Glorious WATERCRESS #2

From Dr. Perricone's book "Forever Young" - a book I highly
recommend you have in your home library.


Watercress, the New Ancient Superfood

Key research findings on watercress and health and nutrition
include:

Watercress is a cruciferous vegetable, and population studies
associate an increased intake of cruciferous vegetables with
reduced risk of cancers at several sites, including the breast
and prostate.

Daily consumption of watercress results in a significant decrease
in lymphocyte (white blood cell) DNA damage; DNA damage is an
important event in cancer development. Watercress is a rich
source of the glucosinolate derivatives phenethyl isothiocyanate
(PEITC) and methylsulphinylakyl isothiocyanates (MEITCs), which
have a range of anticancer activities.

Beneficial effects against the three key stages of carcinogenesis
(initiation, proliferation, and metastasis) were observed in a
study involving watercress extract and colon cancer cells. When
smokers ate watercress with each meal for three days, the
activation of a key carcinogen in tobacco was inhibited. An in
vitro study involving breast cancer cells found that the addition
of a watercress extract inhibited their invasive potential.

A study investigating the effects of a diet supplemented with
PEITC in mice grafted with human prostate tumors resulted in a 50
percent reduction in tumor weight. Watercress is a good source of
key nutrients and carotenoids, including lutein and
beta-carotene, associated with the maintenance of eye and skin
health. Daily consumption of watercress increases plasma lutein
levels by 100 percent and beta-carotene levels by 33 percent.
Daily watercress consumption has been shown to decrease plasma
triglyceride levels by about 10 percent.

Watercress is rich in vitamin A (via beta-carotene) and vitamin C
and a source of folate, calcium, iron, and vitamin E. It also
contains a variety of phytochemicals including glucosinolates,
lutein, flavonoids, and hydroxycinamic acids. As discussed in
chapter 2, the flavor cinnamic aldehyde contains Michael acceptor
pharmacophores, which turn on gene expression of a number of
cell-protective antioxidant enzymes. Cinnamic aldehyde in both
cell culture and animal studies is looking promising as a
therapeutic agent for the deadly skin cancer melanoma.
Watercress has significant antioxidant activity in vitro. Eighty
grams of watercress, one cereal bowl full, provides one of the
"at least five a day" portions of fruit and vegetables.
Watercress is recommended by the U.S. Department of Health and
Human Services to help reduce the risk of many chronic diseases.
As a low-calorie vegetable, watercress may play a role in weight
management. And 85 percent of watercress's calories are in the
form of protein, an extremely high amount. Nutrients and
phytochemicals in fruit and vegetables appear to work
synergistically.

Cancer Protection/Antioxidant

The mix of nutrients and phytochemicals in watercress makes it a
valuable food throughout life as part of a healthy diet and
lifestyle. I find watercress particularly exciting for its
powerful antioxidant and cancer preventing properties. An
important study published in "The American Journal of Clinical
Nutrition" found that in addition to reducing blood cell DNA
damage, a daily serving of watercress increased the ability of
blood cells to resist further DNA damage caused by free radicals.

The dietary trial involved thirty healthy men and thirty healthy
women (including thirty smokers) eating an 85-gram bag (a cereal
bowl full) of fresh watercress every day for eight weeks. The
beneficial changes were greatest among the smokers. This may
reflect the greater toxic burden or oxidative stress among the
smokers, who had significantly lower antioxidant levels at the
start of the study than the nonsmokers.
Professor Ian Rowland, who led the research project, said, "Our
findings are highly significant. Population studies have shown
links between higher intakes of cruciferous vegetables, like
watercress, and a reduced risk of a number of cancers, though
such studies don't give direct information about causal effects.
What makes this study unique is it involves people eating
watercress in easily achievable amounts, to see what impact that
might have on known biomarkers of cancer risk, such as DNA
damage." In other words, you don't need megadoses to get results.

Since the pioneering work by Professor Stephen Hecht in 1995,
when he demonstrated that eating watercress neutralized a
cancer-causing chemical found in the blood of smokers, there have
been many studies linking watercress to potent anticancer
activities. Most have been testtube studies, some have been in
animals, and in 2001, there was one in humans, when Professor
Rowland showed that eating a bowl of watercress a day
significantly reduced DNA damage in blood cells - and DNA damage
is thought to be one of the key processes that can lead to the
development of cancers. It is DNA damage that triggers cancer
cell development, proliferation or uncontrolled growth of cancer
cells, and metastasis, the spread of cancer cells. These are the
three key stages of carcinogenesis, the process that results in
cancer.

How Watercress Prevents Cancer

Recently, two exciting studies were published that provide new
insight into the potential anticancer effects of watercress.
These studies were conducted over two years in the United King-

dom, where watercress has long been popular, and link laboratory
and clinical research. They were led by Professor Graham Packham
at the University of Southampton's School of Medicine at
Southampton General Hospital and by Barbara Parry, senior
research dietician at the Winchester and Andover Breast Unit at
the Royal Hampshire County Hospital.

Professor Packham's main interest was in PEITC (beta-phenethyl
isothiocyanate), which gives watercress its peppery taste. In
fact, watercress is nature's richest source of this fascinating
compound, long associated with anticancer properties.
Hundreds of research publications from around the world show that
PEITC can slow the growth of or even kill cancer cells in
laboratory and animal experiments. The research team set out to
learn more about the ways in which PEITC exerts its effect on
cancer cells and, most important, whether eating watercress could
have a similar effect on cells in the human body. Professor
Packham's group showed that PEITC is able to completely block the
function of a protein called hypoxia-inducible factor, or HIF.
This plays a critical role in cancer development.

Cancer cells are continually developing in our bodies. But
thankfully they very rarely grow to form tumors. As cancer cells
multiply to form a tiny tumor, smaller than 5 millimeters across,
they invariably outgrow their blood supply and run out of oxygen
and nutrients. To get past this roadblock, they send out signals
that can trick the surrounding normal tissues into angiogenesis,
growing new blood vessels. If they are successful in securing a
good blood supply, they rapidly multiply to form a growing tumor.
HIF is at the heart of this process, because it turns on blood
vessel-promoting factors. Since PEITC, which is found in
watercress, can block the function of HIF, watercress might
control cancer growth by depriving tumors of this new blood
supply. Therefore, one way in which watercress might control
cancer growth is by depriving developing tumors of this new blood
supply.
The research team went on to show that PEITC may turn off this
HIF signal by changing the function of a second protein called
4EBP1.

Importantly, this provided a measurable readout indicating that
HIF activity and could be used to find out whether eating
watercress could affect this pathway critical to cancer tumor
growth. Working with Barbara Parry, Graham led a pilot study
using a group of volunteers, all female breast cancer survivors
keen to help in research into new ways to fight the disease. The
women underwent a period of fasting before eating a pack of
watercress (the nice bit!) and then gave regular blood samples
for up to twenty-four hours. The research team was able to detect
significant levels of PEITC in the blood of all the participants
following the watercress meal. Most important, the researchers
showed that the function of 4EBP1 in the women's blood cells was
indeed significantly affected-that is, the watercress meal led to
biologically active compounds, most likely PEITC, getting into
the bloodstream and inhibiting the ability of cells to trigger
blood vessel development something critical to the development of
a tumor.
Professor Packham said, "This work is of significance since we
have discovered more about how PEITC can act to interfere with
key pathways in cancer cells. It will be important to confirm the
clinical findings in a larger group of individuals, but the
results of this pilot study do indicate that eating watercress as
part of a normal healthy diet might modulate these pathways
within cells in the body. This work does not prove that eating
watercress would directly decrease the risk of cancer, but it
does take an important step toward understanding the potential
health benefits of this crop."

Dr. Steve Rothwell of the Watercress Alliance stated, "We are
very excited by the outcome of Professor Packham's work. Many
laboratory and animal studies point to the cancer fighting
properties of PEITC and thus indirectly to the benefit of eating
nature's richest source of this special chemical-watercress."

But this work goes farther, showing a clear link between eating a
serving of watercress and the downregulation of a biochemical
pathway that's known to be involved in the development of breast
cancer. The inference is that regular consumption of watercress
could play a role in reducing the risk of this and other cancers.
Later in this chapter we will report on another study that
demonstrates how the combination of turmeric and watercress can
also help to prevent breast cancer.
..........

To be continued