Watercress May ‘Turn Off’ Breast Cancer Signal

New scientific research from the University of Southampton has revealed that a plant compound 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 tumour of essential blood and oxygen.

The research, unveiled at a press conference today (14 September 2018), shows that the watercress compound is able to interfere with the function of a protein which plays a critical role in cancer development.

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

The research, led by Professor Graham Packham of the University of Southampton, shows that the plant compound (called phenylethyl isothiocyanate) found in watercress can block this process, by interfering with and ‘turning off’ 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 80g 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.

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 research has been accepted for inclusion in the Breast Cancer Research Conference which is taking place in Nottingham from 15 to 17 September.
Breast cancer is the most common cancer in women in the western world and currently affects approximately 1 in 9 women during their lifetime.

Cream of Watercress Soup

This soup is really fast to put together. You can have it on the table in 30 minutes. Watercress has a wonderful, peppery taste and is full of vitamins A, C and K. Adding the finely diced stalks gives the soup extra flavor, while the butter or cannellini beans give it a higher protein content than the usual potatoes and a creamy texture and taste without dairy. If you cook your own beans, add the liquid they were cooked in and cut back on the stock proportionately. If you aren’t vegetarian, try making this soup with chicken stock.

Soups Serves: 4-6 Prep: 20 – 30 min


  • 3 bunches watercress, washed well
  • 1 tablespoon olive oil
  • 1 teaspoon chopped fresh thyme
  • 1 medium onion, diced
  • Salt and pepper, to taste
  • 2 (15-ounce) cans of white or cannellini beans, drained and rinsed
  • 6 cups vegetable stock or water
  • 2 tablespoons chopped Italian parsley, plus more for garnish


  1. Finely dice the thick stalks of the watercress. Set aside. Break up the leafy greens into leaflets, discarding any remaining thick main stems. Set aside and reserve some for garnish.
  2. Heat the oil in a heavy soup pot over medium-high heat. When it starts to ripple, add the onions, diced watercress stalks and thyme. Fry until the onion starts to soften. Turn the heat down to medium, sprinkle with a little sea salt and cover. Sweat the vegetables for 8 to 10 minutes, stirring from time to time. Don’t let them burn or color!
  3. Add the beans and their liquid and stir to mix well with the vegetables. Add the stock if using canned beans. Bring to a boil. Turn the heat down and cook until the beans are heated through and can be easily smashed against the side of the pan with a spoon, about 10 minutes.
  4. Add the watercress leaflets to the soup and cook for 5 minutes, until they wilt. Blend the soup until smooth in a blender or with an immersion blender. Bring back to a simmer, add all the watercress leaves and the chopped parsley, and cook a minute more and taste for seasoning.
  5. Serve immediately.



  • The study published in the British Journal of Nutrition was called ‘In vivo modulation of 4E binding protein 1 (4E-BP1) phosphorylation by watercress: a pilot study.’ Researchers were Syed Alwi SS, Cavell BE, Telang U, Morris ME, Parry BM, Packham G.
  • The second study, ‘Inhibition of hypoxia inducible factor by phenethyl isothiocyanate’ was published in Biochemical Pharmacology. Researchers were Wang X-h, Cavell BE, Alwi SSS, Packham G,


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