Inflammatory Potential of Diet and Odds of Lung Cancer: A Case-Control Study

Lung cancer is one of the common types of malignant disorders and the most prevalent cause of cancer mortality worldwide. Few studies have examined the association of dietary inflammatory index (DII) with lung cancer and findings from these studies are conflicting. Moreover, no study has examined this association in the Middle East. Therefore, the current case-control study was conducted to examine the association between DII and lung cancer among Iranian adults. We recruited 140 pathologically confirmed cases of lung cancer and 140 healthy controls who were matched with cases in terms of age. Dietary intakes were assessed using a 142-item Willett-format dish-based semi-quantitative food frequency questionnaire. DII scores were calculated using the method developed by Shivappa et al. Overall, we found a significant positive association between DII and lung cancer so that after controlling for potential confounders, individuals in the highest tertile of DII scores had 2.03 times more odds of lung cancer compared to those in the lowest tertile (OR: 2.01; 95% CI: 1.02-4.01). This significant positive association was also seen in men, but not in women. In conclusion, adherence to a pro-inflammatory diet was associated with increased odds of lung cancer in adults, particularly in male adults.