A new study has shown that caffeine gets to work in as little as ten minutes and also has a greater effect on men.
Researchers from the University of Barcelona studied 668 university students (238 male and 450 female). Measurements were taken before and after the caffeine was ingested and tests were conducted at various times, to account for differences caused by the time of day.
“Numerous studies have demonstrated the stimulant effects of caffeine, but none of these have looked at their effects in terms of the consumer’s gender. Although both the men and women saw an improvement in their activity levels with the coffee, which increased in later measurements, we observed a greater impact among the males,” said lead author Ana Adan.
They also found that decaf coffee triggered a slightly higher state of alertness, even more noticeable in women. “Although we can’t say it is a placebo, we did note an effect resulting from drinking a decaffeinated coffee (at a quantity insufficient to actually affect mood),” noted Adan.
“45 minutes is the time needed for maximum caffeine concentration to be reached in the blood, but levels reach half this concentration after just a few minutes.”
Researchers state that the effects of caffeine last between two and three hours, but may be as long as five or six hours depending on a person’s sensitivity and metabolism.
This study is published in the journal Progress in Neuro-Psychopharmacology & Biological Psychiatry.