one of the most nutritionally dense leafy greens known. gram for gram it outperforms most vegetables on multiple nutrient metrics.

the signature compound in watercress is phenethyl isothiocyanate (PEITC). a hydrolysis product of gluconasturtiin when watercress is chewed or cut.

compounds in watercress: gluconasturtiin at 640.94 mg/100g DW, 4-methoxyglucobrassicin at 23.47 mg/100g DW, rutoside, quercetin, kaempferol, isorhamnetin, lutein, beta-carotene, zeaxanthin, vitamin K (exceptionally high), vitamin C, calcium, iron, iodine, and nasturtiin.

watercress extracts has shown promising anti-cancer agents against malignant melanoma cells.

PEITC's anticancer mechanism is one of the best characterized of any food compound:

it inhibits phase I cytochrome P450 enzymes that activate carcinogens, induces phase II detoxification enzymes that neutralize them, directly inhibits HDAC (histone deacetylase) — an epigenetic cancer driver — and induces apoptosis in cancer cells through mitochondrial pathway activation. human clinical trial data exists showing PEITC from watercress consumption measurably reduces carcinogen-DNA adducts in smokers.

watercress supplementation may improve lipid profiles, reduce oxidative stress, and modulate inflammation in cardiovascular and respiratory conditions. high vitamin K content- vitamin K2 specifically prevents arterial calcification by activating matrix Gla protein (MGP).

watercress is a documented hyperaccumulator of heavy metals from contaminated water and it's used in bioremediation of agricultural runoff and heavy metal-contaminated waterways.
watercress in contaminated water systems actively extracts cadmium, lead, and other heavy metals from the water column.

watercress extract is used in skin-brightening formulations (PEITC has mild tyrosinase-inhibiting activity), scalp treatments for hair growth promotion (sulfur compounds from glucosinolates support keratin synthesis), and anti-aging preparations.

raw watercress from slow-moving or stagnant water can harbor the liver fluke Fasciola hepatica. always source from clean fast-running water or cultivated watercress.

the PEITC content requires the enzyme myrosinase to be activated. heating destroys myrosinase, so cooked watercress loses much of the isothiocyanate benefit. eating raw is pharmacologically superior for PEITC release.

https://www.youtube.com/watch?v=WNjK6tNCZks