Study population characteristics
The baseline characteristics of the participants among quartiles of MIND diet are shown in Table 2. The mean (±SD) age, height, weight, BMI and physical activity of participants were 34.32 (7.86) years, 1.61 (0.05) m, 69.41 (13.02) kg, 26.50 (4.88) kg/m2, 407.73 (519.13) MET/Min/week, respectively. Quantitative and qualitative variables across MIND diet quartiles did not show any significant differences. The percentages of study population among the MIND diet quartiles were: Q1 25.9, Q2 25.9, Q3 26.3, and Q4 21.8%.
Dietary intake and MIND diet quartiles
Dietary intakes of the participants among MIND diet quartiles are presented in Table 3. Participants in the highest quartile of MIND diet had higher consumption of vegetables, legumes and nut, while had lower intake of refined grain and energy intake compared to the lowest quartile of MIND diet score. However, the consumption of fruits, dairy, whole grain, meat, and water intake across quartiles of MIND diet did not show any significant differences.
MIND diet and migraine headache
The association between duration, frequency, severity and disability of migraine headache across quartiles of MIND diet in crude model and adjusted model are shown in Table S1. In the crude model of multinomial logistic regression, greatest adherence to the MIND diet did not show a significant relation with severity of disability based on MIDAS score (OR= 0.97; 95% CI: 0.68, 1.37; P= 0.87). Even after adjustment for potential confounding factors including energy intake, age, BMI, PA, smoking status, water intake, salt intake, menstruation headaches, and medication usage, no association was observed (OR= 0.89; 95% CI: 0.54, 1.47; P= 0.67). A significant inverse association was observed between MIND diet score and odds of severe headaches in crude model (OR= 0.70; 95% CI: 0.50, 0.97; P= 0.03). After adjustment for the potential confounding factors, individuals in the highest quartile of MIND diet were 33% less likely to have severe headaches (OR= 0.67; 95% CI: 0.43, 0.94; P= 0.01) compared with those in the lowest quartile.
Linear Regression Models analysis (LRM) showed an inverse association between MIND diet score and duration of migraine headaches in crude (β= -0.17, 95% CI: -1.54, -0.29 P= 0.004), and adjusted models (β= -0.15, 95% CI: -1.44, -0.11, P=0.02). Moreover, frequency of headaches indicated an indirect correlation with MIND diet score in crude model (β= -0.14, 95% CI: -1.03, -0.08, P=0.02), and adjusted model (β= -0.12, 95% CI: -0.96, -0.02, P= 0.04).