“Can an old hypothesis explain a new trend? The case of hygiene hypothesis and pubertal timing” with Jasmine McDonald, Columbia University

QUANTITATIVE RESEARCH METHODS WORKSHOP

Abstract: Extensive evidence indicates that the age at pubertal timing has declined for girls. Understanding contributors to early puberty in girls is critical given its relationship to psychosocial adjustment and increased risk for adult chronic conditions including hormonal cancers. Growing trend in childhood obesity has received the most attention as a key driver in earlier puberty. However, the decline in the average age of menarche occurred before the childhood obesity epidemic, and in settings with relatively low prevalence of childhood obesity, suggesting that other factors are at play. Less attention has been given to examining other changes in early life exposures and pubertal timing. Limited, but intriguing evidence, suggests that childhood microbial exposures are associated with the age of pubertal onset, including age at breast development and menarche. These prior studies have not been rigorously designed to examine causality between childhood microbial exposures and pubertal timing. We discuss the myriad of challenges in exposure and outcome measurements as well as temporality and propose design solutions to determine if an old hypothesis can explain the new trend of earlier age of maturation in girls.

Dr. Jasmine A. McDonald received her PhD in Biological Sciences in Public Health in 2009 from Harvard University. She received her B.S. in Biochemistry/Molecular Biology from the University of Maryland, Baltimore County in 2003 where she was a Meyerhoff and MARC U*STAR Scholar. Dr. McDonald is an Assistant Professor of Epidemiology at the Mailman School of Public Health (MSPH) at Columbia University as well as the co-Director of the Herbert Irving Comprehensive Cancer Center (HICCC) Continuing Umbrella of Research Experience (CURE) Program.