If you are planning to take supplements based on green tea extracts as a measure to lose weight, think again. Researchers have warned that the supplements could result in harmful side effects including liver toxicity.
Drinking green tea, instead of taking the supplements, could help you enjoy the benefits associated with the beverage while avoiding the risk of liver toxicity, they pointed out.
Also, drinking green tea in the weeks before taking supplements likely reduces risk of side effects, the findings showed.
"Drinking green tea rather than taking supplements will allow you to realise the benefits and avoid the risk of liver toxicity," explained Josh Lambert, associate professor of food science at College of Agricultural Sciences, Pennsylvania State University.
Tea is rich in catechins, polyphenols that are natural antioxidants. A number of animal studies have shown the preventive effects of green tea polyphenols against obesity.
For the new study, the researchers gave mice high doses of the green tea polyphenol epigallocatechin-3-gallate (EGCG).
The dosage was equivalent to the amount of the polyphenol found in some dietary supplements taken by humans.
Dietary pretreatment with the green tea polyphenol protects mice from liver toxicity caused by subsequent high oral doses of the same compound, the findings showed.
"We believe this study indicates that those who are chronic green tea consumers would be less sensitive to potential liver toxicity from green-tea-based dietary supplements," Lambert noted.
He, however, added that the beneficial effects that people have reported as being associated with green tea are the result of dietary consumption rather than the use of supplements.
The study appeared in the journal Food and Chemical Toxicology.