Patients with migraine who believe that chocolate could provoke their attacks were challenged with either chocolate or a closely matching placebo in a double-blind parallel group study at the Princess Margaret Migraine Clinic, Charing Cross Hospital, London, England. The placebo contained no cocoa butter or cocoa powder and the carob powder used in the placebo was also added to the chocolate and successfully disguised by the use of a peppermint-masking flavor. The two groups of patients, all adults, were matched for age and sex and all were drug-free for at least 48 hours prior to investigation. Chocolate ingestion (40 gram bar) was followed by a typical migraine episode in 5 out of 12 patients, while none of the 8 patients challenged with placebo had an attack (P=.051). The median time interval to onset of symptoms following chocolate consumption was 22 hours (range 3.5-27 hours). 
COMMENT. In a double-blind challenge study in children referred with severe headache, 82 of 99 patients responded to an oligoantigenic diet . Relapses occurred in 74 on the introduction of one or more food stuffs, with chocolate provoking attacks in 30%. Methyl-zanthine, theobromine and phenolic compounds including catechin are some pharmacologically active compounds found in relatively large amounts in chocolate. The relevant chemical agent responsible for initiating a migraine attack requires to be elucidated. My own clinical experience in children suggests that chocolate is a common precipitating factor in migraine susceptible patients. The effects of eliminating chocolate and caffeine containing drinks should be investigated before long-term drug treatment is considered.