The benefits of green and black teas
From the Busy Parents Guide
SARS Wars
Author: Brenda Koth, MS, RD
Article submitted by Linda Sikut http://www.watkinsonline.com/LSikut
The spread of SARS, West Nile and other diseases has us all
on alert, but a study just released provides great hope for
protection against these and other ailments. A new study found
that drinking green, black or oolong tea-but not herbal tea-boosts
the body's defenses by 500% against bacteria, viruses, fungi,
and parasites. After drinking tea for four weeks, tea drinkers
secreted five times more interferon, the body's key infection
fighter, than when they were not drinking tea. Coffee drinkers
showed no increase in immunity. With new diseases emerging,
our best defense is our very own immune system. Tea gives
us the ability to increase our immune defenses fivefold, providing
a tremendous advantage over infection and disease. Watkins
TheraTea beverages, and TheraTrim, our green-tea based weight
management formula, provide the immune boosting benefits of
green tea in a beverage or a supplement, to give you a fighting
force against illness.
After hearing that tea is effective in cancer prevention, writing
the SARS report and having the small article above submitted
the next day, I set off to investigate:
Does green and/or black tea really help your body fight serious
disease?
Charity Wire holds this report from the American Institute for
Cancer Research (AICR) from 1999: "Black and green teas can
help to inhibit cancer [at every stage. From pre-cancer to] initiation,
promotion, progression and metastasis."
While I didn’t find much more on the relation of tea and
SARS prevention (there were several mentions but none as comprehensive
as the article above) I was able to find more information on the
tea link to cancer prevention. For articles on the other wonderous
health benefits of tea, we've included a comprehensive group of
articles.
How does tea work to fight cancer?
Tea has long been recognized in cancer prevention by working
with the cells to block unstable molecules that cause genetic
damage. Now there seems to be more to the process. Tea has more
cancer- fighting elements than originally proposed. Now, instead
of just fighting cancer before it starts, scientists believe it
helps prevent cancer from moving to more serious stages. The AICR
article states that a class of substances, called “flavonoids,
[in tea] inhibit substances called cell-growth factors, which
transform normal cells into cancerous ones.”
Scientists noted years ago that in giving cancerous rats tea,
there was a reduction in the progression of the disease. From
there, they needed to test the cancer-fighting tea on humans.
But what is the appropriate amount of tea in a human’s diet?
There was a marked difference in how much tea used directly on
cells in a lab versus how much tea a test animal needed to have
the same effect.
What kind of tea, and how do I make it?
While the choices are clear, black and green tea, there is some
question as to which one is better. Dr. Roderick Dashwood of Oregon
State University says there are many factors to consider, "Both
green and black teas show anti-cancer activity," he said,
"but they have slightly different components, and are processed
and prepared using different methods.”
Green teas contain more of one type of flavonoid while black
teas contain two additional varieties. Rats responded more effectively
to green tea when prepared the same way as black tea, but humans
prepare tea with different methods and have a completely different
physiology than rats.
There are also questions about boiling water, the use of sugar,
milk and honey, and other factors that could interrupt the effectiveness
of the flavonoids.
While research has not pinpointed which tea is best, the AICR
touts that green tea contains three times the amount of one flavonoid
as black tea. (See an article about green tea from the AIRC here
)
How much do I need?
So, just how much tea must we drink? The AICR notes than Japan
has a lower incidence of cancer, and, typically, the Japanese
drink up to four cups of tea each day. Some argue that only one
cup is needed. A report in USA Weekend.com stated recommends 3-6
8-ounce cups per day.
There seems to be no doubt that tea helps to prevent cancer.
Though the reports are conflicting on how much we should drink,
it seems that any green or black tea traditionally brewed, and
without added honey, sugar or other substances, is better than
none at all. Additionally, no one thing can prevent cancer, but
eating a balanced diet while also drinking tea would increase
cancer prevention.
A 1997 AICR report entitled “Food, Nutrition and the Prevention
of Cancer: A Global Perspective” examined over 4,500 international
studies on the link between diet and cancer. The report's panel
recommended a predominantly plant-based diet, regular exercise,
maintaining a healthy body weight, and avoiding tobacco for everyday
cancer prevention. They estimated that following these guidelines
could lower worldwide cancer rates by as much as 70 percent.
There is one important caveat, however: “Very high amounts
of green tea components (usually associated with over-dosage of
green tea supplements) have been shown to interact with drugs
that affect blood clotting, such as aspirin.” (AIRC http://aicr.org/information/foods/greentea.lasso)
What about my kids?
Jean Carper from USA Weekend.com recommends restricting the amount
of tea given to kids, because tea removes iron from the body.
"That may help combat chronic disease but can cause anemia
in young people," she reports.
Tea also contains caffeine, a drug that brings its own set of
health problems associated with it. One alternative is taking
green tea capsules, but I was unable to find any reports on whether
they are as effective in fighting cancer as a steeped tea.
More articles about health
benefits of green tea
Special Report By
Gina Ritter
BPO Editor
