Watercress, Nasturtium officinale, is a leaf vegetable that is a member of the mustard family, Brassicaceae. It is an aquatic plant grown in temperate areas of Germany, France and the United Kingdom 1. Watercress contain over 90% water, but is also an excellent source of vitamin K, a good source of vitamin A and a source of vitamin C 2. It also contains a number of flavonoid compounds that have antioxidant activities, such as quercetin and hesperetin 3.
Recent attention has been devoted to an additional component of cruciferous vegetables, namely, the glucosinolates. Glucosinolates are sulfur-containing compounds that can be broken down in the human gastrointestinal tract. Isothiocyanates, including sulforaphane, are the metabolites of glucosinolates that can then be absorbed through the intestine 4. Watercress has a moderate glucosinolate content when compared with other cruciferous vegetables 5.