Background

The goal of this systematic review was to determine whether intake of added sugars is associated with risk of cardiovascular disease (CVD). Added sugars were defined as sugars that are either added during the processing of foods, or are packaged as such, and include sugars (free, monosaccharides, and disaccharides), syrups, naturally occurring sugars that are isolated from a whole food and concentrated so that sugar is the primary component (e.g., fruit juice concentrates) and other caloric sweeteners.

Conclusion Statement 

Moderate evidence from prospective cohort studies indicates that higher intake of added sugars, especially in the form of sugar-sweetened beverages, is consistently associated with increased risk of hypertension, stroke, and coronary heart disease (CHD) in adults. Observational and intervention studies indicate a consistent relationship between higher added sugars intake and higher blood pressure and serum triglycerides.

2015 DGAC Grade: Moderate

Methods

Literature searches were conducted using PubMed, Embase, Navigator (BIOSIS, CAB Abstracts and Food Science and Technology Abstracts) and Cochrane databases to identify studies that evaluated the association between added sugars and risk of cardiovascular disease. Studies that met the following criteria were included in the review: randomized controlled trials (RCTs), non-randomized controlled trials, prospective cohort studies, or nested case-control studies; adults who were healthy or at elevated chronic disease risk; subjects from countries with high or very high human development (2012 Human Development Index); and published in English in peer-reviewed journals. The date range was from January 2000 to August 2014. The intervention or exposure was intake of added sugars and sugar-sweetened beverages, compared to different levels of intake of added sugars and sugar-sweetened beverages. The outcomes were cholesterol (low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC):HDL and LDL:HDL ratios), triglycerides, blood pressure and incidence of hypertension, incidence of myocardial infarction (MI), incidence of stroke, incidence of CHD, CVD-related mortality.

Data from each included article were extracted, and risk of bias was assessed. The evidence was qualitatively synthesized, a conclusion statement was developed and the strength of the evidence (grade) was assessed using pre-established criteria including evaluation of the quality and risk of bias, quantity, consistency, magnitude of effect and generalizability of available evidence.

Findings

• This NEL systematic review included 23 articles published since 2000 that examined the relationship between added sugars and risk of CVD or CVD risk factors such as blood lipids and blood pressure. This literature included 11 intervention studies and 12 prospective cohort studies.
• The majority of intervention and observational studies included in this systematic review provide some evidence among adults in support of an association between higher intake of added sugars, especially in the form of sugar-sweetened beverages, and higher risk of CVD or increased CVD risk factors:
  • More consistent associations were seen between added sugars and elevated serum triglycerides, blood pressure, and increased risk of hypertension, stroke, or CHD
  • Evidence for associations between added sugars and dyslipidemia (i.e., low HDL, high LDL and high TC) was not as consistent, especially among intervention studies.

Limitations

The ability to draw strong conclusions was limited by the following issues:

• The intervention studies had extensive heterogeneity in terms of the types and forms of sugars used (i.e., fructose, glucose, sucrose, sugar-sweetened beverages, sweetened milk) and the type of control and isocaloric condition used
• Most intervention studies had a short duration of the intervention and a small sample size
• Most of the observational studies assessed dietary intake only at baseline, and did not take assessments during follow-up
• Residual confounding by other dietary and lifestyle factors in observational analyses could not be completely ruled out.