Infrared Sauna Science and Media
Finnish researchers evaluated medical records from more than 2,300 men who were part of the Kuopio Ischaemic Heart Disease (KIHD) study, tracking their health for an average of 20 years.
Men who used the sauna four to seven times a week had a 66 percent lower risk for dementia, and a 65 percent lower risk for Alzheimer’s disease, compared to men who used the sauna once a week.5 The average length of each sauna was about 15 minutes.
Other research has shown sauna use increases levels of norepinephrine,7 a stress hormone that increases focus and attention, as well as prolactin, which may promote myelin growth (the insulation around the nerve fibres in your brain), helping your brain to function faster and repair nerve cell damage.
Even the boost in endorphins and well-being that’s often felt after exercise (sometimes referred to as a runner’s high) may be related to heat stress, such as that experienced in a sauna. One animal study revealed that heat stress from exposure to a sauna increases endorphins significantly.8
Infrared sauna heat exposure creates brain-derived neurotrophic factor (BDNF), which stimulates neurogenesis (the growth of new brain cells) and protects existing neurons from damage (source), BDNF also triggers numerous other chemicals that promote neural health.
The benefits of sauna usage extend throughout your entire body, including your heart. Using the same KIHD study data, researchers found the frequency of sauna use, and length of time spent in the sauna, correlated with a lowered risk for lethal cardiovascular events.10
Sauna use was also associated with a reduced risk of death from any cause, and the more the men used the sauna, the better. Men who used the sauna seven times per week cut their risk of death from fatal heart problems in half compared to those who only used it once each week.
In addition, frequent sauna bathing was associated with a reduced risk of sudden cardiac death, fatal coronary heart disease and fatal cardiovascular disease. These findings remained stable even when confounding factors such as smoking, blood pressure and triglyceride levels were factored in.
The greatest benefits were found among those whose saunas lasted 19 minutes or more each session. The benefits were so significant that researchers compared sauna bathing to low- or moderate-intensity exercise, noting:11
“Heart rate may increase up to 100 [beats]/min during moderate sauna bathing sessions and up to 150/min during more intense warm sauna bathing, corresponding to low- and moderate-intensity physical exercise training.
These proposed functional improvements associated with sauna bathing correspond to similar benefits seen with regular physical exercise, such as improvement in blood pressure and left ventricular function.
It has been documented that cardiac output is increased mainly because of the increase in heart rate during sauna bathing.”
Saunas’ ‘Hyperthermic Conditioning’ Improves exercise performance.
In another study, those who had a 30-minute sauna session twice a week for three weeks after their workouts increased the time it took to run until exhaustion by more than 30 percent.12
This benefit may be due to hyperthemic conditioning, or “acclimating yourself to heat independent of aerobic physical activity through sauna use,” which boosts endurance because it induces adaptations in your body that make it easier for you to perform when your body temperature is elevated.
As your body is subjected to reasonable amounts of heat stress, it gradually becomes acclimated to the heat, prompting a number of beneficial changes to occur in your body.
These adaptations include increased plasma volume and blood flow to your heart and muscles (which increase athletic endurance) along with increased muscle mass due to greater levels of heat-shock proteins and growth hormone. Other physiologic adaptations that occur from hyperthermic conditioning include:13
Lower core body temperature during workload
Relaxation & Stress Reduction
Have you ever heard of the fight or flight response, like when you are walking in a jungle and suddenly see a tiger? Our lives are typically full of chronic stress and very little running away from tigers. Unfortunately, unlike short-term stressful experiences, which produce a rise in cortisol and a physical response (such as running away) followed by a reduction in cortisol after the event, our bodies stay in “high alert” stage for hours, days and even sometimes months without a reset.
Our bodies often can’t distinguish life-threatening situations from non-critical situations, and therefore react to everything just in case. That’s a problem because:
When you repeatedly experience the mobilization or fight-or-flight stress response in your daily life, it can lead to serious health problems. Chronic stress disrupts nearly every system in your body. It can shut down your immune system, upset your digestive and reproductive systems, raise blood pressure, increase the risk of heart attack and stroke, speed up the aging process and leave you vulnerable to many mental and physical health problems.” (source)
Fortunately, it’s not necessary to renounce civilization and move into a yurt to reclaim relaxation – you can manually reset your stress response. Exercise is one way to do it – sauna therapy is another.
When you expose your body to heat stress, your cortisol levels (an indication of stress) will typically stay the same or even rise. However, when you remove the stress by stepping out of the sauna, they’ll drop almost immediately and set a new baseline that is lower than before. Your body thinks the “tiger” is gone and has reset, leaving you feeling relaxed.
In addition to helping with stress, sauna therapy stimulates the release of “feel good” neurotransmitters such as serotonin and dopamine, which is why I feel AMAZING when I finish a session. (source 1, source 2)
Pain Relief, Detoxification and Longevity
Many people enjoy using a sauna to soothe muscle tension and research suggests it can be beneficial in helping your body recover from strength and endurance training sessions.20 Other research also supports sauna use for reducing pain in fibromyalgia patients.
In one study, 44 patients with fibromyalgia found a reduction in pain between 33 percent and 77 percent after use of a far infrared-ray dry sauna.21 Six months after the study had concluded, the participants continued to report a reduction in pain between 28 percent and 68 percent.
Longevity-wise, research22 shows you can boost your human growth hormone (HGH) levels by two-fold by taking two 20-minute sauna sessions (at 176 degrees F) separated by a 30-minute cooling period. Two 15-minute sauna sessions separated by a 30-minute cooling period may boost your HGH by five-fold.
Some of the benefits of sauna usage also occur due to increased sweating. Many people do not sweat much on a regular basis, but it acts as an important route of detoxification, including helping to excrete toxic metals like arsenic, lead and mercury.23
Researchers writing in the Journal of Environmental and Public Health explained:24 “Sweating with heat and/or exercise has been viewed throughout the ages, by groups worldwide, as ‘cleansing’ … Sweating offers potential and deserves consideration, to assist with removal of toxic elements from the body.”
According to Dr. Rhonda Patrick, “Almost all the primary causes of aging have stress at their root. Inflammation is a prime example and in fact it’s been identified as one of the key drivers of the aging process . . . . However somewhat paradoxically, stress isn’t always bad. Short term stress can result in a reduction in long term chronic stress – in other words we can build resilience. This is because short-term exposure to stress can strengthen the cellular response mechanisms in the body to stress. This is called hormetic stress.”(Source: Sauna Use And Building Resilience to Stress)
Exercise is a type of hormetic stress, as is cold stress and – you guessed it – heat stress. Sitting in a sauna creates heat stress, which causes the body to increase its production of heat shock proteins, which help repair damaged proteins and protect DNA.
Normally we produce fewer heat shock proteins as we age. However, some people have genetic mutations that cause them to maintain higher production. Specifically:
Centenarians, or people who live to be at least 100, tend to have an increased expression of heat shock proteins – the same proteins that are produced in a sauna. (source)
In another study, researchers found that exposing C. elegans worms to sauna-like conditions – thus producing heat shock proteins – extended their lifespan by about 30%. (source)
According to Mark Timmerman, M.D. of the North American Sauna Society, “During a sauna session, white blood cells increase in the bloodstream, suggesting an elevation of the body’s natural defense against illness.”
OTHER AWESOME INFRARED STUFF
“For many, the biggest news in FIR [Far-InfraRed] technology is its application to the evolving science of detoxification, and the device being used is the Far-InfraRed sauna. At home and in clinics, these saunas are said to yield many benefits– including relief from different kinds of pain; stimulation of immune response; improvement in skin tone and conditions such as burns, eczema and acne; and the accelerated burning of calories. But the detox application is health news that can benefit everyone. Traditional wisdom has suggested that saunas work largely by promoting detoxification through sweat.”
– John C. Cline, M.D., B.Sc., C.C.F.P, A.B.C.T.,
Medical Director of the Cline Medical Center and Oceanside Functional Medicine Research Institute
Several published studies have now shown that this hyperthermic [sauna] therapy can bring about the rapid removal of a wide range of toxic substances from the human body.
An estimated 30-50% of the American population (myself included) has the MTHFR genetic mutation, which may impair detoxification
Numerous compounds are released in the sweat.
- Copper and zinc are released in high amounts in sweat
- Nickel and lead were found in lower levels than copper and zinc.
- Manganese, cadmium, and aluminum have also been found in the sweat in much lower amounts than Cu and Zn.
- Cadmium and nickel levels in the sweat have been found to be higher than corresponding levels in the urine, making sweating a prime route of depuration for cadmium or nickel toxicity
- Sweating has also been explored as a valid method for reducing antimony levels in persons with high Sb exposure.
- In persons whose blood lead averaged 8.62 μg/dL, the level in the sweat averaged 5.2 μg/L, which was about 25% that of the urine.
- Dermally absorbed lead was released in both sweat and saliva, but did not show up in the blood.
- A study on the toxicokinetics of lead states that soft tissue lead, not blood lead, is the source for lead released in sweat
- Only 1 published study was found regarding mercury and sweat. This study did not give a measurement of mercury in the sweat, but noted that in a mercury-poisoned person the
mercury blood level continued to drop during the sauna portion of the protocol (which followed chelation therapy).
A large number of medications have been detected in the sweat
Source: Components of Practical Clinical Detox Programs. Sauna as a Therapeutic Tool
Walter Crinnion, ND
According to Dr. Rhonda Patrick, who holds a PhD in biomedical science, the fact that sweat contains both hydrophyllic (water soluble) and lipophilic (fat soluble) components makes it an elimination pathway for a variety of toxins, including:
- xenobiotics such as BPA (often absorbed through store receipts), PCB’s, and phthalates
- Arsenic, cadmium, lead, mercury
Health Status of Rescue Workers Improved by Sauna Detoxification
Townsend Letter for Doctors, April 2006 #273
Marie A. Cecchini, MS; David E. Root MD, MPH; Jeremie R. Rachunow, MD; and Phyllis M. Gelb, MD
“While the data presented in this paper was collected in the context of routine
outcome monitoring rather than in a controlled study, the results are encouraging. The number of WTC exposed individuals (more than 500) who have achieved the rehabilitative goals of sauna detoxification therapy – restoring quality of life and job fitness– is significant. The improvements in self-reported symptoms, an indication of a marked return to wellness, are supported by reduced need for medication.
These findings are further confirmed by objective measures. This regimen has greatly reduced the number of work days that rescue workers miss due to illness, and has resolved anxieties that careers will be end prematurely in disability retirement. Anecdotal reports from spouses, family members, and employers describe dramatic changes in the quality of family life as a result of such improvements.”
Heavy Metal Detox: Why Sweating May Protect the Kidneys
Will dry sauna prove the safest and best method for most people?
” This article presents our opinion regarding the current status of several research questions. We list the average U.S. body burdens of three heavy metals and some health implications, especially the well established correlation with kidney disease and early death.
New studies may show that the cost of this intoxication, especially by mercury (Hg), is even larger than now believed. Public demand for heavy metal detoxification may increase use of the various chelators and procedures that appeared to work well (via the kidneys!) in acute poisoning cases of the last four decades. However, for chronic exposures, we discuss reasons to expect that both the body burdens and the associated risk of kidney injury may be much greater.
On the brighter side, we explain why urgently needed research may find that sweating, especially in dry sauna (180°F dry air produces 1 quart of sweat in 20 minutes!), and the use of ascorbic acid may both protect the kidney. If true, dry sauna may provide the safest, best and most economical therapy by far, for most people.
A major advantage of sweating may be excretion of most of the Hg (Cd, Pb, etc.), out through the skin and liver instead of through the kidneys.”
– John T.A. Ely, Ph.D.
source: Well Mind Association Special Report – March 1994