That high-fructose corn syrup (HFCS) causes weight gain is not surprising; that it leads to a significantly higher weight gain than regular table sugar, even when overall caloric intake is the same? Surprising. Regardless of how innocent the sensitive souls from the Corn Refiners Association may purport HFCS to be, a Princeton University research team begs to differ with new research demonstrating that all sweeteners are not created equal in terms of weight gain.
In addition to causing considerable weight gain in lab tests, long-term consumption of high-fructose corn syrup also led to abnormal increases in body fat, especially in the abdomen, and a rise in circulating blood fats called triglycerides. The researchers say the work sheds light on the factors contributing to obesity trends in the United States.
“Some people have claimed that high-fructose corn syrup is no different than other sweeteners when it comes to weight gain and obesity, but our results make it clear that this just isn’t true, at least under the conditions of our tests,” said psychology professor Bart Hoebel, who specializes in the neuroscience of appetite, weight and sugar addiction.
The results were published March 18 by the journal Pharmacology, Biochemistry and Behavior, the researchers from the Department of Psychology and the Princeton Neuroscience Institute reported on two experiments looking into the connection between the use of high-fructose corn syrup and obesity. They noted that they do not know why HFCS led to more triglycerides and more body fat that resulted in obesity.
HFCS and sucrose (table sugar) are both compounds that contain the simple sugars fructose and glucose, but there at least two distinct differences between them. First, sucrose is comprised of equal parts fructose and glucose (50/50), while typical HFCS has an uneven ratio, usually about 55 percent fructose and 42 percent glucose. Larger sugar molecules called higher saccharides make up the remaining 3 percent of HFCS. Second, because of the manufacturing process for HFCS, 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.
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.
According to the Princeton press release for the study, in the 40 years since the introduction of high-fructose corn syrup as a cost-effective sweetener in the American diet, rates of obesity in the U.S. have skyrocketed. In 1970, around 15 percent of the U.S. population met the definition for obesity; today, roughly one-third of the American adults are considered obese, the CDC reported. High-fructose corn syrup is found in a wide range of foods and beverages, including fruit juice, soda, cereal, bread, yogurt, ketchup and mayonnaise. On average, Americans consume 60 pounds of the sweetener per person every year.
For more on HFCS, see Sugar: The New Health Food?