April 21, 2009 -- New research shows big differences in how the sugars
fructose and glucose are metabolized by the body. But the findings have little
relevance to the current debate about whether high-fructose corn syrup is a
bigger dietary villain than other sugars added to processed foods, experts
Overweight study participants
showed more evidence of insulin resistance and other risk factors for heart disease and diabetes when 25% of their calories came from
fructose-sweetened beverages compared to glucose-sweetened beverages.
Both groups gained weight during the 10-week study, but the fructose group
gained more of the dangerous belly fat that has been linked to a higher risk
for heart attack and stroke.
The study showed clear differences in how fructose and glucose are
metabolized by the body, nutrition researcher and
principal investigator Peter J. Havel, PhD, of the University of California at
Davis tells WebMD.
But the findings do not show that high-fructose corn syrup (HFCS), used in
everything from soft drinks to cereals in the U.S., is worse for your health
than other added sugars.
That's because despite the name, high-fructose corn syrup is chemically
similar to other widely used sweeteners, including table sugar (sucrose),
honey, and even sweeteners made from concentrated fruit juices.
All contain glucose and fructose in roughly equal amounts. The high-fructose
corn syrup used in most soft drinks and other sweetened beverages in the U.S.
contains about 55% fructose and 45% glucose, compared to the 50/50
fructose-glucose ratio found in table sugar.
"Any added sugar used as an alternative to high-fructose corn syrup would
have a similar chemical composition," University of Cincinnati obesity
researcher Matthias H. Tschop, MD, tells WebMD. "While it is possible that
there are differences in how these sugars affect metabolic pathways, I know of
no studies that show this."
But Tschop says the newly reported study is an important step forward in
understanding the metabolic impact of glucose and fructose, even if the
real-world public health implications are less clear.
The study included 32 overweight or obese men and women whose average age
Over a 10-week period, the men and women drank either glucose- or
fructose-sweetened beverages, totaling 25% of their daily calorie intake,
either in an outpatient setting (eight weeks long) or highly controlled
inpatient setting (two weeks long).
Both the groups gained weight during the trial, but imaging studies revealed
that most of the added fat in the fructose group occurred in the belly, while
most of the fat gained by the glucose group was subcutaneous (under the skin).
Belly fat, but not subcutaneous fat, has been linked to an increased risk
for heart disease and diabetes.
The fructose group had higher
total cholesterol and LDL "bad" cholesterol, plus
greater insulin resistance, which are consistent with metabolic syndrome, while the glucose group did
The research appears in the latest issue of the Journal of Clinical