ADA 2010: Blame calories, not fructose

Fructose is the sugar consumers love to hate. It gets the blame for obesity, metabolic syndrome, and a variety of dietary ills.

"Fructose has become the new trans fat,” said Julie Miller Jones, PhD, CNS, LN, professor emeritus, St Catherine University, St Paul, Minnesota. “Consumers are trying to avoid it, especially in the form of high-fructose corn syrup. That's an unfortunate name because the fructose concentration isn't high."

High-fructose corn syrup contains 42% to 55% fructose, Jones told a Sunday-morning symposium, Dietary Sweeteners Containing Fructose - Effects on Metabolism and Impact in the Food Supply.

That is similar to many common fruits and vegetables and lower than the 66% fructose found in apples and pears. Agave, often marketed as a natural sweetener, contains 85% fructose. The problem, Jones continued, is too much sugar and too many calories. "You can get a $0.69 Big Gulp that delivers 800 calories and not a single nutrient," she said. "A calorie is a calorie, whether it comes from glucose or fructose or a jelly donut."

Excess dietary sugar is associated with increased body weight, lipids, blood pressure, and insulin resistance, continued Kimber Stanhope, PhD, associate project scientist in molecular biosciences, University of California, Davis. Excess fructose is associated with distinct metabolic effects.

Recent human studies have found that fructose is associated with increased visceral fat, whereas glucose is associated with increased subcutaneous fat. Fructose also decreases insulin and leptin and elevates triglycerides compared with glucose. Both sugars produce similar weight gains.

"A calorie is not just a calorie when it comes to metabolic syndrome risk factors," Stanhope said.

Weight gain and obesity are the overriding concerns when it comes to type 2 diabetes, noted Michele Doucette, PhD, RN, assistant professor of family medicine, University of Colorado, Denver. Don't eliminate fructose; reduce the total caloric intake.

The risk for type 2 diabetes is 2 to 7 times higher in obese persons than it is for people of normalweight and 20 times higher when body mass index exceeds 35.

"What is important is the total amount of calories, not the source, in terms of weight gain,” Doucette said. "What is really driving the obesity epidemic is energy balance." Obesity is the result of multiple factors, including genetics, food consumption, activity level, food access and availability, urbanization, and more, she continued. Portion size is an obvious problem.

The 7-ounce cup of coffee with milk and 85 calories has morphed into a 16-ounce giant that is mostly milk and delivers 480 calories. The 12-ounce soda, 160 calories, has largely been replaced by the 20-ounce, 240-calorie version.

"We are eating too much of too many foods that are energy rich and nutrient poor," Doucette said. The remedy, she added, is to help patients eat more wisely so that they consume fewer calories and increase their activity level.