Healthy young adults who consumed drinks sweetened with high-fructose corn syrup for just two weeks showed increases in three key risk factors for cardiovascular disease.
The results from a recent study are the first to demonstrate a direct, dose-dependent relationship between the amount of added sugar consumed in sweetened beverages and increases in specific risk factors for cardiovascular disease.
The findings reinforce evidence from an earlier epidemiological study that showed the risk of death from cardiovascular disease—the leading cause of death in the United States and around the world—increases as the amount of added sugar consumed increases.
“These findings clearly indicate that humans are acutely sensitive to the harmful effects of excess dietary sugar over a broad range of consumption levels,” said Kimber Stanhope, a research scientist at the University of California–Davis, School of Veterinary Medicine.
Even a Little May Be Too Much
For the study, published online in the American Journal of Clinical Nutrition, 85 participants, including men and women ranging in age from 18 to 40 years, were placed in four different groups.
During 15 days of the study, they consumed beverages sweetened with high-fructose corn syrup equivalent to zero percent, 10 percent, 17.5 percent, or 25 percent of their total daily calorie requirements.
The zero percent control group was given a sugar-free beverage sweetened with aspartame, an artificial sweetener.
At the beginning and end of the study, researchers used hourly blood draws to monitor the changes in the levels of lipoproteins, triglycerides, and uric acid—all known to be indicators of cardiovascular disease risk.
These risk factors increased as the dose of high-fructose corn syrup increased. Even the participants who consumed the 10 percent dose exhibited increased circulating concentrations of low-density lipoprotein cholesterol and triglyceride compared with their concentrations at the beginning of the study.
The researchers also found that most of the increases in lipid/lipoprotein risk factors for cardiovascular disease were greater in men than in women and were independent of body weight gain.
The findings underscore the need to extend the research using carefully controlled dietary intervention studies, aimed at determining what would be prudent levels for added sugar consumption, Stanhope said.
The National Institutes of Health, the National Center for Research Resources, the Roadmap for Medical Research, the National Institute of Child Health and Human Development, the National Institute of Aging, and the U.S. Department of Agriculture funded the work.