Transcript Coffee and Tea: Impact on cancer risk



All tea comes from plant
Camellia Sinensis

White

Green

Oolong

Black
Type of tea is determined by:

When harvested

Amount of oxidation

Process undergone
http://www.naturalhealthcarestore.com/
 China
 India
 Japan
 Sri
Lanka
 Taiwan
http://www.teekampagne.de/
 White
Tea
Picked before leaf buds fully open
 Leaves are bigger and lighter
 Air dried
 3X antioxidants as green tea

http://en.wikipedia.org/wiki/
 Green

Tea
Undergone minimal oxidation during processing
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
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5-40% oxidized
Heat immediately through steam or dry cooking pans
Processed within one to two days of harvesting
 Oolong
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
Tea
Oxidized more than green tea and
less than black tea
Oxidized two to three days
 Black
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
Tea
Leaves completely oxidize
Oxidized between two weeks and one
month
 Composition
varies according to:
Growing season
 Strain or variety
 Storage
 Brewing conditions

http://www.farawayholidays.co.uk
/faraway/cameron_highlands/
 Not
from Camellia
Sinensis
 Made




from
Seeds
Roots
Flowers
Other parts of
plants and herbs
http://www.northeastcoffeeco.com/
 Polyphenols

Catechins
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
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Powerful antioxidants
 Slow oxidative damage to cells
White and green tea contain highest levels of ECGC
 Least processed
Theaflavins and Thearubigins (1,2)
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Highest in oolong and black tea
 More processed
 Women
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in Shanghai China
20-74 years of age
3454 cancer cases
3474 control
 Participants
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
interviewed for:
Initial age of tea drinking
Amount consumed
Brew strength
Quality of tea
Results
Regular green tea drinkers had 12% lower risk for
breast cancer
 Green tea drinking for <6 years associated with
significantly reduced risk among postmenopausal
women
 Amount of dry tea leaves consumed per month
showed trend toward decreased risk in
premenopausal women
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Conclusion
Green tea may be weakly associated
with a decreased risk of breast cancer
 Majority
of research suggests a modest
reduction in risk of developing breast cancer
with green tea consumption
 More
than 3 cups of green tea per day
slightly reduced risk of breast cancer
recurrence in women with breast cancer
 22

studies reviewed
Green tea and black tea consumption with lung
cancer risk
 Results
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Green tea consumption of two cups/day
associated with 18% decreased risk of lung cancer
No protective effect for black tea
The evidence was too
limited in amount,
consistency, or quality
to conclude a role for
tea in cancer
 Brewed
drink
 Prepared from
roasted seeds of
the coffee plant


Grows on shrubs,
or small trees
Pit inside red or
purple fruit
 Known
for high
caffeine content
Indonesia
Colombia
http://www.ncausa.org
 Diterpenes:
 Cafestol
and Kahweol
 Anticarcinogenic properties
 Polyphenols
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Lignins
Flavonoids
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Anticarcinogenic properties
 Chlorogenic
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Slows release of glucose
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acid
Effect on insulin sensitivity
Antioxidant
 More
than 3 cups of coffee per day slightly
increased risk of gastric cardia cancer, but
not non-cardia cancer
 More
than 3 cups of coffee per day had no
affect on risk of cancer of the pharynx,
larynx, or esophagus
 Consumption
of caffeinated coffee had no
affect on colon or rectal cancers in men or
women
 Consumption
of two cups of decaffeinated
coffee significantly reduced risk of colon and
rectal cancers in both men and women
Product
Caffeine (mg)
Hershey’s Milk Chocolate, 1 bar
9
Arizona Green Tea, 1 bottle
15
Generic instant mix, unsweetened, 1 tsp
27
Hershey’s Dark Chocolate, 1 bar
31
Coca-Cola Classic, 1 can
35
Average cup of black tea
40-100
Mountain Dew, 1 can
54
Starbucks Espresso, 1 shot
58-75
Red Bull, small can
76
5-hour Energy Shot, 2 oz bottle
80
Grande Starbucks Tazo Chai Tea Latte
100
Excedrin, Extra Strength, 2 tablets
130
Grande Starbucks Vanilla Latte
150
Monster Energy, 16 oz can
160
Average cup of coffee
100-200
 Stimulates
central
nervous system
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
Makes you more alert
and boosts energy
Used in pain relievers
 Too

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

much can cause:
Restlessness
Anxiety
Irritability
Headaches
Withdrawal symptoms
500-600 mg per day is considered
to be safe
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Factors affecting
caffeine response
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Body mass
Age
Smoking habits
Drug or hormone use
Stress
 No
correlation between soft drink
consumption (>1 can per day) on cancers of
the mouth, pharynx, larynx, esophagus or
stomach
 High
sugar content of soft drinks may lead to
increased body fat that would increase risk
of some cancers
 No
increased risk and potentially decreased
risk of cancer associated with coffee and tea
consumption
 Further research needed
 Coffee and tea are healthy beverages
 Monitor caffeine and sugar content of
beverages