Industry responds to fructose-obesity study
linking fructose consumption to obesity, stating that fructose
cannot be related to high fructose corn syrup.
Last week FoodNavigator.com reported on a study from Barcelona, published in the journal Hepatology, which fed rats a liquid fructose beverage and found the metabolism of fat in the liver had been changed by impacting a specific nuclear receptor called PPAR-alpha, leading to a reduction in the liver's ability to degrade the sweetener. Talking to FoodNavigator.com, Audrae Erickson, president of the CRA stated that links to high fructose corn syrup (HFCS) are not justified since fructose and HFCS are different. HFCS consists of 55 per cent fructose and 42 per cent glucose. "It's like comparing night and day," she said. "If you feed rats [fructose] beyond what you get in a normal diet you will get results [as seen in the Barcelona study]," said Erickson. "But HFCS contains about 50 per cent glucose, which acts a moderator to fructose." Campaigners against the high fructose corn syrup ingredient point to epidemiological studies that have linked the consumption of sweetened beverages and obesity, as well as some science that claims that the body processes the syrup differently than other sugars due to the fructose content, leading to greater fat storage. However, industry associations like the Corn Refiners Association (CRA) have repeatedly claimed there is no scientific evidence to suggest that HFCS is uniquely responsible for people becoming obese. Indeed, Erickson pointed out that a new study, published in the peer-review journal Nutrition, reported that high fructose corn syrup fed to 30 lean female volunteers showed that the sweetener had the same effects as sucrose. The women (average age 33, average BMI 22.4 kg per sq.m) were randomly assigned to consume either a sucrose- or HFCS-sweetened beverage providing 30 per cent of energy levels for one day. Blood samples were taken and glucose, insulin, leptin, and ghrelin levels measured. The women returned one month later to consume the other beverage. The study was double-blind, meaning neither the subjects nor the scientists knew which beverage was being given. The researchers, led by Kathleen Melanson from the University of Rhode Island reported that no significant differences were observed between any of the measured blood variables were observed as a result of drinking the sucrose- or fructose-sweetened beverages. "These short-term results suggests that, when fructose is consumed in the form of HFCS, the measured metabolic responses do not differ from sucrose in lean women," wrote Melanson. "Further research is required to examine appetite responses and to determine if these findings hold true for obese individuals, males, or longer periods," she concluded. Source: Nutrition 2007, Volume 23, Pages 103-112 "Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin, and ghrelin and on appetite in normal-weight women" Authors: K.J. Melanson, L. Zukley, J. Lowndes, V. Nguyen, T.J. Angelopoulos, J.M. Rippe Hepatology Volume 45, Issue 3, Pages 778 - 788 "Impairment of hepatic Stat-3 activation and reduction of PPAR-alpha activity in fructose-fed rats" Authors: N. Roglans, L. Vilà, M. Farré, M. Alegret, R.M. Sánchez, M. Vázquez-Carrera, J.C. Laguna