Effect of Caffeine Differs in Boys and Girls After Puberty

Reaction to caffeine changes in boys and girls after puberty, a new study shows.

CDC had recently reported that 73 percent of all children in the U.S consume caffeine on a daily basis. The stimulant isn't just present in coffee, but also in several sugary drinks, chocolates and medication.

Previous research has shown that caffeine causes increased blood pressure and reduced heart rate in children, teens and adults. Researchers at the University at Buffalo School of Public Health and Health Professions wanted to know whether or not puberty affects cardiovascular changes in boys and girls.

The study was based on 96 children and was double-blind, dose response and placebo-controlled. Researchers monitored heart rate and blood pressure in children before and after caffeine or placebo intake. The study included pre-pubertal and post-pubertal children.

"We found an interaction between gender and caffeine dose, with boys having a greater response to caffeine than girls, as well as interactions between pubertal phase, gender and caffeine dose, with gender differences present in post-pubertal, but not in pre-pubertal, participants," said Jennifer Temple, PhD, associate professor in the Department of Exercise and Nutrition Sciences, University at Buffalo School of Public Health and Health Professions.

Girls showed different responses to caffeine during menstrual periods.

"Finally," Temple said in a news release, "we found differences in responses to caffeine across the menstrual cycle in post-pubertal girls, with decreases in heart rate that were greater in the mid-luteal phase and blood pressure increases that were greater in the mid-follicular phase of the menstrual cycle."

Hormones govern the menstrual cycle. The follicular phase begins on the first day of menstruation and ends with ovulation. The luteal phase comes after ovulation and is characterized by an increase in progesterone levels.

The study is published in the journal Pediatrics. It was funded by the National Institute on Drug Abuse of the National Institutes of Health.