Everywhere you turn these days it seems as if health and wellness influencers are toting the incredible benefits of regular high heat sauna use. Truth be told, for the most part the proliferation of sauna use into the mainstream of ‘in vogue trends’, is by and large an incredible contribution to collective health. Yet, when practices become a trend and everyone wants to jump on the bandwagon, then there are always those who throw caution to the wind and in doing so lose the meaningful impact that heat therapy has on human health.
As collective awareness grows in the field of gut health and the overall care of gut microbiome in tandem with the widespread use of saunas, it is worthwhile examining the impact that saunas may be having on gut health. Recent studies suggest that sauna users must be aware of the potentiality of thinning the intestinal walls from mostly impermeable to permeable due to dehydration from excess sauna use at high heats without adequate care to make up for lost fluid.
Yes, by all means regular sauna use is correlated with extended healthspan, reduction in all cause mortality, improvement in chronic inflammation, as well as an incredibly positive impact on immunity. It may be used in the treatment of a vast array of diseases. It is critical to note that as sauna use increases, so does our knowledge base with reference to its positive effects, as well as to potentially hazardous effects.
Saunas, when used correctly are truly medicinal. As is the case with all medicine, one must use caution in how the medicine or treatment is administered.
A peer review study published in 2024 that examined how sauna use is affecting gut health revealed that sauna users must be extremely cautious in how they are using their saunas so as to avoid dehydration at all cost. (1)
Find out the details of the collected data on saunas and intestinal changes from sauna induced dehydration below. Also how you can ensure that you are using your sauna in a way that promotes gut health as well as many other expressions of health in the ecosystem that is the human body.
Find Out How High Heat Regular Sauna Use May Affect Intestinal Barrier Protection
As sauna use continues to rise among the general public, so do scientific studies that reveal an increasing number of positive benefits for specific illnesses, as well as overall health. Amidst the increase in studies performed on sauna users there are also results that have increased contraindications for sauna users, not so that individuals stop using saunas, but rather so that they can learn to use saunas safely.
A four author study published in the National Library of Medicine’s journal this year (2024) entitled: “Sauna dehydration as a new physiological challenge model for intestinal barrier function” illustrates the severe danger of using high heat saunas without sufficiently rehydrating and remineralizing the body, and the detriment that this confluence of behaviors has on gut health. (1)
It should be well noted that the intestinal lining should be impermeable and as permeability increases, so does the potential for illness. “The intestinal barrier plays a crucial role in maintaining gut health, and an increased permeability has been linked to several intestinal and extra-intestinal disorders.” (1)
The aim of this study is quite simple. “This study investigated the effect of sauna-induced dehydration on intestinal barrier function.”
The intestinal barrier is very important in its role of protecting the rest of the body from toxins moving through the intestines. (3) Many gut related diseases have been linked to the permeability of sections of intestinal wall such as:
- inflammatory bowel diseases (IBD),
- irritable bowel syndrome (IBS),
- celiac disease
- food allergies
- metabolic syndrome
It is very important to maintain strong impermeability within the intestinal barrier. The study that we are currently examining took place in Sweden (neighbor to the namesake of the ‘sauna’ (only Finnish word in the English language)), and involved 20 participants that were equally divided among the sexes. Dehydration began when 3 % of body mass was lost due to perspiration. Changes of the permeability of the intestines was measured by examining the urine samples of the study participants before and after sauna use.
(“In our study intestinal permeability was assessed using a non-invasive multi-sugar urinary recovery test. This test allows to detect small changes in small and large intestinal permeability and consists of measuring the urinary recovery of orally administered non-metabolizable sugars”) (4)
Here is a visual of how the study was conducted:
(1)
The conclusion of the study does demonstrate that dehydration as a result of sauna use does affect the permeability of the intestinal wall. This is important to note because many individuals can easily fall into dehydration as a result of sauna use. Also anyone living with gut specific conditions should be on hyper alert to their hydration levels if they plan on using a sauna on a regular basis.
Certain Individuals Need to be Concerned With Staying Well Hydrated. Especially those with:
- Inflammatory bowel diseases (IBD),
- Irritable bowel syndrome (IBS),
- Celiac disease
- Food allergies
- Metabolic syndrome
Anyone using a sauna regularly must maintain adequate levels of hydration before, during, and after each sauna session. This means re-fueling with electrolytes, including sodium, potassium, and magnesium. According to Dr. Andrew Huberman of Stanford School of Medicine, anyone using a sauna should follow this basic guideline for hydration:“Drink at least 16 ounces of water for every 10 minutes you spend in the sauna.” (2)
This should be considered the bare minimum of fluid consumption for the sauna user. Each individual sweats at different rates. If you are a heavier sweater than you should be taking in even more fluids to replace what is lost during a sauna session.
For some living with gut specific diseases, you cannot afford to get dehydrated from a sauna. Saunas are known to detoxify the body at higher levels than sweat that is induced from exercise, or simply hot weather. This is significant because it means that along with the toxins that leave via the sweat pathways, so do positive minerals that are essential for health.
Sauna use can dramatically improve some gut health issues. If individuals allow themselves to fall into states of dehydration the possibility of increasing the permeability of the intestinal walls can and will increase.
Please be mindful to hydrate with fluids that contain electrolytes, and stay hydrated throughout your sauna session, and afterward. It is best to prepare for your sauna session ahead of time by at least 24 hours of actively taking in an increase of fluids.
If you are living with a gut related disease, please be sure to consult a health care professional to find out if sauna use is best for your condition.
How Can You Safely Sauna Without Dehydration and Threatening Gut Health?
- Acclimate Your Body To High Temperatures Slowly Over the Course of Weeks, Even Months. Start Slow and Low
- Drink Plenty of Healthy Fluids on an Ongoing Basis That are Rich in Electrolytes
- Do Not Go Into Saunas That Have a Temperature Higher Than 170 Degrees Fahrenheit For Traditional Saunas (140 Degrees Fahrenheit For Infrared Saunas)
- Take Breaks During Your Sauna Session To Rehydrate
- Avoid Excessive Caffeine and Alcohol Use on the Days You Wish To Sauna
When any activity becomes a fad, regardless of how healthy the activity may be, there is always room for the ‘weekend warrior’ type of individual. This catch phrase refers to individuals who may not spend time properly training their body’s for an activity and then dive right into the deep end without taking proper precautions.
With an increase of wellness influencers promoting saunas that go up to 220 plus degrees Fahrenheit, there can be a sense of competition to ‘keep up’, and reach the challenge. The reality is that sauna use must be approached with a healthy caution. Saunas should be viewed as medicinal, and like all medicine appropriate dosages, is the difference between health and disease.
You do not need to take a severely hot sauna to reap all of the benefits associated with sauna use. It is well worth while not using a sauna that ever goes higher than 170 degrees, but rather look for the sweet spot that increases your personal internal temperature for at least 20 minutes 3-4 times per week.
You can take your time acclimating to increases in sauna temperature and duration. This should take at least 4-8 weeks.
Be sure to drink plenty of water, and other fluids high in electrolytes throughout the day, while you sauna, as well as after you sauna to avoid dehydration and therefore potentially putting your gut health at risk.
Furthermore, caffeinated and alcoholic beverages tend to dehydrate the body, so if you know that you will be using a sauna on a particular day, be sure to minimize your caffeine and alcohol intake. (You should never consume alcohol before or during your sauna session)
Sauna Safely, Drink Plenty of Electrolyte Filled Fluids To Avoid Adverse Effects On Intestinal Permeability
Sauna safely by being diligent in your fluid intake, and feel free to take plenty of breaks throughout the sauna session if you feel light headed, dizzy, or severely uncomfortable. Using a sauna is not a competition and the only trophy available is your excellent health.
Put your health first, and leave the extremely high temperatures for the ill informed. You can receive all of the benefits from regular sauna use while still respecting the heat and your body.
If you are living with IBS or any other gut related condition you simply cannot afford to become dehydrated from your sauna use. This sub-group of individuals must be exceptionally responsible when it comes to proper fluid intake. In addition, if you are concerned about how sauna use may affect your gut health please consult a specialist before beginning a program.
Stay safe, respect the heat, and drink plenty of healthy fluids so that you can continue to enjoy the benefits of regular sauna use.
Sources Cited:
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8324874/
- https://www.hubermanlab.com/newsletter/deliberate-heat-exposure-protocols-for-health-and-performance
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5288588/
- https://pubmed.ncbi.nlm.nih.gov/22892368/
- https://www.ncbi.nlm.nih.gov/corehtml/pmc/pmcgifs/wm-journal.gif