Cases when coffee is useless are named
In the US, researchers have figured out when coffee will be ineffective. The Journal of Experimental Psychology: Learning, Memory, and Cognition writes about this.
A group of 275 volunteers participated in the experiment of specialists from the University of Michigan. Half of them slept all night, the other half spent the night awake.
In the morning, everyone received a caffeine capsule or placebo. After that, the study participants were offered a simple attention test and one problem. It turned out that caffeine helped to complete only an easy task. However, in most cases, coffee did little to increase productivity.
The researchers noted that caffeine reduces sleepiness, energizes, and improves mood, but this drink does not completely replace a night's sleep.
Earlier, Australian scientists identified genes for the love of coffee, examining almost 400 thousand people. The age of the people whose genetic data was used for the analysis ranged from 39 to 73 years.