Not All Sugars Are Equal, at Least When it Comes to Weight Gain and Health

PHILADELPHIA, PA -- June 4, 2004 -- Researchers at the Monell Chemical
Senses Center, the University of California, Davis and other collaborating
colleagues report that drinking beverages containing fructose, a
naturally-occurring sugar commonly used to sweeten soft drinks and other
beverages, induces a pattern of hormonal responses that may favor the
development of obesity.

It is estimated that consumption of fructose has increased by 20-30% over
the past three decades, a rate of increase similar to that of obesity, which
has risen dramatically over the same time span. Data from the present study
suggest a mechanism by which fructose consumption could be one factor
contributing to the increased incidence of obesity.

In the study, reported in the June 4 issue of the Journal of Clinical
Endocrinology and Metabolism, 12 normal-weight women ate standardized meals
on two days. The meals contained the same number of calories and the same
distribution of total carbohydrate, fat and protein. On one day the meals
included a beverage sweetened with fructose. On the other day, the same
beverage was sweetened with an equal amount of glucose, another
naturally-occurring sugar that is used by the body for energy.

Following meals accompanied by the fructose-sweetened beverage, circulating
levels of insulin and leptin were decreased compared to when the women ate
the same meals accompanied by the glucose-sweetened beverage. Lower levels
of insulin and leptin, hormones that convey information to the brain about
the body's energy status and fat stores, have been linked in other studies
to increased appetite and obesity.

In addition, levels of ghrelin, a hormone thought to trigger appetite that
normally declines following a meal, decreased less after meals on the day
the women drank the fructose-sweetened beverage. And, the fructose also
resulted in a long-lasting increase of triglycerides, fatty molecules in the
blood that are indicators of risk for cardiovascular disease.

Together, the hormonal responses observed after drinking beverages sweetened
with fructose suggest that prolonged consumption of diets high in energy
from fructose could lead to increased caloric intake and contribute to
weight gain and obesity. Lead author Karen Teff, PhD, a physiologist at
Monell, comments, "Fructose consumption results in a metabolic profile of
hormones which would be predicted to increase food intake, thereby
contributing to obesity in susceptible populations."

Teff notes that this pattern of hormonal responses is similar to that
observed after consuming a high-fat meal, and continues, "Based on our
previously published work, this metabolic profile resembles that of fat
consumption. Thus, despite the fact that fructose is a sugar, metabolically
the responses are similar to those seen following fat ingestion." The
elevated levels of plasma triglycerides observed after fructose consumption
further suggest that frequent fructose consumption could also contribute to
the development of atherosclerosis and cardiovascular disease.

According to co-author Dr. Peter Havel, a research endocrinologist at the
University of California, Davis, "Although this short-term experiment
provides important new data, additional research is needed to investigate
the long-term impact of consuming fructose in humans, particularly its
effects on lipid metabolism and on endocrine signals involved in body weight
regulation. New studies should also be conducted in subjects who are at
increased risk for metabolic diseases such as type-2 diabetes and
cardiovascular disease and who may be more susceptible to the adverse
effects of overconsuming fructose".

The study was funded by the National Institute of Diabetes and Digestive and
Kidney Diseases.


Citation: Teff KL, Elliott SS, Tschoep M, et al. Dietary Fructose Reduces
Circulating Insulin and Leptin, Attenuates Postprandial Suppression of
Ghrelin and Increases Triglycerides in Women. J Clin Endocrinol Metab.
2004,89(6)