Is watercress really the most nutritious vegetable?

By the US density index, which scores nutrients per calorie, it came first out of eighty-seven foods. That is a real result, though it partly reflects how few calories watercress has.

Can I use rocket instead?

Yes. Rocket is in the same family and behaves the same way on the plate, though the pepper is different in character.

Chapter 1 of 15

Watercress

If You Read Nothing Else

Watercress scored the highest of eighty-seven foods on the US nutrient-density index.

The peppery taste comes from glucosinolates, the same family of compounds found in mustard and rocket.

Buy cultivated watercress. Wild cress from a stream can carry liver fluke.

Shāhi grows in running water, which is where its name and its problems both come from. It has a mustard bite that wakes up a mouthful of bread and cheese, and gram for gram it carries more vitamins and minerals per calorie than almost any other food measured. In Iran it sits on the sabzi khordan plate beside tarragon, basil and radish, and it's eaten by the fistful rather than the leaf.

Known to botanists as Nasturtium officinale.