Quick Summary

Watercress (Nasturtium officinale) is a cruciferous leafy green traditionally used for various health conditions. It contains bioactive compounds including glucosinolates and isothiocyanates with antioxidant and anti-inflammatory properties. Clinical evidence from human randomized controlled trials suggests watercress supplementation may improve antioxidant and inflammatory markers. However, evidence on specific therapeutic effects remains limited due to short follow-up durations and heterogeneous study designs.

What is it

Watercress is an aquatic perennial plant belonging to the Brassicaceae family. It is widely consumed as a leafy green vegetable and is noted for its peppery flavor. It grows naturally in flowing water and is also cultivated for culinary and traditional uses.

Traditional Uses

Traditionally, watercress has been used in various cultures for promoting general health and wellbeing. It has been employed as a natural remedy for respiratory conditions, digestive support, and as a nutritive green believed to bolster vitality.

Active Compounds

Key bioactive compounds in watercress include glucosinolates and their hydrolysis products isothiocyanates, such as phenethyl isothiocyanate. These compounds exhibit antioxidant, anti-inflammatory, and potential chemoprotective effects. Watercress is also a source of vitamins and antioxidants like retinol, β-carotene, and α-tocopherol.

Potential Benefits with Evidence Levels

  • Improvement in antioxidant and anti-inflammatory markers (Moderate evidence)

    A systematic review of 7 randomized controlled trials (RCTs) with 302 participants reported that watercress supplementation improved antioxidant enzymes (superoxide dismutase, glutathione peroxidase) and increased antioxidant vitamins (retinol, β-carotene, α-tocopherol). There were reductions in oxidative stress markers (protein carbonyls, malondialdehyde) and inflammatory cytokines (tumor necrosis factor-alpha). Studies varied in dosage and duration (21 to 60 days).
  • Potential anti-inflammatory effects in respiratory tract diseases (Preclinical and limited clinical evidence)

    Bioactive compounds found in Brassicaceae plants such as watercress may modulate molecular pathways involved in respiratory tract inflammation. However, direct clinical evidence specific to watercress remains insufficient.
  • Source of glucosinolates and isothiocyanates with antioxidant and potential chemoprotective effects (Limited clinical evidence)

    Reviews of bioavailability and metabolism indicate that glucosinolates and isothiocyanates in watercress contribute to antioxidant, anti-inflammatory, and possible anticancer properties. Further clinical studies are needed to confirm these effects.

Side Effects

Watercress appears to have a strong safety profile with no major adverse events reported in clinical trials focused on antioxidant and anti-inflammatory effects. No specific adverse effects have been identified; however, due to limited data, potential adverse effects cannot be entirely excluded.

Drug Interactions

There are no documented drug interactions specific to watercress in the available evidence.

Who Should Avoid It

No specific contraindications for watercress use are reported. However, caution is advised during pregnancy and breastfeeding due to lack of clinical safety data. Individuals with specific health conditions or those taking medications should consult healthcare professionals before supplementation.

Evidence Limitations

  • Human clinical studies are limited in number and sample size.
  • Follow-up durations in supplementation studies are short (mean approximately 39 days).
  • There is heterogeneity in study designs, patient demographics, watercress formulations, and dosages.
  • Lack of standardized assessment of adverse events in clinical trials.
  • Most evidence focuses on biomarkers rather than clinical health outcomes.
  • Insufficient data on long-term safety and efficacy.
  • Limited data on drug interactions, contraindications, and use during pregnancy and breastfeeding.

References

  1. Wen J, Karabala M, Muttalib Z, Syed B, Khalil R, Razick D, Razick A, Pai D. Evaluating the Anti-Oxidant and Anti-Inflammatory Properties of Watercress Supplementation at Short-Term Follow-Up: A Systematic Review of Randomized Controlled Trials. 2025. doi:10.1002/fsn3.70407
  2. Narra F, Galgani G, Harris CB, Moreno DA, Núñez-Gómez V. Bioavailability, Human Metabolism, and Dietary Interventions of Glucosinolates and Isothiocyanates: Critical Insights and Future Perspectives. 2025. doi:10.3390/foods14162876
  3. Luo J, Luo J, Fang Z, Fu Y, Xu BB. Insights Into Effects of Natural Bioactive Components on Inflammatory Diseases in Respiratory Tract. 2025. doi:10.1002/ptr.8367

Last Reviewed

June 2024

Informational Disclaimer

This page provides a summary of current evidence related to watercress and is intended for informational purposes only. It does not constitute medical advice and should not replace consultation with qualified healthcare professionals. The scientific understanding of watercress’s health effects is evolving, and readers are encouraged to seek professional guidance before using watercress for therapeutic purposes.