Rationale, Issues, Substances, Evaluation,
and Patient Education
Many health care professionals believe, and many patients report, that certain dietary elements and patterns aggravate or trigger some physical or psychological symptoms. Professionals advise their patients to alter those dietary elements that they believe cause or aggravate those symptoms, many of which are symptoms treated with applied psychophysiological interventions (e.g., migraine headaches, anxiety, irritable bowel syndrome "IBS", insomnia). This chapter helps readers assess dietary factors in clinical practice. It emphasizes the relationship between diet and migraine because of the work in this area, although it does not exclude the other conditions just listed.
There are disagreements about the proposed links between diet and migraine headache, but there is research support for including dietary recommendations in clinical practice with some patients with migraine headaches. One reason for the disagreements is that the association between dietary factors and migraine headaches is variable. Even for a specific individual, a particular food may not trigger headaches every time he or she ingests it, possibly because of differences in stress levels and recent consumption of other aggravating foods.
Nevertheless, most people susceptible to migraines appear to be unusually reactive to events and substances that trigger vasoconstriction or vasodilation. Serotonin plays a major role. Serotonin (also known as 5-hydroxytryptamine or 5-HT) is an important neurotransmitter with vasoconstrictor activity. It seems to be released in large quantities from blood platelets in migraine; its metabolites appear in the urine following migraine, and platelet serotonin level has been shown to decrease by 40% during migraines (Humphrey, 1991). It has also been suggested that immunoglobulins (especially immunoglobulin E "IgE", which is frequently involved in allergic reactions), or other components of the immune system, may be involved in the pathogenesis of migraines. To date, however, evidence for an IgE mechanism