# Turnip (Brassica rapa subsp. rapa)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/turnip
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-24
**Evidence Score:** 2 / 10
**Category:** Vegetable
**Also Known As:** Brassica rapa subsp. rapa, White turnip, Baby turnip, Neep, Swede turnip, Field turnip, Turnip greens, Shalgam

## Overview

Turnip (Brassica rapa subsp. rapa) is a cruciferous vegetable rich in glucosinolates, which are enzymatically converted by myrosinase into bioactive isothiocyanates such as sulforaphane and allyl isothiocyanate. These compounds modulate detoxification enzymes, suppress [oxidative stress](/ingredients/condition/antioxidant), and may inhibit cancer cell proliferation through Nrf2 pathway activation.

## Health Benefits

• [Antioxidant](/ingredients/condition/antioxidant) effects from phenolic compounds (up to 18 g/kg) and flavonoids (119.2-138.85 mg/100g in tops) - evidence from in vitro studies only
• Potential anticancer activity through glucosinolate-derived isothiocyanates - preliminary animal model evidence
• Possible antidiabetic effects via phytochemical modulation - preclinical studies only
• [Antimicrobial](/ingredients/condition/immune-support) properties from sulfur-containing compounds - in vitro evidence
• Nephroprotective potential indicated - animal model studies only

## Mechanism of Action

Glucosinolates in turnip are hydrolyzed by the endogenous enzyme myrosinase upon cell disruption, yielding isothiocyanates (e.g., allyl isothiocyanate) that activate the Nrf2-Keap1 pathway, upregulating [phase II detox](/ingredients/condition/detox)ification enzymes including glutathione S-transferase and quinone reductase. Phenolic compounds, present at up to 18 g/kg dry weight, scavenge [reactive oxygen species](/ingredients/condition/antioxidant) and inhibit lipid peroxidation via direct radical quenching. Flavonoids concentrated in the leaf tops (119.2–138.85 mg/100g) may inhibit alpha-glucosidase activity, slowing postprandial glucose absorption and contributing to reported antidiabetic effects.

## Clinical Summary

Evidence for turnip's health benefits is predominantly derived from in vitro cell studies and animal models, with very limited controlled human clinical trials available. Anticancer properties of isothiocyanates have shown tumor suppression in rodent models, but direct extrapolation to human outcomes remains unestablished. Antidiabetic effects, including alpha-glucosidase inhibition and improved [insulin sensitivity](/ingredients/condition/weight-management), have been demonstrated in diabetic mouse models at specified extract doses, but human dosing equivalents and efficacy have not been confirmed in randomized trials. Overall, while the phytochemical profile is promising, the evidence base does not yet support definitive clinical health claims.

## Nutritional Profile

Turnip root (raw, per 100g): Energy 28 kcal; Water 91.9g; Protein 0.9g (limited essential amino acid profile); Total carbohydrates 6.4g (of which sugars 3.8g, dietary fiber 1.8g); Fat 0.1g; Ash 0.7g. Key macronutrient note: low glycemic index (~62 whole, lower glycemic load due to high water content). Micronutrients (root): Vitamin C 21mg (23% DV - moderate bioavailability, heat-labile); Folate 15µg (4% DV); Vitamin B6 0.09mg; Vitamin K 0.1µg (negligible in root vs. tops); Potassium 191mg; Calcium 30mg (bioavailability reduced by oxalates ~0.2g/100g); Phosphorus 27mg; Magnesium 11mg; Manganese 0.134mg; Iron 0.3mg (non-heme, low bioavailability ~5-12%, further inhibited by phytates); Zinc 0.27mg; Sodium 67mg. Turnip greens/tops (per 100g, distinct nutritional profile): Vitamin C 60mg; Vitamin K 251µg (high bioavailability with dietary fat); Vitamin A (as beta-carotene) 381µg RAE; Calcium 190mg (bioavailability ~5% due to oxalates ~0.45g/100g); Folate 118µg; Flavonoids 119.2-138.85mg (quercetin, kaempferol, isorhamnetin glycosides - bioavailability varies with food matrix). Bioactive compounds (root and tops): Glucosinolates 1.2-4.5µmol/g dry weight (primarily gluconapin, progoitrin, glucobrassicanapin); enzymatic hydrolysis by myrosinase yields isothiocyanates and nitriles - myrosinase activity partially destroyed by cooking, gut microbiota can partially compensate; Phenolic acids up to 18g/kg dry weight (hydroxycinnamic acids, hydroxybenzoic acids - bioavailability 10-50% depending on conjugation form); Anthocyanins present in purple-skinned varieties (cyanidin and pelargonidin derivatives); Indole-3-carbinol formed from glucobrassicin hydrolysis. Anti-nutritional factors: Goitrogens (progoitrin-derived goitrin ~0.5mg/100g) may impair [thyroid](/ingredients/condition/hormonal) iodine uptake at high intake; phytates 0.1-0.3g/100g reduce mineral bioavailability; oxalates moderate in root, higher in tops. Cooking effects: Boiling reduces glucosinolates 35-59%, vitamin C 40-50%, and goitrogenic compounds; steaming preserves more micronutrients (~15-25% vitamin C loss). Fiber composition: insoluble fiber (cellulose, hemicellulose) predominates, with minor soluble pectin fraction supporting [gut microbiome](/ingredients/condition/gut-health) modulation.

## Dosage & Preparation

No clinically studied dosage ranges exist for turnip extracts, powders, or standardized forms due to the absence of human trials. While phytochemical contents vary by plant part, no therapeutic dosing recommendations have been established. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Turnip is generally recognized as safe when consumed as a food, but high intake may cause gastrointestinal bloating and flatulence due to its high fiber and raffinose oligosaccharide content. Individuals taking anticoagulant medications such as warfarin should exercise caution, as turnip greens contain significant vitamin K that can antagonize anticoagulant therapy. Turnip contains goitrogenic compounds (goitrin, derived from progoitrin hydrolysis) that can suppress [thyroid](/ingredients/condition/hormonal) hormone synthesis, particularly relevant for individuals with hypothyroidism or iodine deficiency when consuming large amounts raw. Pregnant women may consume turnip safely in typical dietary amounts, but concentrated supplement extracts have not been evaluated for safety in pregnancy.

## Scientific Research

No human clinical trials, RCTs, or meta-analyses on turnip for biomedical applications were found in the research dossier. All evidence comes from preclinical studies (in vitro and animal models) indicating potential bioactivities, but human data is completely absent.

## Historical & Cultural Context

The research provides minimal traditional use information, noting only a vague reference to turnip as a 'natural health tonic' due to bioactives like peroxidase and kaempferol. No specific traditional medicine systems (Ayurveda, TCM, or folk medicine) or historical contexts are documented.

## Synergistic Combinations

Broccoli, Kale, Cabbage, Brussels Sprouts, Watercress

## Frequently Asked Questions

### What are the main active compounds in turnip?

The primary bioactive compounds in turnip are glucosinolates (notably sinigrin and gluconapin), which convert to isothiocyanates like allyl isothiocyanate upon chewing or cutting. The tops are especially rich in flavonoids (119.2–138.85 mg/100g) and phenolic acids, while the root contains fiber, vitamin C, and carotenoids that contribute to its antioxidant capacity.

### Can turnip help with blood sugar control?

Preliminary evidence from animal studies suggests turnip extracts may exert antidiabetic effects by inhibiting alpha-glucosidase, an intestinal enzyme that breaks down carbohydrates, thereby reducing postprandial blood glucose spikes. Additionally, phytochemicals in turnip have shown improvement in insulin sensitivity in diabetic mouse models, but no large-scale human clinical trials have confirmed these effects or established effective dosages.

### Is turnip good for cancer prevention?

Glucosinolate-derived isothiocyanates from turnip, such as allyl isothiocyanate, have demonstrated antiproliferative and pro-apoptotic effects against cancer cell lines in vitro and reduced tumor incidence in rodent models. However, this evidence is considered preliminary, and no controlled human trials have established a direct cancer-preventive role for turnip or its isolated compounds.

### Does eating turnip affect thyroid function?

Yes, turnip contains progoitrin, which is hydrolyzed to goitrin — a compound that interferes with thyroid peroxidase activity and can reduce thyroid hormone synthesis. This effect is most significant when large quantities are consumed raw, since cooking partially inactivates myrosinase and reduces goitrin formation. People with hypothyroidism or iodine deficiency should moderate their raw turnip intake.

### How does turnip compare to other cruciferous vegetables nutritionally?

Turnip has a lower glucosinolate density compared to broccoli or Brussels sprouts, but its leaf tops are notably high in flavonoids (up to 138.85 mg/100g) and phenolic compounds, rivaling kale in antioxidant potential based on in vitro DPPH assay data. The root is lower in calories (about 28 kcal/100g) and provides meaningful amounts of vitamin C and potassium, making it a nutrient-dense but less concentrated source of the isothiocyanates found abundantly in broccoli sprouts.

### What does the current clinical evidence show about turnip's health benefits in humans?

Most turnip research consists of in vitro (test tube) and animal studies examining its antioxidant and anticancer compounds. Human clinical trials are extremely limited, meaning benefits observed in laboratory settings have not been robustly confirmed in people. Current evidence supports turnip as a nutrient-dense whole food but does not yet establish specific therapeutic claims for disease prevention or treatment in humans.

### Is turnip safe to consume during pregnancy and breastfeeding?

Turnip as a whole food is considered safe during pregnancy and breastfeeding as part of a normal diet, being a common vegetable consumed across many cultures. However, concentrated turnip supplements or extracts have not been adequately studied in pregnant or nursing populations. Pregnant and breastfeeding women should consume turnip in typical food amounts and consult a healthcare provider before using any concentrated supplement form.

### Does cooking or food preparation method affect the bioavailability of turnip's beneficial compounds?

Raw turnips retain higher levels of heat-sensitive glucosinolates (sulfur compounds with potential bioactivity), while cooking can reduce these compounds but may also increase the bioavailability of certain phenolic antioxidants through cell wall breakdown. Steaming or minimal cooking appears to preserve more glucosinolates than boiling, which leaches water-soluble compounds into cooking liquid. The optimal preparation method depends on which compounds are of primary interest, as different cooking methods offer different nutritional trade-offs.

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