Big effect
Red grape flavonoids significantly lowered a liver enzyme in NAFLD patients — but didn't touch inflammation or scarring
This meta-analysis of 689 people with fatty liver disease found a moderate, consistent drop in AST (a marker of liver stress), but the benefit stopped there — inflammatory markers and fibrosis scores didn't budge, and the evidence rests on only four studies, so the picture is promising but far from settled.
AST is an enzyme that leaks into the blood when liver cells are damaged; a lower level suggests less ongoing liver injury. In this analysis, flavonoid supplements (from red grapes and other sources) reduced AST in people with non-alcoholic fatty liver disease, but had no effect on inflammation or liver scarring — meaning the improvement was limited to one aspect of liver health. The findings come from a systematic review of clinical trials, but the dose used wasn't specified, and the results may not apply to people without fatty liver disease.
Where this fits in the evidence
Pillser has synthesized 4 studies on Red Grape for Reduced Aspartate Aminotransferase Level — overall evidence strength: Moderate.
Across 4 studies, 3 reported beneficial effects of red grape or its extracts on reducing aspartate aminotransferase (AST) levels, with one neutral finding. The predominant effect size was small, though one moderate effect was observed. Effects were seen in clinical populations, primarily individuals with NAFLD or thalassemia, over a median duration of 44 days (approximately 6 weeks).
The study
- Systematic Review
- n = 689
- 2025-09-15
- Frontiers in nutrition
This is a plain-language summary of a research finding, not medical advice. Pillser surfaces research signals to help you decide what's worth investigating — always consult a qualified professional before changing what you take.