Vitamins
E and C Beneficial in Fatty Liver Disease
Healthnotes Newswire (February 12, 2004)—Supplementing with
vitamins E and C may improve liver fibrosis in people with nonalcoholic
steatohepatitis (NASH), according to a new study in The American
Journal of Gastroenterology (2003;98:2485–90).
NASH is an
advanced form of a group of conditions collectively referred to
as nonalcoholic fatty liver disease. Nonalcoholic fatty liver
disease is usually not life threatening; however, in some cases
the NASH form may lead to the progressive formation of abnormal
fibrous tissue in the liver (fibrosis), eventually culminating
in generally irreversible liver damage (cirrhosis of the liver),
liver failure, or liver cancer. NASH is often associated with
obesity, high blood levels of fats (called lipids), diabetes,
and high blood pressure.
Although the
disease process is not completely understood, some factors are
thought to contribute to the development of NASH. These include
insulin resistance (the reduced ability of the body to respond
to circulating levels of insulin); free-radical damage to fatty
acids in the body, leading to inflammation and eventual tissue
death and liver fibrosis; and dietary habits that cause blood
fats to accumulate in the liver. Since there is no cure for NASH,
most treatment plans are aimed at reducing the risk factors. Current
recommendations may include lipid regulation (reduction of blood
fats by dietary changes, nutritional supplementation, or lipid-lowering
medications), gradual weight loss, insulin sensitizers (agents
that enhance the body’s response to insulin), and supplementation
with antioxidants. New drugs are also being investigated.
This study
was designed to determine the response of various parameters of
liver health in people with NASH when treated with the antioxidant
vitamins E and C. Specifically, liver inflammation and tissue
death (necrosis), liver fibrosis, and liver enzymes (a measure
of liver inflammation) were assessed. People with a diagnosis
of NASH were randomly assigned to take either (1) vitamin E (1,000
IU) and vitamin C (1,000 mg) or (2) placebo every day for six
months. Both groups were encouraged to follow a weight-loss program
and to consume less than 30 grams of fat per day. The vitamin
group participants had a higher incidence of diabetes than the
placebo group. Liver biopsies were performed pre- and post-treatment.
No significant side effects were noted in the 45 people who completed
the trial.
At the end
of the six-month period, there was a small, yet statistically
significant improvement in fibrosis scores in the vitamin group
but not the placebo group. No difference was noted in the inflammation
or necrosis scores between the groups. In general, there was a
trend toward more improvement in fibrosis scores in those people
with more severe fibrosis. Among non-diabetic participants, there
was no significant change in fibrosis during the study in either
group. Diabetics receiving vitamins E and C were found to have
the most initial fibrosis and subsequently the most improvement
in fibrosis during the study period.
These results
seem to indicate more benefit in diabetics with more severe fibrosis.
However, because the number of diabetics in the vitamin group
was not matched in the placebo group it cannot be said with certainty
that people with NASH who take vitamins E and C will benefit.
Further studies are needed to investigate the usefulness of vitamin
E and C supplementation in people with NASH and to confirm the
finding of selective improvement in diabetics with more severe
fibrosis. Little or no change was seen in the level of liver enzymes
during the study.
Previous preliminary
studies have reported similar findings of reduced liver inflammation
and fibrosis and lowered liver enzymes following treatment with
vitamin E.
NASH may be
best treated using a multifaceted approach aimed at addressing
the underlying causes and preventing further damage. The results
of this study are promising, as fibrosis scores actually improved
over the study period. Since the amount of fibrosis is more predictive
of disease severity than liver enzyme levels, an improvement in
fibrosis may translate to a decreased likelihood of progression
to cirrhosis and liver failure.