Non-alcoholic fatty liver disease (NAFLD) includes a range of liver conditions that begin with simple hepatic steatosis and can progress to non-alcoholic steatohepatitis (NASH), liver cirrhosis and, potentially, hepatocellular carcinoma
The pathogenesis of NAFLD begins with lipid deposition and progresses to involve oxidative stress, inflammation and fibrosis.
NAFLD is increasingly common, with a prevalence of 50–90% in obese individuals and a prevalence that exceeds 70% in patients with type 2 diabetes.
Curcumin, a phenolic compound isolated from Curcuma longa (turmeric) may interfere with the development and progression of NAFLD via numerous mechanisms.
Curcumin improves insulin sensitivity, suppresses adipogenesis, supports mitochondrial function and reduces oxidative stress, inflammation and fibrosis.
Until a study published in 2017 by Panahi, et al., there had been no clinical trials of curcumin in patients with NAFLD.
Panahi and colleague’s randomised controlled trial involved 87 patients with NAFLD (grades 1-3, diagnosed by liver ultrasound).
Patients were randomised to take curcumin (1000 mg/day in two divided doses) or a placebo for 8 weeks.
Curcumin was provided as a phytosomal formulation that contained a complex of curcumin and soy phosphatidylcholine (Meriva, provided by Indena SpA). Participants in both groups were also given dietary and lifestyle recommendations.
After 8 weeks, curcumin supplementation, but not the placebo, produced significant reductions in body mass index (BMI) and waist circumference (p<.001).
Liver ultrasound findings improved in 75% of subjects in the curcumin group and only 4.7% of subjects in the placebo group; liver fat content increased in 4.7% of subjects in the curcumin group and 25.6% of subjects in the placebo group.
Improvements on ultrasound were significant in the curcumin group when compared with the placebo (p<.001).
The effect of curcumin in reducing liver fat remained significant after adjusting for numerous confounding factors. In addition, serum levels of AST and ALT were reduced after 8 weeks of curcumin supplementation but increased in the placebo group. Curcumin was well tolerated, with no reports of serious adverse events.
This study shows that 8 weeks of curcumin supplementation improves sonographic findings and hepatic transaminase levels in patients with NAFLD.
Longer-term studies are needed to determine if curcumin will also reduce progression to NASH or hepatocellular carcinoma.