Watercress

Although a number of studies have shown that watercress is a rich source of chemical compounds that can exert anti-cancer activity in experimental settings, it remains unclear whether normal dietary intake of watercress can impact on the development of cancers.

Watercress contains 15 essential vitamins and minerals. With more vitamin C than oranges, more calcium than milk and more iron than spinach, watercress is low in fat and very versatile. It also contains beta-carotene, Vitamin A equivalents and antioxidants.

The study, led by Graham Packham, Professor of Molecular Oncology at the University of Southampton, involves a dozen breast cancer survivors eating 80g of watercress before providing a series of blood samples.

Scientists determine the levels of watercress- derived chemical compounds in the blood samples and whether potential anti-cancer pathways are activated in the blood cells of the volunteers.  Clinical aspects are being overseen by Mr Dick Rainsbury, Director of the Winchester and Andover Breast Unit at the Royal Hampshire County Hospital, working closely with Senior Research Dietician, Babara Parry.

An exciting discovery of this research has been the elucidation of a mechanism by which watercress derived chemical compounds interfere with cancer promoting pathways. Graham Packham’s team have shown that PEITC, the main compound responsible for watercress anti cancer properties, prevents that accumulation of a key protein within cancer cells when cells are exposed to low levels of oxygen.  This protein can act to drive the development of a new blood supply to growing tumours and inhibition of this pathway might contribute to the potential anti-cancer effects of PEITC.

The £100,000 project has been funded by The Watercress Alliance, made up of Vitacress Salads, Bakkavör and The Watercress Company. It follows research, carried out by the University of Ulster, Coleraine, and published in the American Journal of Clinical Nutrition in February 2007 which found that watercress increased the ability of cells to resist DNA damage caused by free radicals and that daily intake of watercress significantly reduced levels of DNA damage found in blood cells. DNA damage is considered to be an important trigger in the early stages of cancer.

Dr. Steve Rothwell, of The Watercress Alliance, commented: “We are hoping to build on the body of research which supports the idea that watercress may have an important role to play in limiting cancer cell development.  It is quite fitting that the study is being carried out in an area which is at the centre of watercress production.”

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