Newsletter #312

Most of us are all too aware of the toll of sleep loss on our cognition.

A compelling illustration of how much we need sleep in order to think clearly was exhibited in an old experiment that took a group of people and tested them in a driving simulator on two separate sessions: once when they were drunk, and on another when they were seriously sleep deprived. The researchers found that fatigue due to sleep loss produced impairments in performance that were equivalent to being over the legal limit.

Unfortunately, we have to wrestle with sleep loss, and concomitant cognitive issues, at least occasionally. So what can we do about it?

In order to understand ways that we can potentially combat cognitive impairment due to sleep loss, we need to look at why we sleep in the first place, and what happens to the brain when sleep is curtailed.

It has long been thought that the fundamental purpose of sleep (or at least, one of them) is to restore brain energy that was burned during the waking state. The brain is a ridiculously energy-hungry organ, accounting for as much as 20% of the body's total energy consumption despite making up around 2% of total body mass.

But when you are sleeping, brain energy demands go down, leading to a significant reduction in cerebral metabolism of both glucose and oxygen. This ostensibly provides a window of opportunity for the brain to recover from damage and clear metabolic waste accumulated during the active waking period.

So, logically, when you don't sleep, this means that your brain is in effect forced to work overtime, burning through high-energy phosphates to keep ATP from being depleted. Which, in turn, may produce cognitive deficits.

That brings us to creatine.

Creatine, of course, is best known for its impact on exercise performance, and its effects in that domain are rather impressive.

The reason why it provides this benefit is because it is a phosphate donor. When we're training hard, the body recruits energy by breaking ATP (adenosine triphosphate) into ADP (adenosine diphosphate). Creatine helps replenish ATP by donating a phosphate group.

This attribute also makes creatine promising as a supplement for the brain. And perhaps even more so in the face of that energetic challenge of sleep loss. If, indeed, depletion of high-energy phosphate stores in the brain through prolonged wakefulness is a driver of deteriorating cognitive function, it seems logical that enhancing levels of phosphocreatine in the brain could be helpful for “refueling.”

Notably, a new study found that taking creatine could help fend off some of the impairments in thinking and mental processing that accompany sleep deprivation.

But here's the intriguing part — they were apparently able to achieve this in a single dose.

Let's take a look.

Creatine is seldom used acutely for enhancing cognition, with good reason. Creatine has fairly poor bioavailability in the brain, and the uptake of supplemental creatine in the central nervous system usually takes a while – like a week or more – to show up in cerebral metabolites. However, prior research suggests that a very high dose of creatine could elicit a rise in serum creatine levels more rapidly.

To see if a single megadose of creatine could fend off cognitive dysfunction induced by sleep deprivation, researchers at Forschungszentrum Jülich in Germany recruited fifteen healthy young subjects, and had all of them come to the sleep lab on two separate occasions.

Here's how each session worked:

Participants came into the lab to undergo baseline measurements starting at 6pm.

Then, they received either creatine* or the same amount of placebo (corn starch). This was a crossover study, so on their second session, they took the opposite of whatever they had received in the first session.

From there, they were kept awake overnight, and repeatedly underwent cognitive tests at three different intervals, ultimately finishing at 5:30am. Participants also had brain scans (magnetic resonance spectroscopy or MRS) at the same intervals, to see how the protocols influenced markers of brain metabolism.

So, what happened?

Let’s start with bioavailability. As I said earlier, the central nervous system is typically slow to absorb exogenous creatine. However, brain imaging revealed a significant increase in cerebral creatine when these subjects were supplemented. Along with the dosing, the researchers suggest that the metabolic stress of the sleep loss may have actually helped promote creatine uptake in the brain.

What about chemical and cognitive measurements?

Unsurprisingly, sleep restriction took a toll on the participants, leading to "...a profound cognitive and metabolic response.”

Their brain became more acidic, and levels of phosphocreatine (PCr) dropped while levels of inorganic phosphates (Pi) went up, indicating higher cellular energy consumption. And while these metabolites suggested that their brains were working harder, their mental performance suffered — their reaction time slowed and they had a harder time recalling numbers and words.

But when subjects took creatine, these effects were alleviated.

In fact, if we look at the pooled changes in cognitive performance compared to baseline measurements, you can see that their accuracy and processing speed actually got better in multiple metrics. The impact of creatine on cognition was maximized at around four hours after oral administration, but the effect continued to be evident up to nine hours after participants initially took the supplement.

*Final quick note here: the amount of creatine administered in this study was quite high (0.35 g/kg). If you're a 170 pound man, that translates to almost 27 grams, so it’s similar to a classic “loading dose.” A normal daily "maintenance" dose of creatine is around 0.05 g creatine per kg.

It’s been known for some time that activity in the avian brain during slumber occasionally mirrors the neural activity seen in the waking state when they are singing.

In a new paper, published in the journal Chaos, researchers at the University of Buenos Aires revealed that they had found a way to track the vocal muscle activity of birds during these replays.

Even more remarkably, they were able to capture that muscular activity from the vocal apparatus and translate it into sounds, the results of which were similar to actual songs characteristic of the studied species.

One of the synthetic songs that emerged from this effort resembled the vocalization that that species would typically emit during territorial disputes. Could this particular creature have been dreaming about a recent confrontation?

Credit: Romina Kuppe and Ana Amador

As we have said before: There is perhaps no better and more cost-effective supplement than creatine.

BulkSupplements is an inexpensive and reliable source of creatine, as well as other supplements. They also offer creatine in capsules, which might be a little more convenient (unless, of course, you’re shooting for the 20+ gram megadose like in the study above).

If you’d like to learn more about how creatine works and some of its myriad benefits, I’d suggest checking out this pod from our good friend Tommy Wood.

This week, we’d like to highlight one of the courses from the Ideal Weight Program, developed by Stephan Guyenet. Research has shown that multiple aspects of our lifestyle play an important role in body weight. Sleep is one of the most important, and perhaps most underappreciated.

In this course, Stephan reviews the basics of sleep and circadian rhythms, then zooms in on how insufficient or misaligned sleep specifically influences body fatness. He looks at a few key studies that have examined the impact of altered sleep on food intake, which largely mirror the findings that we described above. But it actually gets even worse — sleep loss can also adversely affect nutrient partitioning, making it harder for you to hold onto muscle!

Fortunately, this is for the most part a solvable problem. Stephan covers realistic ways for you to obtain restorative sleep, and hopefully achieve your body composition (and health) goals.

Wishing you the best,

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