Professor Ken Sato, Department of Internal Medicine, Aichi Medical University, Nagakute, Japan
Professor Ken Sato works in the Department of Internal Medicine at Aichi Medical University in Nagakute, Japan. He and his team have recently conducted a meta-analysis examining the beneficial effect of vitamin E on non-alcoholic fatty liver disease (NAFLD), including non-alcoholic steatohepatitis (NASH). The aim was to evaluate the efficacy of vitamin E in improving liver function. Professor Sato concludes his paper thus: “This meta-analysis suggests that vitamin E therapy improves serum biochemical parameters and improves hepatic histology in NAFLD/NASH, especially in regard to adult NASH patients. Vitamin E also improves hepatic fibrosis, hepatic inflammation and ballooning.”
Fatty liver, caused by lifestyle habits rather than by alcohol consumption, is a growing issue worldwide. In the early stages, it often has no symptoms. Non-alcoholic fatty liver disease (NAFLD) is frequently associated with the common effects of metabolic syndrome, namely obesity, insulin resistance and Type 2 diabetes (T2D).
NAFLD, which encompasses a wide spectrum of disorders, has become a major health issue as well as the most common liver disease throughout the world. Its prevalence is estimated at 20–30% in the general population and as high as 70–80% among the obese, but only 16–20% among those of a healthy weight. The histological pattern of NAFLD can progress to NASH, liver fibrosis, cirrhosis, and even hepatocellular carcinoma. Antioxidant therapy in the form of vitamin E has previously been considered to have beneficial effects when it comes to managing NASH, but further work was required in order to fully understand the data. This analysis has a potentially major impact on public health given that non-alcoholic fatty liver disease is also rated as a risk factor for cardiovascular disease, T2D, and chronic kidney disease (2).
While vitamin E has often been used to treat NAFLD/NASH, the magnitude of response associated with vitamin E in improving liver function and histology in NAFLD/NASH patients has not been quantified systematically. In the current study (1), Professor Sato used very strict inclusion and exclusion criteria in order to avoid potential inaccuracies. This restricted the list of relevant publications included in the meta-analysis to just five.
The meta-analysis concluded that vitamin E therapy may result in decreased levels of liver damage related to hepatitis and cirrhosis in children and adults with NAFLD and NASH. Specifically, vitamin E therapy significantly reduces the levels of key liver enzymes that are elevated in people with NAFLD and NASH (e.g., aspartate transaminase, alanine aminotransferase, and alkaline phosphatase). From a cell pathology point of view, vitamin E was shown to reduce steatosis (abnormal retention of lipids in the cell, which distorts the nucleus), lobular inflammation, and even hepatocellular ballooning in the liver.
In 2010, Sanyal et al reported on a 96week, doubleblind, multi-center, randomized trial determining the effect of vitamin E and pioglitazone (a thiazolidinedione insulin sensitizer) on the hepatic histology of NASH patients (the PIVENS trial) not suffering from diabetes. The vitamin E arm of the trial received an intake of 800 IU/day. The result was an improvement in liver histological features in 43% of the cohort, with reductions in hepatic steatosis and lobular inflammation. Pioglitazone only achieved an improvement in 34% of cases. There was no benefit in combining the two treatments. In addition, serum alanine and aspartate aminotransferase levels were reduced in the vitamin E arm of the trial.
Professor Sato and his team concluded from their analysis that “vitamin E significantly improved liver function and histological changes in patients with NAFLD/NASH.”