The migraine group (n = 514, diagnosed according to the International Classification of Headache Disorders 3rd edition [ICHDIII] criteria) was recruited from a tertiary headache clinic. The controls consisted of 582 sex-matched healthy volunteers who were randomly selected from the general population. A validated 168-item semiquantitative food frequency questionnaire was used for dietary intake assessments. Estimation of the dietary acid load was performed using three different measures: potential renal acid load (PRAL) score, net endogenous acid production (NEAP) score, and protein/potassium ratio.
Multivariable logistic regression analysis showed that, in comparison with the lowest tertile, the highest tertile of dietary acid load measures, including PRAL (odds ratio [OR] 7.208, 95% confidence intervals [CI] 3.33-15.55), and NEAP (OR 4.108, 95% CI 1.924-8.774) scores and the protein/potassium ratio (OR 4.127, 95% CI 1.933-8.814), significantly increased the odds of migraine (P value for trend ≤ 0.001).
In this study, high dietary acid load was associated with higher odds of migraine. It is therefore possible that restricting dietary acid load could reduce the odds of migraine in susceptible subjects. However, due to the preliminary nature of the current evidence, caution is advised in drawing a definitive conclusion. More well-designed studies are required for a better understanding of this important issue.