From JAMA Internal Medicine, “Added Sugar Intake and Cardiovascular Diseases Mortality Among US Adults“:
Importance Epidemiologic studies have suggested that higher intake of added sugar is associated with cardiovascular disease (CVD) risk factors. Few prospective studies have examined the association of added sugar intake with CVD mortality.
Objective To examine time trends of added sugar consumption as percentage of daily calories in the United States and investigate the association of this consumption with CVD mortality.
Design, Setting, and Participants National Health and Nutrition Examination Survey (NHANES, 1988-1994 [III], 1999-2004, and 2005-2010 [n = 31 147]) for the time trend analysis and NHANES III Linked Mortality cohort (1988-2006 [n = 11 733]), a prospective cohort of a nationally representative sample of US adults for the association study.
Main Outcomes and Measures Cardiovascular disease mortality.
NHANES is an enormous longitudinal cohort. In other words, it allows us to follow a lot of people over time to see how risk factors affect their health. In this case, researchers wanted to see how sugar intake affected the chance of dying from cardiovascular reasons.
They followed people for a median 14.6 years (163,039 person-years), and over that time, 831 people suffered from CVD deaths. After controlling for the usual stuff including socio-demographic factors, the hazard ratios of CVD mortality went from 1.00 (bottom 20% of sugar eaters and reference), to 1.07 in the second quintile, 1.18 in the third quintile, 1.38 in the fourth quintile), to 2.03 in the highest quintile.
An accompanying editorial made the point pretty well:
Yang et al inform this debate by showing that the risk of CVD mortality becomes elevated once added sugar intake surpasses 15% of daily calories—equivalent to drinking one 20-ounce Mountain Dew soda in a 2000-calorie daily diet. From there, the risk rises exponentially as a function of increased sugar intake, peaking with a 4-fold increased risk of CVD death for individuals who consume one-third or more of daily calories in added sugar. These findings provide physicians and consumers with actionable guidance. Until federal guidelines are forthcoming, physicians may want to caution patients that, to support cardiovascular health, it is safest to consume less than 15% of their daily calories as added sugar.