If kale were a fashion statement, we’d say it’s very “in” right now. In fact, die-hard fans actually do tend to wear their hearts on their sleeves, so to speak, when it comes to this green, leafy wonder. So what calls for the relatively recent boom in admiration (when it’s been around for more than 4,000 years)?
Instead of writing it off as some bandwagon health trend, we thought we’d investigate ourselves to find out why kale is revered by so many people, both vegans and non. Hopefully, the following can serve as your ultimate “Kale 101” crash-course!
- What is kale?
- What does kale taste like?
- Quick facts about kale
- One cup of kale delivers 10 times your daily value (DV) of vitamin K.
- Gram for gram, kale contains more vitamin C than an orange.
- Kale is also an excellent source of calcium.
- That being said, too much kale can complicate existing health problems
- Kale is listed on the Environmental Working Group’s “Dirty Dozen Plus” list.
- That being said, kale is actually highly affordable!
- Even still, “kale” was once used as a slang term for money.
- For a quick, healthy vegan snack, try the ever-so-popular kale chips.
- A couple enthusiasts gave kale its very own day of annual celebration.
- They also co-authored a cookbook called, “50 Shades of Kale.”
- Nutritional profile
- Health benefits of kale
- How to buy kale
- How to prepare kale
- Ways to Eat kale
- Kale recipes
- Are there any downsides?
- Storing kale tips
- Are kale supplements available?
- Can you grow kale at home?
- Kale 101…Done!
What is kale?
Kale, an edible leaf, hails from the mustard family, brassicaceae (also known as Cruciferae).
In 4th century B.C., the Greeks developed kale from wild mustard, and it initially resembled loose-leafed cabbage. During the Middle Ages, this “Sabellian kale,” deemed by the Romans, quickly spread across Europe, and with it, carried a variety of purposes and descriptors. (1, 2)
Italians compared it to “dinosaur scales” while the Scots described kale’s leaves as “frilly petticoats.” In Greece, kale was used to cure hangovers while in Ireland, children yanked kale stalks from the ground to predict their future love lives.
Most interestingly, perhaps, the English grew kale, an extremely endurable crop, as a metaphor for resilience during WWII, in support of a “Dig for Victory” campaign. (3)
Kale entered North America in the 1500s via colonists, who used it to develop cabbage, broccoli variations, cauliflower, kohlrabi and Brussels sprouts (fellow members of the genus, brassica).
In 1993, the Japanese created broccolini, a hybrid of broccoli and kai-lan, as well as various ornamental kales. Today, kale continues to (literally) grow with popularity: The USDA reported farmers producing nearly 60 percent more kale in 2012 than in 2007. (4)
One reason for kale’s global spread is due to its unique ability to thrive in cold climates (and warm, Mediterranean ones). Kale can survive at temperatures as low as 20 degrees Fahrenheit, and it actually becomes sweeter after a heavy frost. While the USDA reported that sunny California is the largest U.S. producer, with 390 farms and 1,680 acres harvested, the much colder state of New Jersey came in third. (5)
Different types of kale
Kale’s legacy is only matched by its diversity. After all, variety is the spice of life! While many versions of kale exist, we’ll peruse the kinds of kale most popularly pursued:
With ruffled leaves and a bright-to-dark green hue, this is the most recognizable kind.
Also called Dinosaur kale or Tuscan kale, this version has tall and narrow, dark blue-green leaves with wrinkled texture.
Red Russian kale
This kind of kale is easy to spot! Just look for reddish-purple stems and leaves like jumbo-sized arugula.
With a deep reddish-purple hue and tight curls, this kind of kale is both edible and ornamental by nature-it makes for a great plate garnish!
Here’s a clip of Martha Stewart herself using the most popular kinds of kale:
Check out this super short slide show for a few lesser known kale varieties, elements of taste and preparation tips:
What does kale taste like?
Kale might not be “sweet,” but there are sweeter kinds. Red Russian and redbor are slightly sweeter than curly kale and lacinato kale. And while curly kale is more bitter and has peppery qualities, lacinato kale offers a softer, earthier taste in comparison.
If you’re looking to get started with kale, we suggest you assess and see for yourself. Try a few kinds, but start with the type you think you’ll enjoy the most. After all, if we don’t enjoy something (even a little), it’s not likely we’re going to continue with it!
And the great news is, if your taste buds have yet make friends with kale or you simply struggle to “get in” your greens, there are a few ways to prepare kale (more on this soon) that will not only soften its flavor but its texture, as well.
Quick facts about kale
From health benefit to potential risk to cultural quip, here are a few interesting aspects of kale, some of which we’ll unpack a bit more later:
One cup of kale delivers 10 times your daily value (DV) of vitamin K.
Kale is rich in phylloquinone (K1) whose emerging functions include improving bone, cardiovascular and cognitive health, and reducing inflammation and risk of diabetes. (6)
Gram for gram, kale contains more vitamin C than an orange.
Kale is also an excellent source of calcium.
A study found that kale, a low-oxalate vegetable, exhibits excellent absorbability, when compared to spinach, which is higher in oxalic acid and can interfere with our body’s ability to absorb available calcium. (9, 10)
That being said, too much kale can complicate existing health problems
While a surplus of cruciferous vegetables can contribute to hyperthyroidism in individuals deficient in iodine, it would have to be a lot. As in pounds, so no need to order kale by the truckload… a little goes a long way! (11)
Kale is listed on the Environmental Working Group’s “Dirty Dozen Plus” list.
Along with collard greens and hot peppers, kale tested positive for highly toxic, partially-banned insecticides. Always choose organic when buying kale! (12)
That being said, kale is actually highly affordable!
Even still, “kale” was once used as a slang term for money.
When Abraham Lincoln’s treasury secretary introduced paper money in 1861, it reminded people of the color of vegetables. By 1911, people were calling their bills kale, and then later, lettuce and cabbage. (15, 16)
For a quick, healthy vegan snack, try the ever-so-popular kale chips.
A couple enthusiasts gave kale its very own day of annual celebration.
Dr. Drew Ramsey and Chef Jennifer Iserloh anointed the first Wednesday of every October, “National Kale Day.”
To take part, they suggest you host a kale-based potluck, share a recipe (@nationakaleday and #kaleday2018) or plant some seeds. (17)
No, really… they did.
According to nutritionvalue.org, 100g of raw kale contains 49 calories, 0.9 g of fat, 8.8 grams of carbohydrates and 4.3 grams of protein. It offers 3.6 g of fiber and 2.3 g of sugar (natural, of course). (18)
While kale is famous for vitamin K, A and C, it also offers 8% of your daily iron, and significant amounts of vitamin B complex, such as B6, Niacin, Riboflavin, and Thiamine.
In addition to calcium, kale contains significant amounts of daily mineral requirements, such as copper, manganese, magnesium, iron, potassium and phosphorus.
And for only 1g of fat, kale packs a punch, offering modest amounts of an omega-3 essential fatty acid, alpha linolenic-acid (with impressive benefits, up next).
Even more? Kale is 85% water, so this food choice is also highly hydrating.
Health benefits of kale
Besides its nutrient density, let’s examine some of the beneficial functions of this so-called “superfood” that are supported by current scientific research.
1. Anti-inflammatory effect
A 2002 study suggests that humans evolved on a diet with an omega-6 to omega-3 fatty acids ratio of about 1:1. Today’s western diets often have a large amount of omega-6 and an insufficient amount of omega-3 (closer to 15:1). (19)
Since kale offers nearly a 1:1 ratio, this balance may help fight off some of the inflammation that results from a surplus of omega-6, typically found in processed foods.
2. Antioxidant content
Why are antioxidants important? Simply, they help protect our cells from free radicals, menacing molecules that we ingest by way of the pollution, toxins and chemical in our air, food and water. (20)
Too many, and we encounter oxidative stress, which impairs our DNA and cell structures while increasing our risk of chronic disease (e.g. type 2 diabetes, cancer) and neurocognitive disorders (e.g. Parkinson’s, Alzheimer’s). (21)
A 2009 study found that curly kale offers 32 phenolic compounds, including large amounts of quercetin and kaempferol. These flavonoids protect the heart, lower blood pressure, reduce inflammation and fight depression. (22, 23, 24, 25)
3. Detoxification and cancer prevention
According to a 2002 study, kale helps remove and eliminate toxins at a cellular level due by way of isothiocyanates (ITCS), which are made from glucosinolates, a large group of sulfur-container glucosides. (26)
These ITCS can also “inhibit mitosis and stimulate apoptosis of human tumor cells,” meaning, they play a vital role in preventing cancer. (27)
4. Cholesterol reduction
A fair amount of research suggests that kale has a positive effect in this area. One 2007 study found that the bile sequestrants in kale may lower cholesterol over time. (28)
After its participants drank kale juice daily for 12 weeks, another study found that HDL (the “good”) cholesterol increased by 27% and LDL levels dropped by 10%. A third study reported that steamed kale is 43% as effective as the cholesterol-lowering drug, cholestyramine. (29)
5. Eyesight preservation
Lutein and zeaxanthin are two of the antioxidants found in kale, and as we age, they’re crucial for maintaining eye health. Since our bodies do not produce these, we must acquire lutein and zeaxanthin from food sources, and kale tops the list of fruits and vegetables with 20.5 – 26.5 mg of each per cup! (30, 31)
6. Improved digestion
Most people do not consume enough fiber, a carbohydrate that passes through the body undigested. Fiber helps to keep our hunger and blood sugar in check. While we need at least 20 to 30 grams per day for optimal health, most people get less than 15.
Since kale contains nearly 4g of fiber per every 100g, it may help make up for that deficit and aid in digestion.
However, scaling your fiber intake from zero to hero status can be a shock to your body’s system. If you experience gas or bloating after eating raw kale or drinking kale juice, lessen these symptoms, or eradicate them entirely, by cooking kale instead!
7. Weight loss
Due to kale’s low caloric content and high nutritional density, it makes for a great weight loss food. And since it contains a fair amount of protein and fiber per gram, it will keep you feeling fuller longer as well. (32)
Check out this article, too, for more healthy weight loss tips.
How to buy kale
Based on our gathering of information thus far, if you’ve decided, “I think I’d like to try some kale,” or eat it more regularly, here are a few things to consider when selecting kale from your local grocer or farmer’s market.
As it thrives in cold weather, kale is in season from August through April.
Curly kale might be the most “widely recognized” kind but that doesn’t mean you have to eat it. We suggest you try as many varieties as possible and prepare them several ways!
As a tip, the University of California at Berkeley’s Wellness website recommends choosing smaller-leaved kale for milder flavor, especially if you plan to eat it raw. (33)
Small leaves equals softer leaves, too. The larger the leaves, the tougher they’ll be.
Kale leaves should not be yellow or brown! Look for greens, reds and purples.
Moist, crisp, kale that has not wilted is ideal. Avoid blemishes or holes, which indicate insect damage. Since the stems are edible, ensure that these are in good condition, too.
Fresh vs. frozen?
While some kale is better than no kale when it comes to health benefits (as long as it is organic!), the vitamin and mineral content of 100g of frozen kale is greatly reduced compared to a fresh 100g.
One study showed that vegetables in kale’s brassicae family are better fresh as they retain more of their antioxidant and phytochemical properties. (34)
“Ready-washed” vs. home-washed?
Ready-washed or pre-washed greens means the manufacturer is claiming their product is safe to eat straight out of the bag or bin.
However, a recent study found that bags of spinach and lettuce, many labeled organic and “triple-washed” or “ready to eat,” still contained harmful bacteria. Overall, it concluded that “microbiologically, these products may be very difficult to clean and process.” (35)
Further, in 2010, when Consumer Reports looked into the sanitation of pre-washed or triple-washed produce, it determined that 39 percent of the samples tested contained high levels of coliforms and 23 percent tested high for enterococcus. (36)
Regardless of what the packaging says, clean your kale in a sanitary environment and get familiar with the Food Poisoning Bulletin’s list of possible solutions. (37)
Organic (last but not least!)
We hope we drove this home with our previous bit about the “Dirty Dozen Plus,” but as a friendly reminder, to avoid consuming toxic pesticides, always go organic with kale.
How to prepare kale
To maximize enjoyment and nutritional benefits, try these tips for having kale at home:
The stem is a tough chew, even after cooking. Enjoy this element? Have it! But if not, peel the leaves off prior to cooking or consuming raw. Use your fingers or get yourself a kale stripper to make this process super simple!
As mentioned, make sure to rinse the leaves under running water for at least a minute.
Separate the leaves into smaller pieces when the kale is still raw. After it’s been cooked, it softens and becomes slightly more difficult to slice (should you have the desire).
You heard us right. Massaging kale (literally, rubbing the leaves against each other) is a great way to soften them in the absence of heat.
This process breaks down their tough cellulose structure, and the leaves will actually darken, gain a silk-like quality and shrink in size. Add a drop of oil of olive or lemon squeeze to enhance the process! (38)
From prep to finish, here’s a quick “kale massage” training video to get you started!
Ways to Eat kale
There’s no right or wrong way! But we suggest you evaluate your purpose for kale consumption. If you want to maximize your nutrient intake, you might want to juice kale. If you’re constantly pressed for time, then a quick blend is your best friend.
And remember, when it comes to making healthy choices, some is always better than none! So, let’s explore a few of the most popular ways to eat kale:
Perhaps this is obvious, but kale (especially after a massage!) makes a great base for your favorite salad ingredients. Try mixing it with spinach, romaine, arugula or iceberg lettuce to diversify your nutrient profile!
Not a salad person? No problem! Toss some massaged or steamed kale on your plate as a complement to your proteins and healthy sources of fat. Or chop it up and sprinkle the bits on top of your dish to create crunchy texture and add a lovely garnish!
A quick and easy path to daily kale consumption is by way of a smoothie or shake! No need to cook your kale. Just strip the stems and toss the leaves in a blender. Add half of a banana and berries or a dusting of cinnamon spice to mask kale’s presence completely.
While smoothies make kale incredibly accessible, so do chips! Like we said earlier, there are plenty of credible brands for you to choose from or you can make your own at home with the help of the best food dehydrator on the market!
Should you adore the taste of kale, we recommend juicing; comparatively, it has quite the opposite, highly concentrating effect.
However, while juicing increases the speed at which your body absorbs kale’s nutrients, you are not receiving its fiber (though if you eat a whole foods, plant-based diet, this shouldn’t be an issue).
If you want to juice kale and struggle with the taste, try adding orange juice for a fantastic vitamin C cocktail!
While our food is most beneficial when consumed in its natural form (raw, cooked, dehydrated, juiced, blended and beyond), there are kale supplements, and we’ll cover these soon.
Time to get specific! May these recipes serve as a few foundational blueprints for your future of kale-filled culinary creations!
Vegan creamy kale, version 2.0
Not only is ConnoisseurusVeg one of the coolest names for a vegan blog that we’ve ever heard, its founder, Alissa, provides a plethora of Dino-mite recipes!
Of the lot, her Vegan Creamy Kale is a great place to start for new kale-nibblers and sure to please long-time kale-lovers! This recipe makes for a scrumptious side dish, for the Thanksgiving/holiday table or just your regular Thursday night. And with minimal ingredients, it takes just 20 minutes to make!
Click here to get cooking with your friendly neighborhood vegan dinosaur!
For a protein-packed meal, count on this combination of kale and quinoa to keep you feeling full! From Christin of VeggieChick.com, this dish has just 8 ingredients and 5 minutes of preparation (with 25 minutes of cooking).
Christin recommends you get creative–feel free to add in your own vegan favorites to this great base, tofu to turnips. While it serves 4, double up and start stylizing your own meals for an entire week!
Check out Christin’s kale quinoa recipe here for the key to your food-prep-freedom and saving hours in the kitchen.
Kale chip nachos
While kale chips are great on their own, naturally, they’re a key component of vegan nachos!
With just 8 ingredients (nutritional yeast, black beans, sweet potatoes and avocado, to name a few) and 30 minutes of kitchen-prep, Dana of The Minimalist Baker says she enjoys this crispy, flavorful, filling concoction as a full-meal (her “single lady dinner”) or as an appetizer for sharing with her girlfriends on Mexican night.
To make your own vegan (and gluten-free) kale chip nachos, and to discover additional plant-based dishes to complement this one, check out her full recipe here.
Healthy kale and cauliflower soup
We love that this recipe, from Deryn at Running on Real Food, pairs kale with its brassicae sibling, cauliflower, to create a tasty yet totally good-for-you meal. From prep to chow-down, it takes just 30 minutes.
This soup is low calorie, gluten-free and fat-free, but hearty and an especially fond option for a cold winter’s day! Deryn also includes a detailed breakdown of the nutritional information based on serving size.
To begin brewing your own batch, check out the recipe here.
Are there any downsides?
A part from ingesting an exorbitant amount or an inorganic supply (problems certainly not unique to kale), let’s asses specific downsides that exist, using facts.
Individuals who take blood thinners must be mindful of their vitamin K consumption. As Vitamin K is an essential part of the blood clot formation process, too much can decrease the intended impact of a given blood thinning drug, such as warfarin. (39)
We suggest you consult with your doctor about your micronutrient levels, and the potential impact of kale consumption, before taking blood thinners. You can learn more about potential risk factors in the findings of this study on food-drug interactions. (40)
While there are several articles out there that mention thallium contamination as a potential risk of kale consumption, according to an actual 2008 study, you would have to consume 154 pounds of kale before your blood would register toxic levels. So, rest easy, even the greatest of kale admirers won’t come close! (41)
Storing kale tips
Now you know that kale should really be in your kitchen, you’re probably wondering how you can keep your favorite green leafy fresh for longer. Let’s find out!
Short-term storage (up to a week)
Again, always begin by washing your kale (remove the leaves from the stems if you’d like). Dry the leaves, and wrap them in paper towel to help absorb the moisture. Store your kale in an airtight container (opt for a freezer-safe glass jar if you can!) and place it as close to the back of the fridge as possible to keep it cold.
Check out this minute-long demonstration for a visual guide!
Long-term storage (Up to 6-8 months)
If you’d like to freeze your fresh kale, you’ll want to blanch it prior to freezing it, which will help preserve taste and texture and strengthen vitamin and mineral retention. Never blanched before? No worries! Follow the steps below:
Step 1: Remove the leaves, whether by hand or with your handy-dandy kale stripper.
Step 2: Boil water. Toss in the leaves. Cook for 1-2 minutes until they brighten in color.
Step 3: Remove the leaves and transfer them to a large bowl of ice water.
Step 4: Dry the leaves with paper towel and set them on a baking tray. Let them sit for 1-2 hours until they are solid.
Step 5: Transfer the leaves to freezer bags or jars. But make sure the leaves are dry first. If you pack sopping wet kale, it will become one big block of kale ice!
Step 6: Tuck your kale away in your freezer! Enjoy the time you’ll be saving in the months to come as you toss your kale straight into your blender.
Here’s a quick, candid video of two people in the midst of the kale blanching process:
Are kale supplements available?
Like we mentioned briefly, kale supplements do exist from pills to powders. However, we’ll borrow a significant quote from an article by Harvard Health, when we say “supplements can plug dietary gaps, but nutrients from food are most important.” (42)
Based on several studies that show no endorsing evidence, it’s crucial to improve our diets prior to using artifice for assistance. While we do stress that vegans supplement B12, it’s only available via animal food sources, and so, there’s no better alternative.
Also, since kale is so nutrient-dense, and incredibly affordable in its whole form, it doesn’t make much sense to spend anywhere from 5 to 20 times as much money on a product that offers a fraction of the benefit.
Before you supplement
Watch for these red flags if you choose to supplement kale…or anything else!
Just as we do with whole food, it’s important to read the ingredients on the box or bottle. Many companies will use gelatin in the casing, and this is made from animal body parts, like hooves. Thankfully, vegetable capsules do exist for many products.
(Check out my article Is Jello Vegan? for more info on gelatin.)
Synthetic vs. live-source
Always look for a supplement that contains real food. For example, look for “broccoli leaf powder” as opposed to the phrase, “Vitamin C.” A supplement for a given vitamin that doesn’t have any real foods listed on the label is almost certainly synthetic.
Some companies cut their supplements with non-nutrient elements to speed up the manufacturing process and create a longer shelf life. This almost always increases toxicity.
Can you grow kale at home?
Want to be certain of where your kale’s been and how it’s been treated? Plant and harvest your very own crop!
Certain factors will vary slightly based on kind of kale, time of year and whether you use seeds or transplants, here are a few general growing tips:
Location, location, location!
During the fall/winter growing season, make sure your growing area, whether a traditional garden or a container (a bucket or a window box) receives 6-8 hours of direct sunlight every day. When planting in the summer, allow your kale to sit in partial shade.
Place seeds at least ½ inch deep in the soil, 12-15 inches apart, in rows 18-24 inches apart. Plant more than you think you’ll need in case some seeds don’t make it.
Make sure your soil is moist, loose, and well-drained with a pH between 5.5 and 6.8. And while kale germinates best in cold temperatures, it sprouts best around 70 degrees. You can use a vegan fertilizer or form of compost and lay mulch (straw or grass) once the leaves are at least six inches high. (45)
Once the leaves are 8-10 inches high, cut two inches above the soil line. The plant will sprout new leaves in 1-2 weeks.Try to harvest before any leaves turn brown or wilt. But, if they do, the good news is they can be used as compost for your current efforts!
We hope this comprehensive look at kale has been illuminating. May this information help you draw your own conclusions about incorporating kale into your diet!
As always, we’re happy to answer any additional questions you might have, if you could please leave us a message in the comment section below.
About The Author:
Carly Keyes is writer and personal trainer who decided to go plant-based after a visit to the True North Health Center in Santa Rosa, CA. The change has completely revolutionized the way she feels, looks, thinks and behaves, making her a very vocal advocate of the vegan lifestyle.
She’s also a keen singer/songwriter and has studied screenwriting at the University of Michigan. Carly lives in Bloomfield Hills, MI.
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- Linda Larsen | To Wash or Not to Wash: Are Pre-Bagged Salads Safe? | https://foodpoisoningbulletin.com/2012/to-wash-or-not-to-wash-are-pre-bagged-salads-safe/
- Kitchen Daily | How To Massage Kale: Why A Rubdown Helps This Leafy Green | https://www.huffpost.com/entry/how-to-massage-kale_n_1601200
- Cleveland Clinic | Why Vitamin K Can Be Dangerous If You Take Warfarin | https://health.clevelandclinic.org/vitamin-k-can-dangerous-take-warfarin/
- Rabia Bushra, Nousheen Aslam, and Arshad Yar Khan | Food-Drug Interactions | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3191675/
- Anna L. Chollet And John W. Brock | Evaluation Of Lead Content Of Kale (brassica Oleraceae) Commercially–available In Buncombe County, North Carolina | Https://dc.lib.unc.edu/cgi-Bin/showfile.exe?cisoroot=/jncas&cisoptr=3890
- Harvard Health | Should you get your nutrients from food or from supplements? | https://www.health.harvard.edu/staying-healthy/should-you-get-your-nutrients-from-food-or-from-supplements
- CCOHS | Titanium Dioxide Classified as Possibly Carcinogenic to Humans | https://www.ccohs.ca/headlines/text186.html
- ND Health Facts | Excipients and Fillers | https://www.ndhealthfacts.org/wiki/Excipients_and_Fillers#Types_of_Excipients_and_Fillers
- Alisa Rutherford-Fortunati | Kale: An Easy Beginner’s Guide to Growing | https://gentleworld.org/kale-an-easy-beginners-guide-to-growing/