Magnesium is essential for circadian rhythms

Magnesium is an important mineral to our health. More than 600 enzymatic reactions in the body require it. Furthermore, the molecule our cells use for energy, ATP, is inactive until magnesium binds to it to form Mg-ATP.

A paper in 2016 found that bacteria, plants, and animals have a circadian rhythm of intracellular magnesium. Clock genes control channels in cells; some bring magnesium in to the cell, others cause it to leave it.

Perhaps the most interesting thing about this study is that it works both ways. While circadian rhythms regulate where magnesium goes, this shift also helps regulate circadian rhythms. And it’s really cool why this happens.

Magnesium and ATP

Adenosine triphosphate, or ATP, functions as the cellular energy currency in our cells. We take the importance of ATP in our cells for granted; we don’t really think about what goes on at the cellular level.

Things like transporting nutrients in to a cell, the movement of mitochondria, DNA replication, and the synthesis and secretion of most things a cell makes all require ATP. And that’s just a start.

However, ATP must bind with magnesium in order to be active. Thus, a deficiency essentially impairs our ability to create the energy necessary for proper cellular function.

This is where it gets pretty interesting. In the paper mentioned above, magnesium entered cells during the active period and exited cell during the rest period. In humans, this means intracellular magnesium increased during the day and decreased at night.

Circadian intracellular magnesium
Image source

This increase in intracellular magnesium during the active period likely helps supply cells with the Mg-ATP necessary to power cellular functions when they are most active. Then, during the rest period, it shifts out of the cell and in to the serum.

Indeed, serum magnesium peaks at night for humans. But it’s important to point out this shifting of magnesium is likely specific to the cell type.

Therefore, this magnesium shift appears to function to move magnesium where needed based on circadian signals.

How magnesium regulates circadian rhythms

By now you all know the spiel on circadian rhythms. Our body takes environmental cues called zeitgebers and uses them to set our physiology to the day/night cycle. This causes variations that follow an approximately 24 hour cycle known as the circadian rhythm.

But when we remove these zeitgebers, the cycle persists for some time. Factors like light, feeding times, physical activity, and temperature help imprint the day/night cycle so that mild perturbations don’t completely knock us out of whack.

In order to do this, the environmental information must be translated in to biological functions. The cells in our master clock don’t “see” light. The information is relayed to them, and they respond by creating proteins that relay the information via cell signaling.

One important pathway through which this works is mTOR, or mammalian target of rapamycin. The mTOR pathway regulates a lot in our cells, acting as a switch between anabolism(growth) and catabolism(breakdown). It also regulates something called translation, the process by which proteins are created in cells.

Evidence indicates that mTOR plays an important role in the regulation of circadian rhythms. Through its role in protein translation, mTOR helps “translate” zeitgebers in to cellular signals. It does this in both the master clock and peripheral clocks.

Like intracellular magnesium, mTOR activation is highest during the day and lowest at night. Oscillations of magnesium into and out of cells regulate rhythmic mTOR activity because protein translation is an energy intensive process. The synthesis of proteins accounts for upwards of 75% of cellular energy consumption.

Depleting cells of magnesium OR knocking out mTOR disrupts circadian rhythms by decreasing translation rate. So even if your zeitgeber exposures are perfect, your cells simply won’t get the signal.

Conclusion

Circadian rhythms have a hyoooooge impact on our physiology. Regular exposure to timesetting cues called zeitgebers help regulate important functions such as:

  • Brain function
  • Mood
  • Energy levels
  • Muscular performance
  • Immune function
  • Digestive function
  • Blood glucose levels
  • And a host of other important aspects of health

But in order to do this, zeitgebers must be translated in to a language that our cells speak. One important pathway through which this occurs is called mTOR, which creates proteins set forth in our DNA in response to zeitgebers. Note: For a glimpse at other pathways, all of which have their own separate nutrient requirements, check out this blog.

Rhythmic fluctuations in intracellular magnesium help regulate rhythmic activation of mTOR. Inadequate intake of magnesium disrupts circadian rhythms by dampening rhythmic mTOR activation, decreasing protein translation.

Recent evidence indicates that more than half of the US population(54%) fails to meet the daily requirement for magnesium intake. Your light exposure and feeding/fasting cycle may be perfect. But without adequate magnesium, the signal will simply be lost in translation.

In this weeks email, coming out Thursday, we’ll discuss the best time to consume magnesium, and what you should do to optimize magnesium status. You can sign up for the email list by filling out the form next to the blog title.

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