Magnesium relaxes our muscles

To fall asleep, there are certain internal requirements our body must meet. The most obvious is the relaxed state of our neuromuscular system. Think how hard it is to fall asleep right after a stressful event whose adrenaline spike has activated your muscles and nerves. Magnesium is essential to relax our muscles, and prevent over-excitation of our nerves:

Our muscles depend on a calcium/magnesium balance to contract and relax. When calcium is released from our muscle cells’ endoplasmic reticulum, it makes our muscles contract.

Magnesium is our body’s calcium antagonist.[1] More specifically in this case, it forces calcium back into the sarcoplasmic reticulum to let our muscles relax.

‍

Magnesium calms our brain & nerves

Magnesium prepares our brain and nerves for sleep primarily by regulating our chemical messengers called neurotransmitters:

Glutamate is the main excitatory neurotransmitter that excites our nervous system and keeps us awake [6,7].  GABA on the other hand is the one that calms our brain [8], which helps us prepare for sleep. Magnesium regulates both of these to help us sleep:

First, it reduces glutamate’s excitatory effects by blocking its membrane receptor. [9-11] (Magnesium also protects us from the nerve damage caused by glutamate over-stimulation.)[12]

Second, magnesium relaxes our brain and nerves because it helps our GABA neurotransmitters to function,[13-16] helping us calm down before sleep.[17] Simply put, magnesium is essential to relaxing our nerves and muscles in preparation for sleep.

Magnesium & restlessness

Magnesium also helps us fall asleep by synthesizing vitamin D, preventing iron toxicity and fighting inflammation. These three factors are necessary to prevent sleep problems like restless leg syndrome and sleep apnea.

In the past decade, it has been shown that up to 29% of adults in western populations experience sleep loss from restless leg syndrome, or RLS.[18,19] RLS is associated with 38 health conditions, 95% of which involve inflammation and immune problems.[20,21] This is why the main blood-test marker for inflammation (c reactive protein), is associated with RLS, [22] and why reducing inflammation lowers RLS symptoms.[23]

Vitamin D deficiency is also strongly associated with this sleep disorder[24-27], which is no surprise given that it has strong anti-inflammatory effects. [28-30] So how does magnesium help?

Magnesium makes Vitamin D

Cholesterol is converted into active vitamin D in our body via a three-step process that requires a set of enzymes belonging to the P450 family of enzymes.[31-34] This family of enzymes needs magnesium to function.[35]  (You can learn more about this on our magnesium & bones page.)

In addition to Vitamin D production, magnesium itself is also anti-inflammatory[36-40] which may in part be explained by its role in creating two of our most powerful antioxidants: glutathione and melatonin. We explore this further in Section 3, but first, let’s look at the other contributor to restless leg syndrome which magnesium alleviates:

Magnesium, iron toxicity & restlessness

Iron “deficiency” is strongly associated with restless leg syndrome[41-45], especially in our brain and nerves, the areas most capable of keeping us awake. Before we see how magnesium helps, we need to realize that iron deficiency is rare, and usually mistaken for iron misplacement:

Iron is meant to circulate in our blood and usually when blood tests show low iron, it isn’t because we don’t have enough iron, it’s because not enough of it is circulating in our blood, and is instead building up in our cells. What is one of the causes of this iron misplacement which is associated with RLS?

A lack of the enzyme ceruloplasmin, whose function is to load iron from our cells on to blood transport proteins in our blood. [46-48] Due to magnesium’s role in creating proteins  as well as its specific involvement in ceruloplasmin recycling [49], ceruloplasmin and the circulation of iron in our blood both depend on magnesium. Thus, low magnesium leads to iron buildup in our cells, because there isn’t enough ceruloplasmin to take the iron out of them. Why is this linked with sleep loss? Because iron buildup in our cells causes oxidative stress and inflammation [50,51]  (which explains why ceruloplasmin is associated with reducing inflammation)[52] and as we recall: inflammation is found in almost all RLS health conditions.

Simply put, magnesium prevents RLS sleep loss by lowering inflammation and oxidative stress. It does this via production of vitamin D, ceruloplasmin, and our main sleep-enhancing antioxidant molecules, melatonin and glutathione:

Magnesium, glutathione & sleep apnea

Glutathione is our body’s most prevalent antioxidant which fights inflammation and oxidative stress in all areas of our body, [53-55] especially in our brain, whose high energy needs result in greater oxidative stress than other body parts. [56] We know inflammation and oxidative stress are linked with RLS sleep loss, thus glutathione helps our sleep that way. Yet a more serious sleep disorder associated with oxidative stress and low levels of glutathione and magnesium, is sleep apnea.[57-59]

Sleep apnea affects approximately 43 million adults in Canada and the U.S. combined,[60,61] and substantially more people exhibit symptoms and risk factors. Sleep apnea obstructs sleep, and is associated with hypertension, ischemic heart disease, irregular heart beat, heart failure, cerebrovascular disease, depression, and diabetes. [62-67] (All of these happen to be known symptoms of magnesium deficiency).

Oxidative stress, inflammation, and low glutathione all contribute to sleep apnea. Magnesium  fights inflammation & oxidative stress, and is required for glutathione production.[68-70] Simply put, we need healthy magnesium levels to prevent obstructive sleep apnea.

Magnesium, DHEA, REM sleep, aging & skills

DHEA (Dehydroepiandrosterone) is a hormone made from cholesterol,[71] and its conversion also requires magnesium-dependent p450 enzymes. [35,72] While DHEA is linked to slowed aging and reproductive health, it also specifically benefits our sleep by increasing REM (rapid-eye-movement) sleep,[73] which is linked to reductions in age-related neurodegenerative diseases. REM sleep is also linked with the formation of memories involving emotions and developing skills.[74]

Besides REM sleep, DHEA also improves our energy, blood flow, immunity, body composition, bone metabolism, brain function, and most importantly it fights inflammation[75] (which we know is associated with sleep problems), further highlighting magnesium’s essentiality to healthy, memory-enhancing sleep.

Magnesium, deep sleep & memory

Magnesium itself also directly improves our sleep by reversing age-related sleep changes, the effects of which can increase memory formation:

When we sleep, much of our day’s experiences are turned into memories in our brain. This is essential for intelligence. From the 5 phases of a night’s sleep, the phase which is most associated with memory formation in youths and adults is the deep sleep phase [76-80] also known as slow wave sleep. Magnesium supplementation reverses age-related hormonal changes in a way which increases our deep, slow wave sleep, increasing the window of opportunity for memory formation.[81]

Slow wave sleep helps form memories, and…

…during this phase of sleep, the memories we form more of, are the ones based on those experiences which we thought we’d need to remember, while they were happening![82] In other words: when you’re learning something important that you want to convert into long-term knowledge, consciously tell yourself you will need this knowledge in the future!

By boosting deep sleep magnesium helps physically preserve our body, because deep sleep is the phase during which much of our physical and metabolic repair takes place.[83-86] Less deep sleep is also associated with insomnia.[79,87,88] Thus chronic magnesium deficiency can lead to a cycle of inflammation/oxidative stress + sleep loss, as well as biological aging of our organs from a lack of nightly repair.

Simply put, our body needs specific nutrients to perform the processes that keep us healthy and prevent sleep loss, and magnesium is needed for more of these processes than any other nutrient.[89] Given its vast roles in our physiology, it makes sense that magnesium is also involved in the timing of these biological processes, yet one thing that often slips our attention, is just how essential their timing is to our health:

Our Circadian Rhythm

The vital processes that keep us alive are regulated in a 24 hour cycle.[90,91] A good way to grasp this is to look at the hormones our body uses to alter its physiological state: Different hormones excite us, calm us, make us feel great, boost our focus, make us stronger, make us sleepy, and so on. Each hormone’s production follows a 24 hour cycle. Let’s look at the 24 hour cycle of the two hormones that most affect our sleep: cortisol and melatonin [92]:  

Cortisol (activates/prepares body for stress): Cortisol production is high in the morning and gradually decreases to low levels in the evening and night until it spikes again next morning.

Melatonin (promotes sleep and detox): Production is low during the day, rises at 8pm, spikes around midnight, and then drops down in the morning and waits to rise again at night.

Our body’s circadian rhythm is essential to good health. When it’s out of sync we experience inflammation, insomnia, and possibly major diseases if the effects last long enough. [93-96]

Magnesium, melatonin & insomnia

Nutrient availability, stress and light are the main factors that can disturb our circadian rhythm and sleep cycle, and magnesium regulates all of these: It’s needed for digestion & nutrient absorption, it helps our adrenals deal with stress, and it’s involved in the creation and healthy levels of the light-sensitive hormone: melatonin.[97-99]

Melatonin lets us fall asleep and is strongly tied to our circadian rhythm[100-104], however it also fights the inflammation and oxidative stress which contribute to sleep loss.[105-109] It comes as no surprise then, that melatonin & magnesium supplements help with insomnia[110] and that magnesium supplements alone also help with insomnia.[111]

Magnesium and our biological clock:

Looking at all its roles in the requirements of sleep, magnesium resembles a master regulator of our circadian rhythm, which is what new research has found:

Our daily magnesium rhythm regulates the timekeeping of our cells [112] and magnesium deficiency is implicated with dysrhythmia: the disturbance of our circadian rhythm.[113]

Magnesium’s benefits also reach outside of regular sleep regulation, as it also helps us to both perform better and fall asleep at times when our body is deprived of sleep. [114]

Any way we look at it, magnesium is absolutely essential to healthy, restorative sleep.