Effects of Caffeine Consumption on Premenstrual Syndrome: A Prospective Study

OBJECTIVE: To test hypotheses concerning patterns of caffeine consumption as a function of menstrual cycle phase in women with premenstrual syndrome (PMS), as compared with controls. METHODS: Daily symptom ratings were obtained online for two consecutive menstrual cycles. Women displaying a 30% increase in PMS symptoms during the luteal phase in both cycles were assigned to the PMS group. Participants were screened using the Patient Health Questionnaire for the following exclusion criteria: pregnancy, caffeine sensitivity, and any diagnosis of psychiatric disorder within the past 6 months.RESULTS: Caffeine intake was higher during the follicular phase than during the luteal phase for both the PMS and non-PMS groups, [F (1, 67) = 7.86, P < 0.01]. There was no significant difference between the two groups in caffeine intake, [F (1, 67) = 0.93, P = 0.338] after adjusting for age, marital status, use of oral contraceptives, regular use of medication, and cigarette smoking. Moreover, caffeine consumption was lower during the luteal compared to the follicular phase of the menstrual cycle.CONCLUSION: Overall, results suggest that PMS-sufferers were as likely to consume caffeine as normal volunteers, and that women consumed more caffeine during the follicular compared to the luteal phase.