Coffee vs. tea: Benefits and
risks
While tea
lovers revel in tea?s likely health benefits, coffee drinkers worry that
anything as deliciously stimulating as java must be unhealthful. But research
shows that coffee is generally safe in moderate amounts and might have
surprising benefits of its own: Large observational studies have linked regular
coffee consumption with reduced risks of type 2 diabetes, gallstones, and
possibly Parkinson?s disease. Still, both green and black tea trump coffee for
protection against cancer, heart disease, and possibly
osteoporosis.
HOW THEY PROTECT
YOU
Coffee. Caffeinated and decaf coffee
each contain antioxidants and other substances that may help regulate blood
sugar; that might explain the apparently reduced diabetes risk. Certain
compounds in coffee also appear to help prevent bile from crystallizing into
gallstones. And caffeine may cut the risk of Parkinson?s by boosting supplies of
the brain chemical dopamine, at least in men.
Tea. Habitual tea
drinkers? reduced cancer risk might stem from tea?s high antioxidant capacity.
Tea might protect the heart by relaxing blood vessels, inhibiting clots, and
reducing cholesterol levels. And researchers speculate that the fluoride and
estrogen-like substances in tea may bolster bone density.
how much is too much?
There?s little or no evidence
that drinking substantial amounts of tea is harmful to the average person. As
for coffee, moderate intake--one or two cups a day--seems to be safe for most
people. At least one large study has suggested that such consumption protects
the heart, though the underlying reason is not clear.
Some research,
however, has linked drinking three or more cups of coffee a day with increased
heart risk. Coffee can raise the level of homocysteine, an amino acid that might
harm the arteries. And coffee?s high caffeine content--typically twice as much
as black tea and several times that of green--may raise blood pressure, though
that hasn?t been proved.
Consuming lots of caffeine can also speed bone
loss, and it might reduce birth weight and raise the risk of miscarriage. Women
who are pregnant or may become pregnant should drink no more than two cups of
coffee or four cups of black tea a day; to guard their bones, postmenopausal
women should probably stick with the same limits. Caffeine can also precipitate
heartburn, anxiety, and rapid heartbeat. People who experience any of those
problems when they drink coffee or tea should at least cut back on the
brew.
|
| |
