A recent study published in the European Journal of Nutrition examined the short-term immunological effects of coffee compared with an equivalent dose of pure caffeine dissolved in water and with water alone in healthy adults. The aim was to determine whether coffee produces distinct immune responses beyond those attributable to caffeine itself.
This randomized crossover pilot study included 10 healthy participants aged 20 to 40 years who were non-smokers and regular coffee consumers with normal body mass index. Individuals with chronic illnesses, medication use, pregnancy, or metabolic or immune-related conditions were excluded. During separate study sessions, participants consumed either brewed coffee, a caffeine solution, or water, each containing approximately 130 mg of caffeine (except plain water). Washout periods were included between sessions.
Researchers assessed post-meal immune responses by measuring circulating cytokines and evaluating caffeine pharmacokinetics. Results showed modest but noticeable differences among the interventions. Pure caffeine led to more pronounced suppression of certain inflammatory cytokines, including interferon gamma and selected interleukins. In contrast, coffee often produced immune responses closer to those observed with water, despite containing the same caffeine dose.
Interestingly, systemic caffeine exposure was higher after coffee consumption than after the caffeine solution, suggesting that other components in coffee—such as polyphenols—may influence caffeine absorption or metabolism. However, the authors cautioned that these findings are preliminary due to the small sample size.
All observed effects were short-lived and not clinically significant. The beverages were well tolerated, and no serious adverse events were reported.
Overall, the findings suggest that coffee may trigger immune responses distinct from those of isolated caffeine, potentially due to its complex mixture of bioactive compounds. Larger and longer-term studies are needed to confirm these observations and clarify their health implications
