|
With espresso shops sprouting on almost every city block
across the country, coffee could win honors as the best new old
drink. Call it java, joe, or truck-stop-special, along with tea
it has long been among the most popular beverages world-wide.
Only water is consumed more than coffee and tea combined. Many
are drawn to coffee's special "wake-up" properties. Indeed,
caffeine has proven itself a potent central nervous system
stimulant.
Coffee is brewed from the seeds of the coffee plant. These
"beans" contain caffeine, a stimulant known in chemical jargon as
"trimethylxanthine," which also is found in cocoa beans and other
naturally-occurring foods. In the case of caffeinated sodas,
trimethylxanthine is added during processing.
The caffeine level in coffee and tea is as varied as the
response of people who drink them. Drip-brewed coffees contain
from 60 to 180 milligrams (mgs) of caffeine per 5-ounce cup.
Instant coffees tend to be lower in caffeine, ranging from 40 to
110 mg per 5 ounces. Brewed teas have from 20 to 110 milligrams.
In coffee, the caffeine content depends both on the type of
bean and on the roasting and brewing process. Beans harvested
from the "robusta" species are typically found in common name
brands like Folgers and Maxwell House. As the name implies, this
plant is robust; it will grow in marginal or unpredictable
conditions, and this means lower production costs.
Beans from the arabica plant require more pampering but
produce a more full-bodied flavor. Arabica beans are largely
responsible for coffee's recently up-scaled reputation. In
general, arabica beans have less caffeine, ounce-for-ounce, than
robusta beans.
As for roasting method, darker-roasted beans actually have
less caffeine than those that are lighter, because heat from
roasting removes the caffeine. Brewing methods that expose coffee
grounds to water for longer periods, as in percolated coffee or
the "French press" method, result in higher caffeine than
standard drip methods.
Is this renewed interest in coffee good or bad for our
health? The answer probably depends as much on what you consume
in the coffee, or with it, as it does on the coffee itself.
Despite years of speculation and research, scientists have not
been able to link normal levels of caffeine intake to major
chronic diseases like heart disease or cancer.
The most common and well-defined effect of coffee stems from
its role as a central nervous system stimulant. Within 30 to 60
minutes of drinking coffee, caffeine levels peak to produce
alertness and heightened concentration. While some people do well
with this boost, others become over-stimulated; side effects
include insomnia, anxiety, irritability and diarrhea.
Some research suggests a link between high caffeine levels
and birth defects and miscarriages. Pregnant women should consult
their physicians about drinking coffee or other caffeinated
beverages during pregnancy. People with high blood pressure or
with an irregular heartbeat should also consult their doctor
about caffeine, as it can worsen both conditions.
For more information, contact your local
Colorado State University Extension office.
|
