Why on earth should you jump into ice water?

The Ancient Romans revitalized themselves in the frigidarium’s chilly waters of the bathhouses [1]. Thomas Jefferson was known to bathe his feet in cold water daily for mental toughness, and Julius Caesar used cold to alleviate ailments. Even explorer Amerigo Vespucci reported that the natives of Honduras used cold baths to reduce fever [2, 3].

Cold water therapy— exposing one’s body to cold temperatures— isn’t a new phenomenon. It dates back to 3500 BC, with the Edwin Smith Papyrus extolling its therapeutic benefits [4]. Today, celebrities, athletes, and health experts continue to popularize this age-old tradition, and for good reason. It turns out that cold immersion offers some extraordinary health and longevity benefits.

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The cold, hard benefits of cold therapy

When you think of cold therapy, you may think of ice baths or cold showers, the most common forms. These methods involve immersing your body in temperatures between 45-60°F for 30 seconds up to several minutes. Cryotherapy—a newer, more extreme form of cold therapy that uses chilled air instead of water—involves stepping into a chamber and exposing your body to extreme temperatures of -140 to -160°F for only a couple of minutes while wearing gloves and socks to protect your extremities.

While stepping into a chilly shower may sound like a shock to the system, this simple practice offers many health benefits.

Reduces inflammation

Cold water constricts blood vessels, which reduces circulation to the area and decreases inflammation. Some research also indicates that cold exposure may facilitate the delivery of more oxygen to the muscles, a strategy sports teams adopt during halftime to bolster athletic performance for the game's second half [5, 6]. s i

Improve immune response

Through the suppression of inflammation, cold exposure also activates the immune system, releasing white blood cells to protect against and fight infection [7, 8]. One study found that participants who included a blast of cold water at the end of their showers (as little as 30 seconds) had 29% fewer sick days than those who only took hot showers [9]. When combined with regular physical activity, hot-to-cold showers also resulted in a 54% reduction in sick days [9].

Boosts dopamine

Research has found that cold-water immersion of 57.2 °C increased dopamine levels by 250% [10]. Dopamine is the “feel-good” hormone that plays a vital role in memory, mood, motivation, and focus and is primary in the reward system [11, 12].

Increases metabolism

Brown fat (a healthy type of fat tissue found in different areas of our upper body) helps maintain body temperature by breaking down sugar and fat molecules to generate heat. When exposed to cold, brown fat burns calories to generate heat and protect our organs in a process known as non-shivering thermogenesis (NST). Activating NST through cold exposure can elevate metabolism up to 30 percent [13]. Cold temperature exposure also increases adiponectin, a protein hormone that regulates glucose levels and insulin sensitivity, and has been shown to boost metabolism [14, 15].

Supports brain health

Cold exposure releases cold shock proteins (stress proteins activated by cold), which provide neuroprotective effects [16]. Increasing levels of cold shock protein, RNA-binding motif 3 (RBM3), protects against cognitive deficits and neuronal loss in Alzheimer-type mice [17]. This research spotlights the therapeutic potential of cold shock pathways in treating neurodegeneration disorders.

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Cold also activates the proteasome, a protein complex degrades damaged or unnecessary proteins. The proteasome is associated with several age-related diseases, including Huntington’s disease [18].

Studies on model organisms have also shown that life expectancy increased when body temperature was lowered [19]. The same study also reported that human body temperature had decreased by 0.03°C per decade since the Industrial Revolution, which suggests a possible link between body temperature and the increase in human life expectancy.

Icebreakers: tips for cold plunging

Start n-ice and easy: It’s important to start slow and ramp up gradually, starting with a shorter exposure period and cool temperatures and then increasing exposure time until you reach 2-3 minutes. Start at 60°F and drop the water temperature by one degree each week, aiming for between 50-59°F. And remember, even a 30-second blast of cold water at the end of your shower provides benefits [9].

Submerge your face: Placing your face in a bowl of ice-cold water also triggers the mammalian dive reflex, which activates the parasympathetic nervous system, lowering heart rate and reducing feelings of stress and anxiety [20]. This simple practice could help you find your calm.

Don’t plunge after powerlifting: Cold exposure after strength training may blunt the anti-inflammatory response needed to build muscle strength [21]. While cold can ease muscle soreness and aid in recovery [22], cold exposure may be best left to rest days or before workouts if your goal is to gain muscle.

Pair with certain supplements: If you’re looking to enhance thermogenesis further to boost metabolism, fish oil (specifically, the EPA within fish oil) has been shown to decrease fat accumulation by 15-20% in mice when combined with cold [23]. Alpha-ketoglutarate (AKG) and resveratrol (two ingredients found in our daily longevity supplement, Vitality) were also shown to increase brown fat thermogenesis in human and animal models [24, 25].

Is cold plunge safe for everyone?

While cold plunge is safe for most healthy individuals, it’s important to note that cold therapy may not be suitable for everyone. If you are dealing with circulatory, heart, or blood pressure issues, consult your doctor before attempting a cold plunge. Individuals with nerve damage, Reynaud’s syndrome, or neuropathy should also speak with their doctor first.

Citations

[1] Allan, R., Malone, J., Alexander, J., Vorajee, S., Ihsan, M., Gregson, W., Kwiecien, S., & Mawhinney, C. (2022). Cold for centuries: A brief history of cryotherapies to improve health, injury and post-exercise recovery. European Journal of Applied Physiology, 122(5), 1153-1162. https://doi.org/10.1007/s00421-022-04915-5

[2] Grazioso, T. P., & Djouder, N. (2023). The forgotten art of cold therapeutic properties in cancer: A comprehensive historical guide. IScience, 26(7), 107010. https://doi.org/10.1016/j.isci.2023.107010

[3] Knechtle, B., Waśkiewicz, Z., Sousa, C. V., Hill, L., & Nikolaidis, P. T. (2020). Cold Water Swimming—Benefits and Risks: A Narrative Review. International Journal of Environmental Research and Public Health, 17(23). https://doi.org/10.3390/ijerph17238984

[4] Wang H, Olivero W, Wang D, Lanzino G. Cold as a therapeutic agent. Acta Neurochir (Wien). 2006 May;148(5):565-70; discussion 569-70. doi: 10.1007/s00701-006-0747-z. Epub 2006 Feb 17. PMID: 16489500.

[5] Yeung, S. S., Ting, K. H., Hon, M., Fung, N. Y., Choi, M. M., Cheng, J. C., & Yeung, E. W. (2016). Effects of Cold Water Immersion on Muscle Oxygenation During Repeated Bouts of Fatiguing Exercise: A Randomized Controlled Study. Medicine, 95(1). https://doi.org/10.1097/MD.0000000000002455

[6] Yeargin SW, Casa DJ, McClung JM, Knight JC, Healey JC, Goss PJ, Harvard WR, Hipp GR. Body cooling between two bouts of exercise in the heat enhances subsequent performance. J Strength Cond Res. 2006 May;20(2):383-9. doi: 10.1519/R-18075.1. PMID: 16686568.

[7] Tipton, M.J., Eglin, C.M. and Golden, F.S.C. (1998), Habituation of the initial responses to cold water immersion in humans: a central or peripheral mechanism?. The Journal of Physiology, 512: 621-628. https://doi.org/10.1111/j.1469-7793.1998.621be.x

[8] Janský L, Pospísilová D, Honzová S, Ulicný B, Srámek P, Zeman V, Kamínková J. Immune system of cold-exposed and cold-adapted humans. Eur J Appl Physiol Occup Physiol. 1996;72(5-6):445-50. doi: 10.1007/BF00242274. PMID: 8925815.

[9] Buijze GA, Sierevelt IN, van der Heijden BCJM, Dijkgraaf MG, Frings-Dresen MHW (2016) The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial. PLOS ONE 11(9): e0161749. https://doi.org/10.1371/journal.pone.0161749

[10] 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. PMID: 10751106.

[11] Bromberg-Martin, E. S., Matsumoto, M., & Hikosaka, O. (2010). Dopamine in motivational control: Rewarding, aversive, and alerting. Neuron, 68(5), 815. https://doi.org/10.1016/j.neuron.2010.11.022

[12] Westbrook A, van den Bosch R, Määttä JI, Hofmans L, Papadopetraki D, Cools R, Frank MJ. Dopamine promotes cognitive effort by biasing the benefits versus costs of cognitive work. Science. 2020 Mar 20;367(6484):1362-1366. doi: 10.1126/science.aaz5891. PMID: 32193325; PMCID: PMC7430502.

[13] Lichtenbelt Wv, Kingma B, van der Lans A, Schellen L. Cold exposure--an approach to increasing energy expenditure in humans. Trends Endocrinol Metab. 2014 Apr;25(4):165-7. doi: 10.1016/j.tem.2014.01.001. Epub 2014 Jan 22. PMID: 24462079.

[14] Diep Nguyen, T. M. (2020). Adiponectin: Role in Physiology and Pathophysiology. International Journal of Preventive Medicine, 11. https://doi.org/10.4103/ijpvm.IJPVM_193_20

[15] Lee, B., & Shao, J. (2014). Adiponectin and Energy Homeostasis. Reviews in Endocrine & Metabolic Disorders, 15(2), 149. https://doi.org/10.1007/s11154-013-9283-3

[16] Preußner, M et al. ASO targeting temperature-controlled RBM3 poison exon splicing prevents neurodegeneration in vivo. EMBO Molecular Medicine; 22 March 2023; DOI: 10.15252/emmm.202217157

[17] Peretti, D., Bastide, A., Radford, H., Verity, N., Molloy, C., Martin, M. G., Moreno, J. A., Steinert, J. R., Smith, T., Dinsdale, D., Willis, A. E., & Mallucci, G. R. (2015). RBM3 mediates structural plasticity and protective effects of cooling in neurodegeneration. Nature, 518(7538), 236-239. https://doi.org/10.1038/nature14142

[18] Davidson, K., & Pickering, A. M. (2023). The proteasome: A key modulator of nervous system function, brain aging, and neurodegenerative disease. Frontiers in Cell and Developmental Biology, 11, 1124907. https://doi.org/10.3389/fcell.2023.1124907

[19] Lee, H. J., Alirzayeva, H., Koyuncu, S., Rueber, A., Noormohammadi, A., & Vilchez, D. (2023). Cold temperature extends longevity and prevents disease-related protein aggregation through PA28γ-induced proteasomes. Nature Aging, 3(5), 546-566. https://doi.org/10.1038/s43587-023-00383-4

[20] Kyriakoulis, P., Kyrios, M., Nardi, A. E., Freire, R. C., & Schier, M. (2021). The Implications of the Diving Response in Reducing Panic Symptoms. Frontiers in Psychiatry, 12. https://doi.org/10.3389/fpsyt.2021.784884

[21] Roberts LA, Raastad T, Markworth JF, Figueiredo VC, Egner IM, Shield A, Cameron-Smith D, Coombes JS, Peake JM. Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training. J Physiol. 2015 Sep 15;593(18):4285-301. doi: 10.1113/JP270570. Epub 2015 Aug 13. PMID: 26174323; PMCID: PMC4594298.

[22] Roberts, L. A., Nosaka, K., Coombes, J. S., & Peake, J. M. (2014). Cold water immersion enhances recovery of submaximal muscle function after resistance exercise. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. https://doi.org/R-00180-2014

[23] Lund, J., Larsen, L. H., & Lauritzen, L. (2018). Fish oil as a potential activator of brown and beige fat thermogenesis. Adipocyte, 7(2), 88-95. https://doi.org/10.1080/21623945.2018.1442980

[24] Liu, X., Zhang, Z., Song, Y., Xie, H., & Dong, M. (2022). An update on brown adipose tissue and obesity intervention: Function, regulation and therapeutic implications. Frontiers in Endocrinology, 13. https://doi.org/10.3389/fendo.2022.1065263

[25] Tian, Q., Zhao, J., Yang, Q., Wang, B., Deavila, J. M., Zhu, J., & Du, M. (2020). Dietary alpha-ketoglutarate promotes beige adipogenesis and prevents obesity in middle-aged mice. Aging Cell, 19(1), e13059. https://doi.org/10.1111/acel.13059

Michael Engle

Cold Therapy