“Green tea is the second most consumed beverage in the world after water, and is grown in at least 30 countries,” said Xuebo Liu, Ph.D., a researcher at the College of Food Science and Engineering, Northwest A&F University, in Yangling, China. “The ancient habit of drinking green tea may be a more acceptable alternative to medicine when it comes to combatting obesity, insulin resistance, and memory impairment.”
A study published online in The FASEB Journal, involving mice, suggests that EGCG (epigallocatechin-3-gallate), the most abundant catechin and biologically active component in green tea, could alleviate high-fat and high-fructose (HFFD)-induced insulin resistance and cognitive impairment. Previous research pointed to the potential of EGCG to treat a variety of human diseases, yet until now, EGCG’s impact on insulin resistance and cognitive deficits triggered in the brain by a Western diet remained unclear.
Green tea does contain caffeine, although varieties and brands may differ. An equal quantity of green tea contains less caffeine than coffee (one cup of green tea contains approximately 35-80 mg compared to approximately 100-400 mg in the same size cup of coffee), but it can still act as a stimulant. As a result, some people find that drinking green tea increases energy levels, concentration and mood, but this effect may vary between individuals.
If you are sensitive to caffeine, it is advisable to limit the total number of cups of green tea you drink in a day. Too much caffeine can disrupt sleep patterns. If this affects you, try cutting back drinking a caffeinated beverage after lunchtime.
Green tea does have more health benefits than black tea which can be attributed to its lack of processing. Green tea is higher in protective polyphenols. The major polyphenols in green tea are flavonoids, the most active of which are catechins and epigallocatechin gallate (EGCG) which function as powerful antioxidants. Antioxidants are known to protect the body against disease and are an important part of a healthy diet. Antioxidants can be found in a range of fruits, vegetables and other unprocessed foods. As part of a balanced diet, green tea can be a good source of antioxidants.
Because of the proposed benefits, many ‘health’ products now include traces of green tea. If you are hoping to use green tea for medicinal purposes, make sure to consult your doctor first.