Content curated by Torrance Laugle
Written by Will Schmidt
When most people think about cryotherapy or cold-water immersion, the first thing that comes to mind is its effect on metabolism, muscle soreness, and recovery. What’s funny is they don’t consider the effects it has on their thinking muscle: the brain.
According to Dr. Rhonda Patrick, there exists evidence that suggests cold exposure affects your brain in a multitude of positive ways. How does standing in a cryo sauna for three minutes bring on these benefits? It all starts with a chemical native to your brain and body called norepinephrine.
What is Norepinephrine?
Norepinephrine acts as both hormone and neurotransmitter in that it:
Releases heat and lactate in the body
Increases vasoconstriction—the constriction of blood vessels—when released into the bloodstream
Has profound effects on mood, pain, metabolism, and inflammation
Is involved with maintaining vigilance, focus, attention, and mood
“One of the most consistent and profound physiological responses to cold exposure is a robust release of norepinephrine into the bloodstream, as well as in the locus coeruleus region of the brain,” says Dr. Patrick.
In other words, norepinephrine has a distinctive impact on your brain. Increases in norepinephrine in your body, brought on by cold exposure, heighten your sense of vigilance, focus, and attention.
Conversely, Dr. Patrick says decreased norepinephrine levels are associated with inattention, decreased focus, impaired cognitive ability, low energy, and poor mood. In some cases, low levels of norepinephrine are believed to cause depression.
To instigate the release of norepinephrine in your body, you have to subject yourself to specific ranges of temperatures through practices like cryotherapy.
In order to achieve the release of norepinephrine into the bloodstream, you have to hit a specific temperature threshold. According to Dr. Patrick’s research:
“Cold-water immersion at 68 degrees F for one hour does not appear to activate norepinephrine release whereas one hour at 57 degrees F increased it by 530 percent and also increased dopamine by 250 percent.”
It might seem like the longer you’re in the cold, the better. However, a recent, long-term study on humans and cold immersion therapy indicates that’s not necessarily the case.
One group of people sat in cold water at 40 degrees F for 20 seconds. The other group did whole body cryotherapy at -166 degrees F for two minutes.
Both did their treatments three times a week for 12 weeks. In each case, plasma norepinephrine increased by 200 to 300 percent.
Norepinephrine, while incredibly beneficial for your body, is only part of the picture. Cold immersion also releases specific proteins in your brain that go well beyond improving your mood and focus.
Cold Shock Proteins
“When the body is cooled, many genes are shut down, the exception, however, are genes involved in lipid metabolism (fat burning) and the group of proteins known as cold shock proteins,” says Dr. Patrick. “The expression of these two categories of genes is increased upon cold exposure.”
One specific, cold shock protein, RNA binding motif 3 (RBM3), is found in the brain, heart, liver, and skeletal muscle, and increases in activity greatly with only mild cold exposure.
According to Dr. Patrick, RBM3 has the potential to directly affect our brain synapses, which are how neurons communicate and how our brain forms memories.
What’s interesting is that synapses break down during cold exposure. This was first observed through studies conducted on hibernating animals.
When the animals awoke from hibernation, almost 100 percent of their synapses regenerated. Further, this phenomenon may not only be limited to hibernating animals—it’s also been observed in lab mice, which don’t hibernate.
The mice were cooled to a temperature of 41 degrees F for 45 minutes. Generally, they experienced a 26 percent loss of synapses in the hippocampus, the part of the brain responsible for learning and memory.
Once the mice were warmed back up, they rapidly regenerated around 93 percent of synapses lost to the cold. How does this relate to humans? The answer is in the RBM3 cold shock protein.
According to Dr. Patrick, the role of RBM3, as a cold shock protein, is to bind with RNA to increase protein synthesis to dendrites, which are part of the neuron that communicates with synapses. Effectively, this enables RBM3 to regenerate neurons damaged in cold immersion.
“A single exposure of this cold shock protocol at 41 degrees F for 45 minutes was enough to increase RBM3 in mice’s brains for three days,” says Dr. Patrick. “When the procedure was repeated once a week for two weeks, not only was the expression of RBM3 robustly increased, but it lasted for an additional six weeks after that.”
RBM3 research is relatively new, and it’s not clear whether the effect would occur the same way in humans. However, it appears that only a 2 degree F reduction in core body temperature is enough to induce RBM3 and other cold shock proteins.
Contrary to what a lot of scientists and researchers claim, there’s an abundance of evidence that suggests cold immersion, like cryotherapy, is great for your body and brain. This is the first post in a series that details the different ways cold immersion therapy, like what we offer at Chill N Out, affects your body. Stay tuned for more!