# Nasturtium Leaf

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/nasturtium-leaf
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-15
**Evidence Score:** 6 / 10
**Category:** Leaf/Green
**Also Known As:** Nasturtium officinale, Watercress, Water cress, Yellowcress, Brooklime cress, Rorippa nasturtium-aquaticum

## Overview

Nasturtium leaf (Nasturtium officinale) contains glucosinolates that break down into benzyl isothiocyanate (BITC), demonstrating [antimicrobial](/ingredients/condition/immune-support) activity against E. coli and Salmonella through membrane disruption. The phenolic compounds, including hydroxycinnamic acid isomers and quercetin glycosides, provide [antioxidant](/ingredients/condition/antioxidant) effects by boosting [glutathione](/ingredients/condition/detox) peroxidase, superoxide dismutase, and catalase while reducing malondialdehyde levels.

## Health Benefits

- **Enhances immune defenses**: and combats infections through high vitamin C and benzyl isothiocyanate content.
- **Supports [cardiovascular health](/ingredients/condition/heart-health)**: and regulates blood pressure via potassium and [antioxidant](/ingredients/condition/antioxidant)s, promoting healthy circulation.
- **Alleviates respiratory congestion,**: coughs, and colds, reflecting its traditional use for respiratory support.
- **Supports [liver detox](/ingredients/condition/detox)ification**: pathways and promotes toxin elimination with glucotropaeolin and polyphenols.
- **Reduces systemic [inflammation](/ingredients/condition/inflammation)**: and protects against oxidative damage due to its rich content of flavonoids and polyphenols.
- **Stimulates digestion and**: balances the [gut microbiome](/ingredients/condition/gut-health) through its fiber and [antimicrobial](/ingredients/condition/immune-support) compounds.

## Mechanism of Action

Nasturtium leaf's glucotropaeolin breaks down into benzyl isothiocyanate (BITC), which disrupts bacterial cell membranes and exhibits [antimicrobial](/ingredients/condition/immune-support) effects. The phenolic compounds, including caffeic acid and quercetin/kaempferol glycosides, scavenge [free radical](/ingredients/condition/antioxidant)s and enhance antioxidant enzyme activity by increasing [glutathione](/ingredients/condition/detox) peroxidase, superoxide dismutase, and catalase. Additionally, 2-methoxy-4-vinylphenol inhibits PCNA and FAK/AKT phosphorylation pathways, contributing to anticancer effects through S-phase cell cycle arrest.

## Clinical Summary

Current evidence is limited to animal studies and in vitro research, with no human clinical trials reported. In rat models of lung [inflammation](/ingredients/condition/inflammation), hydroalcoholic extract significantly increased lung [glutathione](/ingredients/condition/detox) peroxidase levels and showed modest increases in superoxide dismutase (p<0.05). CCl4-induced liver toxicity studies demonstrated restoration of glutathione, catalase, and SOD while decreasing malondialdehyde over 31 days of treatment. [Antioxidant](/ingredients/condition/antioxidant) testing showed ethanolic extract achieved 37.99% DPPH inhibition at 1000 ppm compared to 93.75% for synthetic BHT control, with active fractions showing IC50 values below 200 μg/mL.

## Nutritional Profile

- Vitamins: C
- Minerals: Potassium, Iron, Magnesium
- Phytochemicals/Bioactives: Glucotropaeolin (sulfur compounds), Flavonoids, Polyphenols, Lutein, Zeaxanthin, Benzyl isothiocyanate
- Other: Dietary fiber, Omega-3 fatty acids

## Dosage & Preparation

- Common forms: Fresh leaves (raw), dried powder, standardized extract.
- Traditionally consumed raw, pickled, or powdered for culinary and medicinal purposes.
- Modern applications include immune-boosting teas, detox blends, [digestive health](/ingredients/condition/gut-health) formulations, and culinary dishes like salads and smoothies.
- Dosage: 1–2 cups fresh leaves daily, or 500–1000 mg standardized extract for immune, [cardiovascular](/ingredients/condition/heart-health), and respiratory support.

## Safety & Drug Interactions

Animal studies show no adverse effects and non-genotoxic profiles, though high glucosinolate content may cause goitrogenic effects that could inhibit iodine uptake and potentially lead to hypo[thyroid](/ingredients/condition/hormonal)ism in susceptible individuals. Isothiocyanate compounds may cause gastrointestinal irritation at high doses, though specific thresholds are not established. No documented drug interactions exist, but theoretical concerns include potentiation of anticoagulant or antidiabetic medications due to [antioxidant](/ingredients/condition/antioxidant) properties. Safety during pregnancy and lactation has not been studied, and use should be avoided in individuals with existing thyroid conditions or iodine deficiency.

## Scientific Research

Preliminary research, including in vitro and animal studies, suggests Nasturtium Leaf's potential for [antimicrobial](/ingredients/condition/immune-support), [anti-inflammatory](/ingredients/condition/inflammation), and [antioxidant](/ingredients/condition/antioxidant) effects, attributed to its unique bioactive compounds. Further human clinical trials are needed to fully elucidate its therapeutic applications and optimal dosages.

## Historical & Cultural Context

Nasturtium has been revered by South American indigenous cultures, particularly in Peru and Bolivia, for promoting vitality, immune strength, and resilience. European herbalists and sailors also valued it for preventing scurvy and treating respiratory ailments. It was later celebrated in Europe for culinary uses, sometimes called "poor man's capers," bridging traditional medicine with culinary excellence.

## Synergistic Combinations

Role: Polyphenol/[antioxidant](/ingredients/condition/antioxidant) base
Intention: Immune & [Inflammation](/ingredients/condition/inflammation) | Cardio & Circulation
Primary Pairings: - Ginger (Zingiber officinale)
- Turmeric (Curcuma longa)
- Olive Oil
- Lemongrass

## Frequently Asked Questions

### What are the main active compounds in nasturtium leaf?

The primary bioactive compounds include glucosinolates (particularly glucotropaeolin) that break down into benzyl isothiocyanate, phenolic compounds like hydroxycinnamic acid isomers and caffeic acid, and flavonoids including quercetin and kaempferol glycosides. These compounds are responsible for the antimicrobial, antioxidant, and anti-inflammatory properties of nasturtium leaf.

### How effective is nasturtium leaf for respiratory conditions?

Animal studies show nasturtium leaf extract significantly increased lung antioxidant enzymes like glutathione peroxidase in allergen-induced inflammation models. The extract also modestly reduced inflammatory markers IL-1β and TNF-α expression, though these reductions were not statistically significant. Human clinical trials are needed to confirm respiratory benefits.

### Can nasturtium leaf cause thyroid problems?

Yes, nasturtium leaf contains high levels of glucosinolates that may have goitrogenic effects, potentially inhibiting iodine uptake and leading to hypothyroidism in susceptible individuals. People with existing thyroid conditions or iodine deficiency should avoid nasturtium leaf supplements. The specific dosage thresholds for these effects have not been established.

### What's the difference between nasturtium leaf and garden nasturtium?

Nasturtium leaf (Nasturtium officinale) is watercress from the Brassicaceae family, while garden nasturtium (Tropaeolum majus) is a different plant from South America. Both contain similar compounds like glucosinolates and phenolics, but watercress is the species primarily studied for medicinal properties. The terms are often confused, but they refer to distinct botanical species.

### How much nasturtium leaf extract was used in studies?

Animal studies used various preparations including hydroalcoholic extracts given twice weekly for 31 days in liver toxicity models, though specific dosages per kilogram body weight were not detailed in available research. In vitro antioxidant testing used concentrations up to 1000 ppm, with active fractions showing effects at IC50 values below 200 μg/mL. Human dosage recommendations cannot be established without clinical trials.

### Is nasturtium leaf safe to take with blood pressure or heart medications?

Nasturtium leaf contains potassium and compounds that may have mild blood pressure-lowering effects, so it should be used cautiously alongside antihypertensive or cardiac medications. Consult your healthcare provider before combining nasturtium leaf with medications like ACE inhibitors, beta-blockers, or potassium-sparing diuretics to avoid additive effects or potassium imbalances. Medical supervision is especially important if you have existing cardiovascular conditions or take multiple medications.

### What is the most bioavailable form of nasturtium leaf—fresh, dried, extract, or powder?

Fresh nasturtium leaf may provide the highest vitamin C content and some volatile compounds, but dried leaf and standardized extracts offer better stability and consistent dosing for supplementation. Liquid extracts or concentrated powders typically enhance bioavailability of the active isothiocyanates compared to whole dried leaf, though freshness and extraction methods significantly affect potency. For therapeutic use, standardized extracts (often dosed at 300–600 mg daily) are preferred because they deliver predictable amounts of active compounds.

### Who should avoid nasturtium leaf supplementation?

Pregnant and nursing women should avoid nasturtium leaf due to limited safety data and its traditional use as a stimulant herb. Individuals with kidney disease or those taking potassium-elevating medications should consult a doctor before use, as nasturtium's potassium content could be problematic. People with iodine deficiency or thyroid sensitivity should exercise caution, and those with bleeding disorders or on anticoagulants should seek medical guidance before supplementing.

## References

Sources: https://pubmed.ncbi.nlm.nih.gov/31741289; https://www.sciencedirect.com/science/article/pii/S2213453019301625; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160325/

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