Like kale, broccoli, and horseradish, watercress (Nasturtium officinale) is a brassica vegetable. Watercress has been shown to have antioxidant, anti-genotoxic, and anti-inflammatory properties, and to improve cholesterol profile. Watercress is a good dietary source of riboflavin, vitamin C, vitamin A, and vitamin K. Watercress also is a good source of lutein, nasturtiin (the precursor of phenethyl isothiocyanate), phenylethyl isothiocyanate (PEITC), benzyl isothiocyanate (BITC), indole-3-carbinol (I3C) and its metabolic product 3,3'-diindolylmethane (DIM), and sulforaphane, all of which have been reported to have anti-cancer properties. Brassica vegetables have been shown to inhibit the growth of human pancreatic cancer cells and to reduce the risk of occurrence of lung, gallbladder, bladder, prostate, ovarian and colorectal cancer.
Breast cancer-related effects of eating watercress
Various isothiocyanates derived from watercress have been found to have chemopreventive activity against a variety of breast cancer cell lines in the laboratory and in epidemiologic studies. A Chinese study which measured urinary isothiocyanate levels as a marker of brassica vegetable intake found that higher levels were protective against breast cancer in both premenopausal and postmenopausal women.
Lutein consumption and circulating lutein levels have been found to be associated with reduced risk of breast cancer in several epidemiological studies. Lutein has been shown to inhibit the progression of both ER+ and ER+ breast cancer cells under hypoxia, a low-oxygen condition in which solid breast tumors can thrive. Lutein has also been shown to potentiate the effect of taxane chemotherapy drugs (Taxol and Taxotere) in breast cancer cells.
Watercress is the most abundant dietary source of PEITC, which has been found to reduce the growth of human breast cancer cells, enhance the sensitivity of the breast cancer cells to radiotherapy, decrease angiogenesis (the process by which tumors send out signals to induce surrounding normal tissues to grow new blood vessels into the tumor), inhibit the growth of HER2 overexpressing (HER2+) mammary tumors in mice, and inhibit metastasis to the brain in a mouse model of breast cancer.
Watercress should be eaten raw rather than cooked to obtain the most powerful anti-cancer effects.
Garden cress (Lepidium sativum) is a brassica vegetable related to watercress and has similar chemopreventive properties.
Below are links to recent studies concerning this food. For a more complete list, including less recent studies, please click on watercress.