We have all heard that High Fructose Corn Syrup is NOT created equal – that is a major cause of the obesity epidemic in the US (and growing around the world). While corn manufacturers argue that HFCS is no different than sucrose or glucose, a recent pair of studies on HFCS at Princeton University disproves this.
The two studies found that rats provided with water to which HFCS was added gained more weight than similar rats given sugar water even when they consumed an equal amount of calories. In a long-term study, those rats consuming HFCS also had significant increase in their abdominal fat and increased triglyceride levels.
High-fructose corn syrup and sucrose are both compounds that contain the simple sugars fructose and glucose, but there at least two clear differences between them. First, sucrose is composed of equal amounts of the two simple sugars — it is 50 percent fructose and 50 percent glucose — but the typical high-fructose corn syrup used in this study features a slightly imbalanced ratio, containing 55 percent fructose and 42 percent glucose. Larger sugar molecules called higher saccharides make up the remaining 3 percent of the sweetener. Second, as a result of the manufacturing process for high-fructose corn syrup, the fructose molecules in the sweetener are free and unbound, ready for absorption and utilization. In contrast, every fructose molecule in sucrose that comes from cane sugar or beet sugar is bound to a corresponding glucose molecule and must go through an extra metabolic step before it can be utilized.
This creates a fascinating puzzle. The rats in the Princeton study became obese by drinking high-fructose corn syrup, but not by drinking sucrose. The critical differences in appetite, metabolism and gene expression that underlie this phenomenon are yet to be discovered, but may relate to the fact that excess fructose is being metabolized to produce fat, while glucose is largely being processed for energy or stored as a carbohydrate, called glycogen, in the liver and muscles.