Association between inflammatory potential of diet and self-reported severe headache or migraine: A cross-sectional study of the National Health and Nutrition Examination Survey

Inflammation plays an important role in migraine development. Dietary interventions that reduce the inflammatory state are effective for migraine prophylaxis. However, little is yet known about the association between the inflammatory potential of diet and migraine in the general US adult population. The aim of this study was to evaluate whether the inflammatory potential of diet is associated with severe headache or migraine in US adults.This cross-sectional study analyzed data from adult participants in the 1999-2004 National Health and Nutrition Examination Survey. Severe headache or migraine was determined based on self-reported information. Severe headache or migraine was defined as an affirmative response to the question: "Have you had a severe headache or migraine in the past 3 mo?" The dietary inflammatory index (DII) was used to assess the inflammatory potential of the diet. Multivariable logistic regression models were used to determine the odds ratio (OR) and 95 % confidence interval (95% CI) for the association between DII and severe headache or migraine. A multivariable-adjusted restricted cubic spline model was constructed to establish the OR curves at 3 knots to examine the possible non-linear dose-response association between DII and severe headache or migraine.Of 10359 participants included in this study (mean age, 46.3 [0.3] y; 5116 [49%] men), 2083 (22%) reported previous episodes of severe headache or migraine, whereas 8276 (78%) did not. After adjusting for potential confounders, the DII score was associated with severe headache or migraine (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.03-1.15; P = 0.003). Compared with participants with the lowest tertile (T1) of DII score (i.e., T1; ≤-4.42 to ≤0.77), those with the highest tertile (i.e., T3; <2.44 to ≤5.18) had an adjusted OR for severe headache or migraine of 1.46 (95% CI, 1.20-1.77; P < 0.001). The multivariable restricted cubic spline showed a non-linear association between DII and severe headache or migraine (P = 0.012). In two piecewise regression models, the adjusted OR of developing a severe headache or migraine was 1.19 (95% CI, 1.04-1.37; P = 0.012) in participants with a DII score ≥1.48, whereas there was no association between DII and severe headache or migraine in participants with a DII score <1.48. Subgroup analyses showed that DII was associated with severe headache or migraine in women (OR, 1.73; 95% CI, 1.31-2.28), individuals 20 to 50 y of age (OR, 1.66; 95% CI, 1.29-2.14), those who were married or living with a partner (OR, 1.49; 95% CI, 1.19-1.85), individuals living alone (OR, 1.36; 95% CI, 1.02-1.81), those with a high level of education (OR, 1.72; 95% CI, 1.26-2.36), individuals with a low family income (OR, 1.58; 95% CI, 1.10-2.28), those with a medium or high family income (OR, 1.48; 95% CI, 1.17-1.86), and body mass index <25 kg/m2 (OR, 1.71; 95% CI, 1.21-2.41).The inflammatory potential of the diet is associated with severe headache or migraine in US adults.