Silymarin, the extract of milk thistle long promoted as a liver remedy, may modestly lower two key liver enzymes in cancer patients receiving chemotherapy, according to a systematic review and meta-analysis published in the journal Genes & Nutrition. Pooling results from six randomized clinical trials, the researchers found that patients taking silymarin during chemotherapy had significantly lower serum levels of aspartate aminotransferase (AST) and alanine transaminase (ALT) than patients receiving control treatment.
The analysis, which searched Scopus, Medline, Web of Science, the Cochrane Library and Google Scholar up to January 2026, focused on randomized clinical trials evaluating silymarin’s effect on liver toxicity in cancer patients undergoing chemotherapy. The primary outcomes were four standard markers of liver function: AST, ALT, alkaline phosphatase (ALP) and total bilirubin (TB). Using a random-effects model, the authors computed weighted mean differences with 95 percent confidence intervals.
The pooled results showed a reduction in AST of 7.34 IU/L (95 percent CI: -14.00 to -0.69) and a reduction in ALT of 6.54 IU/L (95 percent CI: -12.56 to -0.43) compared with controls. Both confidence intervals exclude zero, indicating statistically significant effects, though the intervals are wide, spanning ranges that include values close to zero. In contrast, silymarin supplementation did not significantly alter ALP or total bilirubin concentrations.
Subgroup analyses suggested that the hepatoprotective effects on AST, ALT and total bilirubin were most prominent with higher doses above 150 milligrams per day and longer supplementation periods of at least 60 days. The authors note that further robust trials are needed to confirm these findings, and subgroup results based on a limited pool of studies should be interpreted with caution.
Chemotherapy-induced hepatotoxicity is a frequent problem in cancer care and can negatively affect treatment adherence, dose management and prognosis.
The authors conclude that silymarin may provide a significant hepatoprotective effect by lowering serum AST and ALT in cancer patients undergoing chemotherapy, while not significantly affecting ALP or total bilirubin. They emphasize that high-dose, long-term regimens demonstrated the greatest therapeutic efficacy in the pooled data, and that further robust trials are needed to confirm these findings and to elucidate the underlying mechanisms.
Several limitations temper the conclusions. The meta-analysis included only six randomized trials, and the published version reviewed here is an early-release, peer-reviewed accepted manuscript that may still be subject to further edits before the final version of record appears. The confidence intervals, while statistically significant, are broad, and the authors themselves call for additional well-designed studies before firm clinical recommendations can be made.
For patients and clinicians, the findings add to a growing but still unsettled evidence base on milk thistle extracts in supportive cancer care. The results suggest a possible enzyme-lowering benefit, particularly at doses above 150 milligrams per day taken for at least two months, but they do not establish that silymarin prevents clinically meaningful liver injury or improves chemotherapy outcomes.
Subject of Research: The effect of silymarin supplementation on chemotherapy-induced hepatotoxicity markers in cancer patients
Article Title: Effect of silymarin on hepatotoxicity in cancer patients undergoing chemotherapy: a systematic review and meta-analysis
Article References: Behzadi-Azad, S., Behzadi, M., Foshati, S., Mottaqi, S., & Mousavi-Shirazi-Fard, Z. (2026). Effect of silymarin on hepatotoxicity in cancer patients undergoing chemotherapy: a systematic review and meta-analysis. Genes & Nutrition. https://doi.org/10.1186/s12263-026-00821-z
Image Credits: AI Generated
DOI: 10.1186/s12263-026-00821-z
Keywords: silymarin, milk thistle, hepatotoxicity, chemotherapy, liver enzymes, meta-analysis, systematic review, cancer, AST, ALT, randomized clinical trials, hepatoprotection
News Source: Nathaniel Bowman. (October 28, 2026). Silymarin Shows Modest Liver-Protective Effects in Chemotherapy Patients, Meta-Analysis Finds. Scienmag.
