Kale

Hailing from the eastern Mediterranean and Asia minor, the benefits of kale have been enjoyed by Greeks and Romans thousands years ago, along with other collard greens widely cultivated back then. Kale, also known as leaf cabbage and borecol, is not only a dark green leafy veggie with a rich history, but also a powerhouse of nutrition and medicinal properties, many of them corroborated by modern science.

Kale is arguably one of the most popular healthy green foods around the world, and its reputation is well-deserved. Kale is not only nutritious and credited to have detoxifying properties, but numerous scientific studies have revealed that is is helpful for both reducing the risk of chronic diseases.

According to science, the most relevant benefits of kale include:

• Reducing inflammation. Kale dark green leaves are rich in antioxidants and other natural compouds that have proven effective reducing inflammation markers, thus reducing the risk of chronic and age-related diseases.

• Lowering cholesterol. The most relevant factor for cardiovascular health is cholesterol. Kale have been shown to reduce the build up harmful cholesterol (LDL) the arterial walls, helping treat and prevent atherosclerosis and coronary and coronary arthery disease.

Other significant kale benefits for human health are:

• Supporting skin and eye health. The regular intake of kale, along other foods rich in carotene, has been shown to preserve vision, preventing macular disease, and also contributin to skin regeneration, delaying the onset of the first visible signs of aging.

• Promoting brain function. Kale is rich in nutrients and other microcompounds that are essential for brain development and optimal function, as well as for helping prevent neurodegenerative diseases.

The anti-inflammatory properties of kale are mainly attributed to glucosinates. Like other cruciferous vegetables, kale is capable of reducing systemic inflammation by improving microbiota composition, promoting the presence of beneficial microorganisms, and reducing the ratio of harmful bacteria.^1,2

On the other hand, the presence of flavonols, mainly kaempferol and quercetin, is thought to be responsable for the cardioprotective, cholesterol-lowering benefits of kale. These compounds have the ability to interact with fat acid-binding proteins, reducing dangerous levels of cholesterol. ^3,4

High levels of carotenoids are behind the skin protective benefits of kale. These compounds stimulate collagen production, which allows tissue regeneration and speeds-up cicatrization.⁵

Other herbs with anti-inflammatory and hypocholesterolemic properties are avocado,beetroot, broccoli, and oat. 

Side Effects of Kale

Due to its high levels of vitamin K, people taking blood thinning medications must consume kale in moderation. Individuals with thyroid disorders should be aware that kale contains goitrogen, an anti-nutrient that can interfere with iodine absorption, thus affecting the production of hormones.

Kale is arguably one of the most nutritious green vegetables. It is not only rich in dietary fiber, crucial por blood sugar control and digestion, but also provides adequate amounts of plant-based protein, along with outstanding levels of essential nutrients.

Kale is a great addition for supporting bones' health due to the abundance of calcium and manganese in its dark green leaves.  On the other hand, good amounts of potassium improve nerve transmission and muscle contraction as well as kidney and heart functions. Additionally, kale provides good levels of iron and copper, both necessary for the production and transport of red blood cells.

On the vitamins' department, is easy to see why kale is considered as a superfood: it's a surprising powerhouse of vitamin C (ascorbic acid), a water-soluble antioxidant that not only protects cells from free radicals' damage, but also aids proper absortion of other nutrients, mainly calcium, folate, and iron. Kale also boasts provitamin A carotenes, essential for skin regeneration and eye health, vitamin K (phylloquinone), responsable for healthy bones and proper blood clotting, and great levels of B vitamins, chiefly B₂ (riboflavin), crucial for fat absorption and metabolic processes, as well as folate, instrumental for brain function and the nervous system. 

100 grams of raw kale leaves provide 35 calories, 6%DV of plant-based protein, and 16%DV of dietary fiber.

Natural Forms

• Raw. Kale is commonly consumed in salads, alone or mixed with other green leaves. It is worth to notice that, due to their amount of fiber and oxalates, kale leaves can be hard to digest and must be consumed in moderation.
  

• Cooked. Since boiling kale leaves can somewhow diminish their antioxidant power and nutritional value, steaming them is recommended to reduce their oxalate content without losing their wonderful benefits.
  

• Infusion. Kale tea is a popular way of reaping the anti-inflammatory, cholesterol-lowering properties of this greeny vegetable. Roasting the kale leaves before hand will help release the aroma and maximise the benefits of this medicinal infusion.⁶
  

• Powder. For smoothie lovers, this may be the easier way to take advantage of kale's nutrients and medicinal properties; however, kale powder can also be added to culinary dishes, such as mashed potatoes, soups, and more.
  

• Poultice. It is believed that the topical application of kale leaves over sore muscles and joints can reduce inflammation and pain, particularly in people with osteoarthritis.

• Chips. Kale leaves can be made into chips, which are nowadays trendy for a good reason: they are a great, crunchy snack that can be easily prepared at home using an airfryer or an oven. 

Herbal remedies & Supplements

• Liquid extract. Kale leaves are used to obtain a liquid extract, rich in antioxidant carotenoids, concentrating the anti-inflammatory and hypocholesterolemic properties of this Brassicae vegetable.
  

• Tincture. Infused in a base of alcohol or glycerine, this is a medicinal preparation of kale that should be consumed diluting few drops in water, and brings benefits that are similar to those of the liquid extract.
  

• Capsules. Kale extract also can be found in the form of capsules, which are widely available and easy to consume in order to reap kale benefits.

Adapted to temperate and cold climates, kale is a hardy plant, ideal to grow in a backyard for culnary or ornamental purposes. Given few basic conditions of soil, sun exposure, and humidity, this nutritious vegetable can be a great addition to any garden.

Growing Guidelines

• Kale can tolerate different types of soil, as long as they are fertile and well-drained. Adding organic matter and fertilizer beforehand is highly recommended for best results.

• Kale seeds need to be sown 1/4-1/2 inch (  cm) deep in a sprouting tray.  After a germination period of 6 to 12 days, the seedlings can be transplanted, with a space of 12-18 inches ( cm) between each of them, in rows 2 feet ( cm) apart.

Biology of Kale

This popular leafy green is a biennial or perennial plant, but is is usually cultivated as an annual vegetable. It is characterised by its waxy coat leaves, which are borne directly from the stalk and can be about 18 inches (46 cm) long. Kale leaves can be curly of straight, depending on the variety, and come on different colors, from gray-green to purple. A fully grown kale plant can reach 2 - 3.3 feet (61 cm - 1 m).

• Classification

  Are collards leafy greens?
  

  Vegetables like spinach, dandelion, and mustard are often categorized as collards due to their smooth and flat leaves; however, they are still leafy greens, the same as other edible herbs, including kale and cabbage, which have large and stiff leaves. Both terms can be confusing because they are commonly used interchangeably.

  Kale, also known as borecole, leaf cabbage, or non-heading cabbage, is the point of origin of the whole Brassicae botanical group, also known as the cabbage or mustard family, which comprises about 360 genera and over 3709 species - mostly herbaceous plants -, several of them with great medicinal, nutritional, and economic value, such as arugula, broccoli, cabbage, cauliflower, and mustard, all of them often called "cruciferous vegetables." Kale's botanical name, Brassica oleracea var. acephala, is a pretty good description of the plant: acephala is a latin word that means "without a head". The edible kale parts are composed only by leaves.

• Varieties and cultivars of kale

  This ancient vegetable has undergone many processes of hibridization and experimentation, resulting in many cultivars of the classic curly kale. Some popular kale varieties are: Dwarf Siberian, True Siberian, Red Ursa, Premier, Redbor, White Russian, and Beira Tronchuda, all of them hardy to cold climates.

Did you know?

The words "kale" (English), and "kohl" (German) have an Scottish origin, but they can be traced further back to coles or caulis, both words used by Greeks and Romans to classified the entire Brassicae family.

Historical Information

Economic Data

Other Uses