Green Tea Extract
Camellia sinensis. Family: Theaceae
green tea, Chinese tea, green sencha tea, Japanese tea, Yame tea
Green tea comes from the plant Camellia sinensis. Black tea, green tea, and Oolong
tea are all made from different types of the same plant. The teas are made using different
Green tea extract contains polyphenols. These include the most active one, epigallocatechin
gallate. Green tea and Oolong tea have the highest levels of polyphenols. This means
they have the greatest health benefits. The fermentation and processing involved in
making black tea decreases the polyphenols. It does this by converting them to theaflavins
and thearubigins. All of the teas contain catechins and tannins in different amounts.
Other significant parts of tea include caffeine, theobromine, and theophylline. The
polyphenols of green tea are strong antioxidants.
Tea is the second most popular beverage in the world. People drink it for its flavor
and stimulant effect.
Studies suggest that the polyphenols in tea, especially green tea, may help reduce
the risk of some cancers. Or it may slow the growth of certain types of cancers. Studies
done in humans have shown mixed results.
The theophylline and theobromine in tea act as bronchodilators. Tea has been used
to treat mild asthma and bronchitis. Tea may help mild respiratory problems. It’s
even safe for children.
Tea is used as a stimulant drink. The methylxanthines, specifically caffeine, increase
alertness. It’s also a mild stimulant.
Green tea has an anti-microbial effect against the bacteria that cause diarrhea. This
means it may help treat diarrhea. Green tea also stops oral bacteria. Along with fluoride,
tea may help prevent tooth decay.
Green tea extract ointment has been shown to clear external genital and perianal warts.
This product is approved by the U.S. Food and Drug Administration (FDA). It’s available
Please note that this section reports on claims that have not yet been substantiated
Green tea may be a mild diuretic. It may help lower cholesterol.
Green tea extract comes in oral capsules. It’s available in different strengths. Follow
the instructions on the package for the correct dose.
Green tea infused from loose, dried leaves or from tea bags should be steeped in hot
water for a short time. Make sure the water isn’t scalding. This is done to preserve
important chemicals in the leaf.
Green tea can cause side effects due to caffeine. These can include anxiety, tremors,
irritability, and sleeping problems. This is more likely if you’re sensitive to caffeine
or take large doses. Side effects are less common with green tea than with other caffeine-containing
beverages. This is because the leaves are steeped for a shorter time.
The fluoride content of green tea may help prevent tooth decay. However, the tea also
contains tannic acid. This can stain teeth.
Green tea extracts may cause liver problems. Symptoms can include yellowing of your
skin or the whites of your eyes, nausea, and stomach pain. If you have these symptoms,
stop using green tea and see your healthcare provider right away.
Tea is used worldwide without causing harmful effects. But women who are pregnant
or breastfeeding should talk to their healthcare providers before taking any herbal
Green tea contains small amounts of vitamin K. This means it may decrease how well
blood thinner medicines work.
Since green tea acts as a mild stimulant, you shouldn’t use it with other stimulants.
Green tea may also keep the medicine nadolol from lowering your blood pressure as
much as it should.