Cold Water Exposure: Eases Depression, Enhances Immune Function, Increases Antioxidant Production

Exposure to cold water may be a somewhat unlikely yet effective treatment to banish depression, thrust the immune system into enhanced functioning and bolster our stress defenses, among other factors. This application is known in the medical lexicon as hydrotherapy, which is the use of water (in this case cold water) to relieve discomfort and promote physical well-being.

Many of us have experienced the breath-taking sensation upon jumping into a cold body of water, or when the heat cuts out during a shower. This feeling is known as the cold shock response and is undeniably uncomfortable and potentially dangerous in certain conditions. However this is precisely where the health benefits can be reaped, what is comfortable isn't always what is healthiest.

One of the physiological changes that occurs when the body is exposed to cold water is vasoconstriction. During this process the blood vessels are narrowed due to the contraction of the muscular walls of the vessels. Vasoconstriciton therapy is commonly used in athletes on specific areas of the body that have succumbed to injury. It restricts blood flow to the site and slows the metabolism of the targeted area. This results in less cell death and improved recovery.

Exposure to cold temperatures, such as that experienced during a cold shower, may also help to regulate body weight by raising the levels of brown fat within the body which has been shown to have beneficial action on glucose tolerance and fat metabolism. White fat, on the other hand, is more plentiful within the body and actually stores energy. A study conducted on mice demonstrated an increase in a certain protein (transcription factor Zfp516) that enables the formation of brown fat when exposed to cold temperatures and also seemed to enable white fat to act more like brown fat in its ability to burn calories. The researchers involved in the study also observed that mice with higher levels of the protein gained 30 percent less weight than normal mice whilst consuming a high-fat diet.

Optimal Bodies contacted Dr. Manisha Ghei, MD, ABIHM, IFMCP, who is the Founder and Medical Director of Praana Integrative Medicine & Holistic Health Center, PLLC, in Sugar Land, Texas. She is Board Certified in Internal Medicine and Integrative Holistic Medicine and is a pioneer in the field of Functional Medicine being certified in the first ever cohort of practitioners from all over the world to become IFMCPs (Institute for Functional Medicine Certified Practitioners) by the esteemed Institute for Functional Medicine. Ghei provided further information on how cold showers effect human physiology and how these changes can benefits the body and even help to alleviate certain conditions.

Cold showers could be beneficial as a potential treatment for depression:

"This study from 2007 shows that ‘adapted’ cold showers (showering in water at 20°C for 2-3 min.) twice a day could have a significant antidepressant effect. In addition, this therapy may also help in pain reduction. Thankfully, this process does not have to be a sudden exposure to cold water, and a 5 min. period of gradual adaptation from warm to cold temperature, was not found to reduce the efficacy of this form of therapy as far as depression is concerned. The reason this works is that when the body is exposed to extreme cold the sympathetic nervous system, our fight or flight system is activated, and blood, as well as brain levels of certain endorphins and neurotransmitters like noradrenaline (feel good chemicals) are increased, and a huge amount of electrical stimulus from the cold water stimulated nerve endings on the skin are sent to the brain, all of which could result in the depression relieving effect. I certainly feel that cold showers, whether alone, or as an adjunct to other therapies, should be used as an additional tool in the treatment of depression."

Immunity, infections, and cancer:

"Daily brief, but repeated exposure to cold distress in the form of an adapted cold water immersion for 5-7 min. at 20°C over many months was shown to improve the activity of certain immune cells known as natural killer cells and cytotoxic T lymphocytes. The body uses these cells specifically for anti-tumor immunity, as well as immunity against infections caused by organisms that live inside our cells, including parasites. There is some evidence that this form of therapy may even increase survival in some non-lymphoid tumors in the body. There is hope that this knowledge could lead to development of adjunctive immunotherapy regimens for such tumors especially those caused by certain viruses."

Reduction of fatigue in chronic fatigue syndrome (CFS):

"This study showed that repeated exposure to cold stress increases the activity of certain areas of the brain like the reticular activating system, and it also increases the action of certain neurotransmitters (brain signaling chemicals). These areas have been found to have sluggish activity in patient's with CFS, a debilitating condition associated with severe fatigue. Extreme fatigue after exercise in CFS can also be because of a higher level of serotonin in the brain of these people. Cold therapy can reduce the production of serotonin in many brain areas leading to reduction in muscle fatigue post exertion. A third reason it works is, that cold exposure leads to activation of the hypothalamic pituitary adrenal axis causing an increased production of adrenocorticotropic hormone (ACTH), which then leads to an increased production of the stress hormone cortisol.

"You may be aware that cortisol is the survival hormone of the body and literally gives us the energy to get out of bed in the morning. This increase in cortisol levels would be very beneficial in patients with chronic fatigue syndrome who are tired all the time. Lastly, cold-induced stress increases the metabolic rate, and increases the natural opioid tone in the body (opioids are chemicals present in pain killers like morphine). This increase, in turn, leads to faster muscle recovery and reduced pain respectively, after any activity, in this subject group. Findings like these make me optimistic that repeated cold therapy might be a beneficial addition to other treatments in CFS patients who are generally extremely hard to treat."

Cold water may increase stress resilience and antioxidant levels in the body:

"Cold water therapy has been shown to increase levels of glutathione, the master antioxidant of our body, that helps remove free radical damage occurring regularly in the body due to the process of oxidation (equate this to rusting on iron when exposed to air). Healthy Glutathione levels are paramount for daily liver detoxification processes as well. The levels of essential enzymes (superoxide dismutase (SOD), glutathione peroxidase, catalase) which regulate important biochemical pathways thus helping our bodies manage all kinds of environmental stressors, are found to be higher in winter swimmers.

"As is evident, there can be some potential health benefits of cold water therapy, but I would like to caution you to avoid such a practice if you have certain heart conditions and high blood pressure. Sudden immersion in cold water can lead to at least a transient appearance of pulmonary edema (fluid in the lungs) and may cause irregular heart rhythms (arrhythmias). Some research has also shown that it increases the permeability (leakiness) of the blood brain barrier (the lining that protects our brain), leading to a chance of infections from the rest of the body affecting the brain leading to serious consequences."