Good news for all those coffee junkies out there: Caffeine has been found to improve memory. Since researchers from Johns Hopkins University were unsure whether or not caffeine had any long-term memory effects on humans, they decided to investigate the matter.1 And what they found out could mean increased sales for coffee shops!
The study was published in the journal Nature Neuroscience and explained that, in addition to improving focus and attention (immediately), caffeine can enhance short- and long-term memory. The participants in this research were split between caffeine and placebo groups. The caffeinated individuals were administered 100 to 300 milligrams of caffeine once they'd viewed a series of images. It was found that those who consumed 200 to 300 milligrams of caffeine were more likely to remember the images that those in the placebo group. Specifically, authors of the study found that the test group was less likely to forget in a 24-hour period.2
Now, the question remains: How much coffee do I need to experience these benefits? Well, based on the research findings, 200 to 300 milligrams should do it. However, most coffee shops don't sell beverages based on caffeine content. Twenty ounces of coffee can contain up to 400 milligrams, which may be too much, as researchers did not investigate the effects of this amount. So, it may be best to stick to a medium – or 16-ounce – size.
1 Nature Neuroscience, "Post-study caffeine administration enhances memory consolidation in humans" January 12, 2014
2 The Atlantic, "Study: Caffeine can improve memory" January 13, 2014