Teas that Fight
Anti-Cancer Powers Affirmed and Expanded in USDA Study
Black and Green
Teas Fight Cancer
of American and South Korean researchers conducted cell studies that
shed new light on the relative anti-cancer properties of green and
collected to date suggested that tea's proven anti-cancer powers stem
primarily from its powerfully antioxidant flavonoid-type polyphenols.
its been assumed that green and white tea must be the most powerfully
anti-cancer forms of the ancient beverage, since they contains more
flavonoid-type polyphenols than black tea does.
black tea (green tea oxidized by fermentation) contains between 3
and 10 percent water-soluble polyphenols by volume, green tea boasts
ten times that concentration.
as we will see, polyphenols make up only part of the solids in tea:
and they may not be the sole or sufficient explanation for teas
well-documented anti-cancer properties.
and black teas also contain different types and proportions of polyphenols.
tea leaves ferment long enough to turn them black via oxidation, the
majority of their catechin-class flavonoid polyphenols change into
tannin-like flavonoids called theaflavins and theanine.
some population studies have suggested that black tea is as or more
protective against certain cancers (including certain breast tumors)
as green tea.
do five things that work together to stop cancer in its early stages:
Cause programmed suicide (apoptosis) among cancer cells.
2. Block P450 enzymes, which activate pro-cancer compounds.
3. Stop tumor-promoting chemical signals from cancer cells.
4. Disable damaged, cancer-promoting DNA
5. Block growth of new blood vessels in the tumor (angiogenesis)
this context, the general thrust of what the USDA team found came
as no big surprise.
unexpected findings vis a vis the effects of tea flavonoids on human
cancer cells is sure to send scientists back to the bench for further
and green tea work equally well; Benefits not tied tightly to flavonoid
USDA/South Korea team examined the ability of nine green tea catechins,
three black tea theaflavins, and theanine from black tea to induce
cell death (apoptosis) in isolated human cancer cells (Friedman M
et al 2006).
berries, and other polyphenol-rich plants are considered key anti-cancer
agents because they undermine cancer when it is most vulnerable: during
its early, so-called promotion stage.
reported that most of the flavanol-type flavonoids in both green and
black tea -- catechins, theaflavins, and theanine cut the numbers
of cancerous human breast, colon, liver, and prostate cells, without
big differences among them.
the efficacy of each different extract of black or green tea tested
depended not on its flavonoid content, but simply on the sheer amount
of dissolved solids per volume of liquid, regardless of their flavonoid
suggests that something about the non-flavonoid compounds play key
roles, and that therefore, black tea may offer anti-cancer benefits
closer to those of green and white tea than thought.
also found that ethanol/water extracts of tea possess more flavonoids
and are more potently anti-cancer, suggesting that tea supplements
(mostly made this way) may have a bit of an edge over water extracts,
such as plain cups of tea. But any hypothetical anti-tumor advantage
supplemental tea capsules might offer is likely to be quite expensive,
compared with enjoying tea by the cup.
USDA/Korea team said (Friedman M et al 2006), their findings extend
our knowledge of the anti-cancer potential of tea, and suggest, most
that consumers may benefit more by drinking
both green and black teas.
consider organic whole foods from both plant and animal kingdoms
to be a major key to superior health. We also think it's terribly
important to eat fish at least twice a week to get the essential
fatty acids. Here at our house, we only eat wild Alaskan salmon
and other wild seafoods from our friends at Vital Choice. Click
here to visit Vital Choice Seafood.
M et al. Structure-Activity Relationships of Tea Compounds against
Human Cancer Cells. J Agric Food Chem. Published on-line ahead of
print, December 16, 2006: ASAP Article doi: 10.1021/jf062276h S0021-8561(06)02276-X.
Throughout this website, statements are made pertaining to the properties
and/or functions of food and/or nutritional products. These statements
have not been evaluated by the Food and Drug Administration and
these materials and products are not intended to diagnose, treat,
cure or prevent any disease.