Apple added period-tracking to the iOS Health app and launched a clinical study into women’s health back in 2019. Now, the Apple Women’s Health Study team has some preliminary data that affirms that, yes, there is an incredible variety of period symptoms suffered by menstruating people worldwide.
The findings were from the first 10,000 participants who enrolled in the study using the iPhone Research app and provided demographic data. Of that number, 6,141 participants recorded period symptoms and the most commonly tracked were abdominal cramps (83%), bloating (63%), and tiredness (61%). Or, basically, things anyone who’s ever had a period could tell doctors if they just asked. About half the participants also reported acne, headaches, mood swings, appetite changes, lower back pain, and breast tenderness. Some rarer symptoms included diarrhea, sleep changes, constipation, nausea, hot flashes, and ovulation pain.
One takeaway was that regardless of race, ethnicity, age, and geographic location, symptom frequency was nearly universal. The participants reported cramps, bloating, and tiredness as their most frequent symptoms, and in similar numbers. So, you know, hard evidence that these symptoms can affect any menstruating person.
These findings probably seem ridiculously obvious to anyone who is ever regularly visited by Aunt Flo. However, they also illustrate how current medical research is woefully inadequate when it comes to women’s health.
“One of the most important things to note is despite some of the advances in cycle-tracking tools that are available, the research in menstrual cycles and menstrual health remains limited,” said Dr. Shruthi Mahalingaiah, a principal investigator on the study and an assistant professor at Harvard T.H. Chan School of Public Health. “Historically, the menstrual cycle has been under-researched, and women have been under-represented in very important, large studies.”
For example, if you search for “menstruation” in PubMed between 2001 and 2018, you only get some 8,400 studies on the subject. Conversely, a search during that same time period for cardiovascular disease turns up 1.3 million results. If you want to get into gender-specific conditions, prostate cancer gets 121,000 results and erectile dysfunction gets about 16,000 results. The problem gets worse when you consider that most researchers, historically speaking, have been men and excluded women from clinical research. In the U.S., Congress didn’t require women to be included in clinical trials until 1993. The result is a huge lack of foundational data and poorer medical care for women. Take polycystic ovary syndrome, which impacts an estimated 5 million women in the U.S., making it one of the most common hormonal disorders among women of childbearing age—and less than half are diagnosed correctly and 34% with PCOS say it took more than two years and three or more doctors to receive a diagnosis. The numbers are even worse for endometriosis, a painful condition that affects about 10% of women and often takes a decade to be diagnosed. Not helping matters is the general stigmatization of talking about menstrual cycles, vaginas, or uteruses at all.
This is a problem that wearables makers are also guilty of. Fitness trackers have been around since 2011, but it took Fitbit a whole seven years before it added cycle tracking. Garmin and Apple soon followed, with the former also launching pregnancy tracking last November. However, Apple and Ava, a fertility tracker, are the only two that have thus far engaged in clinical research specifically around women’s health.
So while the preliminary results for the Apple Women’s Health Study aren’t exactly mind-blowing, it’s a good thing this study even exists. The potential for wearables, which can capture long-term data in a non-invasive way, to discover new information or lead to more research in women’s health is pretty dang high. When you consider that any woman or menstruating person with an Apple Watch or iPhone could potentially participate in the study, you’re looking at a massive, diverse dataset that may start to help fix the egregious lack of foundational data in women’s health.
“What researchers and physicians in the scientific community want and need to know is more about the menstrual cycle, its relation to long-term health, as well as more about what environmental factors might affect cycle length and characteristics,” Mahalingaiah said. “With this study, we are creating a larger foundational data set on this topic, which can eventually lead to further discovery and innovation in women’s health research and care.”