the science behind getting better sleep as a new mom and through menopause

 Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker, PhD

 book nook (Fall 2022)

I think most women will agree that from the birth of their first child through menopause, disrupted sleep becomes the “new normal”.  And it's not just in our heads. I recently stumbled across the 2018 study, Sleep in Women Across the Lifespan (Pengo et al., 2018), which was reassuring although frustrating. Frustrating in that it seems our biology and life circumstances just don’t support a solid sleep pattern for most of us. The study noted that females (those born with the XX chromosomes) sleep differently than males beginning at puberty and perhaps even earlier. The biological cycles of menstruation, pregnancy, and then perimenopause and menopause itself increases our sleep disturbance progressively.  And, according to this particular study, women not on hormone therapy are at an increased risk of increased sleep disturbance in comparison to those who are receiving therapy. It seems that estradiol is indicated in the pathogenesis of sleep disturbance. The hormone therapy, in theory, prevents the cardiorespiratory disorders and oxidative stress induced by chronic intermittent hypoxia. This hypothesis is based on animal studies only, though, so more research needs to be done.  However, what the researchers did find is that short sleep durations are linked to increased incidences of gestational hypertension and increased incidences of gestational diabetes (but interestingly only in non-obese women) due to decreased amounts of oxygen the placenta experiences when the pregnant person is experiencing sleep disruptions and less than seven hours of sleep a night. And then as any woman going through menopause will tell you, sleep disturbance is one of the key annoying symptoms during that phase of the lifecycle.

As one might imagine, this study propelled me down the rabbit hole of researching more about sleep itself. Which is how I landed on this incredible book by UC Berkley’s director of the Sleep and Neuroimaging Lab. Dr. Matthew Walker is passionate about sleep and has the credibility to back it up. He is well published and is also a former professor of psychiatry at Harvard. 

 We aren’t taught much about sleep in formal health sciences education, so I found this to be a fascinating read and one that informs many aspects of women’s sleep hygiene across the lifespan.  While reading the book, I wished I was back in my undergrad years so I could just start over when it comes to sleep. Walker makes the point that we are the only species that limits its sleep intentionally which is incredibly detrimental as the World Health Organization as well as the National Sleep Foundation says we need at least 8 hours of slumber every night. I would tell my younger self, in light of this, to not stay up all night cramming for exams or socializing. And I would warn her to not take that night shift job as a new nursing grad. And, I would have insisted that the kids’ father wake up in the middle of the night to at least change their diapers after I breastfed them.  That would’ve saved me many hours of lost sleep considering that I breastfed all three of them for at least a year!  Walker emphasizes the sheer importance of sleep and even more so the alarming dire consequences of sleep omission. 

 Two take home messages I’m currently adopting from the book are trashing melatonin supplements and at least reducing my coffee intake. The first is easy considering that melatonin apparently just tells your body when to start dialing down for sleep and doesn’t affect sleep duration at all. And, research shows its really only effective for the elderly. Never mind that its not FDA regulated so you really don’t know what’s in that bottle. 

 Giving up coffee is going to be the hard one. When I was in my 20s and even 30s, I think I must have been a fast caffeine metabolizer. Not so much now. And, did you know that the half-life of caffeine is 5-7 hours? So, half of the caffeine is still active that many hours after consumption. And, like many healthcare professionals, I certainly drink it throughout the day (and during the night when I worked night shift).  It seemed easy to initially justify the coffee consumption as its my only vice. But as I learned more from Walker I’ve realized it’s just not worth it. Sleep improves one’s ability to learn new things the next day and sleeping after learning solidifies the new material learned. And then as far as any sort of athletic pursuits go, you’re hurting your performance and increasing your risk for injury if you skip out on the last 2 hours of a good night’s sleep. Our REM sleep recalibrates our emotions and allows us to come up with new insights as ideas begin to link together while we cut those zzz’s. 

 I’d truly never realized what a powerful tool sleep is in promoting and maintaining our health. You’d think that I’d know given that I’m a medical professional. But they don’t teach you this stuff in school. Yet.  Oh, and if you’re a med school resident you’ll be blown away by the reason med students in the US continue to be socialized with the whole loss of sleep and working long shifts idea. It has to do with a physician who was researching cocaine. (No lie. Read the book.) Walker’s description of the physiology of sleep is fascinating and one finishes it with a new sense of awe about the human body and an awareness that sleep can be our universal health care provider if we would just give it permission. For now, I’m taking baby steps. Decrease my caffeine intake. Sleep with a cooler room temperature. And no night lights in the room. I’m also wanting to figure out how I can more specifically analyze my sleep patterns with a wearable like the Oura ring.

 references:

Pengo, M., Won, C., & Bourjelly, G. (2018). Sleep in women across the lifespan. Chest,  154(1), 196-206. https://doi.org/10.10161j.chest.2018.04.005.

 Walker, M. (2017). Why we sleep: unlocking the power of sleep and dreams. Scribner Publishing. ISBN 978-1-5011-4431-8.