A new study by University of Southern California (USC) and University of Oxford researchers reports that countries that use high fructose corn syrup (HFCS) in their food supply had a 20% higher prevalence of diabetes than countries that did not use the sweetener. The article, "High Fructose Corn Syrup and Diabetes Prevalence: A Global Perspective," is published in the journal Global Public Health.
Use of high fructose corn syrup around the world
Countries with higher use of HFCS had an average prevalence of type 2 diabetes of 8% compared to 6.7% in countries not using HFCS.
The paper reports that out of 42 countries studied, the United States has the highest per capita consumption of HFCS at a rate of 25 kilograms, or 55 pounds, per year. The second highest is Hungary, with an annual rate of 16 kilograms, or 46 pounds, per capita. Canada, Slovakia, Bulgaria, Belgium, Argentina, Korea, Japan and Mexico are also relatively high HFCS consumers. Germany, Poland, Greece, Portugal, Egypt, Finland and Serbia are among the lowest HFCS consumers. Countries with per capita consumption of less than 0.5 kilogram per year include Australia, China, Denmark, France, India, Ireland, Italy, Sweden, the United Kingdom, and Uruguay.
Difference between high fructose corn syrup and sugar
The article proposes that the link between high fructose corn syrup and diabetes is probably driven by higher amounts of fructose in foods and beverages made with HFCS. Fructose and glucose are both found in ordinary sugar (sucrose) in equal amounts, but HFCS has a greater proportion of fructose. The higher fructose content makes HFCS sweeter and provides processed foods with greater stability and better appearance because of the more consistent browning color when foods made with higher fructose are baked.
The body metabolizes fructose differently from glucose, the authors said. Fructose metabolism occurs independently of insulin, primarily in the liver where it may be readily converted to fat, which likely contributes to non-alcoholic fatty liver disease, a condition on the rise in Hispanics in the United States and Mexico.
In a previous related study, the authors found that the fructose content in some U.S.-produced soft drinks, especially the most popular, was about 20% higher than expected, suggesting that some manufacturers might be using HFCS with more fructose than previously estimated. Such differences could "potentially be driving up fructose consumption in countries that use HFCS," the researchers said. The study notes the difficulty in determining the actual amount of fructose in foods and beverages made with HFCS because of "a lack of industry disclosure on food labels."
"Most populations have an almost insatiable appetite for sweet foods, but regrettably our metabolism has not evolved sufficiently to be able to process the fructose from high fructose corn syrup in the quantities that some people are consuming it," said Ulijaszek. "Although this syrup can be found in many of our processed foods and drinks, this varies enormously from country to country."
United States largest consumer of high fructose corn syrup
The U.S. is the single largest consumer of high fructose corn syrup. By the late 1990s HFCS made up 40% of all caloric sweeteners and was the predominant sweetener in soft drinks sold in the United States, according to the researchers. However, since 2008, exports of HFCS from the United States to Mexico increased "exponentially" after trade restrictions were removed, the researchers said. They call for updated public health strategies requiring better labeling of fructose and HFCS content in processed foods.
"If HFCS is a risk factor for diabetes—one of the world's most serious chronic diseases—then we need to rewrite national dietary guidelines and review agriculture trade polices," said Tim Lobstein, director of policy for the International Association for the Study of Obesity. "HFCS will join trans fats and salt as ingredients to avoid, and foods should carry warning labels."