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.
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