Diet Indices Reflecting Changes to Dietary Guidelines for Americans from 1990 to 2015 Are More Strongly Associated with Risk of Coronary Artery Disease Than the 1990 Diet Index

BACKGROUND: The Dietary Guidelines for Americans (DGAs) provide dietary recommendations for the general population with the intent of preventing chronic disease such as cardiovascular disease. An evaluation of whether updated versions of the DGAs accomplish this goal is lacking. OBJECTIVE: The objective of this project was to determine whether updates to DGAs over time, reflected in subsequent versions of diet quality indices, strengthened the associations between diet quality and risk of cardiovascular disease outcomes. METHODS: Dietary data collected using an FFQ in the Framingham Heart Study Offspring cohort were used to assess adherence to sequential versions of the Healthy Eating Index (HEI) (1990, 2005, 2010, and 2015) and Alternative HEI (2000 and 2010) (n = 3267). We conducted prospective analyses using Cox regression to estimate the associations between diet indices and incident cardiovascular disease outcomes. RESULTS: Among the 3267 study participants, 54% were female, mean age was 55 y, and BMI was 27 kg/m(2). There were a total of 544 events for the composite outcome of cardiovascular diseases (324 coronary artery disease events, 153 stroke events, and 187 heart failure events). Adherence to any dietary index was inversely associated with risk of cardiovascular disease, coronary artery disease, and heart failure, but not stroke. Compared with HEI-1990, scores for the more recent diet indices were more strongly associated with coronary artery disease risk, but not cardiovascular disease, heart failure, or stroke. CONCLUSIONS: More recent iterations of diet indices, reflecting updates to the DGAs over time, are more strongly associated with risk of incident coronary artery disease than the original diet index (HEI-1990).