Background: Chronic inflammation is implicated in pancreatic cancer, and can be modulated by diet and other lifestyle factors. We examined the association between Dietary Inflammatory Index (DII) scores and pancreatic cancer risk in the NIH-AARP Diet and Health Study, and examined effect modification by inflammation-related lifestyle factors, including body mass index, cigarette smoking, diabetes, alcohol drinking, and use of non-steroidal anti-inflammatory drugs.
Methods: Energy-adjusted DII scores (E-DII) were computed on the basis of food frequency questionnaire responses for foods and dietary supplements. Cox proportional hazards models were fitted and effect modification was examined by adding a cross-product of each effect modifier with E-DII quintile in the multivariable-adjusted model.
Results: There were 2,824 primary incident pancreatic cancers diagnosed during a median of 13.4 years follow-up, and there was no association between E-DII scores and pancreatic cancer risk among either men [HRQ5vsQ1, 1.00; 95% confidence interval (CI), 0.86-1.16] or women (HRQ5vsQ1, 1.00; 95% CI, 0.82-1.21) in the multivariable-adjusted model, and no association was detected by any cancer stage. The E-DII and pancreatic cancer association was not modified by any of the inflammation-related lifestyle factors examined.
Conclusions: Results from this large prospective study did not support an association between inflammatory potential of diet and pancreatic cancer, or effect modification by other inflammation-related lifestyle factors.
Impact: Inflammatory potential of diet may not be related to pancreatic cancer risk. Future cohort studies with more frequent dietary measures could be useful in determining the appropriate timing of dietary intake in relation to pancreatic cancer etiology.
©2019 American Association for Cancer Research.