HEALTH NEWS

Study Title:

High Fructose Corn Syrup Increases Disease Risk

Study Abstract

Context: Compared with glucose-sweetened beverages, consumption of fructose-sweetened beverages with meals elevates postprandial plasma triglycerides and lowers 24-h insulin and leptin profiles in normal weight women. The effects of fructose, compared with glucose, ingestion on metabolic profiles in obese subjects has not been studied.

Objective: Compare the effects of fructose- and glucose-sweetened beverages consumed with meals on hormones and metabolic substrates in obese subjects.

Design and Setting: Within subject design conducted in the Clinical and Translational Research Center.

Participants: 17 obese men (n=9) and women (n=8), BMI >30 kg/m2.

Interventions: Subjects were studied under two conditions involving ingestion of mixed nutrient meals with either glucose-sweetened beverages or fructose-sweetened beverages. The beverages provided 30% of total kilocalories. Blood samples were collected over 24-h.

Main Outcome Measures: Area under the curve (24 h AUC) for glucose, lactate, insulin, leptin, ghrelin, uric acid, triglycerides (TGs), and free fatty acids.

Results: Compared with glucose-sweetened beverages, fructose consumption was associated with lower AUCs for insulin (1052.6 ± 135.1 vs 549.2 ± 79.7 µU/ml. 23 h, p<0.001), leptin (151.9 ± 22.7 vs. 107.0 ± 15.0 ng/ml. 24 h, p<0.03) and increased AUC for TG (242.3 ± 96.8 vs 704.3 ± 124.4 mg/dl. 24 h, p< 0.0001). Insulin resistant subjects exhibited larger 24 h TG profiles (p<0.03).

Conclusions: In obese subjects, consumption of fructose-sweetened beverages with meals was associated with less insulin secretion, blunted diurnal leptin profiles and increased postprandial TG concentrations compared with glucose consumption. Increases of TG were augmented in obese subjects with insulin resistance, suggesting that fructose consumption may exacerbate an already adverse metabolic profile present in many obese subjects.

From press release:

Obese people who drink fructose-sweetened beverages with their meals have an increased rise of triglycerides following the meal, according to new research from the Monell Center.

"Increased triglycerides after a meal are known predictors of cardiovascular disease," says Monell Member and study lead author Karen L. Teff, PhD, a metabolic physiologist. "Our findings show that fructose-sweetened beverages raise triglyceride levels in obese people, who already are at risk for metabolic disorders such as cardiovascular disease and diabetes."

Triglycerides are manufactured by the body from dietary fat and are the most common form of fat transported in blood. Although normal levels of triglycerides are essential for good health, high levels are associated with increased risk for atherosclerosis and other predictors of cardiovascular disease.

In the study, published online by the Journal of Clinical Endocrinology and Metabolism, Teff and her collaborators studied 17 obese men and women. Each was admitted two times to the Clinical and Translational Research Center at the University of Pennsylvania. On each admission, the subjects were given identical meals and blood was collected from an intravenous catheter over a 24-hour period. The only difference was the sweetener used in the beverages that accompanied the meals; beverages were sweetened with glucose during one admission and with fructose during the other.

Blood triglyceride levels were higher when subjects drank fructose-sweetened beverages with their meals compared to when they drank glucose-sweetened beverages. The total amount of triglycerides over a 24-hour period was almost 200 percent higher when the subjects drank fructose-sweetened beverages.

Although fructose increased triglyceride levels in all of the subjects, this effect was especially pronounced in insulin-resistant subjects, who already had increased triglyceride levels. Insulin resistance is a pre-diabetic condition often associated with obesity.

"Fructose can cause even greater elevations of triglyceride levels in obese insulin-resistant individuals, worsening their metabolic profiles and further increasing their risk for diabetes and heart disease," said Teff.

Fructose and glucose are forms of sugar found in both table sugar (sucrose) and high fructose corn syrup. Both fructose and glucose are present in lower concentrations in many fruits and vegetables. Although fructose tastes much sweeter than either glucose or sucrose, it typically is not used alone as a sweetener.

Study Information

Karen L. Teff, Joanne Grudziak, Raymond R. Townsend, Tamara N. Dunn, Ryan W. Grant, Sean H. Adams, Nancy L. Keim, Bethany P. Cummings, Kimber L. Stanhope, and Peter J. Havel.
Endocrine and metabolic effects of consuming fructose- and glucose-sweetened beverages with meals in obese men and women: influence of insulin resistance on plasma triglyceride responses.
J. Clin. Endocrinol. Metab.,
2009 February