HFCS: From the Lips to the Hips?
by Mary Ann Ryan
Check the label on the container of your favorite soft drink, and, unless it’s the diet variety, you’re likely to find high-fructose corn syrup (HFCS) listed as a primary ingredient after water. HFCS, a mixture of two sugars, dextrose and fructose, has become the sweetener of choice in the United States for soft drinks, but its use extends beyond beverages to many processed foods. Not only is it incorporated into cookies, candies, and other confections, but also in numerous foods where one would not expect to find sugar: hot dogs, Italian-flavored bread crumb mix, ketchup, and the buns around cheeseburgers, to name a few.
Dueling headlines about HFCS have appeared in the media recently as a result of research studies suggesting possible links between the increasing consumption of this sweetener and the growing incidence of obesity and diabetes. “Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity,” reads the title of a report by George Bray and colleagues in the April 2004 issue of the American Journal of Clinical Nutrition. “HFCS is not the cause of Obesity,” retorts the Corn Refiners Association, with a similar statement coming from the National Soft Drink Association.
Comparable volleys have been exchanged over the possible role of HFCS consumption and diabetes.
Production of HFCS
According to the Corn Refiners Association, the making of high fructose corn syrup starts with shelled corn that has been stripped from the cob during harvesting. The corn kernels are put through a wet milling process that separates them into their component parts: starch, germ (the main source of corn oil), fiber, and protein. The starch consists of long chains of sugar molecules, the most basic unit being the simple sugar glucose (also known as dextrose). With further processing, starch is hydrolyzed by enzymes to produce solutions of glucose and other sugars. Finally, some of the glucose is converted to fructose, a sweeter sugar, yielding mixtures of varying composition and sweetness.
The two most widely used mixtures are 42-HFCS (a fructose/glucose mix that is 42% fructose, an isomer of glucose) and 55-HFCS (a sweeter mix containing 55% fructose).
Researchers have been paying increased attention to HFCS because the sweetener has become so prevalent in beverages and processed foods since its introduction in 1967. Bray, a professor of medicine at Louisiana State University and an authority on obesity, writes that consumption of HFCS increased more than 1000% between 1970 and 1990, mirroring the upward trend in obesity statistics. He reports that HFCS now represents more than 40% of caloric sweeteners added to foods and beverages, and he estimates that added sweeteners in general represent an average of 16% of all calorie intake for Americans aged two and over.
Some of the health concerns about the effect of HFCS on health have to do with the fructose component of the sweetener. HFCS contains either 42% or 55% fructose (designated 42-HFCS and 55-HFCS, respectively) combined with 42−52% glucose and a few percent of higher saccharides. Although glucose increases insulin release from the pancreas, fructose does not. Because insulin helps to control sugar consumption by signaling the brain to indicate a sense of satiety, fructose’s lack of a triggering mechanism for insulin may lead to increased calorie consumption, according to Bray and others. Also, fructose appears to convert to fat more readily than glucose because of the ease with which the carbon skeleton of fructose can form the backbone for precursors of long-chain fatty acids. (It should be pointed out that sucrose–table sugar–when digested, yields a 50:50 proportion of glucose and fructose, a mix similar to HFCS, and the intake of too much sucrose may pose the same issues raised about HFCS.) Researchers agree that more study is needed on the effects of HFCS and sucrose, particularly large quantities of these added sweeteners in the diet, to clarify current questions.
HFCS is only one of many factors being studied for its potential contribution to the obesity epidemic. Many aspects of diet, as well as lifestyle and genetic traits, all have a bearing on obesity. But there’s no denying that it’s easy to overdo caloric intake when super-sized soft drinks served in 32-oz cups–and containing the HFCS-equivalent of 20 teaspoons of sugar–are commonly the size of choice. Maybe it’s time to lighten up.
