Green tea and black cohosh products may be required to carry label warnings after a US Pharmacopeia Dietary Supplements Information Expert Committee reviewed adverse event reports suggesting a potential link between ingestion of products containing green tea extracts and black cohosh and liver damage.
USP, a third party product certifier, reviewed more than 150 cases for black cohosh and 250 for green tea of which 30 and 34 respectively showed 'possible' or 'probable' causality for liver damage.
It suggested cautions for each product:
- Caution: In rare cases black cohosh has been reported to affect the liver. Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice.
- Caution: Must take with a meal. In rare cases extracts from green tea have been reported to adversely affect the liver. Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice.
"It would be helpful if the safety reviews that led to the committee's decisions were available to the public so that comments on the proposed cautionary statements could be better informed," said Steven Dentali, PhD, the American Herbal Product Association vice president of scientific and technical affairs. Case details, criteria of evaluation and discussion on the green tea extracts and black cohosh safety reviews are to be published in peer-reviewed journals, according to USP.
USP insisted the cautions were not designed to remove the products from market and acknowledged the liver cases were rare.