Watercress – cultivation methods and health effects

Watercress, Nasturtium officinale R. Br., is a native water or semiaquatic plant that has a high nutrient density. Physiologically relevant are the various glucosinolates, which possess positive health effects in form of their thio- and isothiocyanates. In an interdisciplinary project, we aim to develop a hydroponic, and finally an aquaponic, circulatory cultivation system and to study the health effects of watercress. In humans, there is a lack of data-based knowledge on potential beneficial health effects of watercress. Growth of watercresswas followed during one season in an open-door hydroponic system. Watercress was also cultivated in the greenhouse in different substrates with different concentrations of nutrients and salt. The biomass production is strongly dependent on the temperature. The glucosinolate contents differ significantly during the growing season, especially during flowering. Watercress naturally grows in nutrient rich fresh waters, however, when cultivated at NaCl concentrations of up to 120 mM the gain in biomass is still high. In a human proof of-concept study, indications for antioxidant and anti-inflammatory effects of fresh watercress were observed already after a single dose intake of fresh watercress (85 g). Further in vivo and in vitro studies are planned to study health beneficial effects of watercress and its metabolic activity.