking the kale, you can help reduce its oxalic acid content while maintaining its nutritional benefits. The addition of garlic and lemon adds flavor to the dish and improves the overall taste. Enjoy this delicious and healthy recipe!

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