# Brassica oleracea (Bok Choy)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/brassica-oleracea
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-31
**Evidence Score:** 2 / 10
**Category:** Other
**Also Known As:** Brassica rapa subsp. chinensis, Chinese white cabbage, Pak choi, Pok choi, Chinese chard, White mustard cabbage, Spoon cabbage, Chinese mustard, Qing cai, Shanghai bok choy, Baby bok choy

## Overview

Bok choy (Brassica oleracea var. chinensis) contains glucosinolates—particularly glucobrassicin and sinigrin—that are hydrolyzed by myrosinase into bioactive isothiocyanates and indoles. These compounds modulate cytochrome P450 enzymes and activate Nrf2-mediated antioxidant pathways, supporting detoxification and reducing [oxidative stress](/ingredients/condition/antioxidant).

## Health Benefits

• May support detoxification processes through glucosinolate-derived compounds that modulate phase I/II enzymes (preliminary evidence from general Brassica research)
• Potential [anti-inflammatory](/ingredients/condition/inflammation) effects via indole-3-carbinol metabolites like DIM (mechanism-based evidence only)
• Rich source of vitamins C (45 mg/100g) and K (45.5 µg/100g) supporting immune and [bone health](/ingredients/condition/bone-health) (nutritional data)
• Contains 105 mg calcium per 100g contributing to bone health (nutritional analysis)
• May support cellular health through isothiocyanate-induced apoptosis and cell cycle regulation (preliminary evidence from Brassica vegetables)

## Mechanism of Action

Glucosinolates in bok choy—primarily glucobrassicin—are converted by myrosinase to indole-3-carbinol (I3C), which undergoes acid condensation in the stomach to form diindolylmethane (DIM); both compounds modulate estrogen [metabolism](/ingredients/condition/weight-management) via CYP1A1 and CYP1B1 induction. Sinigrin-derived allyl isothiocyanate activates the Nrf2/Keap1 pathway, upregulating [phase II detox](/ingredients/condition/detox)ification enzymes including glutathione S-transferases (GSTs) and NAD(P)H quinone oxidoreductase 1 (NQO1). Additionally, bok choy's sulforaphane precursors and flavonoids such as kaempferol inhibit NF-κB signaling, attenuating [pro-inflammatory cytokine](/ingredients/condition/inflammation) production including TNF-α and IL-6.

## Clinical Summary

Direct clinical trials on bok choy supplementation are largely absent; available evidence is extrapolated from broader Brassica vegetable research. A randomized crossover study of 20 healthy adults consuming 250g of cooked Brassica vegetables daily for two weeks observed a 30–50% increase in urinary isothiocyanate excretion and upregulation of GST activity, suggesting enhanced detoxification capacity. Observational cohort data, including the EPIC study involving over 500,000 participants, associate higher cruciferous vegetable intake with modest reductions in colorectal and lung cancer risk (HR ~0.82–0.89), though confounding factors limit causal inference. Evidence for [anti-inflammatory](/ingredients/condition/inflammation) and bone-protective effects remains mechanism-based or preclinical, and no established therapeutic dose for bok choy specifically has been validated in human trials.

## Nutritional Profile

Bok Choy (Brassica oleracea, pak choi type) per 100g raw: Macronutrients: Calories ~13 kcal, Carbohydrates ~2.2g, Dietary Fiber ~1.0g, Protein ~1.5g, Fat ~0.2g, Water ~95.3g. Key Micronutrients: Vitamin C ~45mg (50% DV), Vitamin K1 ~45.5µg (38% DV), Vitamin A (as beta-carotene) ~4468 IU (~89µg RAE), Folate ~66µg (17% DV), Vitamin B6 ~0.19mg, Riboflavin ~0.07mg. Minerals: Calcium ~105mg (8% DV — notably higher bioavailability than spinach due to low oxalate content, estimated absorption ~54% vs ~5% for spinach), Potassium ~252mg, Phosphorus ~37mg, Magnesium ~19mg, Iron ~0.8mg (non-heme, moderate bioavailability enhanced by co-present Vitamin C), Zinc ~0.19mg, Manganese ~0.16mg, Selenium ~0.5µg. Bioactive Compounds: Glucosinolates ~35–60µmol/g dry weight, primarily sinigrin and glucobrassicin; hydrolyzed by myrosinase (activated by chopping/chewing) to isothiocyanates (allyl ITC) and indole-3-carbinol. Carotenoids: beta-carotene ~2681µg, lutein+zeaxanthin ~40µg. Flavonoids: quercetin and kaempferol glycosides present at low-moderate levels (~1–5mg/100g combined). Chlorophyll a and b present. Bioavailability Notes: Cooking reduces myrosinase activity (limiting glucosinolate conversion) but gut microbiota retain partial hydrolysis capacity; light steaming preserves ~60–70% of Vitamin C; calcium bioavailability remains high post-cooking due to low oxalic acid content (~105mg/100g oxalate — significantly lower than spinach ~970mg/100g).

## Dosage & Preparation

No clinically studied dosage ranges exist for Bok Choy extracts or standardized forms. Typical dietary consumption is 70g (1 cup shredded raw) providing approximately 70.7 mg glucosinolates. No standardization percentages have been established in studies. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Bok choy is generally safe when consumed as a food, but very large quantities—documented in case reports involving raw consumption exceeding 1–1.5 kg daily—can trigger hypo[thyroid](/ingredients/condition/hormonal)ism by inhibiting thyroid peroxidase via progoitrin-derived goitrin, particularly in iodine-deficient individuals. High vitamin K content (approximately 45 mcg per 100g) poses a meaningful interaction risk with warfarin (Coumadin), potentially reducing anticoagulant efficacy and requiring INR monitoring if intake changes significantly. Individuals with crucifer allergies or those prone to oxalate-related kidney stones should exercise caution, as bok choy contains moderate oxalate levels. Pregnant women may consume bok choy as a food without concern, but concentrated I3C or DIM supplements lack sufficient safety data for use during pregnancy or lactation.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses specifically on Bok Choy were found in the research. General benefits attributed to Brassica vegetables' glucosinolates and indoles for cancer prevention are noted, but these lack Bok Choy-specific human study citations or PMIDs.

## Historical & Cultural Context

Bok Choy has been cultivated in China as a traditional leafy vegetable in Asian cuisine and medicine. While specific historical medicinal uses are not detailed in available research, it has emerged as a cultivated crop in regions like Florida, emphasizing its primary role as a nutritious food rather than documented herbal medicine.

## Synergistic Combinations

Broccoli sprouts, Turmeric, Green tea extract, Vitamin D, Selenium

## Frequently Asked Questions

### How much bok choy do you need to eat to get health benefits?

Epidemiological research suggests that consuming cruciferous vegetables 3–5 times per week—roughly 100–200g of cooked bok choy per serving—is associated with measurable increases in GST activity and urinary isothiocyanate levels. Cooking reduces myrosinase activity by up to 90%, so lightly steaming or eating some raw bok choy maximizes glucosinolate conversion to active isothiocyanates. No specific therapeutic dose has been established in clinical trials focused on bok choy alone.

### Does bok choy affect thyroid function?

Yes, in very large quantities, raw bok choy can impair thyroid function. It contains progoitrin, which is converted to goitrin—a compound that inhibits thyroid peroxidase and reduces thyroxine synthesis. A case report documented severe hypothyroidism in a woman who consumed approximately 1–1.5 kg of raw bok choy daily for several months, highlighting that normal dietary amounts pose minimal risk, especially when iodine intake is adequate.

### Can bok choy interact with blood thinners like warfarin?

Bok choy contains approximately 45 mcg of vitamin K per 100g, and sudden increases in consumption can counteract the anticoagulant effect of warfarin by promoting clotting factor synthesis. Patients on warfarin should maintain consistent cruciferous vegetable intake rather than eliminating bok choy, and any significant dietary changes should be communicated to their prescribing physician for INR monitoring. Large shifts in weekly intake—rather than steady consumption—are the primary concern.

### Is bok choy a good source of calcium for people avoiding dairy?

Bok choy provides approximately 105 mg of calcium per 100g raw, and crucially, its oxalate content is low compared to spinach, making its calcium highly bioavailable—estimated at around 50–60% absorption versus roughly 5% for high-oxalate greens like spinach. This makes bok choy one of the more effective plant-based calcium sources for dairy-free or vegan diets. A 200g serving can contribute roughly 210 mg of well-absorbed calcium toward the adult RDA of 1,000 mg.

### What is DIM and does bok choy contain enough to affect estrogen metabolism?

Diindolylmethane (DIM) is not present directly in bok choy but forms in the stomach when indole-3-carbinol (I3C)—derived from glucobrassicin hydrolysis—undergoes acid-catalyzed condensation. Clinical studies using isolated I3C supplements at 300–400 mg/day or DIM at 108 mg/day have shown shifts in the 2-hydroxyestrone to 16α-hydroxyestrone ratio, favoring a less estrogenic metabolite profile. Achieving equivalent I3C levels from bok choy alone would require consuming several hundred grams daily, so food-based intake likely produces a modest but not pharmacological effect on estrogen metabolism.

### What is the difference between bok choy and other cruciferous vegetables like broccoli or kale in terms of nutritional profile?

Bok choy is notably lower in calories and carbohydrates than kale but contains comparable vitamin K levels (45.5 µg/100g), making it suitable for low-carb diets while maintaining similar bone-health benefits. Unlike broccoli, bok choy has a milder flavor and slightly different glucosinolate ratios, though all three cruciferous vegetables support detoxification through phase I/II enzyme modulation. Bok choy's higher water content and lower fiber density compared to kale make it gentler for sensitive digestive systems while still delivering vitamin C and calcium.

### Does cooking bok choy affect its glucosinolate and DIM content?

Light steaming or stir-frying (3–5 minutes) preserves 70–80% of bok choy's glucosinolates, whereas prolonged boiling can reduce them by up to 50%, making minimal-heat preparation preferable for maximizing DIM precursors. Glucosinolates must be converted by myrosinase enzyme activity to form bioactive indole-3-carbinol and DIM, a process that begins when plant cells are damaged through cutting or chewing but is halted by high heat. Consuming raw or lightly cooked bok choy alongside other raw cruciferous vegetables or fermented foods may enhance glucosinolate bioconversion compared to fully cooked preparations.

### Can bok choy be used as a supplement alternative, and is whole-food consumption as effective as extracted DIM supplements?

Whole bok choy contains the glucosinolate precursors to DIM but typically provides 5–10 mg of DIM equivalents per 100g serving, whereas standardized DIM supplements deliver 100–400 mg per dose, making supplemental forms more concentrated for therapeutic intent. The bioavailability of DIM from whole food may be superior due to synergistic micronutrient co-factors and fiber that support estrobolome diversity, but clinical evidence specifically comparing whole-food versus extracted forms in bok choy is limited. For individuals seeking detoxification support through estrogen metabolism, whole bok choy serves best as a dietary foundation rather than a replacement for concentrated supplemental DIM products.

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