Kale is a leafy green cruciferous vegetable that is chock-full of essential vitamins A, C and K as well as minerals like copper, potassium, iron, manganese and phosphorus. A cup of fresh kale has only about 40 calories but packs almost 3 grams of protein.
One cup of cooked kale has over 1000% more vitamin C than a cup of cooked spinach and unlike spinach, kale’s oxalate content is very low which means that the calcium and iron in kale are highly absorbable in the human digestive system.
1. Antioxidant-Related Health Benefits
Kale’s cancer preventive benefits have been clearly linked to its unusual concentration of two types of antioxidants, namely, carotenoids and flavonoids. Within the carotenoids, lutein and beta-carotene are standout antioxidants in kale. Researchers have actually followed the passage of these two carotenoids in kale from the human digestive tract up into the blood stream, and they have demonstrated the ability of kale to raise blood levels of these carotenoid nutrients.
Within the flavonoids, kaempferol is a spotlight antioxidant in kale, followed by a flavonoid called quercitin. But recent research has also made it clear that at least 45 different antioxidant flavonoids are provided in measurable amounts by kale. This broad spectrum of flavonoid antioxidants is likely to be a key to kale’s cancer-preventive benefits and benefits that we expect to be documented for other health problems stemming from oxidative stress.
2. Impressive Anti-Cancer Benefits
In addition to providing a truckload of vitamins and flavonoids, kale contains several glucosinolates including glucobrassicin, glucoraphanin and sinigrin. When you eat kale, these compounds are converted into isothiocyanates in your digestive tract. A large body of evidence suggests that isothiocyanates may help prevent cancer and, in some cases, even suppress the growth of cancerous tumors. Isothiocyanates work their anti-cancer magic by eliminating potential carcinogens from the body, by conferring protection against DNA damage, and by stimulating apoptosis (self-destruction) of cancerous cells.
Most of the research related to isothiocyanates, kale and cancer has focused on colon cancer and breast cancer, but there’s also evidence that kale and other foods that contain glucosinolates may also provide protection against prostate cancer, ovarian cancer, and bladder cancer.
3. Cardiovascular Benefits of Kale
You can count on kale to provide valuable cardiovascular support in terms of its cholesterol-lowering ability. Researchers now understand exactly how this support process works. Our liver uses cholesterol as a basic building block to product bile acids. Bile acids are specialized molecules that aid in the digestion and absorption of fat through a process called emulsification. These molecules are typically stored in fluid form in our gall bladder, and when we eat a fat-containing meal, they get released into the intestine where they help ready the fat for interaction with enzymes and eventual absorption up into the body.
When we eat kale, fiber-related nutrients in this cruciferous vegetable bind together with some of the bile acids in the intestine in such a way that they simply stay inside the intestine and pass out of our body in a bowel movement, rather than getting absorbed along with the fat they have emulsified. When this happens, our liver needs to replace the lost bile acids by drawing upon our existing supply of cholesterol, and, as a result, our cholesterol level drops down.
Kale provides us with this cholesterol-lowering benefit whether it is raw or cooked. However, a recent study has shown that the cholesterol-lowering ability of raw kale improves significantly when it is steamed. In fact, when the cholesterol-lowering ability of steamed kale was compared with the cholesterol-lowering ability of the prescription drug cholestyramine (a medication that is taken for the purpose of lowering cholesterol), kale bound 42% as many bile acids (based on a standard of comparison involving total dietary fiber). Amongst all of the cruciferous vegetables, only collard greens scored higher at 46%.
4. Promotes Urinary Health
If all the above-listed positive effects associated with eating kale are enough to convince you to eat more of this superfood, consider this: the potential health benefits of kale also include enhanced urinary health, which may extend well beyond protection against bladder cancer. Kale is listed as one of the best foods to fight UTIs due to its extraordinary nutritional profile. Kale is chock-full of pro-vitamin A (kale contains almost as much pro-vitamin A as carrots), and pro-vitamin A is known to promote healthy surface linings of the urinary tracts.
Furthermore, kale is low in oxalates, which offers additional health benefits for people who suffer from certain types of hyperoxaluria (excessive urinary excretion of oxalate) and to people who are prone to developing calcium-oxalate kidney stones. Oxalates are naturally-occurring substances present in significant amounts in many green leafy vegetables such as spinach, purslane and parsley. The link between foods rich in oxalates and kidney stones has caused quite some debate over the purported health benefits of green smoothies, and if you have reason to be concerned about oxalates in your diet, using kale (instead of spinach) in your green smoothies may be the way to go.
5. Helps Build Strong Bones
While many of us may drink milk for strong bones and to improve our overall bone health, kale actually contains more calcium than milk. Kale and oranges are considered to be among the many fruits and vegetables that have a high content in vitamins that can strengthen and protect your skeleton. “Your bones need many nutrients to stay mineralized; your skeleton must get enough calcium to keep up with the process of bone,” said Dr. Maina Sinha, an assistant professor of medicine at Weill Cornell Medical School and metabolic bone disease expert, in the college’s Women’s Health issue. Sinha considers dairy food and leafy green vegetables, such as spinach and kale, as the best dietary sources of calcium. Kale’s vitamin K content is essential for a wide variety of bodily functions, which include normal bone health.
6. Helps Improve Your Eyesight
Kale contains lutein and zeaxanthin compounds, carotenoids, which act like sunglass filters and help prevent damage to the eyes from excessive exposure to ultraviolent light, according to Life Extension Magazine. A study published in the American Journal of Clinical Nutrition found people with a history of eating lutein-rich foods like kale had a 22% lower risk of cataracts, which would otherwise have been severe enough to require extraction. Dietary antioxidants, such as kale, play a role in the prevention of age-related cataracts or the risk of macular degeneration.
7. Helps Boost Your Brain Health
The nutrient-dense veggie contains essential vitamins and minerals that the brain is contingent on to function. Kale contains 684 percent RDA of vitamin K, which is a powerful antioxidant nutrient that protects fat and has long been associated with blood clotting. Vitamin K is needed to make the “specialized fats called sphingolipids that create the structure of our brain cells, and it promotes brain cells being more resilient by influencing gene expression,” wrote Dr. Drew Ramsey, Assistant Clinical Professor of Psychiatry, Columbia University and New York State Psychiatric Institute, in a blog post in The Huffington Post.
The brain food also contains manganese that helps brain function, which can better help you focus on daily tasks at work and give you a pick-me-up. Perhaps next time you eat kale you will notice you feel lighter and brighter, compared to how you feel after eating other foods. If your brain is healthy, you feel happy, and active.
8. Weight Loss Benefits of Kale
Kale has several properties that should make it a weight loss friendly food. It is very low in calories… but still provides significant bulk that should help you feel full. Because of the low calorie and high water content, kale has a low energy density. Eating plenty of foods with a low energy density has been shown to aid weight loss in numerous studies. Despite the low amount of calories, it does contain small amounts of protein and fiber. These are two of the most important nutrients when it comes to losing weight. Although there is no study directly testing the effects of kale on weight loss, it makes sense that it could be a useful addition to a weight loss diet.