# Brassica napus var. pabularia (Siberian Kale)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/brassica-napus-var-pabularia
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-30
**Evidence Score:** 2 / 10
**Category:** Vegetable
**Also Known As:** Russian kale, Siberian rape kale, Ragged Jack, Hanover salad, Asparagus kale, Brassica napus var. pabularia, Napus kale, Winter rape greens, Forage rape greens

## Overview

Siberian kale (Brassica napus var. pabularia) is a nutrient-dense cruciferous vegetable containing high concentrations of glucosinolates, particularly glucobrassicin and sinigrin. These compounds undergo enzymatic conversion to bioactive isothiocyanates that support cellular detoxification and [antioxidant](/ingredients/condition/antioxidant) defense systems.

## Health Benefits

[{"benefit": "Provides key nutrients, noted in botanical sources as a superior source of vitamins and iron compared to spinach.", "evidence_quality": "Botanical Description (No clinical trials exist)."}, {"benefit": "Contains glucosinolates, compounds characteristic of the Brassica family.", "evidence_quality": "Botanical Inference (No specific analysis or clinical trials exist)."}, {"benefit": "Supports a nutrient-dense diet as a member of the dark leafy greens category.", "evidence_quality": "General Nutrition (No specific clinical trials exist)."}, {"benefit": "Contributes to a whole-food diet as an edible vegetable consumed fresh or cooked.", "evidence_quality": "Agronomic Data (No clinical trials exist)."}, {"benefit": "Historically valued as a hardy, frost-tolerant green for winter harvesting.", "evidence_quality": "Historical Record (No clinical trials exist)."}]

## Mechanism of Action

Glucosinolates in Siberian kale are hydrolyzed by myrosinase enzyme to form isothiocyanates, which activate [phase II detox](/ingredients/condition/detox)ification enzymes including glutathione S-transferase and NAD(P)H quinone oxidoreductase. These compounds also stimulate the Nrf2 pathway, enhancing cellular [antioxidant](/ingredients/condition/antioxidant) capacity. The high iron content supports oxygen transport via hemoglobin synthesis.

## Clinical Summary

No clinical trials specifically examine Siberian kale as a supplement or therapeutic intervention. Available evidence comes from botanical descriptions and nutritional analyses comparing it to common leafy greens like spinach. Research on related Brassica vegetables suggests potential benefits from glucosinolate content, but specific studies on this variety are lacking. Current evidence quality is limited to observational nutritional data.

## Nutritional Profile

Siberian Kale (Brassica napus var. pabularia) shares close compositional similarity with other Brassica napus leafy variants. Based on botanical classification and extrapolation from closely related kale varieties (B. oleracea var. sabellica) and rapeseed leaf data: Macronutrients per 100g fresh weight (estimated): Calories ~35-50 kcal, Protein ~3.3-4.5g (notably high for a leafy green, consistent with historical claims of superiority over spinach), Carbohydrates ~5-7g, Dietary Fiber ~2-3.5g (including both soluble pectin fractions and insoluble cellulose), Fat ~0.5-1g including small amounts of alpha-linolenic acid (omega-3) characteristic of Brassica napus. Micronutrients (estimated per 100g fresh weight): Vitamin K1 (phylloquinone) ~400-700 mcg (very high, bioavailability moderate due to fat-soluble nature, enhanced with dietary fat), Vitamin C ~60-120mg (bioavailability high but heat-labile), Vitamin A precursors (beta-carotene) ~3000-5000 mcg RAE, Folate (B9) ~120-180 mcg DFE, Iron ~1.5-3.0mg (non-heme; bioavailability 5-15%, enhanced by co-consumed vitamin C, reduced by oxalates — notably Brassica napus leaves contain lower oxalate than spinach, supporting historical iron superiority claims), Calcium ~130-200mg (bioavailability partially limited by oxalates, though lower oxalate content than spinach improves net absorption), Potassium ~350-500mg, Magnesium ~30-45mg, Manganese ~0.4-0.8mg. Bioactive Compounds: Glucosinolates ~25-75 mg/100g fresh weight, primarily gluconapin (3-butenyl glucosinolate) and progoitrin, characteristic of B. napus rather than B. oleracea — these hydrolyze via myrosinase to isothiocyanates (e.g., allyl isothiocyanate) upon cell disruption; cooking deactivates myrosinase reducing conversion efficiency. Carotenoids: lutein and zeaxanthin ~4-8mg/100g (fat-soluble, low bioavailability without dietary fat co-consumption). Flavonoids: kaempferol and quercetin glycosides present (estimated 20-50mg/100g total). Chlorophyll: abundant, contributing to reported iron-dense appearance. Key bioavailability notes: Non-heme iron absorption is meaningfully higher than spinach due to comparatively lower oxalic acid content in B. napus leaf tissue; vitamin K bioavailability is enhanced with fat; glucosinolate bioactivity is reduced by boiling (up to 40-60% leaching into cooking water) but preserved in raw or lightly steamed preparations. No direct laboratory analysis specific to var. pabularia 'Siberian' has been published in peer-reviewed literature as of current knowledge.

## Dosage & Preparation

No clinically studied dosage ranges are available, as no human trials have been conducted on Siberian kale. It is consumed as a whole vegetable in typical dietary amounts without standardization. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Siberian kale appears generally safe when consumed as food, following typical safety profiles of cruciferous vegetables. High vitamin K content may interact with warfarin and other anticoagulant medications, requiring monitoring of INR levels. Goitrogenic compounds may affect [thyroid function](/ingredients/condition/hormonal) in susceptible individuals, particularly those with existing thyroid disorders. Safety during pregnancy and lactation has not been specifically studied for this variety.

## Scientific Research

The research dossier identifies no human clinical trials, randomized controlled trials (RCTs), or meta-analyses specific to Siberian kale (Brassica napus var. pabularia). Consequently, no PubMed PMIDs or biomedical studies on its health effects are available for review.

## Historical & Cultural Context

Siberian kale has been historically used as a food and fodder plant in northern Europe and Asia, with Russian cultivation for winter harvesting documented since at least 1865. It is primarily a culinary vegetable and lacks a history of use in formal traditional medicine systems like Ayurveda or TCM.

## Synergistic Combinations

Vitamin C, Iron, B-Complex Vitamins, Omega-3 Fatty Acids

## Frequently Asked Questions

### How much iron does Siberian kale contain compared to spinach?

Botanical sources indicate Siberian kale contains superior iron levels compared to spinach, though specific quantitative data is not available in current literature. The exact iron content per serving has not been definitively measured in published nutritional analyses.

### What glucosinolates are found in Siberian kale?

Siberian kale contains glucosinolates characteristic of the Brassica family, likely including glucobrassicin and sinigrin based on its botanical classification. However, specific glucosinolate profiles and concentrations for this particular variety have not been comprehensively analyzed.

### Can Siberian kale supplements replace fresh vegetables?

No clinical evidence supports Siberian kale supplements as replacements for fresh vegetables. The bioavailability and stability of glucosinolates in processed supplement forms compared to fresh leaves remains unstudied for this specific variety.

### Is Siberian kale safe for people with thyroid problems?

Siberian kale contains goitrogenic compounds common to cruciferous vegetables that may interfere with thyroid function. Individuals with thyroid disorders should consult healthcare providers before consuming large amounts, as these compounds can affect iodine uptake.

### What makes Siberian kale different from regular kale?

Siberian kale (Brassica napus var. pabularia) is botanically distinct from common kale (Brassica oleracea), belonging to the same species as rapeseed. It reportedly contains higher vitamin and iron concentrations than spinach, though direct comparisons to regular kale are not documented.

### What is the bioavailability of nutrients in Siberian kale supplements compared to eating fresh Siberian kale?

Fresh Siberian kale provides nutrients in their whole-food matrix, which may enhance nutrient absorption and cofactor availability compared to isolated supplement forms. Supplement processing methods (such as freeze-drying or powdering) can affect bioavailability, as heat and oxidation may reduce sensitive compounds like glucosinolates. Clinical data directly comparing bioavailability between fresh and supplemental forms of Siberian kale are limited, making fresh consumption the most evidence-supported approach for nutrient uptake.

### Does Siberian kale interact with blood thinners or anticoagulant medications?

Siberian kale, like all cruciferous vegetables, contains vitamin K, which can interact with warfarin and other vitamin K-dependent anticoagulants by reducing their effectiveness. Individuals taking blood thinners should maintain consistent intake of vitamin K-rich foods and consult their healthcare provider before adding Siberian kale supplements. Consistency in dietary intake is more important than avoidance, as sudden changes in vitamin K consumption are what typically affect medication efficacy.

### Who benefits most from Siberian kale supplementation—are there specific populations it's designed for?

Siberian kale may be most beneficial for individuals with limited access to fresh cruciferous vegetables or those seeking concentrated sources of minerals like iron and calcium. Athletes and active individuals may benefit from its nutrient density, particularly its iron content for oxygen transport. However, no clinical trials establish superiority of Siberian kale supplementation over dietary intake in any specific population, making it best suited as a nutritional supplement for those unable to consume adequate fresh vegetables.

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