Watercress

The most nutrient-dense vegetable

A 2014 CDC study ranked watercress as the most nutrient-dense vegetable on a scoring system measuring 17 essential nutrients per calorie. It scored a perfect 100. Kale (49) and other leafy greens ranked behind. The reason: watercress concentrates vitamins K, C, and A in dense leaves with very low calorie content.

This is a relatively recent rediscovery. Watercress has been eaten medicinally since ancient times — Hippocrates planted his first hospital near a spring partly to grow watercress.

Aquatic cultivation

Watercress is one of the few commercial vegetables grown in flowing water. Traditional cress beds use natural springs or cold stream water diverted through gravel channels. The plants grow at the water surface, sending roots down into the gravel. The cold flow keeps them crisp and prevents bitterness.

Modern hydroponic cultivation has expanded watercress production into greenhouses, but the best-flavored watercress still comes from wild or traditional spring-fed cress beds.

Foraging caution

Wild watercress in slow or stagnant streams can carry parasites — including liver fluke in regions where livestock grazing contaminates water. Foraged watercress should ideally be cooked, or sourced from clean fast-running waterways. Commercially produced watercress is grown in monitored water and is safe raw.

Beyond the salad

The peppery bite — from the same isothiocyanates that flavor mustard and horseradish — pairs well with rich foods. The British finger sandwich pairs watercress with cucumber and butter on white bread for high tea. French crème de cresson uses it as the base of a creamy soup. In Chinese cooking, watercress is stir-fried with garlic or made into a soothing soup.