Effect of Green Tea Supplements on Liver Enzyme Elevation: Results from a Randomized Intervention Study in the United States

Abstract

Liver injury effects of green tea-based products have been reported in sporadic case reports. However, no study has examined systematically such adverse effects in an unbiased manner. We examined the potential effects of a high, sustained oral dose of green tea extract (GTE) on liver injury measures in a randomized, placebo-controlled, double-blinded phase II clinical trial, which enrolled 1,075 women with the original aim to assess the effect of daily GTE consumption for 12 months on biomarkers of breast cancer risk. The current analysis examined the effect of GTE consumption on liver injury in 1,021 participants (513 in GTE and 508 in placebo arm) with normal baseline levels of liver enzymes. Among women in the GTE arm, alanine aminotransferase (ALT) increased by 5.4 U/L [95% confidence interval (CI), 3.6-7.1] and aspartate aminotransferase increased by 3.8 U/L (95% CI, 2.5-5.1), which were significantly higher than those among women in the placebo arm (both < 0.001). Overall, 26 (5.1%) women in GTE developed moderate or more severe abnormalities in any liver function measure during the intervention period, yielding an OR of 7.0 (95% CI, 2.4-20.3) for developing liver function abnormalities as compared with those in the placebo arm. ALT returned to normal after dechallenge and increased again after one or more rechallenges with GTE. The rise-fall pattern of liver enzyme values following the challenge-dechallenge cycles of GTE consumption strongly implicates the effect of high-dose GTE on liver enzyme elevations. .

Liver Injury Associated with Sporting Activities

“…74 Indeed, a randomized, placebo-controlled trial showed that daily consumption of GTE with total catechins amounting to 1.3 g was associated with moderate to severe ALT elevations in 5.1% of treated women compared with 0.7% in the placebo arm. 75 However, none of the patients had symptoms or concomitant increases in alkaline phosphatase or bilirubin levels and all resolved with GTE discontinuation. Note: Data presented as Median (range) or n (%).…”

Drug‐Induced Liver Injury in GI Practice

“…Results from a randomized Minnesota study showed that the health of postmenopausal women without chronic liver disease were 7 times more likely to have ALT elevations with GTE use. GTE dechallenge leads to a downtrend in ALT levels, and ALT elevation recurred following GTE rechallenge, ( 105 ) indicating a causal relationship between GTE and hepatotoxicity.…”

Protective Effects of Ursodeoxycholic Acid on Valproic Acid Induced Hepatotoxicity in Epileptic Children with Recurrent Seizure; A Double-Blinded Randomized Clinical Trial

“…According to a pervious report, the standard deviation (δ) of liver enzymes was considered 25 IU/l, and the effect size "d" was considered 10 IU/l. 20 The sample size in each group was calculated as 98 which was rounded up to 100.…”