In recent years, one recovery method that’s gained increasing popularity is sauna therapy. In fact, various cultures have embraced saunas for centuries – from Indigenous sweat lodges to Turkish Hammam to Japanese Osen and Sento. Most famous, perhaps, is the modern sauna culture in Finland. The term "sauna" is Finnish, and this practice itself has been an integral part of Finnish culture for thousands of years. The earliest Finnish saunas were dug into the sides of hills, and as building techniques progressed, they evolved into the wood-lined rooms that we’re familiar with today.
Saunas in Finland were used not only for bathing, but also for healing and purification rituals. Traditionally, Finnish saunas are wood-heated and have a stove covered with rocks. Water is thrown on the rocks to create steam, known as “löyly.” They keep it rather balmy, with temperatures typically ranging from 80 to 100 degrees Celsius (176 to 212 degrees Fahrenheit). And sauna is such an essential part of Finnish culture that as of 2020, there were 3.3 million saunas in a country of only 5.5 million inhabitants – your nearest sauna is never very far away. It’s not uncommon for families and friends to gather in saunas, and the practice is deeply embedded in social customs.
Now, as the health benefits of heat therapy have gained global recognition, saunas have become popular worldwide. Unlike traditional saunas that use dry heat, infrared saunas use infrared light to heat the body instead of the air. Both forms encourage the body to sweat and detoxify, increase the heart rate, and mimic the effects of mild exercise.
The Benefits of Sauna Therapy
While previously regarded as a spa activity in America, sauna has since become an everyday practice for many people because of the numerous health benefits it provides. From cardiovascular health to relaxation to improved muscle recovery, there are many reasons to bask in the heat:
- Cardiovascular Health: Several studies have demonstrated that regular sauna use is associated with improved cardiovascular health. In a 2018 study published in Mayo Clinic Proceedings, researchers found that regular sauna is associated with a reduced risk of hypertension, cardiovascular disease, and neurocognitive diseases. The high temperature in the sauna causes blood vessels to dilate, leading to improved blood flow and reduced blood pressure.
Moreover, a study published in JAMA Internal Medicine in 2015 found that men who used a sauna 4-7 times per week had a 50% lower risk of dying from cardiovascular disease over a 20-year study period compared to those who used it once a week.
- Muscle Recovery & Pain Reduction: For those engaged in regular physical activities and exercise, sauna therapy can be extremely beneficial for muscle recovery. A study in the Journal of Science and Medicine in Sport in 2015 demonstrated that sauna after exercise helped in reducing the delayed onset muscle soreness (DOMS) in endurance athletes.
And for individuals with chronic pain conditions, such as fibromyalgia and rheumatoid arthritis, sauna can also alleviate associated pain. A study published in the journal Clinical Rheumatology in 2008 showed that patients with chronic pain and fatigue syndromes experienced a substantial decrease in pain and symptoms after consistent infrared sauna therapy.
- Mental Health Boost: Perhaps it comes as no surprise that sauna therapy has been shown to have positive effects on mental health. But why? The heat exposure leads to the release of endorphins – chemicals in the brain that act as natural painkillers and mood elevators. A study published in Complementary Therapies in Clinical Practice in 2018 showed that using an infrared sauna actually had antidepressant effects on patients with mild depression.
Moreover, sauna therapy might even play a protective role in neurocognitive diseases. The aforementioned 2018 study in Mayo Clinic Proceedings also indicated that regular sauna use was associated with a decreased risk of Alzheimer’s disease and dementia.
- Immune Health & Detoxification: The heat from a sauna stimulates the production of white blood cells, which are crucial in fighting infections. A study published in the Journal of Human Kinetics in 2018 found that regular sauna sessions resulted in an increase in white blood cell counts, indicating a positive effect on the immune system.
From a functional medicine perspective, the detoxification process is crucial for overall health. Sweating is one of the body’s natural ways to eliminate toxins. A 2011 review in the Journal of Environmental and Public Health found that toxins, including heavy metals, can be excreted in our sweat, and so sauna therapy can be a valuable adjunctive intervention for aiding in detoxification.
Your Genetic Response to Sauna Therapy
Precision Medicine has paved the way for personalized interventions in healthcare by assessing an individual’s genetic makeup. Here at Wild Health we take a truly holistic approach – considering not only a person’s genetics, but also their biometrics and lifestyle preferences. When it comes to sauna therapy, certain genes and their single nucleotide polymorphisms (SNPs) can actually impact how you respond to the practice. While research on this topic is still emerging, a few genes that could be relevant to assess include:
- HSP Genes: Heat Shock Proteins (HSPs) are a group of proteins produced by cells in response to stressful conditions – in this case: heat. These proteins help in cell repair and protection against stress. The HSPA1A gene, which encodes for HSP70, is particularly important for the heat stress response. Variations in the HSPA1A gene could potentially affect an individual’s ability to tolerate and benefit from the heat exposure during sauna therapy.
- NFE2L2 (Nrf2) Gene: NFE2L2, or Nuclear Factor (Erythroid-Derived 2)-Like 2, is a gene that plays a critical role in the body's antioxidant response. Sauna therapy has been found to activate Nrf2, which then helps in detoxification and protection against oxidative stress. Genetic variations in the NFE2L2 gene might affect how efficiently an individual can mobilize this response to the oxidative stress that comes with heat exposure in a sauna.
- BDNF Gene: Brain-Derived Neurotrophic Factor (BDNF) is a protein that supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses. Sauna use has been linked to increased levels of BDNF, which could be beneficial for brain health. Variations in the BDNF gene may alter BDNF levels and therefore modify the neuroprotective benefits of sauna therapy.
- IL-6 Gene: Interleukin-6 (IL-6) is a cytokine involved in inflammation and infection responses. Moderate heat stress from saunas can increase the release of IL-6, which plays a role in anti-inflammatory response and helps combat infections. Genetic variations in the IL-6 gene could affect the extent to which an individual's immune response is stimulated by sauna use.
- COMT Gene: Catechol-O-methyltransferase (COMT) is an enzyme involved in the breakdown of catecholamines such as dopamine and epinephrine. These chemicals are involved in our stress response, mood regulation, and pain perception. Variations in the COMT gene could potentially play a part in an individual’s stress response and mood benefits from sauna therapy.
For a Precision Medicine physician, analyzing these genes and their SNPs could offer insights into tailoring sauna therapy and similar temperature-regulated recovery methods, like deliberate cold exposure, according to an individual's genetic makeup. However, it is imperative to exercise caution and work with your physician or health coach to ensure you’re safely practicing these different therapies, in terms of duration, temperature, and timing.
In conclusion, the centuries-old practice of sauna bathing has a myriad of benefits that are supported by extensive scientific evidence. Regular sauna use can improve cardiovascular health, aid in muscle recovery, alleviate pain, boost your mood, support detoxification, and enhance your immune function. More and more healthcare providers – particularly those practicing precision and functional medicine – are embracing the role of sauna as part of an integrated approach to optimal wellbeing.