If you have not tried kale yet, now may be the time. This super green is packed to the max with nutrition that puts it high on the list of the world's healthiest foods.
Even spinach cannot come close in comparison to the number of nutrients that kale provides. Eating kale is beneficial for maintaining healthy skin, hair and strong bones, as well as helping with digestion and lowering the risk for heart disease.
The possible health benefits of consuming kale include improving blood glucose control in diabetics, lowering the risk of cancer, lowering blood pressure, improving bone health, lowering the risk of developing asthma and more.
This MNT Knowledge Center feature is part of a collection of articles on the health benefits of popular foods, all written and reviewed by our qualified nutritionist. It provides a nutritional breakdown of kale and an in-depth look at its possible health benefits, how to incorporate more kale into your diet and any potential health risks associated with its consumption.
Possible health benefits of consuming kale
Studies have shown that type 1 diabetics who consume high-fiber diets have lower blood glucose levels and type 2 diabetics may have improved blood sugar, lipids and insulin levels. One cup of chopped fresh kale provides about 2.6 grams of fiber.
The Dietary Guidelines for Americans recommends 21-25 g/day for women and 30-38 g/day for men.
Kale contains an antioxidant known as alpha-lipoic acid, which has been shown to lower glucose levels, increase insulin sensitivity and prevent oxidative stress-induced changes in patients with diabetes. Studies on alpha-lipoic acid have also shown decreases in peripheral neuropathy and/or autonomic neuropathy in diabetics.3
Of note, most studies have used intravenous alpha-lipoic acid and it is unsure whether oral supplementation would elicit the same benefits.3
Kale is packed with nutrition that puts it high on the list of the world's healthiest foods.
The fiber, potassium, vitamin C and B6 content in kale all support heart health. An increase in potassium intake along with a decrease in sodium intake is the most important dietary change that a person can make to reduce their risk of cardiovascular disease, according to Mark Houston, M.D., M.S., an associate clinical professor of medicine at Vanderbilt Medical School and director of the Hypertension Institute at St. Thomas Hospital in Tennessee.2
In one study, those who consumed 4069 mg of potassium per day had a 49% lower risk of death from ischemic heart disease compared with those who consumed less potassium (about 1000 mg per day).2
High potassium intakes are also associated with a reduced risk of stroke, protection against loss of muscle mass, preservation of bone mineral density and reduction in the formation of kidney stones.2
For blood pressure, increasing potassium intake may be just as important as decreasing sodium intake for lowering blood pressure because of potassium's vasodilation effects.
According to the National Health and Nutrition Examination Survey, fewer than 2% of US adults meet the daily 4700 mg recommendation.2 One cup of chopped fresh kale provides 329 milligrams of potassium.
Also of note, a high potassium intake is associated with a 20% decreased risk of dying from all causes.2
Kale and other green vegetables that contain chlorophyll have been shown to be effective at blocking the carcinogenic effects of heterocyclic amines, which are generated when grilling foods at a high temperature.4 If you tend to like your grilled foods charred, make sure to pair them with green vegetables to help negate these effects.
Low intakes of vitamin K have been associated with a higher risk for bone fracture. Adequate vitamin K consumption is important for good health, as it acts as a modifier of bone matrix proteins, improves calcium absorption and may reduce urinary excretion of calcium.5
One cup of kale provides a whopping 550 micrograms of vitamin K, over 680% of our daily needs.
Kale is high in fiber and water content, both of which help to prevent constipation and promote regularity and a healthy digestive tract.
Healthy skin and hair
Kale is high in vitamin A, a nutrient required for sebum production to keep hair moisturized. Vitamin A is also necessary for the growth of all bodily tissues, including skin and hair.
Adequate intake of vitamin C, which kale can provide, is needed for the building and maintenance of collagen, which provides structure to skin and hair.
Iron-deficiency is a common cause of hair loss, which can be prevented by an adequate intake of iron-rich foods, like kale.
On the next page we look at the nutritional breakdown of kale, how to incorporate more kale into your diet and we examine the health risks associated with kale.