RESUMO
RATIONALE: Caffeine is the most widely consumed psychoactive substance in the world. Caffeine administered acutely in a laboratory environment or as a medication adjuvant has known properties that help alleviate pain. However, much less is known about the potential impact of habitual dietary caffeine consumption on the experience of pain. OBJECTIVES: The primary objective of this observational study was to determine whether caffeine consumed habitually as part of a daily diet was associated with experimental pain sensitivity using noxious stimuli in a non-clinical sample of 62 community-dwelling adults between 19 and 77 years old. METHODS: Study participants monitored their daily dietary caffeine consumption (e.g., coffee, tea, soda, energy drinks, and chocolate) across a period of seven consecutive days using a caffeine consumption diary. On the seventh day of caffeine consumption monitoring, participants presented to the laboratory to complete experimental pain sensitivity testing. Noxious thermal and mechanical stimuli were used to obtain threshold and tolerance for painful heat and pressure, respectively. RESULTS: Data analysis revealed that greater self-reported daily caffeine consumption was significantly associated with higher heat pain threshold (ß = .296, p = .038), higher heat pain tolerance (ß = .242, p = .046), and higher pressure pain threshold (ß = .277, p = .049) in multiple regression models adjusted for covariates. CONCLUSIONS: Results of this study completed with community-dwelling adults revealed that individuals who habitually consume greater amounts of caffeine as part of their daily diets demonstrate diminished sensitivity to painful stimuli in a laboratory setting.