The current experiment found no support for previous findings of caffeine's general ability to protect against cognitive deficits associated with normal aging. However,we are the first to report an interaction between caffeine use and participant BMI on task performance and thus provide evidence that caffeine's effect may not be one of broad preservation, but may provide focal defense against the deleterious impact of social and dietary stress on cognitive performance. In conclusion, we suggest that caffeine's effect may be directly influenced by measures of individual difference such as
BMI and thus more studies should explore the possible interaction
effects between these factors when looking at the long term effect
of caffeine.