Brain Freeze, Please! Why Your Mind Loves the Cold
Hello and welcome to this month’s dose of Georgia’s Grey Area! I hope you have all had a wonderful holiday with much joy and delicious food.
Winter, in and amongst the joy and festivities, often brings challenges: biting winds, icy streets, and seemingly endless dark, cold days. However, today I am going to give you some insight into how you can translate these challenges into a surprising ally for your brain. Braving and embracing the cold, as uninviting as it seems, can actually unlock numerous cognitive benefits!
Icy Neural Pathways
Voluntarily braving the cold isn't just about physical endurance – it can be a powerful workout for your mind. Cold exposure works as a "hormetic stressor" - basically, it's a good kind of stress that makes your brain stronger, exercise challenges your muscles to grow. Brain scans using functional MRI machines have shown something fascinating: people who regularly practice cold exposure develop stronger connections between different parts of their brain, especially areas that handle emotions, attention, and decision-making. It's like upgrading your brain's internal communication network [1].
When you choose to step into that cold shower or dip into chilly water, you're not just gritting your teeth through it. You're actually teaching your brain to initiate something called 'top-down control’. Sounds fancy but it's basically you (the conscious, thinking you) telling your automatic responses (like the "get me out of here!" feeling) to take a backseat. This mental override happens in your prefrontal cortex – think of this as your brain's CEO, the part that handles planning and keeps your impulses in check [2]. When you deliberately face the cold and tell yourself “I can handle this,” you're strengthening this mental muscle. It's like having an internal coach that says, "Yes, this is uncomfortable, but we've got this”. This mental strength isn't just about conquering aversion to cold, that same ability to keep your cool (pun intended!) can carry over into everyday life. Had a stressful day at work? Dealing with a difficult conversation? That same mental toughness you built in the cold can translate into staying calm and clear-headed in everyday situations. Each time you choose to embrace the cold, you're not just surviving those few minutes – you're building up resilience and grit for handling life's challenges better.
Temperature Drop, Mood Lift
Additionally, cold exposure has been shown to trigger a flood of dopamine, your brain's feel-good messenger. Dopamine is the molecule that makes you feel focused, motivated, and ready to tackle whatever life throws at you. When you regularly brave the cold, whether through quick cold showers, a walk in the chill or cold water dips, you're essentially giving your brain a natural happiness boost [3]. It's like hitting a reset button on your mood - people who make cold exposure a habit often find themselves feeling less down and more energised (and yes, science backs this up!). Here's where it gets even better: while that first cold plunge might feel like a shock to your system, your body can actually get smarter about handling stress over time, since regular cold exposure can train up your stress response system. Your body learns to keep stress hormones like cortisol in check, making you more resilient not just to cold, but to all kinds of life's pressures [4].
Cool Immunity Boost
The brain's response to cold stress can also trigger the release of norepinephrine, a neurotransmitter that is involved in regulating immune cell activity and reducing inflammatory signals throughout the body. This neuro-immune connection works through what’s known as the inflammatory reflex, where the vagus nerve - the body’s bidirectional communication between brain and organs - can send signals that dampen excessive inflammation [5]. It's fascinating how this brain-directed response to cold can create almost a full-body reset: immune cells become more efficient at targeting potential threats while simultaneously dialing down unnecessary inflammatory responses that could impact cognitive function. This is particularly relevant for brain health since chronic inflammation has been linked to cognitive decline and mood disorders [6]. By regularly engaging in cold exposure, we're essentially training our brain to better orchestrate this delicate balance between immune function and inflammation, potentially protecting our neural tissue while maintaining sharp cognitive function.
Chill Out for Deeper Rest
If you've been sleeping better during these chilly months, there's some fascinating science behind why the relationship between temperature and sleep quality reflects an interplay of body temperature regulation and brain function. Our bodies naturally follow a circadian rhythm where core temperature drops slightly in preparation for sleep. A colder bedroom temperature, particularly in the hours before bedtime, can help kickstart this natural cooling process, essentially sending a stronger signal to your brain that it's time to wind down. This temperature drop also triggers the release of melatonin, our primary sleep hormone, while simultaneously reducing the production of cortisol (our stress hormone mentioned above) [7].
What's particularly interesting is how this pre-sleep cooling affects our sleep architecture: research suggests it can help us fall asleep faster and spend more time in slow-wave sleep, the deeply restorative phase when our brains clear out metabolic waste products and consolidate memories. The brain's glymphatic system - its waste clearance mechanism - becomes more active during quality sleep, making those precious hours of temperature-optimised rest crucial for maintaining long-term cognitive health and reducing the risk of neurodegenerative conditions [8]. So before you crank up the heating before bedtime, consider that a cooler bedroom isn't just better for your energy bills - it's your brain's preferred environment for optimal sleep, offering a free and natural way to boost your cognitive health while you rest.
A cool approach
It is important to remember that, while the benefits of cold exposure are compelling, it's crucial to approach this practice with respect and mindful awareness of your body's limits. Start gradually and build your tolerance over time, listening carefully to your body's signals and distinguish between beneficial discomfort and genuine distress. If you have any underlying health conditions, particularly cardiovascular issues, please consult your healthcare provider before starting cold exposure practices. The goal is to challenge yourself while staying within safe limits - remember that even mild cold exposure can trigger beneficial adaptations. In particular if you are swimming in cold water, never go alone and choose supervised locations. What works for someone else might not work for you, so focus on finding what works for you with cold exposure, whether that's just three or 30 seconds in the shower to begin. The key is consistency with manageable doses rather than extreme challenges - this isn't about proving your toughness, but rather about sustainably enhancing your physical and mental wellbeing!
--Georgia
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References
Yankouskaya, A., Williamson, R., Stacey, C., Totman, J. J., & Massey, H. (2023). Short-Term Head-Out Whole-Body Cold-Water Immersion Facilitates Positive Affect and Increases Interaction between Large-Scale Brain Networks. Biology, 12(2), 211. Short-Term Head-Out Whole-Body Cold-Water Immersion Facilitates Positive Affect and Increases Interaction between Large-Scale Brain Networks
Yankouskaya A, Williamson R, Stacey C, Totman JJ, Massey H. Short-Term Head-Out Whole-Body Cold-Water Immersion Facilitates Positive Affect and Increases Interaction between Large-Scale Brain Networks. Biology (Basel). 2023 Jan 29;12(2):211. doi: 10.3390/biology12020211
Srámek P, Simecková M, Janský L, Savlíková J, Vybíral S. Human physiological responses to immersion into water of different temperatures. Eur J Appl Physiol. 2000 Mar;81(5):436-42. doi: 10.1007/s004210050065.
Leppäluoto, J., Westerlund, T., Huttunen, P., Oksa, J., Smolander, J., Dugué, B., & Mikkelsson, M. (2008). Effects of long‐term whole‐body cold exposures on plasma concentrations of ACTH, beta‐endorphin, cortisol, catecholamines and cytokines in healthy females. Scandinavian Journal of Clinical and Laboratory Investigation, 68(2), 145–153. Effects of long‐term whole‐body cold exposures on plasma concentrations of ACTH, beta‐endorphin, cortisol, catecholamines and cytokines in healthy females
Peake JM, Roberts LA, Figueiredo VC, Egner I, Krog S, Aas SN, Suzuki K, Markworth JF, Coombes JS, Cameron-Smith D, Raastad T. The effects of cold water immersion and active recovery on inflammation and cell stress responses in human skeletal muscle after resistance exercise. J Physiol. 2017 Feb 1;595(3):695-711. doi: 10.1113/JP272881. Epub 2016 Nov 13
Sartori AC, Vance DE, Slater LZ, Crowe M. The impact of inflammation on cognitive function in older adults: implications for healthcare practice and research. J Neurosci Nurs. 2012 Aug;44(4):206-17. doi: 10.1097/JNN.0b013e3182527690
Harding EC, Franks NP, Wisden W. The Temperature Dependence of Sleep. Front Neurosci. 2019 Apr 24;13:336. doi: 10.3389/fnins.2019.00336. PMID: 31105512; PMCID: PMC6491889
Besedovsky L, Lange T, Haack M. The Sleep-Immune Crosstalk in Health and Disease. Physiol Rev. 2019 Jul 1;99(3):1325-1380. doi: 10.1152/physrev.00010.2018. PMID: 30920354; PMCID: PMC6689741
