Kale is considered a cruciferous vegetable and is related to vegetables such as broccoli and Brussels sprouts, and cauliflower. Cruciferous vegetables are known to have many beneficial phytonutrients, with one group being sulfur containing compounds. Consuming cruciferous vegetables daily may possibly reduce risk of certain types of cancer and promote cardiovascular health (1-4).
This leafy green is also one of the best sources of the phytonutrient lutein. Lutein is similar in structure to beta-carotene, but does not have any vitamin A activity. Instead, lutein is concentrated in the center of the retina (the macula) where it absorbs blue light and protects the eye from damage (5).
One cup of cooked kale contains 885% to 1180% of your daily vitamin K and 98% of your daily vitamin A. It also contains 71% of your daily vitamin C and is a good source of fiber, calcium, and vitamin B6 (6).
Shopping, Storage, and Cooking Tips:
- Kale is available throughout the year, but its peak is mid-winter through the beginning of spring.
- Smaller leaves will be more tender and have a milder flavor.
- Warm temperatures cause kale to wilt, so make sure to store it in a refrigerator.
- Many of the nutrients in kale are best absorbed with fat present in the meal (7).
- Liu X, Lv K. Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis. Breast. 2013;22(3):309-313.
- Wu QJ, Yang Y, Vogtmann E, et al. Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies. Ann Oncol. 2013;24(4):1079-1087.
- Zhang X, Shu XO, Xiang YB, et al. Cruciferous vegetable consumption is associated with a reduced risk of total and cardiovascular disease mortality. Am J Clin Nutr. 2011;94(1):240-246.
- Higdon, J., Drake, V., Delage, B., & Traka, M. (2017, September 28). Cruciferous Vegetables . Retrieved October 12, 2017, from http://lpi.oregonstate.edu/mic/food-beverages/cruciferous-vegetables
- Krinsky NI, Landrum JT, Bone RA. Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye. Annu Rev Nutr. 2003;23:171-201.
- US Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Revised May 2016. Website: https://ndb.nal.usda.gov/ndb/.
- Karin H van, h. H., West, C. E., Weststrate, J. A., & Joseph, G. A. J. H. (2000). Dietary factors that affect the bioavailability of carotenoids. The Journal of Nutrition, 130(3), 503-6.