Higher consumption of dietary added sugars associated with unfavourable lipid levels

Consuming a higher amount of added sugars in processed or prepared foods is associated with lower levels of high-density lipoprotein cholesterol (HDL-C, the 'good cholesterol') and higher levels of triglycerides, which are important risk factors for cardiovascular disease, according to a study in the April 21 issue of JAMA.

'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. No known studies have examined the association between the consumption of added sugars and lipid measures, such as HDL-C, triglycerides and low-density lipoprotein cholesterol (LDL-C).

Jean A. Welsh, M.P.H., R.N., of Emory University, Atlanta, and colleagues 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.

The researchers found that daily consumption of added sugars averaged 3.2 ounces (21.4 tsp., 359 calories), which represents 15.8 percent of total daily caloric intake. 'This represents a substantial increase from 1977-1978, when added sugars contributed only 10.6 percent of the calories consumed by adults,' the authors write.

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 consuming 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).

The researchers also found that higher consumption of added sugars was associated with higher triglyceride levels and higher ratios of triglycerides to HDL-C.

'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 recognised by consumers and have been proposed for specific labelling 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.'

'Although long-term trials to study the effect of reducing added sugars and other carbohydrates on lipid profiles are needed, our data support dietary guidelines that target a reduction in consumption of added sugar.'