A new study suggests that after puberty, males and females experience different effects from caffeine consumption, including varying changes in heart rate and blood pressure levels. Girls also experience distinct changes during their menstrual cycles.
“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 researcher Jennifer Temple, Ph.D.
Researchers evaluated heart rate and blood pressure before and after administration of placebo and two doses of caffeine in pre-pubertal (eight to nine year-old) and post-pubertal (15- to 17-year-old) boys and girls.
Previous studies, including some conducted by this research team, have shown that caffeine raises blood pressure and decreases heart rate in children, teens, and adults, including pre-adolescent boys and girls.
The goal of this new study was to determine whether gender differences in cardiovascular responses to caffeine begin after puberty and if those responses fluctuate during the various phases of the menstrual cycle.
“Finally, 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,” said Temple, of the University at Buffalo School of Public Health and Health Professions.
“In this study, we were looking exclusively into the physical results of caffeine ingestion,” she said.
Two main phases of the menstrual cycle (marked by hormone changes) were studied: the follicular phase, which begins on the first day of the period and ends with ovulation, and the luteal phase, which begins just after ovulation and consists of significantly higher levels of progesterone than the first phase.
“Future research will evaluate a variety of factors in more detail, including the extent to which gender caffeine differences are affected by steroid hormone levels or by differences in patterns of caffeine use, caffeine use by peers or more autonomy and control over beverage purchases,” Temple said.
The study, funded by a grant from the National Institute on Drug Abuse of the National Institutes of Health, is published in the journal Pediatrics.
Source: University at Buffalo