Associations between Two Dietary Quality Scores and Pancreatic Cancer Risk in a US National Prospective Cohort Study

ObjectiveMost previous studies investigated the associations between intake of individual nutrients and risk of disease, which failed to consider the potential interactions and correlations between various nutrients contained in food. Although dietary quality scores provide a comprehensive evaluation of the entire diet, it remains elusive whether they are associated with the risk of pancreatic cancer.MethodsDietary intake data collected with the Dietary Questionnaire (DQX) and Diet History Questionnaire (DHQ) were used to calculate HEI-2015 and DQI-R scores for participants in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. A high score indicates an increased intake of adequacy components and a decreased intake of moderation components. This study included 252 cases of pancreatic cancer documented from 58,477 persons during a median follow-up of 12.2 years in the DQX cohort and 372 cases of pancreatic cancer ascertained from 101,721 persons during a median follow-up of 8.9 years in the DHQ cohort. Cox proportional hazards regression analysis was performed to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the associations between the two dietary quality scores and pancreatic cancer risk.ResultsAfter adjustment for confounders, HEI-2015 and DQI-R scores were not significantly associated with pancreatic cancer risk. However, a significantly lower risk was observed for overweight persons with a higher HEI-2015 score in the DQX cohort (HR [95% CI] comparing the highest with lowest tertile: 0.52 [0.32, 0.85], p for trend = 0.009) and those with higher scores of some individual components.ConclusionCollectively, overall dietary quality is not associated with an altered risk of pancreatic cancer in this US population. Previous studies evaluating the roles of individual nutrients in the etiology of pancreatic cancer fails to consider the potential interactions and correlations between various nutrients contained in food. We investigated the associations between overall dietary quality scores (HEI-2015 and DQI-R) and pancreatic cancer risk in a large prospective cohort study. The findings of this study can help inform a novel and practical approach to primary prevention of this deadly disease through dietary modification and intervention.