Kale

Kale (also called borecole or leaf cabbage) is a cruciferous vegetable that is titled as a superfood due to its many health benefits. It is in the plant family Brassicaceae (cruciferae) with the genus/species of Brassica oleracea under the group acephala, meaning without a head. Kale is related to broccoli, cauliflower, collards, brussel sprouts, kohlrabi, and cabbage.

The origin of Brassica oleracea it not truly known due to its wide variety. What is known is that this family of plants originated from a form of wild cabbage, with kale believed to have more similarities to the original wild form. The cultivation of kale is not known but this vegetable has been used as a food source for thousands of years, with Greek and Romans having it as a well-established garden vegetable. Kale’s establishment as a common garden vegetable continued when it was introduced into Europe and is a popular choice of vegetable for many common meals.

Kale’s richness in nutritional benefits allows it to claim the title as a superfood. It contains high amounts of vitamin A and its carotenoids. Containing 500 mcg of vitamin A (RAE) per 100 grams, with 5927 mcg coming in the form of beta-carotene. RAE stands for retinol activity equivalent and refers to the amount of retinol (vitamin A) acquired when factoring the conversion rate of a provitamin, such as beta-carotene, and its activity as retinol. Vitamin A is an important vitamin for our entire body and is used in the growth and development for all the body’s cells. It is also used in embryonic development and in the organ formation during fetus development. Our immune system requires this vitamin for normal function and our eyes need it for proper vision. Deficiency of this vitamin increases our susceptibility to infections, thyroid and skin disorders, and blindness. It is a lack of this vitamin that is the leading cause of blindness worldwide.

Beta carotene is a carotenoid that not only provides these benefits, but also has its own benefits. The body is able to convert beta-carotene into vitamin A when needed. It is the main source of vitamin A for most people and is one of the best sources since too high amounts of vitamin A is toxic, but beta-carotene does not have this toxicity. The body will only convert beta-carotene into vitamin A for the amount that it needs. Beta-carotene is also an antioxidant, protecting our cells from damage due to oxidation and free radicals and is shown to help in the prevention of cancer and heart disease.

Kale contains two other carotenoids that are important for eye health. The two carotenoids are lutein and zeaxanthin, with kale providing a combined 8198 mcg per 100 grams. These carotenoids are found in plants, which use them for protection against sun damage. When consumed these vitamins are able to provide our bodies with this same protection. The largest concentration of the vitamins is in the retina (macula) of the eyes, where it protects our eyes from harmful light energy such as high-energy blue wavelength. The carotenoids help with regular eye health and in the prevention of cataracts. Both lutein and zeaxanthin act as antioxidants, helping to remove free radicals in our system.

Kale contains high amounts of vitamin C containing 120 mg per 100 grams. This important vitamin is necessary in the body’s ability to synthesize collagen, which is the main structural protein in the body. Collagen accounts for ¹/₃ of the protein in the body and is used in the formation and creation of bones, cartilage, and muscle, along with many other structural components of the body. Vitamin C plays important roles in tissue repair, protein metabolism, immune system function, iron absorption, and protection against heart disease. In addition, it is able to decrease unwanted LDL (“bad” cholesterol) and triglycerides (a type of lipid or fat in the blood) and has antioxidant abilities which removes free radicals from the system and helps in the prevention of conditions such as cancer and cataracts.

High amounts of vitamin K are present in kale with 704.8 mcg per 100 grams. This vitamin is necessary in the formation of blood clots. One of the ways it does this is by altering proteins, allowing them to bind with calcium. This binding creates a structure that prevents the blood from leaving the system. The ability for proteins to bind with calcium is also used in the formation and strengthening of our skeletal system. These altered proteins, due to vitamin K, are used for a number of vital tasks in the body, such as the prevention of vessel mineralization, and are used in a variety of cell functions.

Kale is a good source of potassium with 491 mg, making kale a beneficial vegetable for our heart. Potassium intake is associated as a major way of reducing cardiovascular disease. High potassium intake is shown to reduce the risk of stroke, protect against loss of muscle mass, help prevent kidney stones, preserve bone mineral density, and help reduce dying from all diseases by 20%.

Kale contains the components sulforaphane and indole-3-carbinol. These two components have anti-cancer properties and are beneficial for all cancer types but they have a particular benefit for colon, prostate, and bladder cancer. Indole-3-carbinol also helps in regulating the inflammatory system by altering the response of the immune system messaging molecules, and helps detoxify our bodies by reducing the toxic load placed on our cells.

Kale contains a good amount of other nutrients as well. It is high in the mineral manganese with 0.66 mg and provides a good source of the minerals iron, with 1.47 mg, and folate, with 141 mcg. For vitamins, kale contains a good amount of riboflavin (0.13 mg), thiamine (0.11 mg), and folate (141 mcg). Per 100 grams, kale contains 84.04 g of water, 4.28 g of protein, and 3.6 g of fibre and 8.75 g of carbohydrates, resulting in 5.15 g of counted carbohydrates. The exact amount of nutrients that kale contains does vary depending on its growing condition such as soil and weather, along with other factors. Even so, all kale is well-known to be rich in nutritional content.

When picking kale, ones with yellow leaves should be avoided as it is a sign they are turning bad. Kale should be washed before being used to remove dirt and/or bugs that might be present on the kale leaves. A person will want to wash them thoroughly as in certain types of kale, such as curly kale, the dirt and/or bugs can hide in the folds of the leaves. If it is not being used right away the leaves need to be dried. This can be done with a salad spinner or with the use of a paper towel or tea towel to remove the water before placing them in a container in the fridge. The stalk of the kale is not always consumed and some recipes might call for its removal. This is due to how tough the stalk can be, with different varieties of kale having different toughness of the stalk. The stalk is edible, though, if a person so chooses to they can incorporate the stalks into the meal. Kale should be bought organic as it is one of the top foods for pesticides and herbicides. These chemicals are toxic to our bodies.

Kale is considered a goitrogenic food, meaning that it has potential to interfere with the thyroid’s uptake of iodine. This results in the release of the thyroid-stimulating hormone (TSH) causing the thyroid to grow in size to cover more area, possibly leading to a condition known as goiter. In the case of kale and other vegetables a significant amount would have to be eaten to lead to this condition. The possibility of kale preventing iodine uptake is often ignored since there is a very little chance of it affecting a person who eats a proper diet. The major cause of goiter is iodine deficiency and not goitrogenic foods. Another reason its effect is ignored is because kale provides significant benefits that easily overshadow this negative.

Kale is a powerful vegetable that deserves the title of superfood. It provides plenty of nutrients essential to our health such as vitamin C, vitamin K, beta-carotene, potassium, and fibre, along with many other nutrients. These nutrients in turn provide many benefits to our system, including proper bone growth and vision, the removal of toxins, and in promoting overall body health. Kale is a beneficial food that provides much when incorporated into a person’s diet for a healthy lifestyle.