High fructose corn syrup, which
some studies have linked to obesity, may also be harmful to the liver,
according to Duke University Medical Centre research.
“We found that increased
consumption of high fructose corn syrup was associated with scarring in the
liver, or fibrosis, among patients with non-alcoholic fatty liver disease,”
said Manal Abdelmalek, associate professor of medicine in the Division of
Gastroenterology/Hepatology at Duke University Medical Centre.
Her team of researchers at Duke,
one of eight clinical centres in the Non-alcoholic Steatohepatitis Clinical
Research Network, looked at 427 adults enrolled in the network. They analysed
dietary questionnaires collected within three months of the adults’ liver
biopsies to determine their high fructose corn syrup intake and its association
with liver scarring.
The researchers found only 19 per cent
of adults with non-alcoholic fatty liver disease reported no intake of
fructose-containing beverages, while 52 per cent consumed between one and six
servings a week and 29 per cent consumed fructose-containing beverages on a
An increase in consumption of
fructose appeared to be correlated to increased liver fibrosis in patients with
the disease, they found.
“We have identified an
environmental risk factor that may contribute to the metabolic syndrome of insulin
resistance and the complications of the metabolic syndrome, including liver
injury,” Dr. Abdelmalek said.
Research Dr. Abdelmalek published
in the Journal of Hepatology in 2008 showed that, within a small subset of
patients, high fructose corn syrup was associated with non-alcoholic fatty
liver disease. Her latest research goes one step further and links high
fructose corn syrup to the progression of liver injury.
“Non-alcoholic fatty liver
disease is present in 30 per cent of adults in the United States,” she said.
“Although only a minority of patients progress to cirrhosis, such patients
are at increased risk for liver failure, liver cancer, and the need for liver
transplant,” she explained.
“Unfortunately, there is no
therapy for non-alcoholic fatty liver disease,” she said. “My hope is
to see if we can find a factor, such as increased consumption of high fructose
corn syrup, which, if modified, can decrease the risk of liver disease.”
“High fructose corn syrup,
which is predominately in soft-drinks and processed foods, may not be as benign
as we previously thought,” she said.
The consumption of fructose has
increased exponentially since the early 1970s, and with this rise, an increase
in obesity and complications of obesity have been observed, Dr. Abdelmalek
“There is an increasing amount
of data that suggests high fructose corn syrup is fuelling the fire of the
obesity epidemic, but until now no one has ever suggested that it contributes
to liver disease and/or liver injury.” She said the next step is more
studies looking at the mechanisms of liver injury.
“We need to do formal studies
that evaluate the influence of limiting or completely discontinuing high
fructose corn syrup from one’s diet and see if there are health benefits from
doing so,” she said.
Refiners Association, which represents manufacturers of high fructose corn
syrup, rejected the findings, saying fructose had not been proven to be a cause
of non-alcoholic fatty liver disease and that the study “unnecessarily confuses
consumers about the impact of dietary fructose”.
The association said “Although the
researchers acknowledged that beverages containing fructose accounted for only
50 per cent of total dietary intake of fructose – leaving out other important
dietary sources of fructose such as fruits and vegetables – they nevertheless
elected to base the findings of the recall study on beverages sources only.
“Magnifying these problems with
their data interpretation still further, the researchers counted intake of
fruit juices and other beverages containing fructose from sugar, even though
those beverages contain no high fructose corn syrup at all,” a press release
from the association stated.