Eight Health Benefits of Cold Plunge?

By Dr.Panchajanya Paul, MD

Recently, cold showers, cold plunges, and cryotherapy have gained popularity, with many celebrities, athletes, and fitness influencers endorsing them. However, the concept of cold exposure and its health benefits is not a recent discovery. Let's take a journey back in time before the luxury of electricity and indoor plumbing. Energy was a precious resource, and people would use water at the prevailing outside temperature wherever they could find it. The human relationship with cold dates back even further to prehistoric times. Humans, through their evolutionary journey, have been exposed to extreme cold weather during multiple Ice ages, when most of the Northern Hemisphere was covered by ice for a significant part of the year. All living species, including our primate ancestors, have survived the extreme cold of the Ice Age. Although we are hardly exposed to extreme cold today, our body's system to fight cold is still intact. The cold adaptation system is present in all living beings and has been passed across generations since the dawn of life. The good news is - we can still harness the body's cold-adaptive mechanism to boost our physical and mental wellbeing.

What exactly happens in a cold plunge? Our body, a marvel of adaptability, responds to cold exposure in remarkable ways. The skin, our body's largest organ, is equipped with many thermoreceptors that detect changes in ambient temperature. Regardless of the outside temperature, the hypothalamus in the brain must maintain the body's internal temperature between 97°F and 99°F for survival. When the body is exposed to a sudden cold, it shocks the body. In response to cold, the body releases a special set of proteins called cold shock proteins ( CSP ) that are present in the liver and are released into the bloodstream. These proteins facilitate several metabolic and hormonal processes, enabling the body to become more adept at handling the stress of cold. However, the benefits of cold-induced body changes do not stop at cold but rather are part of a generalized stress response that increases physical and mental resilience to fight other disease processes.

Cold can help, but extreme, prolonged cold can also harm. Let's review what constitutes beneficial cold exposure. Exposure to lower temperatures, such as short outdoor walks in winter, bathing in river water, cold baths, cold showers (like standing under a cold water shower for a few minutes), ice plunges (like jumping into a cold pool or a natural body of water), and specialized cold cryotherapy chambers, will all trigger the release of cold shock protein. Shivering is an adaptive response to acute cold. Acute and sudden changes in cold exposure for short periods will lead to a massive release of health-promoting cold shock proteins. Shivering is not a prerequisite, but it is a good indicator that the temperature is low enough. In the next section, I will enumerate eight positive health benefits of cold exposure.

 

1.Improved Metabolism: When exposed to cold, our body produces a special kind of fat called Brown Fat. This type of fat is different from the white fat that we usually think of when we talk about body fat. Brown fat is a metabolically active type of fat that burns calories to generate heat. It's like a furnace in your body, burning calories to keep you warm. Research has shown that people who work outdoors during the winter months have a higher percentage of brown fat. Most of the fat in our body is white fat, which is the type of fat that accumulates and leads to obesity, insulin resistance, and diabetes. Cold exposure will reduce white fat in the body and increase the percentage of brown fat. Humans are born with more brown fat, but as we get older, the percentage of brown fat diminishes. Brown fat boosts the body's metabolic rate, making the body burn more calories even at rest. Brown fat also has more Glut 4 receptors, which enables glucose absorption directly into the muscles and fat without the use of insulin. In addition, brown fat cleans up the excessive branched-chain fatty acids (BCAA) from the bloodstream and transfers them to the mitochondria to burn as heat. Removal of excess glucose and BCAA will increase insulin sensitivity and has the potential to treat insulin resistance, obesity, and diabetes.

2.Fat Burn: Animals in the wild, with no access to artificial heaters, harness their body fat to survive winter. Cold exposure can help burn body fat due to its thermogenic effects. The word calorie means heat; a calorie is the unit of heat energy needed to raise the temperature of 1 gram of water by 1 °C. During cold exposure, the body must expend extra energy to maintain its internal temperature. The colder the temperature, the more calories have to be burnt to keep the inside of the body heated. Exercises like swimming, water exercises, and regular workouts performed in cold outdoors will challenge the body to burn more calories for energy and warmth. Additionally, cold exposure stimulates the production of more brown fat, which contributes to fat loss. The areas of the body more receptive to cold-induced fat burn are the back, neck, and shoulders, which have the maximum amount of brown fat.

3.Better Sleep: In our modern world, where we often do more mental work than physical work, it's common to struggle with sleep due to overstimulation and information overload. Cold showers before bedtime can break this autonomic arousal loop, slowing the body and the brain. At night, the temperature of the earth drops, and the human body, following the circadian rhythm, also experiences a neural drop in temperature by about 0.9 Fahrenheit. However, modern humans living indoors under artificial temperature regulation do not experience the decline of outside temperature. Hence, the body misses an essential clue about the time of sleep. A cold shower at night helps lower body temperature and signals the body to prepare for sleep. Another option is to immerse the face in cold water or rub ice over the face. Cold exposure to the face and jaw will stimulate the Vagus nerve, shifting the body from the fight-or-flight sympathetic mode into the parasympathetic mode, which brings a sense of calm and rest. Following a cold shower, as the body recovers, there is a decrease in heart rate, a drop in blood pressure, a slowing of breathing, and a calming of the mind, all of which prepare the body for a restful sleep.

4.Exercise Recovery: It has been a common practice among athletes to use cryotherapy to facilitate rapid physical recovery, especially when playing multiple games over short intervals. The practice of using cold for post-exercise recovery is gaining mainstream popularity, mainly due to increasing awareness about health and fineness. A cold plunge following exercise causes blood vessels to constrict, reducing peripheral blood flow. The reduced blood flow reduces the inflammation and swelling following exercise or injury. The practice dates back to ancient Greece, where athletes would dip in cold, icy river water to soothe their muscles after intense exercise. However, some concerns exist that reduced blood flow may impair muscle growth, so individuals seeking muscle hypertrophy may want to avoid cold plunges immediately after strength training.


5.Mood Boost: Cold exposure is an excellent way to start the day and beat the morning blues. The skin has cold receptors that detect a drop in temperature, causing the body to experience discomfort and pain. To relieve this stress, the body releases natural pain-relieving substances called endorphins, which also boost mood and induce a feeling of euphoria. Additionally, cold exposure also releases the hormone dopamine, which is associated with feelings of wellbeing and happiness. The increase in dopamine from cold exposure can be as high as 250 percent and lasts throughout the day, contributing to a sense of wellbeing and positive feelings. Moreover, cold also triggers the release of the stress hormone norepinephrine, also known as noradrenaline. Noradrenaline release is a component of the fight-or-flight response, which increases focus, alertness, and energy. The combined effects of endorphins, dopamine, and noradrenaline can significantly boost mood, give a sense of wellbeing, and reduce feelings of depression.


6.STRESS RESILIENCE: Mental illness is on the rise across the world, and one primary reason is the increase in chronic stress people face in daily life related to work, family, finances, and health. Any time the body faces stress, cortisol level goes up, and in chronic stress, cortisol remains high, causing mental illnesses like anxiety, depression, insomnia, addiction, and suicidality. In addition, chronic stress can accelerate the aging process, causing thinning of hair, wrinkles, and diseases like obesity, diabetes, and hypertension. Regular cold exposure lowers the baseline cortisol level, thereby helping the body better fight the stress of cold. However, the benefits do not stop with cold; the body becomes more resilient to fight other stressors. In addition, there are psychological benefits. Each time the body handles the acute stress of a cold and comes out unharmed, it boosts mental toughness and improves confidence. If one can tolerate subzero colds without giving up, they can later handle any stress that may come on their way.

7.Pain Relief - Many people suffer from chronic pain related to musculoskeletal injuries or chronic inflammation. Cold plunge can help relieve muscle soreness. Additionally, alternating cold and hot plunges can accelerate the healing process by flushing out accumulated lactic acid. In addition, cold releases endorphins, which are natural painkillers. Many people suffer from autoimmune diseases, in which the body's immune system mistakenly attacks its cells. Cold exposure can modulate the immune response and help alleviate the pain associated with autoimmune diseases.

8.Immunity Boost – Brief Cold exposure activates the body’s immune system. In response to cold, there is increased production of white blood cells, cytokines, and lymphocytes. The white blood cells are the body's natural defense mechanism, applicable to fight germs and pathogens. In addition, cold also activates the lymphatic system, which promotes the removal of toxins from the body. A study in the Netherlands found that healthy individuals switching to cold showers reported fewer instances of illness and took fewer sick days off work. However, prolonged cold exposure, particularly in individuals with preexisting illnesses, can overwhelm and exhaust the immune system, making one more vulnerable to infection.



Lastly, one can look at cold exposure as a form of physical exercise. Cold exposure offers many similar health benefits to exercise, but, like exercise, it can also be harmful if done excessively or in poor health. Begin cold exposure slowly and gradually over a period so that the body can acclimatize to these positive, healthy adaptations. People with prior heart or lung disease must be careful, as cold-induced sudden vasoconstriction can put too much stress on the heart to pump blood, leading to irregular heart rhythms and heart attacks. Avoid cold exposure if you are already suffering from fever, infection, sleep deprivation, anemia, and hypothyroidism, which reduces the body's cold tolerance. In addition, individuals with reduced immunity due to old age or those with any immunocompromised condition should exercise caution, as cold exposure can increase the risk of infection and pneumonia. Healthy cold exposure is short and controlled. Always avoid prolonged, excessive cold exposure. Any form of chronic stress is detrimental to the body over the long term. Chronic cold exposure can create chronic stress. Working outdoors all day in extreme cold or keeping the air conditioning too low for both day and night is also not beneficial as it can exhaust the body's reserves, making one more susceptible to illness.
In summary, cold exposure is a new tool to boost health and lifespan. Brief controlled cold exposure offers health benefits and may provide an additional approach to weight loss, blood sugar control, immune system enhancement, inflammation reduction, and pain mitigation. Like any exercise, practice with caution; if in doubt, seek guidance from a health professional before you take your first cold plunge.


References :
https://www.nih.gov/news-events/nih-research-matters/how-brown-fat-improves-metabolism#:~:text=Brown%20fat%20breaks%20down%20blood,fat%20builds%20up%20in%20obesity

https://www.bodyspec.com/blog/post/the_incredible_benefits_of_cold_shock_protein
https://www.webmd.com/a-to-z-guides/cold-plunge

https://pmc.ncbi.nlm.nih.gov/articles/PMC9518606/


https://longevity.stanford.edu/lifestyle/2024/05/22/jumping-into-the-ice-bath-trend-mental-health-benefits-of-cold-water-immersion/