Plain language summary
Pancreatic cancer has the highest mortality rate amongst gastro-intestinal cancers and evidence suggests that diet plays a pivotal role in the aetiology of the disease. Chronic inflammation is often present with cancers however it is not known if inflammation has a causal role or is simply part of the body’s natural response mechanism. This 2015 case control study evaluated food frequency questionnaire (FFQ) data from 326 incident cases and 652 controls and indexed foods based on their inflammatory status using a global database derived from previous studies: the dietary inflammatory index (DII). The DII ranks foods against forty-five nutrient parameters to generate an overall score. The higher DII scores reflect a greater pro-inflammatory potential of the diet. Food parameters measured included: carbohydrate; protein; fat; alcohol; fibre; cholesterol; SFA; MUFA; PUFA; n -3; n -6; niacin; thiamin; riboflavin; vitamin B6; Fe; Zn; vitamin A; vitamin C; vitamin D; vitamin E; folic acid; β-carotene; anthocyanidins; flavan-3-ol; flavonol; flavonones; flavones; isoflavones; caffeine and tea. The DII is designed to consider all pro-inflammatory foods (such as red meat) and all anti-inflammatory foods (such as fruits and vegetables) to represent the potential inflammatory effect of diet as a whole. After adjustments for sex, age and other lifestyle factors the results showed that subjects with higher DII scores (i.e. representing a more pro-inflammatory diet) had a higher risk of developing pancreatic cancer.
Abstract
Previous studies have shown that various dietary components may be implicated in the aetiology of pancreatic cancer. However, the possible relationship between diet-related inflammation and the risk of pancreatic cancer has not yet been investigated. We examined the ability of a newly developed literature-derived dietary inflammatory index (DII) to predict the risk of pancreatic cancer in a case-control study conducted in Italy between 1991 and 2008. This included 326 incident cases and 652 controls admitted to the major teaching and general hospitals for non-neoplastic diseases, frequency-matched to cases by study centre, sex and age. The DII was computed based on dietary intake assessed using a validated and reproducible seventy-eight-item FFQ. Logistic regression models were used to estimate multivariable OR adjusted for age, sex, study centre, education, BMI, smoking status, alcohol drinking and history of diabetes. Energy adjustment was performed using the residual method. Subjects with higher DII scores (i.e., representing a more pro-inflammatory diet) had a higher risk of pancreatic cancer, with the DII being used as both a continuous variable (ORcontinuous 1.24, 95% CI 1.11, 1.38) and a categorical variable (i.e., compared with the subjects in the lowest quintile of the DII, those in the second, third, fourth and fifth quintiles had, respectively, OR(quintile2 v. 1) 1.70, 95% CI 1.02, 2.80; OR(quintile3 v. 1) 1.91, 95% CI 1.16, 3.16; OR(quintile4 v. 1) 1.98, 95% CI 1.20, 3.27; OR(quintile5 v. 1) 2.48, 95% CI 1.50, 4.10; P trend= 0.0015). These data suggest that a pro-inflammatory diet increases the risk of pancreatic cancer.
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