80% of Migraines Affect Women—So Why Is There No Gender-Specific Research?
Headaches are never fun, but for a billion people worldwide, they’re more than an occasional annoyance. About 14 to 15% of people globally report chronic migraines—having 15 or more severe headache days in a month for over three months.
When you break it down by gender, women have more migraine attacks than men; 85% of chronic migraine attacks occur in women, according to the American Migraine Foundation.
Migraines commonly cause dizziness, nausea, throbbing pain on one side of the head and increased sensitivity to light. The symptoms are so debilitating they disrupts women’s lives. They’ll spend hours in a dark, quiet room waiting for the attack to pass, unable to focus on anything else for the day.
Because migraines have many triggers, many women shift their lifestyles, like cutting out caffeine and avoiding loud venues to avoid another attack. Yet some causes, such as shifting hormone levels and menopause, are unavoidable.
Given how chronic migraines are the leading cause of female disability, you would think migraine research would be tailored to women. Yet only in recent decades have efforts been made to close the gender gap and better help women with debilitating migraines.
What’s behind the gender gap in migraine research?
Research Largely Focused on Men
Historically, research has been based on males, leading to gaps in understanding and a lack of treatment options tailored to the female body. Dr. Danielle Wilhour, an assistant professor of neurology at the University of Colorado Anschutz Medical Campus who studies chronic migraines, explains that originally, researchers wanted to avoid hormones potentially influencing migraine results, so they usually avoided using female mice. This practice eventually led to the exclusion of women from human studies.
Studying the Female Body Was Considered Too Complex
Having to include biological sex as a variable made experiments too complicated, so scientists historically excluded it.
“As a scientist with cycling mice or rats, you had to consider the variability of estrogen, progesterone and controls for both of them,” explains Dr. Jaideep Kapur, a professor of neurology and director of UVA Brain Institute in Virginia.
Kapur says it was only when the National Institute of Health specifically focused on sex as a variable in biomedical research that the field began taking a closer look at diseases more common in women.
“Over time, they realized there is a large hormonal component of migraines, so that has been corrected over the years,” Wilhour adds. “Hopefully, there will be more equal representation in the future, starting with animal studies.”
Lack of advocacy for funding women’s research
Another issue is the lack of women in STEM who are available to advocate for women’s health. Less than 30% of researchers worldwide are women.
“I wish there were more ladies in science,” says Dr. Clifford Segil, a neurologist at Providence Saint John’s Health Center in Santa Monica, California.
He believes having more women in STEM would create more discussion and push for research on women and migraines along with other women-centered conditions.
More discussion on women-specific research would also help with funding efforts and expanding the currently small scientific workforce studying these research questions. Kapur notes that finding answers to migraine treatments would require grants and government funding for preclinical and clinical trials.
“It’s expensive and challenging to do, but it has to be done to understand how to help women with disabling, chronic migraines,” he explains.
What have we learned about women and migraines?
Since including biological sex and hormones in migraine research, scientists have learned there’s a hormonal component to migraines.
Wilhour says shifting estrogen and progesterone levels are one of the major underlying reasons why women experience more migraines than men. This is first seen when girls get their periods and experience menstrual migraines from the shift in estrogen and progesterone.
“Estrogen is usually pro-headache, and progesterone is usually anti-headache,” adds Segil. He notes certain hormones like estrogen make blood vessels more reactive, which can trigger a migraine attack. It’s why women experience fewer headaches and migraine frequency decreases when entering perimenopause as estrogen levels decline.
However, continued fluctuations in hormones appear to increase migraine frequency while in menopause.
“Any rapid shift in estrogen can be very provocative in triggering migraine,” says Wilhour. “That’s going to make women more likely to experience migraines, including a subset who may not have ever [experienced a] migraine until they entered menopause.”
How can women manage migraines?
One way scientists and doctors are working to close the gender gap is by understanding the effectiveness of migraine treatments on women. Segil notes that new classes of migraine treatments, such as CGRP inhibitors, help to prevent episodic migraines for both men and women.
“[CGRP inhibitors] are marketed aggressively to ladies, but they work for both men and women. And there are oral versions and once a month injectable that are really fantastic,” Segil explains.
Segil adds that taking progesterone-only birth control helps in reducing headaches more than combined oral contraceptives for women of childbearing age or in perimenopause. Additionally, hormone replacement therapy for women in menopause would also help balance out progesterone and estrogen levels.
