Association between the dietary inflammatory index and chronic daily headache: findings from Dena Persian cohort

Purpose: While several studies have reported a relationship between chronic daily headache (CDH) and different dietary patterns, no study has investigated the association between CDH and the dietary inflammatory index (DII). This study aims to hypothesize that a higher DII score (proinflammatory diets) is associated with higher odds of CDH. Design/methodology/approach: This cross-sectional study was performed using the baseline data of the Dena PERSIAN cohort study, including demographic information, body mass index, medical history, laboratory tests, sleep duration and blood pressure. The DII was computed based on the data collected by a valid 113-item food frequency questionnaire and a 127-item indigenous food questionnaire. The association between CDH and DII score was analyzed by simple and multiple logistic regression. Findings: Out of 3,626 people included in the study, 23.1% had CDH. The median DII was −0.08 (interquartile range = 0.18). People in the third and fourth quartiles of DII (proinflammatory diet) had a 20% (odds ratio: 0.80; 95% confidence interval: 0.65–1) and a 25% (odds ratio: 0.75; 95% confidence interval: 0.61–0.94) lower chance of having CHD than those in the first quartile, respectively. After adjustment for confounding variables, this association did not remain statistically significant (p > 0.05). Originality/value: Although the analysis conducted without adjustment for medical history showed a significant association between proinflammatory diet and reduced CDH, considering the diverse etiology of different types of headaches and the paucity of studies in this area, further studies are needed to investigate the DII score of patients by the type of headache, its severity and duration.