– A natural plant chemical – phenylethyl isothiocyanate – found in watercress may have the ability to suppress breast cancer cell development by ‘turning off’ a signal in the body and thereby starving the growing tumor of essential blood and oxygen, according to new research from the University of Southampton.

The research, unveiled at a press conference on September 14, 2010, shows that the watercress phytochemical is able to interfere with the function of a protein which plays a critical role in cancer development.

As tumors develop they rapidly outgrow their existing blood supply so they send out signals which make surrounding normal tissues grow new blood vessels into the tumor which feed them oxygen and nutrients.

The research, led by Professor Graham Packham of the University of Southampton, shows that the plant compound (phenylethyl isothiocyanate, or phenethyl isothiocyanate, or PEITC) found in the cruciferous vegetable watercress can block this process, by interfering with and ‘turning off’ in the function of a protein called Hypoxia Inducible Factor (HIF).

Professor Packham, a molecular oncologist at the University of Southampton, comments: “The research takes an important step towards understanding the potential health benefits of this crop since it shows that eating watercress may interfere with a pathway that has already been tightly linked to cancer development.

“Knowing the risk factors for cancer is a key goal and studies on diet are an important part of this. However, relatively little work is being performed in the UK on the links between the foods we eat and cancer development.”

Working with Barbara Parry, Senior Research Dietician at the Winchester and Andover Breast Unit, Professor Packham performed a pilot study in which a small group of breast cancer survivors, underwent a period of fasting before eating 80 grams of watercress (a cereal bowl full) and then providing a series of blood samples over the next 24 hours.

The research team was able to detect significant levels of the plant compound PEITC in the blood of the participants following the watercress meal, and most importantly, could show that the function of the protein HIF was also measurably affected in the blood cells of the women.

The two studies, which have been published in the British Journal of Nutrition and Biochemical Pharmacology, provide new insight into the potential anti-cancer effects of watercress, although more work still needs to be done to determine the direct impact watercress has on decreasing cancer risk, and whether watercress or other cruciferous vegetables should be categorized as functional foods possibly helpful in the fight against breast cancer.

Breast cancer is the most common cancer in women in the western world and currently affects approximately 1 in 9 women during their lifetime.

Watercress Alliance member Dr Steve Rothwell says: “We are very excited by the outcome of Professor Packham’s work, which builds on the body of research which supports the idea that watercress may have an important role to play in limiting cancer development.”

A summary of the watercress research was accepted for inclusion in the Breast Cancer Research Conference (September 15-17, 2010, Nottingham).


1. Syed Alwi SS, et al. “In vivo modulation of 4E binding protein 1 (4E-BP1) phosphorylation by watercress: a pilot study.” British Journal of Nutrition.

2. Wang X-h, et al. “Inhibition of hypoxia inducible factor by phenethyl isothiocyanate.” Biochemical Pharmacology.