5.
Sleeping Soundly
Why We Seriously Need Sleep
We all know that we need sleep—in the same way that we understand that exercise is good for us. But in reality, when we’re busy and there just doesn’t seem to be enough hours in the day to get everything done, our sleep time is often the first thing that gets compromised. It’s easy to rationalize staying up an extra hour to finish work, to watch one more mindless episode after a long day, to finally do the kids’ laundry. In his book 10 Reasons You Feel Old and Get Fat (not getting enough sleep is #7), Dr. Frank Lipman reports that America is having a sleep crisis: Between 50 and 70 million Americans have some trouble sleeping, and several million Americans take prescription sleep aids. “Trouble sleeping” is perhaps so common and pervasive that we don’t even think of it as a problem. It might be hard for us to wake up, or we wake up feeling tired, or we need a Diet Coke to get us through the afternoon, or we’re too wired when we get in bed to doze off, or we toss and turn throughout the night—but we don’t necessarily consider any of these circumstances real problems. Just the way it is.
Although it often seems like no big deal to skimp on sleep—there’s always coffee, I’ll sleep in on Sunday—the truth is that it’s a really big deal. And our sleeping hours should really be one of the last elements of our lives that we shortchange. Dr. Lipman explains that lack of sleep is linked to a host of unwanted conditions, including:
Unsettling your metabolism and hormonal balance, leading to weight gain (more coming on why and how).
Negative moods.
Impaired memory and brain fog.
Leaky gut—gut walls are repaired during sleep.
Inflammation—increasing the likelihood of chronic disease.
Decreased immune function, and even shorter life span.
And it goes without saying that poor sleep is terrible from a beauty perspective. Although there are beauty tricks that really do make a difference—we’ll talk waking up with tired eyes later in this chapter—there’s no comparable substitute for good sleep in terms of how well rested you’ll feel and look. That’s because sleep is a magical time for your body—it’s when some of the body’s most important repair and revival work happens. Again, we turned to Dr. Lipman to fill us in on what happens to the body when we’re asleep:
The secretion of human growth hormone (HGH)—“a natural fountain of youth” with major anti-aging effects. Some people even inject doses of it, although Dr. Lipman doesn’t recommend it, especially when you can get it naturally through sleep (and also, side note, through intense exercise).
Overall hormonal balance—you need enough sleep to produce the right amount of a variety of hormones, including the sex hormones.
Muscle repair—working out naturally breaks muscles down, and the work of repairing and growing them takes place when you’re sleeping.
Parasympathetic nervous system work—the system also shines during sleep hours, meaning bedtime is an important time for your body to heal aches and pains.
Immune support—quality sleep is important for staying healthy and warding off inflammation and chronic disease.
Vital brain activity—key amino acids and other biochemicals that your brain uses when under stress are restored during sleep. Also, the glymphatic system, which removes toxins from your brain, is only active when you’re asleep. Plus you consolidate memories when you sleep—which is significant for processing, storing, and retrieving information while awake.
How does sleep, or lack of it, affect our weight?
Lack of good sleep affects our weight because it disrupts our metabolism and hormonal balance in a number of ways, and they all reinforce each other. For instance, lack of sleep is a stressor… stress stimulates cortisol… and cortisol cues your body to retain fat. Excess cortisol also disrupts your insulin response, which further cues your body to retain fat. And just as it throws your insulin out of whack, when you don’t sleep enough you don’t produce enough glucagon. And just as insulin cues your body to store fat, glucagon tells your body to burn it. So not enough sleep means you don’t make enough glucagon to keep that fat burning.
We often hear that we should be getting 7 to 9 hours of sleep—is that true?
Yes, that’s true; most research has shown we need 7 to 9 hours of sleep a night. If you are feeling irritable, anxious, and/or depressed, if you get easily frustrated, if you are suffering from a loss of mental clarity, an impaired memory, or a decreased ability to tolerate physical and emotional stress, a weak immune function, or a tendency to gain weight and a hard time losing it, you may not be getting enough sleep.
If we know we are inevitably going to be running low on sleep during a busy time at work/in life, is there something we can do to otherwise keep our metabolism and weight steady?
Yes: Cut out sugar, meditate, exercise, and keep your microbiome healthy and balanced.
HORMONAL SLEEP
As mentioned already, part of the reason sleep is so important is that we need it to maintain healthy, balanced levels of our most essential hormones. We asked our resident hormone advisor, Dr. Laura Lefkowitz, to tell us more.
How does sleep or lack thereof play into hormone levels?
Not getting enough sleep is almost a badge of honor in modern society, one bad lifestyle factor that I believe is becoming far too comfortable. Some people even boast about their ability to function on very little sleep. Sleep is not a waste of time. Sleep is vitally important to good health. During sleep the brain rests and processes the day’s thoughts, learning, and activities. During sleep the body repairs itself and detoxifies from all it is exposed to during a long, busy day. Before electricity, we were awake in daylight hours, and slept when it was dark. Today, many people are in bed only 4 to 6 hours per night on a regular basis and are not getting restorative sleep. Now, with electricity, you can work any hour of the day. When sleep is poor in quality and quantity, hormone output is affected.
The two major pathways by which sleep affects the release of hormones are through the autonomic nervous system and the hypothalamic-pituitary axis.
Autonomic Nervous System
The body has two opposing autonomic nervous system states. The first is called the parasympathetic nervous system, which is our state of rest and calm. The second is the sympathetic nervous system, our fight-or-flight state. This system activates your body for stressful situations, such as raising your breathing and heart rate so you can run away from danger.
Most hormone-secreting organs are sensitive to changes in the sympathetic nervous system. During deep sleep, the sympathetic nervous system activity should be decreased, as you safely rest. Sleep deprivation is associated with higher sympathetic activity and an increase in insulin and cortisol secretion (both fat-storing, inflammatory hormones).
Hypothalamic-Pituitary Axis
The hypothalamus and pituitary gland are very important glands located in the brain that start many of the hormone cascades throughout the endocrine (hormone) system. The pituitary is often called the “master” endocrine organ because it controls the secretion of many hormones in peripheral glands throughout the body, e.g., the thyroid, ovaries, adrenals. This hypothalamic-pituitary axis is markedly influenced by sleep. During adequate states of sleep, hypothalamic-pituitary factors are activated or inhibited to keep the body in sync. Sleep deprivation can alter the appropriate activation/inhibition and cause hormonal imbalances.
The following hormones are affected by sleep deprivation:
Cortisol: An abdominal fat-storing hormone that causes inflammation in the body and raises blood sugar levels in order to have energy when sleep is deprived. Chronic sleep loss causes elevated cortisol levels and the development of insulin resistance, a risk factor for obesity and diabetes. Chronically relying on your adrenal glands to produce cortisol to keep you functioning on inadequate sleep can also lead to adrenal fatigue.
Free thyroxin (FT4): The main hormone produced by the thyroid that increases metabolic rate and affects growth and development. Sleep deprivation causes an increase in circulating thyroxin in order to keep the metabolism humming to get through the day in a sleep-deprived state. Chronic elevated blood levels of thyroxin from sleep deprivation make the brain think there is too much thyroxin in circulation. This causes a negative feedback loop on the pituitary gland, leading it to decrease production of thyroid-stimulating hormones to quiet the thyroid gland down, but over time this suppression can cause decreased thyroid function and hypothyroidism.
Human growth hormone (HGH): A hormone that plays a role in muscle health, how our bodies store fat (especially around the abdomen), brain function, the ratio of high-density to low-density lipoproteins in our cholesterol, and bone density. Normally there is one big HGH pulse after sleep onset. With chronic sleep deprivation the normal single HGH pulse splits into two smaller pulses, one before sleep and one after sleep. This is a problem because our organs are now exposed to HGH for an extended period of time, which, because HGH has fat-storage anti-insulin-like effects, adversely affects glucose metabolism, causing obesity and diabetes.
Recent studies in humans have shown that the levels of hormones that regulate appetite are profoundly influenced by sleep duration. Sleep loss is associated with an increase in appetite that is excessive in relation to the caloric demands of the extended wakeful period.
Leptin: An appetite suppressant hormone, released by fat cells, that signals satiety to the brain and suppresses appetite. Leptin production is dependent on sleep duration. Studies in humans have shown that sleep deprivation causes a decrease in blood leptin levels, so with less sleep you feel less satiated by the food you eat, causing you to overeat, gain weight, and further aggravate insulin resistance and glucose metabolism.
Ghrelin: An appetite stimulant hormone that is released in the stomach and is also dependent on sleep quality and quantity. Sleep deprivation causes a rise in ghrelin levels, causing increased hunger and appetite, especially for foods with high carbohydrate contents. This is a nasty combination with lower leptin levels and a decreased ability for achieving satiation from your meals, so you overeat, specifically glucose-dense foods that need insulin to be processed, which causes weight gain and further aggravates insulin resistance and glucose metabolism, leading to diabetes.
Sleep loss therefore alters the ability of leptin and ghrelin to accurately signal our caloric needs and could lead to excessive overeating, especially when food is in abundance.
All these disturbances in hormone function caused by inadequate sleep cause a metabolic shift in the body’s ability to metabolize sugar, even with normal insulin levels, and puts everyone at risk for insulin resistance and type 2 diabetes.
If we look one step further as menopause approaches, changes in sex hormones can affect sleep more than during any other period in a woman’s life. The declining levels of estrogen affect sleep quality before you are in actual menopause. Hot flashes and irritability can happen on and off throughout the decade before menopause hits, causing wakefulness throughout the night and poor sleep quality.
Once you’ve actually made it into menopause, hot flashes should disappear and sleep issues should settle down, but perimenopausal women may struggle with sleep disturbances for years.
Clearly, sleep is not only for the brain but essential for the entire body. Sleep is not a waste of time. If you want to age gracefully, with a slim waistline, glowing skin, and lush hair, you must prioritize getting 7 to 9 hours of sleep every day of the week. Before all the scientific research, the old saying, “You must get your beauty sleep,” could not be truer.