Reasons Women Need Periods: The Role of the Menstrual Cycle in Heart Health
Welcome back for our third installment of “Reasons Women Need Periods,” a series dedicated to taking a deep dive into some of the reasons women actually need their cycles for optimal health. This week we examine periods and heart health.
The two primary female reproductive hormones are estrogen and progesterone. When estrogen zigs, progesterone zags. They are like foil characters that have important balancing characteristics. We see the impact of this balancing act on our bone health, mood stabilization, and even our libido. We also see it in our heart health: recent research has found a connection between cardiac functioning and our natural monthly cycles of endogenous estrogen and progesterone, and it has also indicated a relationship between our cycles and heart disease risk. As heart disease is one of the leading causes of death for post-menopausal women, it is crucial to understand why and how Fertility Awareness-Based Methods (FABMs) can help.
The estrogen-dominant phase of the menstrual cycle is often referred to as spring and summer: Libido is high, the endometrium proliferates and grows, brain cells are stimulated, and bone mass is built. Following this is the progesterone-dominant phase, which is often compared to fall and winter: Libido drops, moods are stabilized, the endometrium maintains, and brain cells restore and repair, as does bone mass.
As these hormones have an effect on our brain, bones, libido, and moods, it should come as no surprise that even our heart is affected by them, too.
Your heart loves your hormones (especially estrogen and progesterone)
Recent findings show that resting heart rates follow distinct patterns across the menstrual cycle. Resting heart rate is slower in the menstrual and follicular phase (the first half of the cycle, when estrogen dominates), while it is significantly faster in the ovulatory and luteal phase (the second half of the cycle, when progesterone dominates).
We also know that estrogen has a preventative effect on coronary artery calcification (CAC). CAC can cause blood vessels to narrow and lead to the development of heart disease, but estrogen helps prevent the buildup of calcium in the arteries. Estrogen also positively influences myocardial contractile reserve, which gives the heart the ability to pump harder when it needs to, and to rest easier when it doesn’t.
Progesterone plays an important role in cardiovascular health, too: it decreases blood pressure through vasodilation and decreases angiotensin-II vaso-responsiveness. Vaso what? Angiotensin-II is a blood vessel constrictor that increases blood pressure, and progesterone helps moderate that response. See? Zig and zag.
When you pair these effects of estrogen and progesterone on cardiovascular functioning with other research that connects reproductive factors and incidence of heart failure, the importance of the cyclical effects of these hormones for optimal heart health becomes even more striking. In a 2017 paper, researchers found that a “shorter total reproductive duration [defined as the time from menarche to menopause] was associated with a higher risk of incident total heart failure hospitalization in post menopausal women.”
More research is needed to determine the exact relationship between endogenous (that is, naturally occurring) progesterone and estrogen exposure, but these results seem to indicate that a longer reproductive lifespan seems to reduce one’s chances of developing cardiovascular disease and/or having a cardiovascular event later in life: according to the study, “a total of 1494 women (5.2%) were hospitalized for adjudicated incident heart failure, with women who had fewer total menstrual cycles having a greater risk for incident heart failure at 1 year.”
Your heart on birth control
But reproductive duration isn’t necessarily measured in time alone. It’s what is actually happening during those cycles throughout those prime years of reproductive potential that matters the most.
So what should be happening during those prime reproductive years? Well, ideally, you’d be ovulating and menstruating in a predictable, healthy manner. But if you are on hormonal contraception of any kind, you are not ovulating or cycling at all. This, by definition, means shorter time of potential fertility. Even though the same amount of time is passing than would be off the Pill, your reproductive duration is shortened because there is no exposure to biological cycles—the zig-and-zag of your naturally occurring estrogen and progesterone.
When a woman takes hormonal birth control, instead of ovulating and experiencing the cyclical effects of her naturally occurring sex hormones, the menstrual cycle is suppressed, and the heart is no longer experiencing this beneficial balancing act. And, in case you’re wondering whether the synthetic forms of estrogen or progesterone found in hormonal contraception have this same beneficial effect, the answer, unfortunately, is “no.”
It is commonly known that smokers and women over 35 are not good candidates for hormonal contraception, but women with high blood pressure, diabetes, and high blood cholesterol are also at higher risk for developing coronary heart disease, which makes hormonal contraception a riskier family planning choice for them, too. Hormonal contraceptive use itself has been linked with increased risk of blood clots, and their associated cardiovascular events like stroke and heart attack. High blood pressure, diabetes, and high cholesterol are all associated with hormonal contraceptive use, too.
Healthy cycles for a healthy heart
Of course, even if you aren’t on birth control, cycling alone is not enough to reap the benefits of your hormones’ balancing act for optimal heart health. Similar to our discussion with Dr. Prior on bone health and ovulation, we know that healthy, ovulatory, and functional cycles are needed for our bodies to reap the benefits of our cycles. Hormonal disorders—which usually correspond with irregular, anovulatory, progesterone deficient, and/or estrogen dominant cycles—can mess with this delicate balance, even if a woman is not on birth control.
Good nutrition and regular, moderate exercise can go a long way in balancing hormones, but they are not the *only* variables—sometimes more interventions may be needed to find balance. This is where charting cycles with a Fertility Awareness-Based Method (FABM) can be a vital tool in assessing a woman’s overall health. Healthcare providers who understand how to use the biological information gleaned from a woman’s menstrual cycle can diagnose and treat the hormonal disorders that may be affecting a woman’s health—from her fertility, to her immune functioning, to her bone and heart health, and everything in between.
What’s happening to my heart if I’m pregnant or breastfeeding?
Obviously, pregnancy is a time of anovulation (that is, when ovulation does not occur). Women who are breastfeeding also may not see a return to fertility for weeks, months, or even years. But whether you are breastfeeding, pregnant, or both, those are the only times (except for puberty and pre/post menopause) when it is considered biologically normal to go without the zig-and-zag of progesterone and estrogen that cause the regular cycle of ovulation and menstruation. And your body—savvy as it is—has a fix for that! The incredible amounts of endogenous progesterone and estrogen that a woman is exposed to throughout her pregnancy more than recoup for the effects of anovulation due to pregnancy or breastfeeding. Further, prolactin (better known as the lactation hormone) has indirect, beneficial effects on the new mom’s heart. Prolactin actually modulates neural pathways in the brain to decrease stress, which decreases cortisol. And as we all know, cortisol is that greedy stress hormone that (when left unchecked due to chronic or long term stress), can rob your body of estrogen and progesterone, and raise your risk for heart disease.
It is true that pregnancy is a time of complicated risk factors for heart disease—and pregnancies before age 20 especially seem to increase one’s risk for heart disease. But this is where it comes in handy to have had those years of protective exposure to endogenous hormones prior to pregnancy. Just another reason why teens and young women need a (regular, functional) period! It’s also another big point in favor of FABMs, which allow women to cycle naturally whether they are trying to achieve pregnancy or not.
Women need periods
If we haven’t already convinced you how important menstruating (and ovulating) is for your heart health, consider that heart disease is one of the leading causes of death for post-menopausal women. While more research is needed to determine the exact effects of progesterone and estrogen on the heart, the decades of natural, cyclical, endogenous hormone exposure throughout a woman’s reproductive life could have an important impact on her heart disease risk. It’s certainly something to take into account when considering your family planning options.
The more we learn about feminine health, the more reasons we encounter why #womenneedperiods. Regular and functional ovulation benefits the development and maintenance of your immune system, the building and protecting of your bone mass, and the functioning and preservation of your heart. As hard as it may feel to appreciate at times, your period actually does a lot of good for you.
Want to learn more about how your cycle impacts your health? Check out the other articles in our series “Reasons Women Need Periods,” below–and stay tuned for future installments by following us on Facebook and Instagram, and by signing up for our weekly Newsletter!