Home • AltMed Home • Search • Feedback

Research Support for Health Benefits of Infrared Sauna

There are not enough scientific studies to provide definitive answers on the efficacy of this product. 

In general, the following factors must be considered when exploring the "benefits" of Far Infrared therapy:  

• The effects of the infrared modalities are primarily superficial and directly affect the cutaneous (skin) blood vessels and nerve receptors.
   

• Penetration of energy into a medium is dependent on the intensity of the source of IR, the angle at which the ray hits the surface and the coefficient of absorption of the material.
  

• Skin is a complex material and its reflective and absorptive characteristics are not uniform, especially between individuals.

Detoxification

• There are no scientific data to support the idea that toxins are expelled from the human body through sweating, making claims that this treatment is "detoxifying" questionable.
  

• "There is no evidence that mercury is eliminated from the body through perspiration."

- Judge Nancy Connick in her ruling against Hal Huggins DDS, concerning mercury poisoning from fillings.

• "No such 'toxins' have ever been found.  Instead of promising to cure your disease, some quacks will promise to 'detoxify' your body." (quackwatch.com)
  

Metabolic Changes

• An increase in temperature will result in an increase in the metabolic activities in the superficial tissues only due to the direct effect of heat on chemical processes.
  

• Metabolic rate increases approximately 13% for each 1 degree C increase in temperature. 

Circulatory Effects

• There is an increase in circulation due to vasodilatation of the skin vessels.  This may be mediated through the direct effect of heat on the vessels themselves or via their vasomotor nerve supply.
  

• Body core temperature or blood pressure do NOT rise significantly.
  

• Most research shows the effect of IR to be local.  There is an increase in circulation superficially but does not extend far in terms of depth.

• Cutaneous vasodilatation, increased skin blood flow and heart rate, and profuse sweating are the most effective mechanisms whereby the body can combat the thermal stress of the sauna.  Peripheral vascular resistance decreases by 40% and cardiac output increases by 70% (in proportion to heart rate).  Mean arterial pressure decreases moderately in response to heat.  The change in systolic blood pressure is small.  The intense vascular dilation in the skin and the drop in peripheral resistance explain the finding that the load on the heart and the oxygen demand are lower than physical or emotional stress with the same heart rate. 

Weight Loss

• Reports say although weight may drop by as much as four pounds during a long session, you are primarily losing fluids and not burning fat.  This weight will return as soon as you drink fluids.
    

• However, to produce one gram of sweat requires 0.568Kcal.  Thus, reports state a conditioned person can easily lose 500 grams of sweat in a sauna, consuming nearly 300Kcal (equivalent to a 2-3 mile run).  While the weight of the water will be regained easily by drinking, the calories will not.  There are no studies that support sauna use as an effective means for weight loss.  There is also no release of toxins that is documented to help with weight loss.
  

Fighting the Common Cold

• The heat from a sauna may temporarily alleviate the symptoms of colds, but they do not shorten the duration of infection.

Arthritis

• The heat itself may help control pain and increase joint mobility.  However, sauna use alone does not modify the natural process of the disease.
  

• The joints are more supple through altered properties of joints and tendons, which may help temporarily improve motion.

Elderly

• It is generally safe for the elderly to use a sauna but they should consult with a physician before doing so.

Collagen

• Studies do show that heat does alter the behavior of collagen and therefore may be used prior to applying passive stretch or active exercise in order to facilitate the lengthening of scars or contractures.
  

• Heat increases the elasticity and decreases the viscosity of connective tissue.

Joint Stiffness

• Studies show there was a 20% decrease in stiffness at 45 degrees C as compared to 33degrees C in rheumatoid finger joints.

Muscle Spasms

• Muscle spasms are known to be reduced by heat, be they secondary to underlying skeletal, joint or neuro-pathological conditions.
  

• Newer studies show cold may be better in reducing muscle spasms.
  

• Information about the physiological basis for the clinical observation that heat relieves muscle spasm is limited.
  

• Possible reduction in muscle spindle firing or inhibition of the golgi tendon organ

Neurological/Pain Relief

• There has been documented pain relief with the application of heat.  There are two theories associated with this:

1. Vasodilatation brings cells and chemicals to the area to assist healing and remove breakdown products of injury.
   
   

2. The pain gate control theory might indicate that the transmission of thermal sensations may take precedence over nocieceptive impulses( pain).

• Studies do show that when IR was applied to a region of the body,  there was an analgesic effect distal to that point.  
  

• Some researchers are now saying there may be an increase in endorphins.
  

• Local superficial heating is recommended in subacute conditions for reducing pain and inflammation through analgesic effects.
   

• Superficial heating produces lower tissue temperatures at the site of injury relative to the higher temperatures in the superficial tissues, resulting in analgesia.
  

Endocrine System

• The endocrine system does respond to thermal changes, mainly through activation of the sympathetic nervous system and activation of the hypothalamus-pituitary-adrenal axis.

Respiratory

• Studies show no enhancement of tracheobronchial clearance and physiologic changes return to normal soon after exiting the sauna.

Wound Healing

• Research does show that there is a positive effect on wound healing.  Thus  this product can play a role in treatment of skin ulcers and delayed postoperative wounds.  More research is needed