According to new research, a naturally occurring compound in watercress may prevent breast cancer development by 'turning off' a signal that deprives breast cancer cells of the blood and oxygen they need to grow.
Breast cancer is the most common cancer in women living in the west, affecting roughly 1 in 9 women during their lifetime.
Watercress, also known as Nasturtium, is a fast-growing aquatic or semi-aquatic plant native to Europe and Asia and one of the oldest known leaf vegetables consumed by humans. It is related to garden cress, mustard and radish - like them, it has a peppery, tangy flavor.
Typically, as breast cancer cells develop they tend to outgrow their existing blood supply. So they send out signals to make surrounding normal tissues grow new blood vessels into the tumor, to deliver much-needed oxygen and nutrients.
The present study shows that a natural compound found in watercress called phenylethyl isothiocyanate or PEITC can block the ability of tumor cells to stimulate new blood supply by interfering with and 'turning off' the function of a protein called Hypoxia Inducible Factor (HIF).
In other words, eating watercress interferes with a pathway that has already been closely linked to cancer development and tumor growth.
In a related pilot study, a small group of breast cancer survivors underwent fasting before eating a cereal bowl full of watercress. They then provided a series of blood samples over the next 24 hours.
The research team was able to detect significant levels of PEITC in the blood of the participants after watercress consumption - further, they observed that HIF function was affected in blood cells.
These two studies provide new insight into the anti-cancer effects of watercress, although clinical trials are needed to determine the direct effects of watercress on decreasing cancer risk.