Watercress and Cancer Prevention
Disclaimer: All information provided should be considered as generalizations and not as specific information for any individual. Nor should this information be considered medical advice. This information needs to be considered in consultation with your family physician. Specific food allergies or medical conditions may make the provided information unsuitable for some individuals.
Summary: A recent study by Gill et al.1 demonstrated the effectiveness of Watercress (a cruciferous vegetable) in reducing laboratory markers of white blood cell DNA damage and thus possibly reducing the risk of cancer in those consuming the vegetable. When taken in the context of epidemiologic studies that suggest a link between vegetable intake and decreased cancer risk it does suggest that watercress may have a true anti-carcinogenic property. However, the one piece lacking in this line of evidence is a true comparison of Watercress versus placebo in a randomized controlled trial with a long period of follow-up to see if this effect is real and of significant degree.
Interpretation: Just as your parents
always said "eat your veggies!"
Due to a link in recent population/epidemiologic studies between the benefits of vegetables and decreased risk of cancer, scientists have been studying specific vegetables with high contents of compounds considered to be anti-carcinogenic.2 A recent study showed that supplementation of 85 grams per day of watercress for eight weeks reduced laboratory markers of cancer risk such as white blood cell DNA damage.
Click the image to see the Watercress Mango Salad
recipe
Recent investigations of cruciferous vegetables have identified several mechanisms that may be anti-carcinogenic. Read the article on vegetables and cancer. One identified group of compounds, glucosinolates, are metabolized to form isothiocyanates that have been shown to possess anti-carcinogenic properties. Watercress (Rorippa nasturtium-aquaticum) contains "one of the highest concentrations of glucosinolates per gram of weight of any vegetable". High levels of carotenoids such as lutein and β-carotene are also found.
Dr. Lawrence Korngut, M.D.
Chief Neurology Resident
London Health Sciences Centre
London, Ontario, Canada
1Gill, C,. Haldar S., Boyd, LA. et al., Watercress supplementation in diet reduces lymphocyte DNA damage and alters blood antioxidant status in healthy adults. American Journal of Clinical Nutrition 2007;85(2):504-510.
2Vainio H., Weiderpass, E., Fruit and vegetables in cancer prevention. Nutrition and Cancer 2006;54(1):111-142.
