Why is the Sauna so Healthy for You?

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Exploring the specific ways the sauna affects your body to make it more healthy. Do you want to reduce your risk of dementia? Do you want to get sick less often? Perhaps experience pain relief and stress reduction? Integrating the sauna into your weekly routine may deliver these results and more. 

 

Thousands of Years of Heat Therapy

Various forms of heat therapy have been popular for thousands of years. Ancient and more recent peoples seem to have had an understanding of the health effects of these sort of treatments. 

Harvard Medical School, August 2017, Sauna Health Benefits: Are saunas healthy or harmful? (https://www.health.harvard.edu/staying-healthy/saunas-and-your-health)

Sweating is an impulse that goes far back in human history. About 3,000 years ago, the Mayans of Central America used sweat houses for religious ceremonies and good health. Nearly every culture has its own way of using heat for relaxation, therapy and ritual; ancient Roman baths, modern Turkish steam baths, and trendy American hot tubs are but a few examples.

One of the oldest — and hottest — of these techniques is the sauna. Saunas have been used for thousands of years in Finland, where nearly a third of all adults take them regularly. And saunas are increasingly popular in the United States, where over one million are in use.

 

Simulating a Fever

When someone sits in a sauna, their body temperature increases by around two degrees centigrade (Journal of Human Hypertension). This increase in internal body temperature almost exactly mimics having a fever, which is your body’s natural response to sickness. 

This increase in body temperature has two different beneficial effects. First, it slows down the replication of viral cells, which makes it harder for them to take over your body and make you sick. Secondly, it turbocharges your T-cells, which are immune system cells who fight tumors and viruses to keep your body in a healthy state. 

Science Daily, December 2011, Elevated body temperature helps certain types of immune cells to work better, evidence suggests, (https://www.sciencedaily.com/releases/2011/11/111101130200.htm)

With cold and flu season almost here, the next time you're sick, you may want to thank your fever for helping fight off infection. That's because scientists have found more evidence that elevated body temperature helps certain types of immune cells to work better. This research is reported in the November 2011 issue of the Journal of Leukocyte Biology.

Scientists found that the generation and differentiation of a particular kind of lymphocyte, known as a "CD8+ cytotoxic T-cell" (capable of destroying virus-infected cells and tumor cells) is enhanced by mild fever-range hyperthermia. Specifically, their research suggests that elevated body temperature changes the T-cells' membranes which may help mediate the effects of micro-environmental temperature on cell function. To test this, researchers injected two groups of mice with an antigen, and examined the activation of T-cells following the interaction with antigen presenting cells. Body temperature in half of the mice was raised by 2 degrees centigrade, while the other half maintained a normal core body temperature. In the warmed mice, results showed a greater number of the type of CD8 T-cells capable of destroying infected cells.

"Having a fever might be uncomfortable," said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology, "but this research report and several others are showing that having a fever is part of an effective immune response. We had previously thought that the microbes that infect us simply can't replicate as well when we have fevers, but this new work also suggests that the immune system might be temporarily enhanced functionally when our temperatures rise with fever. Although very high body temperatures are dangerous and should be controlled, this study shows that we may need to reconsider how and when we treat most mild fevers."

Similar to during a fever, the increase in body temperature from using a sauna consistently has been shown to increase your white blood cell count. White blood cells are the specific mechanism your immune system uses to fight off disease. 

Women’s Health, February 2018, Saunas Might Actually Be Really Good For You—Here's Why, (https://www.womenshealthmag.com/health/a18698157/sauna-health-benefits/), referencing this study -> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3916915/

In fact, in one study published in the Journal of Human Kinetics, athletes who spent 15 minute in the sauna experienced an immediate increase in their white blood cell count, a marker for immune strength.

However, it’s important to note this immunity-boosting effect was higher in regular exercisers than in non-exercisers, so the sauna really shouldn’t be the only way you sweat.

 

How Your Body Responds to the Sauna

Healthline, May 2016, Are Saunas Good for You?, (https://www.healthline.com/health/fitness-exercise/are-saunas-good-for-you#1)

When you enter a sauna, your skin temperature rises, your pulse rate soars, and your blood vessels become more dilated. This happens as your heart begins to pump more blood. Of course, you also begin to sweat.

The result of these physiological changes is that your heart pumps way more blood - twice as much as the usual amount. This is very, very good for you on a temporary basis. 

Harvard Medical School, August 2017, Sauna Health Benefits: Are saunas healthy or harmful? (https://www.health.harvard.edu/staying-healthy/saunas-and-your-health)

The dry heat has profound effects on the body. Sweating begins almost immediately. The average person will lose a pint of sweat during a brief sauna. However, it evaporates so quickly in the dry air that a person may not realize how much he is perspiring. Skin temperature soars to about 104° within minutes, but internal body temperature rises more slowly. It usually stays below 100°.

Changes in body temperature are easy to understand, but the heart's responses to heat are even more important. The pulse rate jumps by 30% or more. As a result, the heart nearly double the amount of blood it pumps each minute.

Remember that getting very hot in a sauna is healthy for a short period of time, but you need to cool down afterwards. 

Journal of Human Kinetics, December 2018, Effect of a Single Finnish Sauna Session on White Blood Cell Profile and Cortisol Levels in Athletes and Non-Athletes, (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3916915/)

Finnish sauna has a substantial effect on the human body. Alternate hot and cold conditions used in sauna bathing are considered to accelerate biomedical athletic recovery and are frequently used as therapies in sport, recreation and rehabilitation. During a sauna session, human body is alternately exposed to hot and cold stimuli. Hot air in the sauna room affects the skin and the respiratory system. Consequently, this leads to a rise in body core temperature up to 39°C, while the temperature at the skin surface might even increase to 42°C. If heat release is impossible, the human body is likely to overheat.

Proper sauna session should be completed with a fast cool-down so that the body is quickly cooled and stops sweating. Prolonged sweat release leads to a decrease in intravascular plasma volume and consequently causes an increase in hematocrit (HCT), total red blood cell (RBC) count and leukocyte (WBC) count.

 

A Time to Relax

A key benefit to the sauna is its ability to induce relaxation. In this stressful world we live in, it’s helpful to have a calming respite from the business of everyday life. 

Healthline, May 2016, Are Saunas Good for You?, (https://www.healthline.com/health/fitness-exercise/are-saunas-good-for-you#1)

Saunas have been traditionally used to produce a feeling of relaxation. As your heart rate goes up and your blood vessels dilate, there is an increase in blood flow to the skin. Saunas may also improve blood circulation.

Your sympathetic nervous system becomes more active in order to maintain a temperature balance in your body. Your endocrine glands begin to get involved in this response. Your body’s reaction to the heat can make you less perceptive to pain, more alert, and give you a feeling of elation. The heat relaxes your muscles, including those in your face and neck. 

In fact, sauna use has even been shown to positively effect people who are suffering from depression. Pretty much all of us can benefit from increased relaxation and from the mild euphoria chemicals that are produced in the brain when we sauna. 

Women’s Health, February 2018, Saunas Might Actually Be Really Good For You—Here's Why, (https://www.womenshealthmag.com/health/a18698157/sauna-health-benefits/), referencing this study -> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3916915/

One study published in Psychosomatic Medicine even found that daily sauna sessions improved ratings of relaxation in patients with depression. Anytime you can escape the world for a moment of peace and quiet, it's going to have a positive effect on your mental health and stress she says. That’s why she regularly prescribes sauna usage to her patients who like and can tolerate the heat.

 

What About Blood Pressure?

Initial findings seem to suggest that the sauna may decrease blood pressure. 

Time Magazine, January 2018, Why Saunas Are Ridiculously Good for You, (http://time.com/5096264/sauna-health-benefits/)

The new research, published in the Journal of Human Hypertension and the European Journal of Preventive Cardiology, showed that time in a hot, dry sauna reduced people’s systolic blood pressure from 137 to 130 mmHg, and their diastolic pressure from 82 to 75 mmHg. While the systolic pressure drop was only temporary, diastolic pressure remained lower 30 minutes after people came out of the sauna.

Here are some more details, directly from that Journal of Hypertension Study:

Journal of Human Hypertension, September 2017, Acute effects of sauna bathing on cardiovascular function, https://www.nature.com/articles/s41371-017-0008-z.epdf

This study showed that sauna bathing leads to significant decrease in BP, which is a clinically important finding among participants with cardiovascular risk factors. As sauna bathing produces acute vasodilation, which causes a significant drop in BP, it can be postulated that regular sauna bathing could potentially result in longer-term reduction of BP. Systolic BP remained lower com-pared to pre-sauna levels during the whole 30-min recovery period. It is suggested that a short sauna session may reduce BP in patients with hypertension. In patients with slightly elevated BP, sauna therapy produced positive effects on systemic BP, including 24-h BP levels.

All indicators of cardiovascular compliance were improved after a single session of sauna bathing. 

 

Sauna’s May Protect You Against Dementia

I was shocked to read a study which indicated that regular sauna use could decrease your risk of developing detention and Alzheimer’s by 65%! That’s an enormous reduction in a really scary risk at the end of your life. 

Women’s Health, February 2018, Saunas Might Actually Be Really Good For You—Here's Why, (https://www.womenshealthmag.com/health/a18698157/sauna-health-benefits/), referencing this study -> https://www.ncbi.nlm.nih.gov/pubmed/?term=27932366

In the study, men who sat in a sauna multiple times per week had a 65 percent lower risk of developing dementia and Alzheimer’s disease than those who used them only once a week. The researchers say this could be connected to increased blood flow to the brain. That makes sense, because research has previously linked decreased blood flow to the brain with cognitive decline and dementia.

This study suggests that, to really get the brain boost, sauna sessions should become a regular habit.

 

Recovery After a Workout

As you might expect from the fact that many gyms also have sauna facilities, saunas turn out to be great for exercise recovery as well. 

Women’s Health, February 2018, Saunas Might Actually Be Really Good For You—Here's Why, (https://www.womenshealthmag.com/health/a18698157/sauna-health-benefits/)

The health benefits of saunas include better workout recovery. In a study published in Springerplus, both traditional steam saunas and infrared saunas decreased DOMs and improved exercise recovery.

 

Pain Relief

For those suffering from pain symptoms, regular sauna use could potentially reduce that pain by 40% - 60%. In other words, existing pain levels could be cut in half as a result of a regular sauna usage program. 

Healthline, May 2016, Are Saunas Good for You?, (https://www.healthline.com/health/fitness-exercise/are-saunas-good-for-you#1)

Using a dry sauna can leave people feeling invigorated. Since the blood vessels relax and dilate in a sauna, blood flow increases and the experience can help reduce tension in the joints and relieve sore muscles.

Saunas might also help those with chronic pain and arthritis. A study in people with chronic musculoskeletal diseases including rheumatoid arthritis and ankylosing spondylitis discovered that sauna sessions improved pain, stiffness, and fatigue over the course of four weeks.

Here’s an excerpt from that study:

Clinical Rheumatology, Jan 2009, Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis, (https://link.springer.com/article/10.1007%2Fs10067-008-0977-y)

In all patients, a clinically relevant improvement was seen during the IR sauna treatment with pain and stiffness decreasing 5 to 24 points on the VAS. Pain reduced approximately 40% and 60% and stiffness approximately 50% and 60% for patients with RA and AS, respectively (Table 3). All patients felt well during and after IR treatment, and 30 min after the end of treatment, 88.2% of patients felt “comfortable” or “very comfortable” (Table 6).

I’ve traditionally been someone who has suffered from headaches fairly consistently throughout my life, so I was delighted to read that saunas could help with those as well! 

Women’s Health, February 2018, Saunas Might Actually Be Really Good For You—Here's Why, (https://www.womenshealthmag.com/health/a18698157/sauna-health-benefits/)

One study in the Journal of Alternative and Complementary Medicine examined the use of saunas to help relieve pain and treat the symptoms of chronic tension-type headache, frequent headaches that occur more than 15 days per month. After eight weeks of sauna exposure, the 37 participants reported a significant improvement in headache intensity. The study was small, but the results suggest that regular sauna bathing is a simple way to reduce some types of chronic pain.

 

A Word of Caution

The major risk in using the sauna is getting too dehydrated. Always get out when your body tells you to do so and avoid drinking alcohol before or immediately after your sauna usage. Put your body in the best possible position to benefit from the light stress it is undergoing while you are using the sauna. 

Healthline, May 2016, Are Saunas Good for You?, (https://www.healthline.com/health/fitness-exercise/are-saunas-good-for-you#1)

The average person loses about a pint of sweat in just a short period of time in the sauna, so be sure to drink plenty of water before and after using one. Don’t spend long periods of time in the sauna, as prolonged periods increase your risk of dehydration.

Severe dehydration is a medical emergency. You should leave the sauna immediately if you feel dizzy/lightheaded, have a headache, or get very thirsty.

Harvard Medical School, August 2017, Sauna Health Benefits: Are saunas healthy or harmful? (https://www.health.harvard.edu/staying-healthy/saunas-and-your-health)

A few simple precautions to have sauna safety are important for healthy people and heart patients alike. Avoid alcohol before or after your sauna.

Lastly, if you have heart problems or have any concerns about having a basic level of fitness, please check with your medical provider first to make sure you are healthy enough to undergo the build stress on your body of using a sauna. 

Harvard Medical School, August 2017, Sauna Health Benefits: Are saunas healthy or harmful? (https://www.health.harvard.edu/staying-healthy/saunas-and-your-health)

Still, heart patients should check with their doctors before using saunas. People who can perform moderate exercise, such as walking for 30 minutes or climbing 3 or 4 flights of stairs without stopping, will likely get an okay. But patients with poorly controlled blood pressure, abnormal heart rhythms, unstable angina and advanced heart failure or heart valve disease will be advised to stay cool.

 

Conclusion

The sauna seems to be a very promising way to live longer (see previous episode about the Finnish study), experience less pain, guard against dementia, and overall to live a healthier life. These studies also indicate that including sauna use into your routine multiple times per week has significantly larger health benefits than only going once per week. Think about how you can get consistent access to a sauna or other form of heat therapy and then potentially include it in your daily routine so you remember to use it frequently. We hope this article has intrigued you regarding the health possibilities of heat therapy and we’d love to hear about your experiences as you try it out for yourself!