|April 4, 2024

The Kale Shake is Awesome—So Upgrade It

By Bulletproof Staff
Reviewed by Theresa Greenwell for Scientific Accuracy on 04/04/2024

The Kale Shake is Awesome—So Upgrade It

Kale and fruit breakfast shakes are all the rage now. But, there are ways to make this nutrient-dense drink even better for you. Kale has nutrients that make people feel healthier, manage their weight and get more done. It’s a big step up from sugar-filled cereal and muffins commonly known as “breakfast.”

People turn to raw kale shakes because they want to start their day with a massive dose of nutrients and a revved-up digestive system. But what if kale had a dark side, and knowing about it could make your kale shake even better, with more health and performance benefits? Believe it or not, there are some long-term problems that come with daily raw kale shakes.

The good news is that you can totally upgrade your kale shake by removing kale’s natural self-defense mechanisms and increasing your vitamin absorption from it. The small steps outlined below will transform your kale shake’s nutritional benefits and increase your energy levels.

The pros and cons of consuming kale

Raw kale on a cutting board with a knife

Before you begin to integrate kale shakes into your daily diet, let’s unpack the ups and downs…

The pros[1]

  • Provides vitamin A & K
  • High concentration of antioxidants
  • Sulphur-based nutrients
  • Carotenoids and flavonoids
  • Carotenoids and flavonoids
  • Lutein and zeaxanthin for your eyes

What kale nutrients do for you

Kale provides a wealth of vitamins to support good health and performance. Most of kale’s health benefits are linked to high concentrations of antioxidant vitamins A, C and K. Vitamin A promotes healthy eyesight, tissue growth, and skin and hair repair.[2] It also helps protect against infection from pathogenic organisms.

Plus, the vitamin C found in kale facilitates tissue repair, boosts the immune system, and provides antioxidant protection against pathogens and toxins.[3] Except, well, one vitamin C capsule will kick your kale’s tail. So add some ascorbic acid (vitamin C) powder to your smoothie, too.

Additionally, kale is incredibly rich in vitamin K1, which is necessary for a variety of bodily functions, including normal blood clotting and antioxidant activity.[4]

Because kale contains an abundance of health and performance-optimizing vitamins, you should view it as a Bulletproof food—but only if you take action against its built-in problems.

The cons[5]

  • Kale’s oxalates are an anti-nutrient
  • Kidney stone risk
  • Lowered thyroid function (goitrogenic)

What are oxalates?

Oxalic acid, aka oxalates, form in kale to protect it from predation by animals, insects and fungi. Animals that eat too much of it die unpleasantly unless they have well-developed oxalate-detoxifying systems. Oxalates are anti-nutrients and can cause lots of problems, such as kidney stones and muscle pains.[6] To lower your smoothie’s oxalates, you can mix calcium and magnesium in your blender. These minerals bind to the oxalic acid so you don’t absorb as much of it.[7][8]

The oxalates can negatively impact your body in the following ways:

  • Oxalates are a mycotoxin, a toxin produced by the fungus aspergillus and the common yeast candida.[9] Candida is the cause of most yeast infections and some gut problems.[10]
  • Oxalate crystals can form anywhere in your body when oxalic acid binds to calcium to form crystals, causing muscle pain. It’s very similar to the way uric acid crystals form in joints in cases of gout. Oxalic acid also causes most kidney stones when it binds to calcium in the kidney.[11]
  • Oxalates can also cause painful sex in some women when oxalic acid crystals form in the vulvar area of the vagina.[12] Vulvodynia, or pain in the vulva, is considered a “mystery condition” in Western medicine with links to yeast problems, antibiotic use and emotions.

Unfortunately, oxalates are not just in kale. Other high sources of oxalates include buckwheat, black pepper, parsley, poppy seeds, rhubarb, amaranth, spinach, chard, beets and beans. In short, oxalates are something you should minimize, no matter where they come from.

Keep in mind, you are also adding to your oxalate burden by eating raw kale regularly. There’s no reason to burden your body with oxalates without getting a large benefit at the same time.

Raw kale as a goitrogenic food

Kale and other cruciferous vegetables like broccoli, cabbage, cauliflower, etc. contain goitrogens which can disrupt the production of thyroid hormones. Goitrogens can inhibit the uptake of iodine into the thyroid gland, which slows the production of thyroid hormone.[13]

Thyroid hormones such as T3 and T4 play an incredibly important role in regulating your metabolism. If thyroid production slows down, your metabolism slows down, and your fat-burning ability slows way down. Being Bulletproof is all about minimizing the things that sabotage your hormone system and maximizing the things that rebalance your hormone levels.

Goitrogens are no joke. Reducing the amount of uncooked cruciferous vegetables (i.e. kale) you eat will reduce the amount of goitrogens you let in your body.

Fret not; there are safe ways to get the good stuff from kale…

4 ways to optimize your kale shake

Kale cooking in boiling water

A raw kale shake might seem easy to make—just blend together some raw kale and whatever other raw fruits or other vegetables you like. This common formula raises a few red flags in terms of optimizing health and human performance. Luckily, you can overcome the problems and upgrade your kale to make your body and mind Bulletproof!

1. Try “calcium loading” with kale

The Bulletproof perspective on calcium is that most people get too much of it compared to magnesium, so supplementing should be done in moderation for most people. But for kale fans, we change the rules. Excessive supplementation is still a bad idea, but adding it, along with magnesium, to your blender with kale is a great idea.

Because oxalic acid binds vital minerals in the gut, long-term consumption of foods high in oxalates can lead to nutrient deficiencies. When calcium supplements are taken with foods high in oxalic acid, the oxalates bind with calcium and reduce the levels of oxalates absorbed by the body.[14]

Additionally, a 1997 study showed that “mineral water containing calcium and magnesium deserves to be considered as a possible therapeutic or prophylactic agent in calcium oxalate kidney stone disease.” The study utilized French mineral water containing calcium (202 ppm) and magnesium (36 ppm). Each of 80 subjects provided 24-hour urine collection samples daily for the study, and drank mineral water for three days, then tap water for three days. The water with minerals improved nine risk factors for kidney stones.[15]

Pro Tip: Taking calcium with your kale or tossing it in your blender are two ways of helping mitigate the anti-nutrient effects of oxalates.

2. Eat kale with fat for optimal absorption of vitamins

Many vitamins and micronutrients are fat-soluble, meaning they are not well absorbed without the presence of adequate fat. One study showed that people who consume salads with fat-free salad dressing absorbed far less of the helpful phytonutrients and vitamins from spinach, lettuce, tomatoes and carrots than those who consumed their salads with salad dressing containing fat.[16]

Another study of over 1,782 Swedish men showed that consumption of fruits and vegetables was associated with a decreased risk of heart disease, but only when combined with full-fat consumption like full-fat butter.[17]

People always tell their kids to eat their vegetables but few parents realize that children also need to consume an adequate amount of fats with vegetables to fully support proper physical and mental development. Without adequate fat in the diet, children don’t receive the nutrients necessary for development.

The bottom line: Make sure you put plenty of fat in your smoothie. Many vitamins and nutrients can’t be absorbed without enough fat, so a fat-free smoothie is a waste of nutrients.

3. Steam your kale to reduce oxalates and goitrogens

In 2005, a study found that different ways of cooking foods, especially boiling or steaming, reduced the amounts of oxalates available.[18] With all the potential damage high oxalates in the body can cause—steam and drain your kale!

Lightly steaming kale and other cruciferous vegetables also significantly reduces the amount of goitrogens.[19]  Reducing goitrogens in your kale reduces the likelihood of disruption to your thyroid.[20]

Lightly cooking vegetables also helps break down the cellular structures to increase the digestibility and nutrient absorption of nutrients in the vegetables. Nutrient absorption is also important in terms of the amount of energy your body is actually getting from the food you eat. Studies also show that women who predominantly eat raw food have lower energy intake and higher rates of menstrual irregularities than those eating predominantly cooked food.[21]

4. Don’t eat battered kale

No, battered kale is not a new recipe. It’s what happens to kale that is roughly treated in the field. Kale that is stressed by the environment—insect predation, fungal infestation or drought and heat problems—will create more toxins, including oxalates.

So pick the prettiest kale you can find!

Upgraded Kale Shake recipe to supercharge your body and brain

Biohackers know cooking is one of the variables that leads to better personal performance. It’s not just the quality of your food, it’s how it’s prepared.

This upgraded kale recipe shows you how to serve your kale shake warm, not cold. It tastes amazing without any sugar or fruit, carries protein well and fuels your body and mind.

Print Recipe Print Recipe Icon

Upgraded Kale Shake

Learn how to mitigate oxalates and level up your morning kale shake.
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Prep10 minutes
Total Time10 minutes
Servings1 serving



  • Steam kale with about a cup or so of water until cooked (about 5-7 minutes).
  • Drain water. Add more fresh hot water if you want a thinner consistency.
  • Blend drained kale with calcium citrate, salt, herbs, vinegar, grass-fed butter and MCT Oil until super creamy.
  • Add Unflavored Collagen Peptide to the mixture and lightly blend until it is mixed in.
  • Pour shake into a glass and sip away!


Using a high-speed blender (e.g. Blendtec) is best. You’ll be happy with this functional, time-reducing, texture-enhancing investment.

Nutritional Information

  • Calories: 418
  • Fat: 39 g
  • Protein: 14 g
  • Fiber: 5 g
  • Sugar: 1 g
  • Carbohydrates: 6 g
  • Net Carbs: 1 g
  • Sodium: 285 mg