Adherence to five diet quality indices and pancreatic cancer risk in a large US prospective cohort

Few prospective studies have examined associations between diet quality and pancreatic ductal adenocarcinoma (PDAC), or comprehensively compared diet quality indices. We conducted a prospective analysis of adherence to the Healthy Eating Index (HEI)-2015, alternative HEI-2010 (AHEI-2010), alternate Mediterranean diet (aMED), and two Dietary Approaches to Stop Hypertension (DASH, Fung and Mellen) indices and PDAC within the National Institutes of Health (NIH)-AARP Diet and Health Study (United States, 1995-2011). The dietary quality indices were calculated using responses from a 124-item food frequency questionnaire completed by 535,824 (315,780 men and 220,044 women) participants. We used Cox proportional hazard regression models to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each diet quality index and PDAC. During follow-up through 2011 (15.5-year median), 3,137 incident PDAC cases were identified. Compared to those with the lowest adherence quintiles (Q1), participants with the highest adherence (Q5) [HRs (95% CIs)] to the HEI-2015 [0.84 (0.75, 0.94)], aMED [0.82 (0.73, 0.93)], DASH-Fung [0.85 (0.77, 0.95)], and DASH-Mellen [0.86 (0.77, 0.96)] had a statistically significant lower PDAC risk but not the AHEI-2010 [0.93 (0.83, 1.04)]. This prospective observational study supports the hypothesis that greater adherence to the HEI-2015, aMED, and DASH dietary recommendations may reduce PDAC