Know2eat

Watercress

Nasturtium officinale

What watercress has been studied for

2 associations assessed — 2 with at least some human evidence behind them. Strongest first.

  • 2 Limited
3 things to know first — allergies, interactions and intake limits

About watercress

A semi-aquatic peppery brassica grown in flowing water, sold as loose sprigs or bunches. Its bite comes from gluconasturtiin, which breaks down to phenethyl isothiocyanate when the leaf is chewed.

Also known as Water cress, Berro, Yellowcress

Cellular HealthAntioxidant & Oxidative Stress

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how impressive the food is. How we rate evidence.

DNA and cellular integrity

Cellular Health
Limited evidence

A small number of human trials have fed daily watercress and reported reduced DNA damage in circulating lymphocytes measured by the comet assay. The trials are small, mostly from one group, and the marker is a laboratory measure whose relationship to any health outcome is unsettled.

What may be going on: Phenethyl isothiocyanate induces phase II conjugation enzymes and inhibits some phase I activation enzymes in human cells.

Limited evidence. Early human work, or mostly lab and animal research.

3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Oxidative stress markers

Antioxidant & Oxidative Stress
Limited evidence

Some short trials report higher plasma carotenoid concentrations and modest shifts in oxidative-stress markers after daily watercress. Findings are inconsistent between studies and the participant numbers are small.

Limited evidence. Early human work, or mostly lab and animal research.

4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Ask about Watercress

Ask about Watercress

Answers are written only from the entries on this page — the same nutrients, compounds, claims and citations you can read above. Nothing is added from outside the database, and every answer lists what it was built from.

AI explanations are not switched on for this site, so there is nothing to ask here. Everything above is read straight from the database and does not need them.

Key nutrients

Nutrient content per 100 grams
NutrientAmount% DV
Macronutrients
Calories11 kcal1%
Protein2.3 g5%
Total fat0.1 g0%
Carbohydrate1.29 g0%
Fibre0.5 g2%
Total sugars0.2 g—
Water95.1 g—
Fats
Saturated fat0.027 g0%
Monounsaturated fat0.0080 g—
Polyunsaturated fat0.035 g—
Cholesterol0 mg0%
EPA (omega-3)0 g—
DHA (omega-3)0 g—
DPA (omega-3)0 g—
Linoleic acid (omega-6)0.012 g—
Vitamins
Vitamin A160 µg18%
Vitamin C43 mg48%
Vitamin D0 µg0%
Vitamin E1 mg7%
Vitamin K250 µg208%
Thiamin (B1)0.09 mg8%
Riboflavin (B2)0.12 mg9%
Niacin (B3)0.2 mg1%
Pantothenic acid (B5)0.31 mg6%
Vitamin B60.129 mg8%
Folate9 µg2%
Vitamin B120 µg0%
Choline9 mg2%
Minerals
Calcium120 mg9%
Iron0.2 mg1%
Magnesium21 mg5%
Phosphorus60 mg5%
Potassium330 mg7%
Sodium41 mg2%
Zinc0.11 mg1%
Copper0.077 mg9%
Manganese0.244 mg11%
Selenium0.9 µg2%
Other measured compounds
Beta-carotene1914 µg—
Alpha-carotene0 µg—
Lycopene0 µg—
Lutein + zeaxanthin5767 µg—
Caffeine0 mg—
Ash1.2 g—

Nutrient values are per 100 g of the USDA reference entry named on this page and vary with variety, growing conditions, storage and preparation.

Source record: Watercress, raw (USDA FoodData Central, FDC ID 170068).

% DV uses the FDA Daily Values for adults and children aged 4 and over. A dash means no Daily Value has been established for that nutrient.

Bioactive compounds

Compounds present in meaningful amounts. Presence is banded rather than quantified, because whole-food levels vary enormously with variety, growing conditions, storage and preparation.

How preparation changes things

Only effects with real support are listed. If a preparation method is missing, it is because nothing dependable is documented — not because it makes no difference.

  • crushedIncreases phenethyl isothiocyanate yield

    Chewing or chopping brings myrosinase into contact with gluconasturtiin, which is what generates the isothiocyanate. Watercress is usually eaten raw, so this happens by default.

  • boiledReduces glucosinolates and myrosinase

    Cooking inactivates myrosinase and leaches glucosinolates into the water, which is why watercress soup tastes mild compared with the raw leaf.

Things to know

Allergies, interactions and intake concerns. Every food gets this section — a reference where everything is uniformly good is not a reference.

  • Worth knowing

    Wild watercress and liver fluke

    Watercress gathered from streams grazed by sheep or cattle can carry the infective stage of the liver fluke Fasciola hepatica, and human outbreaks have been traced to it. Commercially grown watercress from controlled water is the safe option; foraged cress should be cooked, not eaten raw.

  • Interaction

    Vitamin K and warfarin

    Watercress is high in vitamin K1 for its weight, though portions are usually small. Anyone on warfarin should keep intake consistent rather than eating large bunches only occasionally.

  • Worth knowing

    Goitrogens at very high intake

    Like other raw brassicas, watercress releases thiocyanates that compete with iodine at the thyroid. Culinary amounts are not a concern; the caution applies to sustained very large intakes alongside low iodine status.