# Komatsuna (Brassica rapa var. perviridis)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/komatsuna
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-24
**Evidence Score:** 2 / 10
**Category:** Vegetable
**Also Known As:** Brassica rapa var. perviridis, Japanese mustard spinach, Japanese spinach, Spinach mustard, Komatsuna greens, Tendergreen mustard, Japanese turnip greens

## Overview

Komatsuna (Brassica rapa var. perviridis) is a Japanese leafy green vegetable rich in calcium, vitamin A, and vitamin C. Preliminary animal studies suggest hydroponically zinc-enriched komatsuna may enhance zinc absorption and tissue distribution.

## Health Benefits

• May support zinc absorption when hydroponically enriched - mouse studies showed increased zinc levels in liver, kidneys, muscle, and bone (preliminary animal evidence only)
• Contains calcium, vitamin A, and vitamin C as notable nutrients (no clinical trials on health outcomes)
• Provides dietary phospholipids including phosphatidic acid that form naturally during milling (no human studies on effects)
• No human clinical trials have evaluated health benefits of komatsuna consumption
• Currently consumed primarily as a nutrient-dense vegetable rather than for specific therapeutic effects

## Mechanism of Action

Komatsuna contains calcium carbonate and oxalate compounds that provide bioavailable calcium for bone [metabolism](/ingredients/condition/weight-management). When hydroponically enriched with zinc, the vegetable may facilitate zinc transport through metallothionein proteins and zinc transporter proteins (ZIP and ZnT families). The glucosinolates present in this brassica may also modulate [phase II detox](/ingredients/condition/detox)ification enzymes.

## Clinical Summary

Evidence for komatsuna's health benefits is extremely limited. One mouse study examined zinc-enriched komatsuna and found increased zinc accumulation in liver, kidneys, muscle, and bone tissue compared to controls, but no human trials exist. Nutritional analyses confirm meaningful levels of calcium (150mg/100g), vitamin A, and vitamin C, but clinical outcomes from consuming these nutrients via komatsuna specifically have not been studied. The evidence base consists only of preliminary animal research and basic nutritional profiling.

## Nutritional Profile

Komatsuna (Brassica rapa var. perviridis) is a leafy green vegetable with a notable micronutrient profile per 100g raw weight. Macronutrients: approximately 2.2g protein, 0.2g fat, 3.9g carbohydrates, 1.9g dietary fiber, and ~23 kcal. Micronutrients: calcium is a standout mineral at approximately 170mg per 100g, making it notably higher than many leafy greens; vitamin C approximately 55-60mg (60-70% of RDI); vitamin A as beta-carotene approximately 250-300mcg RAE; vitamin K approximately 250-270mcg; potassium approximately 210mg; magnesium approximately 14mg; iron approximately 2.1mg; phosphorus approximately 45mg; zinc approximately 0.2mg (with hydroponic enrichment potentially increasing zinc content as suggested by animal studies). Bioactive compounds include glucosinolates typical of Brassica species (primarily gluconapin and sinigrin), which hydrolyze to isothiocyanates upon chewing or cooking; chlorophyll; lutein and zeaxanthin as carotenoids supporting eye health. Dietary phospholipids including phosphatidic acid may be present in trace amounts. Bioavailability notes: calcium bioavailability is moderate (estimated 40-50%) as oxalate content is lower than spinach, making it a more bioavailable calcium source; beta-carotene absorption is enhanced by co-consumption with dietary fat; vitamin C content degrades with heat, so light cooking or raw consumption is preferred for maximum retention; iron is non-heme and absorption is enhanced by co-consumed vitamin C.

## Dosage & Preparation

No clinically studied dosage ranges exist as no human trials have been conducted. Komatsuna is consumed as a food vegetable with leaves eaten at any growth stage, with no standardized extracts or supplement forms studied. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Komatsuna appears safe for most people when consumed as a food vegetable, with no documented adverse effects in healthy populations. As a brassica family member, it contains goitrogens that may interfere with [thyroid function](/ingredients/condition/hormonal) in individuals with existing thyroid conditions or iodine deficiency. No specific drug interactions have been reported, though the vitamin K content may theoretically affect warfarin therapy. Safety during pregnancy and lactation is presumed similar to other leafy greens, but specific data is lacking.

## Scientific Research

No human clinical trials, randomized controlled trials, or meta-analyses on komatsuna have been conducted. Available research focuses on plant physiology, including pesticide uptake studies (PMID: 29510368) and zinc enrichment via hydroponics with only mouse feeding tests (PMID: 33215704).

## Historical & Cultural Context

Komatsuna has been cultivated in Japan since the Edo period (1603-1868), with varieties bred for sweeter taste. An old spicy variety called Goseki bansei was historically served to shoguns. It is primarily a culinary vegetable eaten raw, boiled, stir-fried, or in soups, with no documented use in traditional medicine systems.

## Synergistic Combinations

Other dark leafy greens, zinc, vitamin C, calcium, vitamin A

## Frequently Asked Questions

### How much calcium does komatsuna contain compared to other leafy greens?

Komatsuna contains approximately 150mg of calcium per 100g, which is higher than spinach (99mg/100g) but lower than collard greens (232mg/100g). The calcium in komatsuna appears to be well-absorbed due to its relatively low oxalate content compared to spinach.

### What is zinc-enriched komatsuna and how is it different?

Zinc-enriched komatsuna is grown hydroponically with elevated zinc levels in the nutrient solution, resulting in higher zinc content in the leaves. Mouse studies showed this enriched version increased zinc accumulation in organs by 15-30% compared to regular komatsuna, though human studies are needed.

### Can komatsuna affect thyroid function?

Yes, komatsuna contains goitrogenic compounds that may interfere with thyroid hormone production, particularly in people with existing thyroid conditions or iodine deficiency. Cooking reduces but doesn't eliminate these compounds, so individuals with thyroid disorders should consume it in moderation.

### How should komatsuna be prepared to maximize nutrient absorption?

Light steaming or sautéing komatsuna helps break down cell walls to improve nutrient availability while preserving heat-sensitive vitamins like vitamin C. Consuming it with a small amount of fat enhances absorption of fat-soluble vitamin A.

### Is komatsuna safe during pregnancy?

Komatsuna is generally considered safe during pregnancy when consumed as part of a varied diet, providing beneficial folate, calcium, and vitamin A. However, pregnant women should wash it thoroughly and avoid excessive amounts due to potential goitrogenic effects on fetal thyroid development.

### What is the evidence quality for komatsuna's health benefits?

Most evidence for komatsuna's benefits comes from its nutrient composition rather than human clinical trials. While preliminary mouse studies suggest zinc-enriched komatsuna may improve zinc bioavailability to organs like the liver and kidneys, these findings have not been replicated in humans. The vitamin A, C, and calcium content is well-documented, but specific health outcome studies in people are lacking.

### Does komatsuna contain phospholipids, and what do they do?

Yes, komatsuna naturally contains dietary phospholipids including phosphatidic acid, which form during plant milling and processing. However, no human studies have evaluated whether these phospholipids provide functional health benefits when consumed through komatsuna or supplements. These compounds are present in many plant foods but their effects in the body remain largely unstudied in clinical research.

### Who should consider eating komatsuna as a nutritional source?

Komatsuna is most beneficial for individuals seeking plant-based sources of calcium, vitamin A, and vitamin C, particularly those who follow vegetarian or vegan diets or have limited leafy green variety. People interested in zinc-enriched varieties may explore hydroponically grown komatsuna, though human evidence supporting superior zinc absorption from this form is currently unavailable. It is generally suitable for most healthy adults, though those with thyroid conditions should prepare it properly as with other cruciferous vegetables.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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