Daily consumption of added sugars in the U.S. averages 3.2 ounces (15.8 percent of daily caloric intake) and has increased substantially since 1977-1978, when added sugars contributed only 10.6 percent of the calories consumed by adults, according to a new study in JAMA.

The study also points out that consuming higher amounts of added sugars is associated with lower levels of high-density lipoprotein cholesterol and higher levels of triglycerides, which are important risk factors for cardiovascular disease.

"In the United States, total consumption of sugar has increased substantially in recent decades, largely owing to an increased intake of 'added sugars,' defined as caloric sweeteners used by the food industry and consumers as ingredients in processed or prepared foods to increase the desirability of these foods," the authors write.

Researchers assessed the association between consumption of added sugars and blood lipid levels in U.S. adults. The study included 6,113 adults from the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Respondents were grouped by intake of added sugars using limits specified in dietary recommendations (less than 5 percent of total calories [reference group], 5 percent to less than 10 percent, 10 percent to less than 17.5 percent, 17.5 percent to less than 25 percent, and 25 percent or more of total calories).

Various measures calculated in the study included average HDL-C, average triglycerides, and average LDL-C levels and adjusted odds ratios of dyslipidemia (abnormal amounts of lipids and lipoproteins in the blood), including low HDL-C levels (less than 40 mg/dL for men; less than 50 mg/dL for women), high triglyceride levels (150 mg/dL or greater), high LDL-C levels (130 mg/dL or greater), or high ratio of triglycerides to HDL-C (greater than 3.8). Results were weighted to be representative of the U.S. population.

Adjusted average HDL-C levels were lower among respondents consuming higher amounts of added sugars: 58.7 mg/dL among those consuming less than 5 percent energy from added sugars, 57.5 mg/dL among those consuming 5 percent to less than 10 percent, 53.7 mg/dL among those con¬suming 10 percent to less than 17.5 percent, 51.0 mg/dL among those consuming 17.5 percent to less than 25 percent, and 47.7 mg/dL among those consuming 25 percent or greater.

 Among higher consumers (10 percent or greater added sugars) the odds of low HDL-C levels were 50 percent to more than 300 percent greater compared with the reference group (less than 5 percent added sugars).

"Monitoring trends in consumption and understanding the effect added sugars have on risk of cardiovascular and other diseases is critically important, because added sugars are a potentially modifiable source of calories," the authors write.

"Added sugars are food additives that can be recognized by consumers and have been proposed for specific labeling on food and beverage packaging. The results of our study demonstrate that increased added sugars are associated with important cardiovascular disease risk factors, including lower HDL-C levels, higher triglyceride levels, and higher ratios of triglycerides to HDL-C."

The authors note, however, that the scope of their study is limited. The cross-sectional design used for the research means that "exposures and outcomes [were] measured at the same time" and, as a result, their data  cannot be used to establish causality.

Citation: Welsh et al., 'Caloric Sweetener Consumption and Dyslipidemia Among US Adults', JAMA, April 2010, 303(15)