The body may absorb more fructose from high fructose corn syrup (HFCS) than it does from sucrose, according to a new study published in the journal Metabolism.
Food industry consultant and cardiologist Dr. James Rippe says this was “not surprising”, although he disagreed with the findings of the study.
HFCS and sucrose have historically been considered to have nearly identical effects on the body. Numerous studies have linked the consumption of high levels of fructose alone with health risks – including high blood pressure, kidney disease and diabetes – but little fructose is consumed in this way.
It is most commonly consumed in conjunction with glucose as sucrose or HFCS. According to USDA figures, Americans consumed about 34.8lbs of HFCS per capita in 2010, with the type used in soft drinks composed of about 55% fructose, 42% glucose and 3% oligosaccharides, compared to about 47lbs of sucrose, made up of 50% fructose and 50% glucose.
The Corn Refiners Association (CRA), which represents the interests of the HFCS industry, has long defended the sweetener on the basis that “your body can’t tell the difference”, and uses this slogan to compare HFCS with sucrose in advertising campaigns.
This latest study, from researchers at the University of Colorado School of Medicine and the University of Florida, looked at how much fructose was absorbed into the bloodstream within the first few hours after consuming a soft drink sweetened with either HFCS or sucrose.
They found that there was a difference between the two, albeit slight.
Co-author in the study and chief of the Division of Renal Diseases and Hypertension at the University of Colorado, Dr. Richard Johnson, said: “Although both sweeteners are often considered the same in terms of their biological effects, this study demonstrates that there are subtle differences. Soft drinks containing HFCS result in slightly higher blood levels of fructose than sucrose-sweetened drinks."
Rippe told FoodNavigator-USA: “It’s not surprising that if one product contains slightly more fructose, that the levels [in the blood] at the end of the study are higher.”
Different fructose levels
The researchers looked at blood fructose levels in 40 study participants who consumed 24-oz. drinks sweetened with either HFCS or sucrose.
They found higher levels of fructose in the bloodstream of those who drank the HFCS-sweetened beverages, and said that this was likely due to the slightly higher amount of fructose in HFCS.
They also found higher levels of uric acid and higher systolic blood pressure soon after study participants had consumed the HFCS-containing drinks than with the sucrose-sweetened drinks. Previous research has suggested that fructose raises uric acid, and linked it to higher blood pressure.
The study authors hypothesized that these differences could be due to the makeup of the different sugars, as HFCS provides an immediate source of free fructose and glucose, whereas sucrose must first be broken down by sucrase, making it potentially less efficiently absorbed. However, they also acknowledged limitations to the study, including that much of the sucrose had already been broken down into fructose and glucose in the beverage prior to consumption.
“Results of this study cannot be used to form conclusions about the similarities or differences between HFCS and sucrose,” Rippe said in a CRA statement.
“Although the treatment effects on acute metabolic responses were small, the effects may increase with continued chronic exposure to these sweeteners,” the study’s authors wrote.
Johnson added, “The next step is for new studies to address whether the long-term effects of these two sweeteners are different.”
President of the CRA Audrae Erickson criticized the study for not using real-life diets as a model, and pointed to studies cited on the association’s website suggesting that sucrose and HFCS are nutritionally and metabolically equivalent.
She also noted that co-author Dr. Richard Johnson had declared a conflict of interest, saying he has a patent application for inhibiting fructose as a potential way of treating sugar cravings.
“Effects of high-fructose corn syrup and sucrose on the pharmacokinetics of fructose and acute metabolic and hemodynamic responses in healthy subjects”
Authors: MyPhuong T. Le, Reginald F. Frye, Christopher J. Rivard, Jing Cheng, Kim K. McFann, Mark S. Segal, Richard J. Johnson, Julie A. Johnson.