The Cellular Fortitude of Cold Adaptation: An Investigation into Leukocyte Apoptosis in Seasoned Winter Swimmers

• Dr. Keryn M. Falvek

  Department of Physiology and Biophysics, University of Tartu, Estonia

  Author

• Dr. Tomasz E. Drelvik

  Faculty of Health Sciences, University of Lapland, Rovaniemi, Finland

  Author

The practice of regular immersion in low-temperature water, commonly known as winter swimming, is associated with a range of physiological adaptations. While the systemic benefits on the circulatory and respiratory systems are increasingly recognized, the specific cellular responses within the immune system remain a nascent field of inquiry. This article delves into a critical and under-researched aspect of this extreme sport: the impact of acute cold water exposure on the programmed cell death, or apoptosis, of peripheral blood leukocytes in habituated individuals. Apoptosis is a fundamental biological process essential for maintaining immune system homeostasis and eliminating damaged or superfluous cells. Its dysregulation is implicated in numerous pathological states, from autoimmune disorders to malignancies. Understanding how an extreme environmental stressor like cold water influences this delicate balance can provide profound insights into the adaptive capacity of human immunology. This study was conceived to address this knowledge gap by directly examining the prevalence of apoptotic leukocytes in a cohort of experienced male winter swimmers immediately following a cold water bath. The investigation employed light microscopy to analyze blood smears, a direct and established method for identifying the morphological hallmarks of apoptosis. The primary objective was to quantify the percentage of leukocytes undergoing apoptosis to determine if the acute thermal stress triggers a significant cell death response. The findings were striking in their indication of immune resilience. Apoptotic leukocytes were exceptionally rare in the blood samples, with only a small fraction of participants exhibiting a minimal apoptotic rate of 2-3%. The overwhelming majority of subjects showed no significant increase in leukocyte death. This suggests that the physiological adaptations developed through regular winter swimming extend to the cellular level, fostering a state of immunological resilience that protects white blood cells from stress-induced apoptosis. This work contributes a novel and significant finding to the fields of sports physiology and immunology, suggesting that habituated exposure to cold water may enhance the robustness of the immune system, a favorable adaptation for practitioners of this activity. The study underscores the potential for controlled environmental stress to beneficially modulate fundamental cellular processes.

{1} Teległów A, Bilski J, Marchewka A, Głodzik J, Jaśkiewicz J, et al. Cechy reakcji organizmu na wysiłek fizyczny w niskiej temperaturze wody. Med Sport Pract. 2008;9(4):66–72.

{2} Teległów A, Dąbrowski Z, Marchewka A, Tabarowski Z, Bilski J, et al. Effects of cold water swimming on blood rheological properties and composition of fatty acids in erythrocyte membranes of untrained older rats. Folia Biol. 2011;59(3–4):203–209, https://doi.org/10.3409/fb59_3-4.203-209.

{3} Vybíral S, Lesná I, Jansky L, Zeman V. Thermoregulation in winter swimmers and physiological significance of human catecholamine thermogenesis. Exp Physiol. 2000;85(3):321–326, https://doi.org/10.1111/j.1469-445X.2000.01909.x.

{4} Przybylski G, Wielikdzień J, Kopiński P. Mechanisms of programmed cell death of effector T lymphocytes. Postepy Hig Med Dosw. 2013;67:1374–1390, https://doi.org/10.5604/17322693.1085092.

{5} Solomon EP, Berg LR, Martin W (eds.) Biologia. Bilińska B et al. (tłum.). Warszawa: Multico, 2007:807–812.

{6} Cichocki T, Litwin JA, Mirecka J. Krew i powstawanie komórek krwi (hemopoeza). In: Kompendium histologii. Wyd. 4 popr. i uzup. Kraków: Wydawnictwo Uniwersytetu Jagiellońskiego, 2009:116–124.

{7} Gołąb J, Jakóbisiak M, Lasek W, Stokłosa T (eds.). Immunologia. Warszawa: Wydawnictwo Naukowe PWN, 2009.

{8} Hordyjewska A, Pasternak K. Apoptotyczna śmierć komórki. Adv Clin Exp Med. 2005;14(3):545–554.

{9} Renehan AG, Booth C, Potten CS. What is apoptosis, and why is it important? Education and debate. BMJ. 2001;322(7301):1536–1538, https://doi. org/10.1136/bmj.322.7301.1536.

{10} Kopaczewski B, Kopaczewska M. Apoptoza – podstawy molekularne patogenezy guzów mózgu. Neuroskop. 2004;6:132–135.

{11} Smolewski P, Grzybowska O. Regulacja procesu apoptozy komórek w celach terapeutycznych – dotychczasowe doświadczenia i perspektywy rozwoju. Acta Haematol Pol. 2002;33(4):393–401.

{12} James ER, Green DR. Manipulation of apoptosis in the host-parasite interaction. Trends Parasitol. 2004;20(6):280–287, https://doi.org/10.1016/j. pt.2004.04.004.

{13} Korzeniewska-Dyl I. Kaspazy – struktura i funkcja. Pol Merk Lek. 2007; 23(138):403–407.

{14} Łabędzka K, Grzanka A, Izdebska M. Mitochondrium a śmierć komórki. Postepy Hig Med Dosw. 2006;60:439–446.

{15} Yeretssian G, Labbé K, Saleh M. Molecular regulation of inflammation and cell death. Cytokine. 2008;43(3):380–390, https://doi.org/10.1016/j. cyto.2008.07.015.

{16} Inoue N, Matsuda F, Goto Y, Manabe N. Role of cell-death ligand-receptor system of granulosa cells in selective follicular atresia in porcine ovary. J Reprod Dev. 2011;57(2):169–175, https://doi.org/10.1262/jrd.10-198e.

{17} Cowling GJ, Dexter TM. Apoptosis in the haemopoietic system. Philos Trans R Soc Lond B Biol Sci. 1994;345(1313):257–263, https://doi.org/10.1098/ rstb.1994.0103.

{18} Koury MJ. Programmed cell death (apoptosis) in hematopoiesis. Exp Hematol. 1992;20(4):391–394.

{19} Mazur L, Darżynkiewicz Z. Apoptoza w układzie hemopoetycznym. In: Dąbrowski Z (ed.). Fizjologia krwi. Warszawa: Wydawnictwo Naukowe PWN, 1998:286–315.

{20} Vermes I, Haanen C. Apoptosis and programmed cell death in health and disease. Adv Clin Chem. 1994;31:176–246, https://doi.org/10.1016/s0065- 2423(08)60336-4.

{21} Biffl WL, Moore EE, Moore FA, Barnett Jr CC, Carl VS, et al. Interleukin-6 delays neutrophil apoptosis. Arch Surg. 1996;131(1):24–29, https://doi. org/10.1001/archsurg.1996.01430130026005.

{22} Hara S, Halicka HD, Bruno S, Gong J, Traganos F, et al. Effect of protease inhibitors on early events of apoptosis. Exp Cell Res. 1996;223(2):372–384, https://doi.org/10.1006/excr.1996.0092.

{23} Sachs L. The molecular control of haemopoiesis and leukaemia. Eur J Cancer. 1994;30(6):852–860, https://doi.org/10.1016/0959-8049(94)90305-0.

{24} Haanen C, Vermes I. Apoptosis and inflammation. Mediators Inflamm. 1995;4(1):5–15, https://doi.org/10.1155/S0962935195000020.

{25} Lømo J, Blomhoff HK, Beiske K, Stokke T, Smeland EB. TGF-beta 1 and cyclic AMP promote apoptosis in resting human B lymphocytes. J Immunol. 1995;154(4):1634–1643, https://doi.org/10.4049/jimmunol.154.4.1634.

{26} Williams GT. Role of apoptosis in the immune system. Biochem Cell Biol. 1994;72(11–12):447–450, https://doi.org/10.1139/o94-059.

{27} Seki H, Iwai K, Kanegane H, Konno A, Ohta K, et al. Differential protective action of cytokines on radiation-induced apoptosis of peripheral lymphocyte subpobulations. Cell Immunol. 1995;163(1):30–36, https://doi.org/10.1006/ cimm.1995.1095.

{28} Delic J, Magdelénat H, Barbaroux C, Chaillet MP, Dubray B, et al. In vivo induction of apoptosis in human lymphocytes by therapeutic fractionated total body irradiation. Br J Radiol. 1995;68(813):997–1003, https://doi. org/10.1259/0007-1285-68-813-997.

{29} Grelli S, Macchi B, Favalli C, Stagliano M, Matteucci C, et al. Studies on the induction of human lymphocyte apoptosis by prostaglandin-E2. Fundam Clin Immunol. 1995;3(2):86–87.

{30} Sakaguchi Y, Stephens LC, Makino M, Kaneko T, Strebel FR, et al. Apoptosis in tumors and normal tissues induced by whole body hyperthermia in rats. Cancer Res. 1995;55(22):5459–5464.

{31} Xu G, Shi Y. Apoptosis signaling pathways and lymphocyte homeostasis. Cell Res. 2007;17(9):759–771, https://doi.org/10.1038/cr.2007.52.

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