Changes in Diet Quality Scores and Risk of Cardiovascular Disease Among US Men and Women

BACKGROUND: Adherence to several diet quality scores, including the Alternative Healthy Eating Index, Alternative Mediterranean Diet score, and Dietary Approach to Stop Hypertension, has been associated with lower risk of cardiovascular disease (CVD), but little is known about how changes in these scores over time influence subsequent CVD risk. METHODS AND RESULTS: We analyzed the association between 4-year changes in the 3 diet quality scores (Alternative Healthy Eating Index, Alternative Mediterranean Diet score, and Dietary Approach to Stop Hypertension) and subsequent cardiovascular disease (CVD) risk among 29 343 men in the Health Professionals Follow-up Study and 51 195 women in the Nurses' Health Study (1986-2010). During 1 394 702 person-years of follow-up, we documented 11 793 CVD cases. Compared with participants whose diet quality remained relatively stable in each 4-year period, those with the greatest improvement in diet quality scores had a 7% to 8% lower CVD risk in the subsequent 4-year period (pooled hazard ratio, 0.92 95% confidence interval (CI), 0.87-0.99 for the Alternative Healthy Eating Index; 0.93 95% CI, 0.85-1.02 for the Alternative Mediterranean Diet score; and 0.93 95% CI, 0.87-0.99 for the Dietary Approach to Stop Hypertension; all P for trend <0.05). In the long term, increasing the diet scores from baseline to the first 4-year follow-up was associated with lower CVD risk during the next 20 years (7% 95% CI, 1-12 for the Alternative Healthy Eating Index, and 9% 95% CI, 3-14 for the Alternative Mediterranean Diet score). A decrease in diet quality scores was associated with significantly elevated risk of CVD in subsequent time periods. CONCLUSIONS: Improving adherence to diet quality scores over time is associated with significantly lower CVD risk in both the short term and long term.