Apple Women’s Health Study releases preliminary data to help destigmatize menstrual symptoms

For immediate release: Tuesday, March 9, 2021

Boston, MA – The Apple Women’s Health Study team at Harvard T.H. Chan School of Public Health has released preliminary scientific data on women and their menstrual symptoms, contributed by a cohort of 10,000 participants of varying ages and races across the U.S. participating in the study through Apple’s Research app. The data could advance the science around women’s health and help destigmatize menstruation, according to the researchers.

Many physicians regard women’s menstrual cycles as an important window into their overall health, but the subject is under-researched. Medical research on menstruation has often been limited to smaller-sized studies, which are not representative of the broader population. Without substantial scientific data, women’s menstrual symptoms have historically lent themselves to dismissal, or have even been minimized as overreaction or oversensitivity.

“Our study will help to achieve a more gender-equal future, in which all people with menstrual cycles have access to the health services and menstrual products needed to feel safe and empowered,” said Michelle Williams, dean of the faculty of Harvard Chan School. “By building a robust generalizable knowledge base, the Apple Women’s Health Study is helping us understand factors that make menstruation difficult and isolating for some people, in addition to elevating awareness of a monthly experience shared by women around the world.”

As part of their participation in the study, women contribute their menstrual cycle tracking and other health data and answer related surveys. For the current study, Harvard Chan School researchers analyzed data from a cohort of the first 10,000 participants who enrolled in the study and responded to a demographics survey. Participants controlled the data types that they contributed to the study, with transparency into how the data will be used for the purposes of the study.

The researchers’ work validates women’s experiences of a wide range of menstrual cycle symptoms, including some that are less commonly known or discussed. The most frequently tracked symptoms were abdominal cramps, bloating, and tiredness, all of which were experienced by more than 60 percent of participants who logged symptoms. More than half of the participants who logged symptoms reported acne and headaches. Some less widely recognized symptoms, like diarrhea and sleep changes, were tracked by 37 percent of participants logging symptoms.

Initial analysis also suggests these symptom trends hold true across a wide range of demographics, including age, race, and geographic location. For example, across Black, Hispanic, and white participants, abdominal cramps, bloating, and tiredness were the most commonly reported symptoms.

“The preliminary data we are sharing today suggests women across the country have a shared experience of a wide range of menstrual symptoms, and that this natural monthly occurrence is something we should be having more discussions about,” said Shruthi Mahalingaiah, one of the study’s principal investigators and an assistant professor of environmental, reproductive, and women’s health at Harvard Chan School. “We look forward to continuing our work to create a long-term, foundational data set over time, which can inspire more research going forward.”

“These findings take us a step further in validating and destigmatizing period symptoms,” said Sumbul Desai, Apple’s vice president of Health. “Harvard Chan School researchers are leaders in the field on this critically important subject, and we couldn’t be more proud to support and help scale their efforts through the Research app.”

The study team will further investigate the preliminary data and submit a detailed analysis, including a breakdown of methods, for peer review and journal publication.

The Harvard Chan School, the National Institutes of Health’s National Institute of Environmental Health Sciences (NIEHS), and Apple are collaborating to conduct the Apple Women’s Health Study. iPhone and Apple Watch users in the U.S. enroll by downloading the Research app. Participants must be at least 18 years old (at least 19 years old in Alabama and Nebraska and at least 21 years old in Puerto Rico) and have menstruated at least once in their life.

image: Shutterstock/Melitas

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Harvard T.H. Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to take innovative ideas from the laboratory to people’s lives—not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 faculty members at Harvard Chan School teach 1,000-plus full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the School is recognized as America’s oldest professional training program in public health.