EVIDENCE-BASED ANSWER
Migraine frequency, duration, and severity are not increased by dietary choices (strength of recommendation [SOR]: A, individual randomized trial [RCT]); they can be decreased by a low-fat diet (SOR: B). Regular supplementation with high-dose riboflavin or magnesium reduces frequency and intensity of migraines (SOR: B, single RCT).
CLINICAL COMMENTARY
Have patients keep a migraine diary; experiment with dietary/activity modifications
Jennifer Hoock, MD
University of Washington, Seattle
Interestingly, this review of the literature seems to both disavow commonly accepted beliefs about migraine triggers and suggest new dietary interventions. In my experience, foods like chocolate, cheese, and citrus are rarely reported by patients as migraine triggers. Alcohol is reported as a trigger, though the possibility that it is a cofactor with stress and fatigue seems plausible. Certainly patients perceive that various foods and activities trigger their migraines. It is possible that no universal food triggers exist, but that persons have individual triggers. In the end, I think the practical approach remains to have patients keep a diary of the events surrounding their migraines, identify patterns and experiment with dietary and activity modifications. An empiric trial of magnesium or riboflavin certainly seems worth consideration, as does a recommendation for a healthy low-fat diet that incorporates omega-3 fatty acids/olive oil. Migraine treatment remains a process of educated trial and error to find the optimal combination of lifestyle modifications and medications.
Evidence summary
Contrary to what many physicians learned from their mentors—and to what many patients believe—no food or food additive has been proven to cause migraine headaches; and in fact, good evidence disproves this notion. The primary foods once thought to trigger migraines were cheese, alcohol, chocolate and citrus fruit.1 Conversely, it appears that regular supplementation with some nutrients reduces the frequency and intensity of migraines (TABLE 1).
Vasoactive amines. Vasoactive amines (ie, tyramine and phenylethylamine) are present in aged cheese and red wine. One randomized trial of 80 patients with frequent migraines showed that tyramine and placebo induced migraine at the same rate.2 A systematic review on the relation of vasoactive amines to migraine found no evidence that any biogenic amines in red wine, cheese, or chocolate cause migraine.3 Furthermore, an uncontrolled prospective trial failed to show that amount or type of alcohol correlates with migraines, but it did find a correlation between stressful events and migraines. These stressful events also correlated with a higher alcohol intake.4 One final small randomized controlled trial enrolling children found no difference in migraine frequency between high fiber/high vasoactive amine and a high fiber/low vasoactive amine diet.5 In contrast to these RCTs, one series of lower-evidence-level patient surveys from a tertiary clinic reported that approximately 12% to 28% of patients perceived migraines were triggered by various foods (ie, cheese, wine, beer, chocolate).6
Chocolate. The role of chocolate in instigating headache was investigated in a 63-subject double-blind RCT comparing chocolate with carob. Chocolate was not more likely to provoke headache than carob in any of the headache diagnostic groups (P=.83). These results were independent of subjects’ beliefs regarding the role of chocolate in the instigation of headache (P=.39). Unfortunately, this trial included multiple headache types, with only 50% being migraine.7
Omega-3 fatty acids. A small double-blind crossover study of 27 adolescents over 5 months showed no difference between fish oil supplementation and “placebo supplementation” with olive oil. The dose of fish oil used is approximately equivalent to 1.5 g of the recently approved Omacor fish oil capsules. Interestingly, the subjects reported dramatic decreases in headache frequency (15 per month down to 2 episodes per month) and decreases in headache severity (reduction from 5 to 3 on a 7-point Likert scale) with both compounds.8 The possibility of olive oil being an active comparator muddles interpretation of the results.
Riboflavin. A good-quality RCT compared riboflavin 400 mg/d with placebo for prophylaxis of migraines.9 Using intention-to-treat analysis, riboflavin was superior to placebo in reducing attack frequency (P=.005) and headache days (P=.012). The proportion of patients who improved by at least 50% was 15% for placebo and 59% for riboflavin (P=.002). The number needed to treat (NNT) was 2.3. Adverse events were very rare—1 case of diarrhea was reported causing withdrawal (number needed to harm [NNH]=33.3). The effect of riboflavin on migraine began at 1 month but was maximal at 3 months, when this study ended. The most pronounced effect was shorter migraine attacks followed by fewer migraine attacks. An additional large case series found that high-dose riboflavin reduced headache days by 50% (P<.05) and use of abortive medicines by 36% (P<.05).10