Here at Gene Food, we’ve talked a lot about genetic pathways and supplements that help our bodies detoxify. For example, John has written long posts about superoxide dismutase and glutathione, both antioxidants our bodies make and use to clear toxins, but supplements aren’t the only way to detox. In fact, ancient practices such as sauna have been used for generations to clear the body of toxins.
Much like Swedish, deep-tissue, or relaxation massage, there are actually a few different types of saunas. Infrared sauna therapy is one of the most talked about, with celebrities like the Kardashians touting its health benefits that supposedly include weight loss, stress relief, and even anti-aging. Infrared saunas are becoming so popular that you can buy them on Amazon, but are they healthy?
Should you include infrared sauna as part of your health regimen?
Let’s take a look at some of the evidence for and against.
How does an infrared sauna work?
Unlike a normal sauna that just uses heat, infrared saunas use both heat and light. Infrared light waves heat your body, which causes the release of toxins through sweat and the relaxation of muscles. And this is the big takeaway here: infrared sauna is healthy primarily because it makes us sweat, and good old-fashioned sweat is one of the best ways to get rid of toxic metals like mercury, lead, cadmium, and arsenic.1
Infrared saunas utilize a type of “far infrared radiation,” or FIR, also referred to as thermal radiation. Special lamps also may be FIR, and FIR technology can be woven into fabrics so the benefits are wearable. FIR is absorbed as well as emitted from the body; it’s the only type of radiation perceived by the body as “gentle radiant heat” — and it can penetrate up to 1.5 inches beneath the skin.2
What does that mean?
In layman’s terms, the heating elements inside infrared saunas are heated to 300 to 400 degrees Celsius — that’s really hot. But the temperature inside the sauna is about 40 degrees Celsius, or less, and remains there (104 degrees Fahrenheit, about the top-level temperature of a hot yoga class). As such, you may feel warmer faster in an infrared sauna than another type of sauna because the light penetrates your skin to warm you, versus just the air around you, as in a regular sauna.
Again, the technology is cool, but it’s really the sweat that is of the greatest health benefit, and the only element of infrared sauna therapy that is somewhat proven.
Is infrared radiation harmful to the body?
OK, so you may see the word “radiation” and think, yikes, I don’t want that. While it’s true that some types of radiation are harmful to us, infrared technology generally falls in the safe zone.
Consider the following graphic as a way to better illustrate the difference between infrared technology and other types of radiation:
While infrared saunas can alter cell membranes, water molecules, and DNA proteins, they do so in a positive manner that is generally considered safe and may even improve metabolism.
Do infrared saunas help us detox?
Release of toxins will be the main benefit of infrared saunas, or any sauna, despite the differences between the two methods, though we’ll take a look at some studies regarding other purported infrared sauna health benefits in a minute.
Going back to toxins, it’s important to understand a little bit better how toxins work, what they do in our body, and how we get them out. Do we detox most through our skin, or our liver, or our kidneys?
We’re going to take the opposite approach of this recent article in The Atlantic to say that yes, saunas do help with removing toxins from the body. Of course, you’re not going to feel 100% better after a hangover by going to a sauna, but you can help your body release some toxic metals with a quick session.
Our daily exposure to toxins can have adverse health effects, ranging from cancers and cardiovascular diseases. A majority of naturopathic doctors use “detoxification” therapies in their practices.3 This is done for everything from general/preventative medicine to treating inflammation and gastrointestinal disorders. While therapies such as cleansing foods, increased fruit/vegetable intake, increased probiotics, and increased fiber were more popular, 66% of naturopathic doctors say they use sauna as part of their detox therapies.
Mercury levels have been shown to normalize after repeated sauna use, and when one Canadian study tested the excretion of toxic elements in sweat after sauna or exercise in 10 healthy individuals and 10 with chronic conditions, it found the following:45
- 17 of 20 participants had arsenic in their sweat, blood, and urine samples after a sauna or exercise session (blood and urine toxins come from what our kidneys and liver help us filter out);
- 16 of 20 participants had mercury in their sweat, blood, and urine samples after a sauna or exercise session;
- 3 of 20 participants had cadmium in their sweat, blood, and urine samples after a sauna or exercise session — the amount of sweat recorded more cadmium than what was collected via blood or urine; and
- A high amount of lead was also found in the sweat of participants, and an additional Russian study6 recommended sauna use for removing lead from the body.
Of the systemic review cited earlier, lead was examined in 11 studies total, with one7suggesting that “sauna bathing might provide a therapeutic method to increase elimination of toxic trace metals.” Infrared saunas may simply be more comfortable for people looking at detoxification methods because the air stays cooler than in a traditional sauna.
If you do choose trying to “detox” through a sauna, it is important to drink plenty of fluids and stay hydrated. It’s important to remember that sweat is mostly water, after all, and you aren’t going to be able to detox simply through sweating. The liver is the body’s principal filter8, and keeping it and our other organs healthy (intestines, lungs, kidneys) plus a tip-top immune system is our best way of detoxing.
Another interesting detox sauna study
This is a little out there but worth mentioning when considering whether or not saunas may help with detox methods. Take the example of a high-profile clinic in Manhattan associated with the controversial Church of Scientology. This clinic is using what it calls the Hubbard Purification Program for treatment of World Trade Center rescue workers, which includes sauna sessions, graduating doses of niacin, exercise, diet changes, and electrolytes.
While methodological descriptions of the program lack specificity, particularly regarding rationale, medical monitoring, and poor characterization of endpoints, it has been shown to decrease serum and adipose levels of lipophilic chemicals, including polycholorinated biphenyls and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane.
However, a similar regimen that included sauna use helped improve cognitive function in a study of 14 firefighters years earlier who had been exposed to polychlorinated biphenyls (PCBs). Their scores for depression, anger, and fatigue did not change from before and after the sauna session.9
Infrared sauna health benefits
Japanese and Korean people have been using infrared saunas for years, namely for alleged improvement of cardiovascular conditions including chronic heart failure and peripheral arterial disease. They also use infrared saunas in general to reduce oxidative stress.
While these conditions may not be the main reason for using an infrared sauna in the U.S. by those catching onto the fad, we’ll start with heart health studies and move down the line of some of the other top perceived benefits of infrared saunas. It should be noted that many studies on infrared saunas use small sample sizes (we didn’t review ones with just two or three people studied, but they’re out there), so the actual scientific evidence of infrared sauna benefits could be a lot better.
According to review of published evidence regarding infrared saunas and heart health, FIR may normalize blood pressure and treat congestive heart failure, but this evidence is limited and moderate at best.10 At least three scientific papers support using infrared saunas for people with coronary risk factors, such as hypertension, obesity, and smoking; however, there were problems with some of the reporting methods used by study authors to give the results more validity, or the studies were too short of duration.
That said, there is one long study on heart health and saunas, and it’s a good one, involving 2,300 middle-aged men in Finland.11
Over a period 20 years, researchers found that the men who went to sauna more frequently died less, particularly from cardiovascular disease and stroke. The Finnish consider their saunas “unique” (and they’re not infrared), with nearly as many saunas in Finland as TV sets. Most Finnish people go to the sauna once a week but only half of men and one-third of women meet exercise recommendations, leading researchers to note that the saunas may have an effect on cardiovascular conditioning as they raise the heart rate, similar to exercise. But, even the authors of this study noted that further research should be done, and we don’t really see how they could have tracked all other lifestyle and environmental factors that could have led to these results.
In another systemic review of heart health studies, infrared saunas were found to to possibly increase peripheral blood circulation and artery blood flow, along with promote capillary dilatation.12 Because saunas may simply decrease oxidative stress, some of the claims may hold true, but we’d like to see more human studies and larger sample sizes before truly weighing in.
A summary of findings from the system review sums this up nicely (bolding emphasis is mine):
Although previous studies have shown that FIR radiation produces thermal and non-thermal effects, such as increasing artery blood flow and peripheral blood circulation, improving endothelial function, alleviating fatigue and pain, reducing blood pressure, and promoting capillary dilatation, the precise mechanism has yet to be thoroughly understood.
Infrared saunas may be helpful in at least relieving serious pain for patients with conditions such as rheumatoid arthritis. In one study, 17 rheumatoid arthritis patients and 17 ankylosing spondylitis patients were treated over a four-week period with eight infrared sauna sessions. Improvements of pain and stiffness were “statistically significant,” with comfort felt especially after sessions and no enhancements in disease activity.13
While chronic pain relief and FIR technology have been studied, the evidence of its positive effects is limited. Of 46 patients with chronic pain, people in the sauna test group were more likely to have improved sleep and/or have returned to work after two years of therapy, in addition to improvement in pain behavior and anger scores.14
When it comes to pain relief from strength or endurance training, a small study involving 10 healthy and physically active men found that the deep penetration of infrared heat may help athletes recover from tough workouts faster.15
Outside of tests of endurance athletes and people with heart conditions, we couldn’t find any studies that specifically showed how infrared saunas lowered general stress levels in people after sessions. Because heat works up our heart rate, sitting in an infrared sauna or regular sauna for 15 minutes may be a “stress” on its own, similar to a standard treadmill stress test. However, because many of us feel relaxed in a sauna or similar environment (hot tub, etc.), and we tend to feel good after a light workout gets our endorphins going, an infrared sauna session may help us feel less stressed afterward.16
Moving back to some of the heart health benefits, infrared saunas may also help people who are overweight. A group of patients with type II diabetes were studied after using infrared saunas three times a week for 20-minute sessions over 3 months. A variety of measurements for stress and fatigue showed each of those areas improving. Infrared saunas also were an easier treatment method for people with type 2 diabetes to stick with than other lifestyle interventions.17
Additionally, you may have heard of “weight loss belts.” Some of these belts are made with the same FIR technology as infrared saunas to help wearers lose weight. In one study, 42 women wearing FIR belts experienced reduced body measurements, though this may have been due to the belts improving circulation and blood flow and therefore, overall health.18
Many infrared sauna owners promote a “natural anti-aging” benefit to their saunas to help get customers in the door. But can we really reverse the effects of aging with a sauna session?
Researchers in one study looked into the effects of infrared radiation on collagen and elastin production in dermal fibroblasts, in addition to how the technology would affect photo-aged facial skin lesions. Twenty patients with mild-to-moderate face wrinkles and hyper-pigmented lesions received daily FIR treatments for six months, after which, collagen and elastin production were found to have increased. Most patients thought their skin texture improved, while about 1 in 4 thought their skin color tone did as well — though researchers did not see any improvements in hyper-pigmented lesions.19 Although infrared saunas could help reduce wrinkles, some of the results may be in the eye of the beholder.
It should be noted that some types of near infrared radiation (NIR) have detrimental effects to the skin, with chronic exposure to heat via NIR leading to more wrinkles. However, NIR is also used as a type of light therapy, and it all depends on the level of irradiance.20
Risks of infrared saunas
Although infrared saunas are widely seen as useful, they may cause some negative side effects for some people. You may experience an increased heart rate and moderate to heavy sweating, and you would experience a cardiovascular demand similar to walking at a moderate pace or riding a bicycle.21 And if you’re a man concerned about your fertility, the heat from any type of sauna may affect the motility of your sperm count and motility.22
Key takeaways on infrared saunas
So, you’ve decided you want to give infrared sauna therapy a try. But how many times per week should you use an infrared sauna? Experts recommend 20-minute sessions a few times a week, typically, in addition to staying hydrated and avoiding alcohol before and after sessions. Make sure to talk with your doctor if you have a history of heart disease or other cardiovascular problems before using any kind of sauna, or if you get lightheaded easily (low blood pressure). You can feel exhausted after a sauna session, so it’s better to be as safe as possible.
All in all, while some studies have shown a few benefits to infrared saunas, others may not notice any at all outside of simple relaxation or sweating out toxins. If you have a heart condition, it’s worth going over options with your doctor to see if infrared sauna therapy may be helpful to you.