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The Hidden Dangers of Kale and Why You Shouldn't Eat It


a green drink smoothie
Raw Kale Can Cause Health Problems

In recent years, kale has skyrocketed to fame as a superfood, hailed for its high nutrient content and numerous health benefits. From smoothies to salads, this leafy green has found its way into countless diets of health enthusiasts around the globe.


However, there is a lesser-known side to kale that warrants caution, particularly when it is consumed raw. This post aims to shed light on the potential risks associated with eating raw kale, focusing on the issues related to oxalates and the symptoms of resulting imbalances.



The Nutritional Powerhouse of Kale is a Lie


Before delving into the risks, it’s important to breakdown the nutritional profile that has made kale so popular.


Kale is often celebrated for its high levels of vitamins A, C, and K, along with its fiber, antioxidants, and various beneficial plant compounds. However, it is important to clarify that the vitamin A and K found in kale are actually precursors, not the active vitamins themselves.



Vitamin A Precursors


Kale is rich in beta-carotene, a precursor to vitamin A. Beta-carotene is a type of carotenoid that the body converts into retinol, the active form of vitamin A. This conversion process is efficient in many individuals but can vary based on genetic factors, overall health, and the presence of other nutrients in the diet.



Vitamin A is crucial for vision, immune function, and skin health, but its precursor, beta-carotene, requires this additional step to become bioactive.


In My Opinion, Kale is not a source of Vitamin A. Try incorporating liver, butter, eggs, beef and lamb into your diet for more available Vitamin A. Remember Vitamin A is only available through animal sources of food. No plants offer this extremely important vitamin.


Vitamin K Precursors


Similarly, the vitamin K in kale is predominantly in the form of vitamin K1 (phylloquinone), which is different from vitamin K2 (menaquinone), the form most associated with cardiovascular and bone health benefits.


While K1 is beneficial for blood clotting and can be converted to K2 in the body, the conversion rate is not very high. Therefore, while kale contributes to vitamin K intake, the form and efficacy of the vitamin can differ from direct sources of vitamin K2, such as fermented foods and animal products.


In my opinion, Kale is not a good source of Vitamin K. Much better and more easily absorbed choices are dairy, eggs, liver, beef and chicken.


The Dark Side of Raw Kale


Despite its impressive nutrient profile, consuming raw kale can lead to health issues, primarily due to its oxalate content.


While moderate consumption of kale can be beneficial, overconsumption or regular intake of raw kale can contribute to severe imbalances in the body.



Understanding Oxalates


Oxalates, also known as oxalic acid, are naturally occurring compounds found in many plant foods, including kale. These compounds can bind to minerals such as calcium and iron in the gut, forming insoluble compounds that the body cannot absorb. This process not only reduces the bioavailability of these essential minerals but can also lead to the formation of kidney stones and other health issues when oxalates accumulate in the body.



The Problem with Raw Kale

When kale is cooked, the oxalate content is significantly reduced, making it safer to eat. However, consuming kale in its raw form preserves its high oxalate levels, posing potential risks. Here are some of the primary concerns:



1. Kidney Stones: One of the most well-known risks associated with high oxalate consumption is the formation of kidney stones. These painful stones occur when oxalate binds with calcium in the kidneys, creating hard deposits. Individuals who are prone to kidney stones or have a history of kidney issues should be particularly cautious about consuming raw kale.



2. Mineral Absorption: As mentioned, oxalates can interfere with the absorption of essential minerals. This can lead to deficiencies, even if you are consuming a diet rich in these nutrients. Calcium and iron are particularly affected, which can impact bone health and lead to conditions such as anemia over time.



3. Digestive Distress: High oxalate foods can cause gastrointestinal issues such as bloating, gas, and stomach cramps. For those with sensitive digestive systems, raw kale can exacerbate these symptoms and lead to discomfort.



4. Thyroid Function: Kale is also a goitrogenic food, meaning it can interfere with thyroid function when consumed in large quantities, especially in its raw form. This is because goitrogens can inhibit the uptake of iodine, a mineral crucial for thyroid health. While cooking reduces the goitrogenic compounds, eating raw kale frequently can pose a risk to thyroid function.



Symptoms of Oxalate Imbalance

Recognizing the symptoms of oxalate imbalance is crucial for anyone who consumes large amounts of raw kale or other high-oxalate foods. Here are some common signs to watch for:



1. Kidney Stone Formation: Symptoms of kidney stones include severe pain in the back, side, lower abdomen, or groin, as well as blood in the urine, nausea, vomiting, and frequent urination. If you experience these symptoms, it is essential to seek medical attention promptly.



2. Joint Pain and Inflammation: High oxalate levels can lead to the formation of crystals in the joints, causing pain and inflammation similar to arthritis. This condition is known as oxalate arthropathy.



3. Fatigue and Weakness: Due to impaired mineral absorption, individuals with high oxalate levels might experience chronic fatigue, muscle weakness, and general malaise. Iron deficiency anemia is a common result of poor iron absorption.



4. Gastrointestinal Issues: Persistent digestive issues such as bloating, cramps, and diarrhea can be a sign of high oxalate intake. These symptoms are often mistaken for other gastrointestinal disorders, making it important to consider dietary sources as a potential cause.



5. Thyroid Dysfunction: Symptoms of thyroid dysfunction include unexplained weight gain, fatigue, cold intolerance, dry skin, and hair loss. If you consume large amounts of raw kale and experience these symptoms, it may be worth evaluating your dietary habits.



Balancing Kale in Your Diet



The key to enjoying the health benefits of kale without the associated risks lies in balance and preparation. Here are some practical tips if you choose to include it in your diet:



1. Cook Your Kale: Cooking kale, whether by steaming, boiling, or sautéing, significantly reduces its oxalate content and goitrogenic compounds. Eat it with a good amount of animal fat like butter. This makes it safer and easier for your body to process.


2. Diversify Your Greens: Instead of relying solely on kale, incorporate a variety of leafy greens into your diet. Spinach, collard greens, and Swiss chard also contain oxalates but can be rotated to avoid excessive intake of any one type. Always cook your greens well and eat them with adequate amounts of animal fats.



3. Moderation is Key: Even healthy foods can be detrimental in large quantities. Ensure you are not overloading on kale by keeping portion sizes reasonable and not consuming it daily in its raw form.



4. Stay Hydrated: Adequate hydration helps prevent the formation of kidney stones. If you consume oxalate-rich foods, drinking plenty of water can aid in flushing oxalates out of your system.



5. Pair with Calcium-Rich Foods: Eating calcium-rich foods alongside oxalate-rich foods can help bind oxalates in the gut before they reach the kidneys. Dairy products, fortified plant milks, and certain leafy greens are good sources of calcium.



6. Consult with a Healthcare Professional: If you have a history of kidney stones, thyroid issues, or other health concerns, it’s advisable to consult with a healthcare provider or a registered dietitian. They can provide personalized advice based on your health needs and dietary habits.



Should You Avoid Kale Altogether?


Given the potential risks associated with consuming raw kale, it might be prudent for some individuals to avoid kale entirely.


This is especially true for those who are experiencing symptoms of oxalate imbalance or have a history of related health issues.


As a 25-year veteran in nutrition, my professional opinion is that while kale has been marketed extensively as a superfood, it often does more harm than good when consumed especially raw.

It's important to recognize that kale is not essential for a healthy diet.


Many other vegetables and greens provide similar or even superior nutritional benefits without the associated risks. By focusing on a varied diet rich in a wide range of vegetables, you can achieve optimal health without relying on kale.


For example, leafy greens like arugula, romaine lettuce, and bok choy offer valuable nutrients with lower oxalate content.




While kale is undoubtedly has huge nutritional the risks associated with consuming it raw that should not be overlooked. Oxalates and other compounds in raw kale can lead to serious health imbalances, particularly when consumed in large quantities.


By cooking kale, balancing it with other greens and eating it with adequate amounts of animal fats, you can continue to enjoy it without compromising your health. However, for those who experience symptoms of oxalate imbalance or have related health concerns, avoiding kale altogether might be the best option.


Remember this: You can be healthy without Kale.

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