In a very well-attended session on high fructose corn syrup, cardiologist Dr James Rippe, professor, biomedical sciences at the University of Central Florida, told delegates that feeding ultra-high levels of fructose in isolation to rats in a bid to work out whether high fructose corn syrup is bad for humans is not a valid scientific approach.
In the human diet, fructose is almost never consumed in isolation but is typically consumed along with glucose in the form of HFCS or sucrose (both of which contain similar levels of glucose and fructose).
And when you compare trials that feed high levels of HFCS or sucrose to humans (eg. 30% of calories from sucrose or HFCS) and then test blood glucose, lipids, liver function, blood pressure, uric acid, the effects are the same, said Rippe.
For example, both had the same effect on triglycerides - which were raised very slightly with excessive consumption of sucrose or HFCS - and both had no significant effect on blood pressure, uric acid, LDL, HDL or fatty infiltration of the liver and muscle.
As for weight gain, both HFCS and sucrose have the same number of calories, and eating both in moderation is wise, he said. "Every time we've taken one part of the diet and blamed it for obesity it hasn't worked. The problem is that we're eating too darned much of everything and not exercising enough."
In a separate session sponsored by Coca-Cola asking whether fructose is the 'cardiometabolic villain' some critics have made it out to be, John Sievenpiper, MD, PhD, from St Michael's Hospital at the University of Toronto, said: "15 years ago, the hot topic was fat, then it switched to fructose, but we should learn from this debate that we need to rely on evidence and data and not on opinions."
Recent studies published in the New England Journal of Medicine on the relationship between sugary drinks and obesity, meanwhile, were "terrific examples of energy control", he said, in that if you feed people a low or zero calorie beverage vs a sugary drink and change nothing else, the group consuming the sugary drink will put on weight because they are consuming more calories.
"It's a beautiful expression of energy balance, calories in, calories out", he said. "It's entirely predictable."