Higher intake of added sugars associated with higher CVD risk

Higher intake of free sugars was linked to a higher risk for CVD, and substituting them with non-free sugars was inversely associated with both total CVD and stroke incidence, a recent study showed.

Free sugars are added sugars and sugars naturally present in unsweetened fruit juice, syrups and honey, according to Rebecca K. Kelly, PhD, RD, an assistant professor and director of health enhancement planning at the University of Alabama, and colleagues.

Writing in BMC Medicine, Kelly and colleagues noted that recent research has indicated associations between CVD and dietary carbohydrates might have more to do with the quality of carbohydrates consumed rather than the quantity.

The researchers conducted a prospective cohort study to examine the links between CVD incidence and dietary carbohydrates. They evaluated data from 110,497 U.K. Biobank participants who had at least two 24-hour dietary assessments and did not have CVD or diabetes at baseline. They then used multivariable-adjusted Cox regressions to estimate risks for incident total CVD, stroke and ischemic heart disease (IHD) by carbohydrate intake over a follow-up time of about 9.4 years.

Kelly and colleagues found that while carbohydrate intake was not linked to CVD outcomes, consumption of free sugar was positively associated with:

• total CVD (HR = 1.07; 95% CI, 1.03-1.1);
• IHD (HR = 1.06; 95% CI, 1.02-1.1); and
• stroke (HR = 1.1; 95% CI, 1.04-1.17).

They also found that free sugars were positively linked to higher triglyceride concentrations within lipoproteins. However, substituting free sugars with non-free sugars was inversely associated with both total CVD (HR = 0.95; 95% CI, 0.92-0.98) and stroke (HR = 0.91; 95% CI, 0.86-0.97).

“Free sugars were most strongly associated with total stroke risk in our whole cohort analyses; however, a majority of participants were women,” the researchers wrote. “Although we observed no significant heterogeneity by sex in our subgroup analyses, we found that risk estimates for free sugars and total stroke tended to be larger for women (HR = 1.15; 95% CI, 1.05–1.26) compared with men (HR = 1.06; 95% CI, 0.98–1.16).”

Fiber consumption was also inversely associated with total CVD (HR = 0.96; 95% CI, 0.93–0.99).

“Meta-analyses of RCTs have found that higher fiber intake lowers body weight and serum LDL cholesterol concentrations, which may partly explain the beneficial associations observed for each 5 g/d higher fire intake in this study,” the researchers wrote. “Moreover, highest consumers of fiber in our study had lower mean BMI, waist circumference, and LDL cholesterol.”

Kelly and colleagues also examined the effects of modeled dietary substitutions. They found that substituting 5% energy from refined grain starch with 5% energy from whole grain starch was inversely associated with risks for total CVD (HR = 0.94; 95% CI, 0.91-0.98) and IHD (HR = 0.94; 95% CI, 0.9-0.98). In addition, substituting 5% energy from free sugars with 5% energy from non-free sugars was linked to lower risks for total CVD (HR = 0.95; 95% CI, 0.92-0.98) and total stroke (HR = 0.91; 95% CI, 0.86-0.97).

“Our findings support the importance of the type and source of carbohydrate consumed for cardiovascular health,” the researchers wrote.