While the catechin content of green tea infusions and similar drinks are generally safe there may be health concerns when taken as a food supplement, says a report from the European Food Safety Authority (EFSA).
The scientific opinion from the EU science agency provides a safety assessment of green tea catechins after concerns were passed on regarding possible harmful effects on the liver in Nordic countries.
Now EFSA’s ANS Panel has provided a scientific opinion on the safety of green tea catechins from dietary sources, including preparations such as food supplements and infusions. In its report, the panel concludes that while intake of green tea catechins from green tea infusions are generally safe, there is potential for liver damage from supplementation with doses of EGCG above at 800 mg per day.
EFSA said it was unable to determine a ‘safe level’ for catechins in supplements, but noted that green tea products – and in particular supplements – should include the content of catechines and the proportion of EGCG on labels.
“The Panel recommended that studies should be performed to determine a dose–response of hepatotoxicity of green tea catechins and examine inter and intra species variability,” the scientific opinion states.
In that study 50% of products contained at least one catechin, but the presence of catechins was not indicated on the label in 40% of all cases.
According to that same data, the concentration and composition of catechins varied widely. In supplements that declared catechins on the label, the team reported concentrations ranging from non‐detectable to 486 mg/g. Meanwhile in supplements not labelled with green tea or catechins concentration were much lower and varied from 3 μg/g to 6 mg/g.