How fast you fall asleep and your ability to stay asleep through the night are products of your body’s interworking biological systems.
To maintain a healthy sleep wake cycle these systems rely on adequate daily intake of calcium, magnesium, and potassium, as well as natural light exposure, and properly timed secretion of the stress hormone cortisol.
The sleep wake cycle is regulated by our body's internal clock: the circadian rhythm, which also influences the rhythm and timing of other important body functions such as hormone release, digestion, and body temperature.
Here are three simple, scientifically backed ways to optimize your circadian rhythm so you can fall and stay asleep naturally.
Eat these 3 minerals | Get proper light exposure | Limit pre-sleep arousal | Takeaway
1. Eat Magnesium, Calcium, and Potassium
In addition to building strong bones, producing your next heartbeat, and hundreds of other roles in the body, the minerals calcium, magnesium, and potassium are essential to falling and staying asleep.
Research suggests that many of us experience diminished sleep quality as a result of not getting enough of these minerals in our daily diet [1].
For example, studies show that some 98% of Americans are deficient in daily potassium intake, 75% are deficient in magnesium, and 70% are deficient in calcium [1].
I already take a magnesium supplement so I recently charted my dietary intake of Calcium and Potassium. Having considered myself a healthy eater, I was surprised to learn that my daily diet only provided about 50% of my recommended calcium intake, and less than 30% of recommended potassium.
Dietary intake recommendations for minerals and other nutrients are developed by committees of the National Academies of Sciences, Engineering, and Medicine (NASEM).
To increase my calcium and potassium intake, I upped my consumption of bananas, cherries, cheese, macadamia nut milk, leafy greens, and coconut water. Still short on potassium, I supplemented with potassium bicarbonate powder.
Since increasing my mineral intake to meet dietary intake recommendations, my ability to fall asleep, the quality of my sleep, and how awake I feel when I wake up have all improved drastically.
Because most potassium and magnesium in the body is found inside of cells, assessing deficiency is difficult and not routinely done in clinical practice.
Calcium assessment presents difficulty as well because our bodies carefully control calcium levels in the blood by pulling calcium from our bones and teeth.
These assessment challenges mean tracking your mineral intake is crucial to determining whether you’re consuming enough, because by the time mineral deficiency becomes apparent in blood tests, you’re in real trouble.
Your body will source magnesium, calcium, and potassium as efficiently as it can from your bones and teeth, until you run out. If you want to avoid holes in your bones, experts suggest meeting the recommended mineral intakes.
Not only do your cells need these three minerals to fall asleep and stay asleep, but they also need them to perform healing processes such as DNA repair, cell cleanup, finding and killing off bad cells, as well as other restorative immune functions.
It’s important to note that not all magnesium supplements are created equal or for the same purpose.
Natural Calm Magnesium powder, for example, contains only magnesium citrate, which makes it a great laxative that can help with occasional constipation. Too much magnesium citrate, however, can cause dependence and lead to intestinal gas, nausea, as well as changes in blood electrolyte levels.
Compared to Ned's full spectrum Mellö Magnesium Superblend, which combines 3 highly bioavailable forms of chelated magnesium, other popular magnesium supplements aren’t as easily absorbable and often pass right through your body.
Magnesium and Sleep Research
Research suggests that magnesium is an important modulator of sleep quality. Dietary magnesium deficiency, which leads to central nervous system (CNS) hyperexcitability, is associated with sleep disorders and is thought to be a common occurrence, especially in older adults [2].
In fact, chronic insomnia, characterized by agitated sleep and frequent nighttime awakenings, is one of the main symptoms of magnesium deficiency. In contrast, a diet high in magnesium and low in aluminum has been linked to deeper, less interrupted sleep [3].
Studies have shown that magnesium regulates melatonin production and increases levels of the neurotransmitter GABA or Gamma-Aminobutyric acid, which helps quiet down neuron activity in the brain and nervous system [4]. Mellö Magnesium is enriched with extra GABA to help promote relaxation and healthy sleep.
Magnesium also activates the parasympathetic, aka the rest and relax nervous system, which is responsible for processes such as physiological recovery, digestion, and a good night’s sleep [5].
Calcium and Sleep Research
Calcium’s critical role in our sleep cycle is well established. Not consuming enough calcium and magnesium is linked to frequent nighttime awakenings and difficulty returning to sleep.
Calcium helps the brain use the amino acid tryptophan to make melatonin, the body’s sleep inducing hormone. This is why dairy products such as cheese, which are high in both calcium and tryptophan are one of the top sleep-inducing foods. I often eat a few slices of cheese before bed to fall asleep.
Research published in the European Neurology Journal found that calcium levels are higher during some of the deepest levels of sleep such as rapid eye movement (REM) sleep, the phase during which we have our most vivid dreams and when our brain is most active. The study showed that sleep disturbances, especially those related to REM sleep, are related to calcium deficiency and that normal sleep could be achieved by normalizing calcium levels [6].
Potassium and Sleep Research
Research suggests potassium plays a role in the regulation of sleep duration and our ability to stay asleep at night without waking up [7]. Low potassium levels have been associated with higher daytime sleepiness [8].
One study examined the effects of oral potassium chloride supplementation compared to placebo on normal young males who consumed a low potassium diet. The researchers found that after 1 week of potassium supplementation subjects experienced significant improvements in sleep efficiency and a reduction in nighttime awakenings following sleep onset [9].
2. Avoid Light Exposure After Sundown
In addition to being required for vision, light plays an important role in the sleep cycle and hormone secretion. Our bodies’ functions are synchronized with this cycle and therefore also reliant on light exposure. That is during daytime our body performs functions associated with activity, while functions associated with rest and healing take place at night.
Our circadian rhythms are thus highly dependent on daytime light exposure and the absence of light at night. In fact, even dim light at night can disturb a person’s circadian rhythm as well as secretion of the wakefulness inducing hormone cortisol and the sleep inducing hormone melatonin.
Researchers have found that cortisol levels are significantly elevated by evening light exposure [10]. In contrast, nighttime light exposure has been found to significantly suppress the secretion of the sleep inducing hormone melatonin [11].
Studies have linked nighttime melatonin suppression to increased risk of sleep disruption, obesity and even more serious diseases such as breast cancer [12].
Although some people try to combat melatonin suppression with melatonin supplements, doing so has not yet been confirmed to have a positive benefit on sleep onset or sleep efficacy and is not recommended on a regular basis [13].
Research suggests that use of melatonin by healthy adults shows promise with regards to preventing jet lag related circadian rhythm shifts and improvements in insomnia, but only to a limited extent. Users should be careful as melatonin supplements are not regulated and can have various gastrointestinal, cardiovascular, central nervous system, and dermatological side effects [14]
Further an independent review of 31 melatonin supplements found that the amounts of melatonin contained in the supplements varied widely from doses listed on the labels as well as that 26% of the supplements analyzed also contained the neurotransmitter serotonin, a controlled substance used in the treatment of several neurological disorders [15].
Because our biological clocks use light as the main environmental cue for setting our body’s day-night cycle, inappropriate light exposure can be involved in the pathophysiology of sleep disorders [16]. Nightlights appear to be okay, researchers suggest that light emitted by an average bedside table lamp is enough to suppress melatonin production.
Blue light exposure appears to be the most damaging, however. In one study, Harvard University researchers compared the effects of 6.5 hours of blue light exposure to 6.5 hours of green light exposure. They found that blue light not only suppressed melatonin for approximately two times as long as green light, but that it also shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).
Red light is the least likely to negatively affect sleep, so using dim red nights for night lights can help. As can wearing blue light blocking glasses at night and getting plenty of bright light exposure during the day.
However, nothing is quite as effective as shutting down all of your devices three hours before bed, dimming and then turning off the lights, and relaxing before a deep restful slumber.
3. Get Excited During the Day, But Not Before Bed
Pre-sleep cognitive arousal has been cited as an important contributor to the development and preservation of insomnia and increases in stress or worries before bedtime are associated with sleep impairments [17]. In one study, researchers compared 15 subjects under 2 conditions: pre-sleep cognitive arousal and no pre-sleep cognitive arousal [18].
Subjects took significantly longer to fall asleep after working through 30 minutes of cognitive tasks prior to retiring for bed in the pre-sleep cognitive arousal condition, than they did when they did not perform pre-sleep cognitive tasks.
Subjects didn’t just take longer to fall asleep in the cognitive load condition, however. They also exhibited differences in heart rate and temperature during sleep onset and in subsequent phases of deep sleep. For example, subjects in the cognitive arousal condition presented with significantly more high frequency brain activity in the first and second periods of deep sleep.
One reason for this may be that the performance of mental tasks increases levels of the stress hormone cortisol [19]. In one study of 24 subjects in 2 conditions: 4 hours of continuous mental activity vs. a control session. Subjects experienced significantly higher cortisol numbers in the continuous mental activity condition compared to the control session.
Our bodies wake up and function thanks in part to the stress hormone cortisol, which helps provide us with energy and kicks our sympathetic (i.e. fight or flight) nervous system into motion. Cortisol thus enables us to tackle work projects, exercise, and socialize with friends. Its levels peak about an hour after we wake up and decline thereafter [20].
In the evenings, cortisol levels drop, allowing our parasympathetic system to kick in. The parasympathetic system is responsible for sedation, relaxation, healing, and growth. When the parasympathetic system takes over, our bodies can easily succumb to sleep.
Although cortisol is often viewed as public enemy number one due to the damage it can wreak when your cells are chronically exposed to it, we need it to stay awake and function. High nighttime levels of increased cortisol, however, inhibit us from easily falling, staying asleep and feeling awake the next morning.
One way to help ensure these awake hormones are not keeping you up at night is to spend them during the day via exercise, thinking, taking risks, or whatever other process heavy cognitive and physical activities make you happy.
Interestingly, although exercise increases cortisol levels during and immediately following activity, cortisol levels normalize shortly after, suggesting evening exercise may also be a good way to drain your body of excess energy.
Don’t subject yourself to unnecessary evening thinking, excitement or stressors such as thinking about work, yelling at your husband or betting $1 on the word search app that you’ll find more words than your online opponent. If you do, your body will likely release the stress hormone cortisol thereby destroying the quality of your subsequent sleep and your ability to feel awake the next morning.
In one study of school teachers, researchers looked at the relationship between work related rumination in the evening and salivary cortisol levels at 10pm and the following morning [21]. Rumination is the process of continuously thinking about the same thoughts, which tend to be negative or sad, and it is thought to prolong stress-related physiological activation.
The study found that of the 108 teachers tested, those who scored higher on rumination had significantly higher cortisol levels at 10pm and significantly lower levels the next morning compared to their counterparts. The researchers attributed the low morning cortisol levels in this group to sleep disturbances during the night.
Takeaway
Managing light exposure, stress, and proper mineral consumption are key to a good night’s sleep and feeling awake the next morning.
Unfortunately not thinking or getting excited before sleep is difficult or not possible for many people, such as anyone with a job or dog, parents of young children, and anyone who thinks or looks at their phone at night.
The number of people who can fall asleep with the luxury of being able to switch off their minds each night 3 hours before bed to blissfully think of nothing before lulling into a long, deep and uninterrupted sleep is pretty slim.
If you’ve made it this far I have to assume that you too suffer from the affliction of thinking. To combat its negative effects on sleep, try turning off your brain with ample daytime light exposure and exertion, sleep promoting minerals such as the three powerful forms of magnesium found in Mellö, and relaxation in complete darkness (or at worst dim red light) three hours before bed time.
When this is not possible, do the best you can.
Sweet dreams.
Scientific Sources
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