RE: Consumption of added sugars and indicators of cardiovascular disease risk among US adolescents.
To the Editor:
A recent paper by Welsh et al.1 claims an association between consumption of added sugars and cardiovascular disease (CVD) risk factors among U.S. adolescents. The significance of the association is in doubt, however, given the failure of the authors to substantiate that added sugars are specific risk factors in CVD, or that added sugars intakes and CVD risk factors are both increasing among adolescents.
First, proffered evidence that added sugars uniquely and adversely affect CVD risk factors in real-world diets is unconvincing. The cited example from Teff et al. (author reference 13) featured fructose exposures twice those quoted by the authors for adolescents, and fructose was tested in isolation (i.e., in the absence of ever-present glucose). Indeed, the authors’ own data in Table 2 are unable to show a dose-response effect for added sugars in either normal weight or overweight adolescents. And it should be noted nearly all the CVD risk indicators in Table 2 – even those with relatively high added sugars intakes – fall within normal/desirable population ranges.2
Second, the authors offer as evidence that adolescents are consuming increasing amounts of added sugars only a single, outdated snapshot from 1994-1996. In fact, USDA-ERS disappearance data demonstrate quite convincingly that added sugars in general – and fructose and high fructose corn syrup in particular – have been in decline since 1999.3 And the authors’ assertion that fat consumption has decreased in recent decades is simply incorrect. USDA-ERS data again clearly demonstrate that per capita intake of added sugars has increased 58 kcal/d since 1970, while that of added fats has increased four times as much (231 kcal/d).4,5
And third, deficiencies in the authors’ methodology are substantial and should not be lightly dismissed: reliance on a single 24-h dietary recall assessment conducted nearly a decade ago, now long-outdated; use of an unvalidated database to estimate added sugar content; and use of unvalidated methods for assessing important covariates like exercise.
In conclusion, unproven claims that adolescents are consuming increasing amounts of added sugars, and inability to show meaningful and dose-dependent changes in CVD risk factors cast doubt on the authors’ claim of an association between added sugars and CVD risk factors in adolescents.