Adherence to Mediterranean-Style Dietary Pattern and Risk of Esophageal Squamous Cell Carcinoma: A Case-Control Study in Iran

Objective: The benefit of adherence to a Mediterranean-style dietary pattern in relation to the risk of esophageal squamous cell carcinoma (ESCC) has not been investigated among non-Mediterranean high-risk populations. The objective of the present study was to examine the association of compliance with the Mediterranean dietary pattern as measured by Mediterranean-Style Dietary Pattern Score (MSDPS) and the risk of ESCC in Iranian population. Methods: This case-control study was conducted on 47 ESCC cases and 96 hospital controls aged 40-75 years. Participants were interviewed using validated questionnaires, and dietary patterns were characterized using the MSDPS. Results: Generally, the mean MSDPS in this population was low (30.84 +/- 8.58). MSDPS showed content validity through having expected positive associations with several lifestyle characteristics and dietary intakes. Being in the highest quartile category of MSDPS, compared to the lowest, was independently associated with 37% reduction in risk of ESCC. Two-unit and 3-unit increases in the MSDPS resulted in 41% and 47% reduction in risk of ESCC, respectively. Higher intakes of olive oil (odds ratio [OR] = 0.15, 95% CI: 0.01-0.49), fish and other seafood (OR = 0.48, 95% CI: 0.23-0.98), whole grain (OR = 0.57, 95% CI: 0.28-0.76), and fruits (OR = 0.77, 95% CI: 0.38-0.86) were significantly associated with reduced ESCC risk. In contrast, higher sweet (OR = 1.86, 95% CI: 1.04-2.12) and meat intakes (OR = 1.61, 95% CI: 1.25-2.49) were associated with higher ESCC risk. Conclusion: Consuming a diet in concordance with the principles of the Mediterranean dietary pattern may protect against ESCC. Preventive strategies to reduce ESCC risk in high-risk countries should focus on overall dietary pattern and dietary habits to be effective.