Kids appear to process caffeine -- the stimulant in coffee, energy drinks and soda -- differently after puberty. Males then experience greater heart-rate and blood-pressure changes than females, a new study suggests.
Although the differences are small, "even what we might consider low doses of caffeine can have an effect on heart rate and blood pressure in kids," said study lead author Jennifer Temple, an associate professor at the University at Buffalo in New York.
About three out of four U.S. children consume caffeine each day, but little is known about their safety.
For this study, about 100 preteens and teens consumed the equivalent amount of caffeine found in a can of soda or a cup of coffee. Half were 8- and 9-year-olds; the others were 15 to 17 years old.
"Although our data do not suggest that this level of caffeine is particularly harmful, there is likely no benefit to giving kids caffeine, and the potential negative effects on sleep should be considered when deciding which beverages to give to kids," Temple said.
The researchers found that caffeine lowered the heart rates of the kids past puberty by about 3 to 8 beats per minute. Boys were affected more than girls.
Caffeine also boosted systolic blood pressure in boys past puberty to a greater extent than girls, although the effect was slight.
"This suggests that boys may be more sensitive to the effects of caffeine than girls," Temple said.
Girls also experienced different heart-rate and blood-pressure changes throughout their menstrual cycle, the researchers said. This further supports their theory that sexual maturity changes the body's reaction to caffeine.
Caffeine's effects were relatively similar between boys and girls before puberty.
Read more from U.S. News.