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High fructose corn syrup in detail: what does the science say?

What is high-fructose corn syrup?

High-fructose corn syrup, also called HCFS or glucose-fructose, is a corn-derived liquid sweetener that is chemically similar to table sugar. It was first introduced to the food and beverage industry in the 1970s. HFCS immediately became an attractive alternative to sucrose because it is stable in acidic foods and beverages, and it is not granular in form, so it’s easier to add to liquid foods (such as pop). It is not meaningfully different in composition or metabolism from other fructose-glucose sweeteners, such as sucrose, honey, and fruit juice concentrates. Both HFCS and table sugar are made of glucose and fructose, and deliver 4 kcal/g.

Why is high fructose corn syrup at the centre of controversy and confusion?

The controversy started with the publication of a commentary in the American Journal of Clinical Nutrition (AJCN) in 2004, which suggested that HFCS in beverages might play a unique role in the epidemic of obesity, since increased use of HFCS in the United States mirrored the rapid increase in obesity. Although the authors of this commentary clearly stated that they were only describing a unique association and not a cause-and-effect relationship, a media frenzy ensued. Even though the original authors of the AJCN commentary were clear that they were simply offering a hypothesis, other investigators, the media, food manufacturers, and the public at large have contributed to this controversy, often without distinguishing between an association and cause and effect, while frequently confusing the sugars used in research studies, or exaggerating the implications of animal studies.

Is high fructose corn syrup the cause of the obesity epidemic?

No single food is the cause of obesity. Rather, obesity is a multifactorial condition that takes diet, exercise, genetics and environment into account. The hypothesis that HFCS is a unique cause of obesity is not supported by science because:

  • HFCS has the same sugars composition as other “benign” fructose-glucose sweeteners such as sucrose, honey, and fruit juice concentrates. And they are all metabolized the same way.
  • Increased caloric intake since 1970 was not due to added sugars (including HFCS) but rather was due to increased consumption of all calories, especially fat, flour and cereals.
  • Although pure fructose can cause metabolic upsets at high concentrations and in the absence of glucose, such experiments are irrelevant for HFCS, which is not consumed at extreme high levels and is not pure fructose.
  • There is no longer an association between HFCS and obesity in the United States: per capita consumption of HFCS has declined in recent years, whereas obesity rates continue to rise.
  • There is absolutely no association between HFCS use and worldwide obesity; HFCS is really a minor sweetener in the global perspective. There are epidemics of obesity and diabetes in areas where little or no HFCS is available (e.g., Mexico, Australia, and Europe).

Is high fructose corn syrup worse for our health than table sugar?

At this time, there’s not enough scientific evidence to show that HCFS is any less healthy than any other type of sweetener. One notable study compared the effects of HFCS and sucrose at 30% of calories in two randomized 2-day visits in normal-weight women. Concluding that there is nothing uniquely quantifiable about HFCS, they reported no significant difference between the two sweeteners in fasting plasma glucose, insulin, leptin, or ghrelin or in energy or micronutrient intake.

Studies show that there are no metabolic or endocrine response differences between HFCS and sucrose related to obesity or any other adverse health outcome. This is not surprising given that both of these sugars have or are:

We do know, however, that too much of any type of added sugar — not just high-fructose corn syrup — can contribute unwanted calories that are linked to health problems, such as weight gain, type 2 diabetes, metabolic syndrome and high triglyceride levels. All of these boost your risk of heart disease. For health concerns, it’s advised to cut back on added sugar, regardless of the type.