Why Sleep Matters

Scientists have discovered a revolutionary new treatment that makes you live longer.  It enhances your memory and makes you more creative.  It makes you look more attractive.  It keeps you slim and lowers food cravings.  It protects you from cancer and dementia.  It wards off colds and the flu.  It lowers your risk of heart attacks and stroke, not to mention diabetes.  You’ll even feel happier, less depressed, and less anxious.

–Matt Walker, Why We Sleep

Sounds too good to be true, doesn’t it?  But if even half of these claims were attached to a celebrity product on TikTok, it would be a bestseller.  The honest truth is that all of these claims are in fact true regarding the power of a full night’s sleep. 

As I will show you, sleep is not merely a state of unconsciousness.  Believe it or not, it is more important than nutrition, or physical activity in terms of its impact on chronic disease.  It is not only an amazing period of rest and rejuvenation, but also a process that is important for almost all parts of your body.  Your metabolism, immune system, cognitive functioning and hormonal balance are all closely tied to the quantity/quality of your sleep. Good sleep is foundational to good health, and as critical as the food we eat and the air we breathe.

a good night’s sleep is not just about racking up 7-8 hours

If we think about sleep from an evolutionary standpoint, it must be important, because we are at our most vulnerable when we sleep. Yet all species sleep. Even unicellular organisms such as bacteria have active and passive phases that correspond to the sun’s light/dark cycle.  Interestingly, only mammals and birds experience the phase of sleep known as Rapid Eye Movement (REM) sleep. And humans’ sleep cycles differ markedly from other mammalian species. We get more deep sleep in relatively shorter duration, and have significantly more REM stage sleep compared to our closest primate relatives. Humans spend on average 25% of the night in REM, vs their 9 %. 

These differences in sleep are felt to have been critical to the advancement of the human species above other animals, and likely explain our ability to easily dominate the animal kingdom. While the mysteries of sleep are still not fully understood, scientists are now realizing that sleep is foundational to our individual health and survival as well as that of our species.  

But a good night’s sleep is not just about racking up the 7-8 hours recommended for an adult.  It turns out that the quality and structure of sleep are just as, if not more, important than the quantity of time spent sleeping.   And current research indicates that adults who are short sleepers, defined as less than seven hours across a 24 hour period, are more likely to have one of the top 10 chronic health conditions including heart disease, diabetes, obesity, asthma and depression.  Sleep deprivation is not only a source of emotional instability in the short term, but is actually associated with all causes of mortality in the long run. 

But who has time for sleep anymore?  As a busy mom of 3, working full time as an obstetrician gynecologist, I spent decades NOT prioritizing my sleep.  There just wasn’t enough time in the day for it, and I assumed I was one of ‘those people’ who could naturally survive on less.

Plus, as you’ll learn, I am a bit of a control freak, and I viewed it as a way to control the uncontrollable things in my life.  I couldn’t control if a patient was having a baby in the middle of the night. But I could control not wanting to give up my tightly packed plans to suddenly needing to catch up on sleep.  It’s not that I always wanted to go to the office, or run my kids around to various activities, or do all the mindless housework administration required in a modern day household instead of taking a nap….

It’s really that I couldn’t imagine the work involved in rescheduling it all. Or explaining how to do it to my husband. So I sacrificed my sleep so I could get it done, and know that it was “off the list”.  To me, it was always more stressful to have things hanging around needing to be done, and a huge source of relief to check them off my never-ending list.

the depths of my sleep deprivation were insane

And for a time, in my twenties and thirties, I got away with it for the most part. It became a joke in my relationship with my husband how I could literally fall asleep anywhere.  And I mean anywhere! Restaurant dinner table, comedy club (yes I got heckled mercilessly, but since I was sleeping, fortunately it didn’t bother me), the elevator ride to our 27th floor NYC apartment, and most dangerously, at red lights on my way home from the 24 hour call that capped my insane 80-100h work week.

I did my residency back in the old days, before there were limits on work hours for resident doctors in training.  In those days I was commuting from the Nassau/Queens County border home to lower Manhattan.  Only after my 24 h weekend call shift would I splurge and take the Midtown tunnel instead of hitting the traffic on the free 59th St bridge.  The ride from the hospital to my apartment was about 15 miles, and I would ride with the windows open, radio blaring, drinking ice water and pinching myself or slapping my face to stay awake.  Typically at 7 am on a Sat or Sun morning there was no traffic, and this would work pretty well.  However, without fail, as I came through the tunnel at 34th St and crossed over to Lexington Ave, I would hit a red light before I could take my south-bound L turn. 

Because I drove a stick shift in those days, I learned I had to put the car in N, and pull up the emergency brake to prevent myself from drifting into the car in front of me. Because before the light turned green I would be asleep, and my foot would inevitably fall off the brake pedal.  The annoyed honk of the person behind me would rouse me, and I would jam the car back into gear, tear forward, and wave apologetically in my rear-view mirror.

Looking back, the depths of my sleep deprivation were insane, and as society seems to reward it, so did I. It became my badge of honor that I could power through a whole day on just 2-3 hours of sleep. While my situation may be different from yours, the sad truth is that sleep deprivation is a universal issue in this country.

We are living in a time where the great majority of Americans are chronically sleep deprived. With the mounting evidence regarding the health consequences of inadequate sleep, the Centers for Disease Control have labeled sleep deprivation a national health crisis since 2014.  About 1 in 3 adults in the United States report not getting enough rest or sleep every day. And  70% of adults in America report that they obtain insufficient sleep at least one night a month.  Sadly, some 50-70 million Americans suffer from a chronic sleep disorder.

Additionally, sleep deprivation seems to hit women harder than men.  Whether it’s our children’s sports schedules getting pushed later and later into the evening. Or needing to care for young kids or aging relatives before or after work. Or the endless amount of laundry, housework, and homework that demand our attention after getting home from a busy day. Or god forbid a little guilty self-pleasure in the form of exercise, socializing with friends, or binge-watching or scrolling. We are all short on time. And often the first thing to go is our sleep.

Not to mention the amount of time we ruminate on stress in our relationships, or think about the never-ending to-do list for tomorrow, both of which can impact the quality of our sleep. Additionally, there are physiologic hormonal changes that occur for women in their 40s and 50s that are also known to disrupt sleep.  Putting all of this together, it is easy to see why it is so incredibly hard for some women to get any good quality or quantity of sleep!

how much your body needs sleep, and the consequences of not getting it

But what is sleep about anyway?  For something we should spend approximately one third of our life doing, the majority of us have very little understanding of what is really happening when we finally get ourselves to bed. Nor why we really need it.

I think all of us recognize the restorative power that a good night’s sleep has.  We wake feeling refreshed, energized, and emotionally prepared to face whatever is coming at us that day.  Conversely, we easily recognize that when we are either struggling to sleep, or chronically burning the candle at both ends, we may feel cranky, irritable, and out of sorts. 

But what you may not realize is just how much your body needs sleep. Or what the consequences are for not getting it. The science is mounting that sleep is more than just needed rest. It is in fact an extremely active part of the body important for repair and regeneration. 

While scientists have recognized sleep’s impact on learning and memory for several decades, there is fascinating new evidence to suggest that getting enough sleep allows for continued neuroplasticity in adults. There is a pervasive understanding that brain function declines with age. The reality is that for most of us this decline begins in early adulthood, usually in our 30s!  After birth, there is tremendous growth in our brains.  But the average adult only has about ½ the number of synapses compared to a 3 yo.  Why?  Because as you gain new experiences, some connections are strengthened while others are eliminated. This process is known as synaptic pruning.

It was once thought that the process of growing new neural networks in the brain was only possible in children. That in adulthood, we only pruned.  There is remarkable evidence however, that while young brains generally tend to be more sensitive and responsive to experiences, adult brains retain the capacity to grow.  The theory is that this is mediated by both our exposure to new challenging stimuli, as well as to the quantity and quality of our sleep. 

Basically, getting enough sleep can help with our baseline cognitive functioning, and also promote rewiring of the brain to function in a new way that differs from how it previously functioned, indicating you really can teach an old dog new tricks! 

In addition, the newest research seems to indicate a bi-directional association between sleep and the risk for dementia such as Alzheimer’s Disease. As recently as 2012 a new waste clearance system in the brain was discovered, called the glymphatic system.  While there is still much being learned about it, it appears to be a macroscopic waste clearance system in the brain. It utilizes a unique system of perivascular channels formed by astroglial cells to promote efficient elimination of soluble proteins and metabolites that build up in the brain during normal day-time wakeful use. 

Multiple studies show that it is significantly more active during sleep. And when it does not function adequately, there appears to be a build up of some of these toxic metabolites and proteins, such as beta amyloid. Without removal, these proteins can aggregate to form plaques. Which are thought to be one of the hallmarks in the diagnosis of Alzheimer’s disease.  Unfortunately, the same modern lifestyle habits that are affecting your sleep are wreaking havoc on the glymphatic system as well.

what you need to know goes far beyond your ovaries

And no discussion of sleep would be complete without understanding how it impacts our hormones.  As women all over the world know, disruptions in sleep become more common with age. This coincides with changes in your hormones and with many physical changes in your body, all of which seem related.  Trust me, while a discussion of the interaction of ovarian hormones and sleep deserves its own blog post, there is much more to the story to explain what most women experience.  The relationship of sleep to hormone production all over the body is well documented. But what you need to know goes far beyond your ovaries. 

In fact, poor sleep contributes to dysregulation of many hormones, such as ghrelin and leptin, human growth hormone, and cortisol,.  These are hormones that are involved in controlling your hunger and satiety, your metabolism, and your ability to react to situations internally and externally.

Ghrelin is produced by your stomach. It acts on the hypothalamus and pituitary in your brain to stimulate a feeling of hunger. It promotes feeding, and ultimately fat storage. Leptin is produced by fat cells, and works to subdue the need to eat by reassuring the brain that energy reserves are adequate for the time.  The feedback between these opposing forces is complicated. But it is clear that sleep deprivation ultimately increases ghrelin levels and lowers leptin levels in the blood. This sends a signal of a limited energy supply to the brain. 

Thus, our metabolism changes with sleep deprivation, and becomes more primed for storage.  While this seems unfair, if you think about it evolutionarily, it makes sense.  We are the only species to voluntarily deprive ourselves of sleep. All other species do it to find food, in times of stress and need. There was a time in history when this was likely true for us as well. But in modern times, none of us are spending the night hunting or gathering.  Ufortunately, our biology has not had time to catch up to our abundance.

Human growth hormone (HGH) is the primary mechanism for your body to heal and repair itself. It is released during times of vigorous exercise and during sleep. However, medical experts agree that as much as 75% of your HGH is released during sleep. In addition to helping your body to repair itself during sleep, HGH also promotes a healthy metabolism, enhances your physical and mental performance, and helps you to live a long and healthy life.

Cortisol is known as the stress hormone because it activates your fight or flight response. But it is also critical for allowing you to get out of bed and function under normal circumstances. It controls blood pressure, regulates metabolism and blood sugar response, suppresses inflammation and supports immune system response. Ideally, your cortisol level spikes in the am, which actually triggers you to wake up and enables you to get out of bed and start your day. But it should drift down throughout the day, and reach its lowest after you’ve fallen asleep.

Unfortunately, stress in your life can cause your cortisol levels to remain elevated. And high night time cortisol levels can lead to insomnia, or increased wakefulness throughout the night.  This creates a vicious cycle. The more sleep deprived you get, the higher your cortisol levels go in an attempt to just keep you standing. 

In addition to sleep deprivation, chronically elevated cortisol can lead to a host of other symptoms :

• weight gain
• high bp
• decreased libido
• depression
• anxiety
• irregular periods
• osteopenia
• insulin resistance and glucose intolerance
• thin skin
• digestion problems
• brain fog
• acne

I don’t know about you, but this list sounds awfully familiar to me personally. Not to mention encapsulating the the majority of complaints that I heard from patients above age 40 throughout my career as a gynecologist.  

All of this, and I haven’t even gotten to the ovaries yet!

Knowing what I do now,  I am horrified and amazed at how little I prioritized my sleep when I could. I left myself chronically sleep deprived.  And ultimately, I experienced first hand how vulnerable that made me. Fortunately, I’ve also learned how much I have gained back by simply getting more sleep.  

But hindsight is 20-20, and it literally took me hitting rock bottom to make changes. Had I not changed my lifestyle, I might never have gotten to where I am now.  I am hoping that by showing you the power of sleep, you can begin to make choices that will ultimately help you feel and live better.  Because the data is clear that in addition to the ill effects of sleep deprivation on your mood and cognitive function, the long term impacts on your weight, metabolism and immune system lead to increased risks of type 2 diabetes, heart disease, cancer and early death. 

Although I am far from perfect slumber, I now strive to give myself close to 8 hours in bed hoping to hit something above the 7 hour mark.  Even with moderately consistent dedication to this goal, there are lots of things in my life that still get in the way, but I am working on it.

Let me know if you want more info on how to improve your sleep! Sweet dreams…..