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The
british have been drinking tea for more than 300 years, today,
it accounts for nearly half the fluid intake of a British adult.
But can you have a too much of a good thing ?
There
is sometimes nothing more reviving than a cup of tea, but in
fact it has little nutritional value although the milk or sugar
added may supply around 40n calories. However, the stimulant
such as caffeine that tea contains can accelerate the heart
rate, increase alertness, and help respiration by dilating
the airways of the lungs. Asingle cup of tea provides about
40 mg of caffeine, which is almost wtice the amount present
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most
cola drinks and about two thirds the level found in a cup of
instant coffee.The
tannins in tea are not as useful however. They give it body but
can interfere with iron absorption, especially if tea is drunk
with iron rich foods. Toddlers should not be given tea because
their digestive system are less able to cope with its chemicals
stimulant and there is the posibility of developing iron deficiency
anemia. Tanins can also stain teeth, particularly dental work.
Mouthwashes which contains chlorhexidine should not be used immediately
prior to drinking tea because the chemical can accentuate the
staining effect. |
Tea also contain considerable levels of quercetin, one of the many
naturally occuring chemical compounds thatare known as bioflavonoids.
Although preliminary research indicates that quercetin might be involved
in causing cancer, more recent work suggests that high intakes of bioflavonoids,
which are strong antioxidants, are associated with a decreased risk
of cancer and heart disease.In particular,green tea and Oolong are
thought to have specific anti cancer properties. However, there is
still conflicting evidence and the encouraging results of the laboratory
experiments have not yet been replicated in population studies. Other
constituents of the besides added flavourings such as bergamot, include
fluoride (0.25 mg in a cup) and manganese (0.5 mg per cup).
people suffering from peptic ulcer should avoid strong black tea because,
light coffee,it stimulates acidic, gastric,seretion and may cause irritation;
insted, they should drink weak tea with milk. Tea as also been known
to precipitate MIGRAINE in sensitive individuals; it is not known,
however, whether this is due to its bioflavonoid or its caffeine content.
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