Kale. It’s become massively popular over the past decade. What was once a forgotten leaf only seen as a decor piece on salad bars has risen to a smoothie superstar and juicing staple.
However, as I’m sure you know, popular doesn’t necessarily equate to good, especially in the world of diet and health where misinformation and marketing tactics are rampant. As a result, many people find themselves asking the following questions:
“Is this really good for me? What are the actual benefits?”
But fear not…
We put together the ultimate, no nonsense guide to kale. It’s everything you wanted to know – and more – backed by peer-reviewed scientific research with no fluff!
Even though for most people, kale seemed to just pop up recently out of no where as the latest new “superfood”, it has actually been around for a long time!
Looks Yummy Right?
Conservative estimates state the cultivation of kale dates back over 2,000 years ago. It was widely popular in Europe up until around the time of the middle ages. Over time, kale cultivation was phased out to grow what become modern-day cabbage.
Kale and cabbage are actually part of the same family of species known as Brassica oleracea. The reason why they are so drastically different in our eyes today is due to countless generations of selective breeding.
If you’re a history buff and want to learn more about the nitty gritty details, we suggest this article by Veraveg.com
Before we get into the nutrients kale provides and the specific research has been done on the leafy vegetable, one should be aware how this information may differ from other sources.
We've compiled only information that has been backed by peer-reviewed scientific studies, which should be the gold standard when it comes to understanding nutrition. We've removed all anecdotal claims and speculation from this review. Anecdotal and speculative claims are often used to promote products such as diet books and supplements. While not inherently malevolent, these claims can often be misleading and are not scientific.
By taking a look at the macro and micronutrient profile, we can see a 100 gram serving of both raw and cooked kale are high in Vitamin K, C, and A. While raw kale may have more vitamins and minerals overall than cooked, cooked kale does have higher vitamin K availability.
While these nutrition facts indicate that raw kale may pack a more nutritious punch than cooked gram for gram, cooking kale may make the leafy green more palatable and allow one to to consume more volume. This would result in more nutrient consumption overall.
Now that we know the nutrient content of kale, let us take a deeper look at the actual effects it has when consumed and in vitro (studied inside a test tube or petri dish).
A special thank you to Dr. Greger from NutritionFacts.org who made these awesome, easy to understand, and informative videos using only peer-reviewed scientific literature. We will be referencing some of his work as well as individual peer reviewed studies during this article.
A very simple laboratory study done with kale and white blood cells revealed that kale can have an extremely positive impact in our white blood cell’s ability to produce antibodies.
It also made no difference if the kale was cooked or raw. In fact, in terms of antibody production, the cooked kale outperformed its raw counterpart!
Kale and the Immune System by NutritionFacts.org
We couldn’t find an actual human trial on this (probably because they are extremely time consuming and expensive to fund), but that’s not to say that this study isn’t extremely indicative of the positive impact kale can have on the human immune system.
The actual study can be found here.
Another study done in Japan (on actual humans this time), showed the amazingly beneficial impact that kale shots had on cholesterol levels. In this case, the (34) study participants drank 3-4 shots of kale juice over a 12 week period.
This nutrition intervention had a tremendous impact on their Serum Lipid Profiles (good and bad cholesterol).
It also had massive impact on the levels of antioxidants on their blood (more on that in the next section).
Check out this short video below from Dr. Greger for the full study breakdown:
A link to the actual study can be found here.
As noted in the previous section, the participants in the kale shot study had a huge increase in the antioxidant levels in their blood (aside from the participants who smoked).
We hear about antioxidants all the time, but why are they actually important and how do they work?
Delicious Looking Free Radical Neutralizing Foods
Free radicals (the stuff that antioxidants neutralize) are produced as a part of digestion.
When we have too many of these free radicals floating around it can cause a whole host of problems including (but not limited to):
That's why it is important to neutralize these free radicals with anti-oxidant rich foods, including kale, that have a drastic impact on the antioxidant levels in the blood (see previous section).
Other foods such as berries are crucially important in this equation as well.
I highly suggest checking out this comprehensive piece to get the full scoop on why you should strive to keep yourself in an antioxidant surplus.
Consuming kale (and collard greens) will give you an abundant amount of zeaxanthin, a phytonutrient with eye-protecting properties.
A study done on African-American women showed that a mere 2 to 3 servings per 3 month of kale/collard greens reduced the risk of glaucoma by half!
Check out the video below for more details on the study:
The Relationship of Greens and Glaucoma
It's a common claim among "snake oil salesmen" that a certain food or supplement can prevent or treat cancer. Because cancer is a complex thing, it's important to take everything in it's proper context.
Bile acid is an integral part of our digestive system, one of its main functions is to help us get rid of excess cholesterol. This is why our liver puts bile acids into our intestines for this very function.
However, these bile acids have the potential to be absorbed back into the body and promote cancer growth. This is especially true within the breast tissue where these carcinogenic bile acids seem become concentrated.
One way to combat this is having a diet rich in whole plant food based fiber which can speed up the process of food moving through the body.
But what does this have to do with kale?
It turns out that another way to effectively get rid of bile acids is to consume foods that absorb the acids themselves. Kale is one of the most effective plant foods in absorbing bile acids topped only by Okra and Beets (see details in the video below).
While many people on the internet falsely use clickbait and scare tactics to say that there are health downsides to kale, it does not mean that it is completely false. Just like anything in life, you can indeed get too much of a good thing. But how much is too much?
Much like all cruciferous vegetables, there are compounds (called goitrogens) that can actually interfere with thyroid function if you consume them raw. They do this by blocking the thyroid's ability to uptake iodine. However, you can mitigate this somewhat by increasing your intake of iodine rich foods such as sea vegetables. While there's no exact amount that can be cited to cause damage, you're most likely better off cooking your kale anyway.
Cooking the kale (as we'll get into below) deactivates the culprit enzymes and will make it more delicious as well! That is unless you're making a kale salad multiple times a day. If this is the case (even though we don't recommend it), be sure to keep an eye on your iodine intake and either supplement or regularly intake iodine rich foods such as seaweed.
You can learn more on this subject of over-consuming kale or other greens here.
So you’ve learned all about kale and want to eat more of it, but you’re unsure on how to properly integrate the bitter tasting leafy green into your diet.
We’ve gone and hand-selected some of the most delicious and easy to prepare recipes you can integrate into your daily routine (all without any animal products of course). You can also check out this comprehensive article on green smoothies which is a great way to get in your greens. We recommend sticking with their almond milk suggestion in the recipe.
There’s something unique about Doritos that makes them one of a kind. Crunchy, tangy, cheesy… delicious.
Wouldn't it be great if there was a way to make Doritos healthy?
Well, this recipe comes pretty close.
The EdgyVeg makes the most delicious Dorito Kale chips in this short recipe below. They might just be better than the super expensive (but delicious) Brad’s Kale Chips.
We've had some awesome results making kale chips in our air fryer. If you don't have a convection oven its an awesome alternative.
If you're in a pinch and don't have the time to make the Dorito kale chips, here's a quick and simple Spicy Kale Chip recipe. It doesn't require a blender or any special tools and only takes around 15 minutes to make. It's a great substitute for potato chips or to satisfy any crunchy cravings you might have. Preparing kale doesn't have to be long and complicated (unless of course you want it to be)!
Its amazing how you can transform seemingly bland and boring bowl vegetables into an amazing looking meal. This Spiralized Sweet Potato and Kale Salad from Inspiralized has tons of textures, flavors, and colors. We promise that you'll forget you're eating vegetables.
If you want to learn more about the tools they used to make the salad, our Top Zoodle Makers / Spiralizer post as well as our blender section might be helpful. Having the right tools in the kitchen can be the difference between being motivated to cook a healthy meal and going to get takeout.
Shout out to The Happy Pear for this quick and easy stir-fry!
Gianna from Gianna North Beach has a really delectable Italian recipe for sautéed kale. He really gets into the nitty gritty as to the proper cooking methods so pay attention!
Even though this gentleman doesn’t always do vegan recipes (like most of the people that we feature), he gives so many great tips in this video on properly sautéing kale that I just had to link to it.
Huge shout out, again, to the Edgy Veg for making this video. Not only do the recipes themselves look great, but she throws in a few preparation tips which shouldn’t be skipped over, such as massaging the kale and storing it for later.
As someone who struggled to prepare kale salads properly for the longest time, believe me that massaging the kale will completely transform how you view and prepare it!
You’ll need her pesto recipe (in a separate article seen here) which will be critical to making one of the two salads that she mentions in this video.
If you want to make something truly exquisite with kale, you're going to want to check out the recipe below by Levana Kirschenbaum owner of Levana's Whole Food Kitchen and Levana's Complete Meal Replacement.
Black Rice Risotto with Kale and Oyster Mushrooms
This recipe is going to require some special ingredients such as saffron, but we always encourage people to explore and expand their culinary abilities. Even those who say that they "can't cook" have the ability to exceed their expectations with a bit of practice and patience.
For cooking grains like in the recipe above, having the right rice maker can make a huge difference in convenience and clean up.
Unlike most "fads" in the health world, it's safe to say that the popularity of kale shouldn't be dismissed as just another meaningless craze.
Here's a final list of our kale pros and cons:
As our featured recipes have shown, it's also really versatile and can be eaten in so many delicious ways.
So what's our conclusion?
Eat more kale (just not a boatload of raw kale!)
Cooking healthy, delicious, plant-based meals has been Joey’s true passion since he went vegan in 2015. He has a masters in Nutrition and Food Science and is committed to making the internet a place of education and knowledge rather than misinformation and clickbait. He currently lives in Delaware with his wife.