Bok choy (or pak choi) is a relative of cabbage, scientifically named Brassica chinensis. It is most often associated with Chinese cuisine, and has been grown in China for over six thousand years. Today, bok choy is also grown in Europe, Canada, and the U.S, and is available almost year-round – it is said to be most tasty in the winter months.
Bok choy has crisp, white stalks and dark green leaves, and in Chinese its name means “white vegetable.” There are over twenty different varieties of bok choy – the two most common seen here in the U.S. are the traditional and “baby” or “Shanghai” bok choy – however, if you visit your local Asian market, you may see several more of these varieties.1-2
Bok choy provides abundant amounts of vitamins A, C, and K as well as folate and calcium.3 A recent study detected 28 different polyphenols - antioxidant phytochemicals - in bok choy. Some of these were more concentrated in the leaves, and some in the stems.4 The most abundant polyphenol these scientists found in bok choy was kaempferol, a molecule shown to have anti-cancer properties.5
Bok choy falls under the category of cruciferous vegetables, a family of especially nutrient-dense vegetables that contain unique anti-cancer compounds. Like all cruciferous vegetables, more cancer-preventive compounds are produced when bok choy is chopped before cooking.
Bok choy is one of the most nutrient-dense foods in the world, and it is uniquely beneficial for its calcium availability – bok choy is lower in oxalate, a substance that binds up calcium and prevents it from being absorbed, than most other leafy greens. 54% of the calcium in bok choy can be absorbed by the human body – compare this to 5% in spinach, a high oxalate vegetable, and 32% in milk. We can much more readily absorb calcium from bok choy than from dairy products.
Bok choy can be eaten raw in salads, green smoothies, or vegetable juices, or cooked in stir-fries, soups, or other vegetable dishes.
Braised Bok Choy
8 baby bok choy or 3 regular bok choy
1 teaspoon Bragg Liquid Aminos or low sodium soy sauce
2 cups coarsely chopped shiitake mushrooms
2 large cloves garlic, chopped, optional
1 tablespoon unhulled sesame seeds, lightly toasted *
Cover bottom of large skillet with 1/2 inch water. Add bok choy (cut baby bok choy in half lengthwise or cut regular bok choy into chunks).
Drizzle with liquid aminos. Cover and cook on high heat until bok choy is tender, about 6 minutes.
Remove bok choy and add mushrooms and garlic to the liquid in the pan.
Simmer liquid until reduced to a glaze. Pour over bok choy. Top with toasted sesame seeds.
*Lightly toast sesame seeds in a pan over medium heat for 3 minutes, shaking pan frequently.
4. Harbaum B et al. Identification of flavonoids and hydroxycinnamic acids in pak choi varieties (Brassica campestris L. ssp. chinensis var. communis) by HPLC-ESI-MSn and NMR and their quantification by HPLC-DAD. J Agric Food Chem. 2007 Oct 3;55(20):8251-60. Epub 2007 Sep 12.
5. Luo H et al. Kaempferol inhibits angiogenesis and VEGF expression through both HIF dependent and independent pathways in human ovarian cancer cells. Nutr Cancer. 2009;61(4):554-63.