Cardiologist: High fructose corn syrup is 'one of the most misunderstood food ingredients'

23-Sep-2012 - Last updated on 12-Oct-2012 at 21:14 GMT

Dr Rippe: 'While the scientific debate is largely over, the public debate related to HFCS and obesity has, by no means, concluded'

High fructose corn syrup (HFCS) is “one of the most misunderstood food ingredients”, and continues to be lambasted in the media and on the internet long after the scientific debate over its relative contribution to the obesity epidemic vs sugar has run its course, says food industry consultant and cardiologist Dr James Rippe.

Dr James Rippe, professor, biomedical sciences at the University of Central Florida, who also works on a consultancy basis for the Corn Refiners Association, has co-written a viewpoint article in the International Journal of Obesity seeking to dispel myths about the much-maligned sweetener.

In the scientific community, he told FoodNavigator-USA, there is “no longer any debate” about HFCS being metabolized differently to sucrose.

Even Barry Popkin - co-author of the high-profile 2004 Bray et al paper that sparked the whole debate about whether sugar plays a unique role in rising obesity levels - has since acknowledged that it is metabolically equivalent to sucrose (Popkin now says “it’s all sugar, it’s equally bad”), observed Rippe.

However, many people have not caught up with the science, and continue to cite the 2004 paper Popkin has now “publicly decried”, said Rippe.

Thousands of postings on the internet relate to putative links between HFCS and obesity

He added: “In the past decade, a number of research trials have demonstrated no short-term differences between HFCS and sucrose in any metabolic parameter or health related effect measured in human beings including blood glucose, insulin, leptin, ghrelin and appetite.

“[Yet] while the scientific debate is largely over, the public debate related to HFCS and obesity has, by no means, concluded.

“There are literally thousands of postings on the internet related to putative links between HFCS and obesity as well as a variety of other metabolic abnormalities.”

There is not a serious scientist that thinks the bond between glucose and fructose is relevant in human nutrition

The Sugar Association and others frequently observe that while HFCS and sucrose each contain similar amounts of glucose and fructose (and the same number of calories and sweetness), they are metabolized differently because the fructose and glucose in sucrose is joined by a covalent bond, said Rippe.

In reality, this bond is broken by our digestive enzymes as soon as sucrose hits the small intestine, he pointed out, which means that sucrose is metabolized (absorbed) as free fructose and free glucose, exactly the same way that HFCS is.

Indeed, sucrose in an acidic carbonated soft drink left sitting on a warm shelf often starts to break down into free fructose and free glucose well before it even hits our digestive system, he pointed out.

“Thus, in a major source of sucrose consumption in the human diet (soda), most of the sucrose may have already been hydrolyzed to free fructose and free glucose.”

He added: “I don’t think there is a serious scientist that thinks the bond between glucose and fructose is relevant in human nutrition.”

Meanwhile, the consumption of HFCS has declined for the past decade while obesity levels have continued to rise, he observed, noting that obesity is also a problem in countries such as the UK and Australia where there is little or no HFCS available.

Click here to read the Viewpoint article in full, which was co-authored by DM Klurfeld, J Foreyt and TJ Angelopoulos.

Dr Rippe is the founder and director of the Rippe Lifestyle Institute, Associate Professor of Medicine (Cardiology) at Tufts University School of Medicine, and Professor of Biomedical Sciences at the University of Central Florida.