There are plenty of differences between boys and girls, and now it has been revealed that they are most likely different when it comes to how their bodies react to caffeine.

According to Time, a research study published in the Pediatrics journal that caffeine affects males and females in different ways involving the heart, and it begins at puberty.

Research began after the FDA wanted to look into whether it would be safe to add caffeine in products geared toward adolescents. There was a concern over the correlation between teen illness and deaths and energy drinks.

The study did have its limits and further research would need to be continued, but it is seen as important for the medical community in terms of finding how caffeine has an impact on the health of children.

Medical News Today reported that in the study, when caffeine levels were increased, boys experienced increased blood pressure and a decrease in heart rate. The result was not found in girls. Only doses of caffeine, 1 and 2 mg to be precise, were given and the gender differences were found in the teenagers after puberty, but no differences were found in children between eight and nine years of age in the study.

The study also apparently found that the menstrual cycle does contribute to the response of caffeine in girls. Doctor Jennifer Temple, the lead author of the study, found that during the menstrual cycle, girls’ heart rate decreased and their blood pressure increased.

The cause of these gender differences was not found in the study, but further research could be used to discover this.