A new study, presented at the American Heart Association's Scientific Session last week found that consuming fructose from added sugars does not lead to weight gain or an increased risk for heart disease. But that finding may not be the whole story, according to experts who point out imperfections in the study.
The double-blind study, which was supported by an unrestricted grant from the Corn Refiners Association, followed 64 overweight and obese people who were placed on a weight-stable diet for 10 weeks. The diet incorporated sucrose-sweetened or high fructose corn syrup-sweetened low-fat milk, at 10 percent or 20 percent of total calories.
The AHA recommends men and women consume no more than approximately 38 grams of sugar a day. The fructose consumption levels in the study were two- to four-times greater than AHA recommendations
After 10 weeks, researchers found no change in body weight in the group. Total cholesterol, triglycerides or “bad” LDL cholesterol remained the same as did levels of "good" HDL cholesterol.
Experts question the trial design and suggest the information could mislead consumers if not framed responsibly. "The study did not include that many people, and was not conducted for a significant period of time," said Dawn Jackson Blatner, RD, spokeswoman for the American Dietetic Association and author The Flexitarian Diet (McGraw, 2008). "Most significantly, recipients were fed a calorie controlled diet so they wouldn't gain weight. When you feed someone the right number of calories, regardless of the quality of those calories they're not going to gain weight. This information isn't really new."
The study also did not offer enough time to assess how participants may metabolize HFCS compared to sucrose. "Considering who sponsored the study it's easy to see why it defends HFCS as much as it does," said Kantha Shelke, principal at Corvus Blue, a Chicago-based food science and research firm. "HFCS is not, chemically speaking, in the same class as sucrose and our bodies recognize them as different and respond to them differently."
Shelke pointed to the fact that though the study argues that HFCS contains glucose and fructose in the same proportion that sucrose does, how these sugars enter the bloodstream is like comparing apples to oranges. HFCS is a man-made sweetener and is absorbed by the body immediately when ingested, she said. Sucrose is a double molecule that must be broken down into its components fructose and sucrose before it can be absorbed.
The duration of the study was not significant enough to ultimately determine the effects of sugar consumption on heart disease, Blatner said. When it comes to weight loss, both agreed it's not the type of sugar but rather the quantity and frequency that can lead to obesity.
"What Paracelsus said is still relevant today," Shelke said. "All things are poison and nothing is without poison, only the dose permits something not to be poisonous."