One of the primary ways that your body excretes toxins is through your sweat, so doing things that encourage sweating is an important part of KetoFasting. As you’ll soon learn, not all forms of sweating are effective at releasing toxins. The good news is that you won’t need to exert yourself to work up a cleansing sweat. In fact, the ideal way to excrete toxins through your sweat is to relax in a specific type of sauna. But before I get into the specifics of sauna bathing, let’s take a look at what toxins might be lurking in your sweat.
Some of the toxins that researchers have found lurking in sweat include phthalates (a chemical family found in everyday consumer products);1 cadmium and mercury, and bisphenol A (BPA).
BPA is a ubiquitous chemical contaminant found in the lining of cans, on-the-go drink bottles, shower curtains, and receipts, to name just a few everyday items you may be exposed to. It was identified in the sweat of 80 percent of the participants in one 2012 study, even in some individuals who had no BPA detected in serum, blood, or urine.2
Cadmium is a carcinogenic heavy metal that is typically used in batteries and pigments, but has also been found in jewelry sold in large chain stores as recently as 2018.3 Notably, cadmium has been found to be concentrated in sweat more than in blood plasma, and mercury levels have been found to normalize with repeated sauna use.4
Another study evaluated the blood, urine, and sweat from 20 individuals and analyzed them for approximately 120 compounds.5 According to the authors: “Many toxic elements appear to be preferentially excreted through sweat. Presumably stored in tissues, some toxic elements readily identified in the perspiration of some participants were not found in their serum. Induced sweating appears to be a potential method for elimination of many toxic elements from the human body.”
While it is certainly possible to do KetoFasting without access to a sauna, it is not ideal, and you will not experience as many of the benefits. Remember, one of the primary benefits of KetoFasting is to help you eliminate toxins, and it is very difficult to do this optimally without access to a sauna. The best type to use is a near-infrared sauna. If at all possible, it should be in your home so it is convenient and you will use it. Cost is an issue for many, so I discuss some inexpensive options below.
While you could exercise to sweat, active sweating is not the same as passive sweating and it will not release as many toxins. Perhaps even more important, when you are KetoFasting you really don’t want to engage in vigorous exercise, as this will impair your body’s ability to maximize the benefits of partial fasting.
Again, while you certainly can sweat up a storm with exercise, if you’re working on detoxifying heavy metals and other pernicious toxins from your body, passive sweating is far more effective than active sweating. Active sweating is caused by physical exertion such as during exercise. Research has shown the toxin concentration in sweat during exercise is actually quite low.
Sweat samples taken during sauna bathing, on the other hand—i.e., during passive sweating—reveal that high amounts of toxins are being released in the sweat. The reason for this has to do with sympathetic versus parasympathetic nervous system activation. Your autonomic nervous system has two states, commonly referred to as “fight or flight” and “rest and digest.”
When you’re exercising vigorously enough to start sweating, your body is allocating energy toward your muscles, lungs, and heart. There’s no cellular reserves or hormonal gearing for detoxification or cellular repair or anything like that. During passive sweating, however, your body is heated, which helps release toxins through your sweat. Since you’re not exerting yourself in any way, your body is able to use the energy generated from the incandescent heat lamps to heal and repair itself.
The vast majority of infrared (IR) saunas are far IR. While these certainly have many benefits, they also have many drawbacks. The difference between far and near IR is the wavelength of the light. Many people (including me until relatively recently when I studied this more carefully) don’t understand the penetration of the two types of saunas.
Near-infrared light is just beyond the light spectrum of visible red light; it starts around 700 nanometers and goes up to 1,400 nanometers. Mid-infrared ranges from 1,400 to 3,000 nanometers, and far infrared is from 3,000 to 100,000 nanometers.
It is important to understand these frequencies, as they have significant biological consequences. Near IR actually can penetrate into your body up to 100 millimeters (3.9 inches), while far IR only penetrates a few millimeters, or a tiny fraction of an inch. Even though far IR has more energy than near IR, water in your body absorbs the radiation from far IR before it can penetrate effectively into your tissues.
Let me explain. Water absorbs different wavelengths to different degrees. Water actually starts absorbing the energy at about 980 nanometers—right in the middle of the near-IR spectrum. But it’s a continuum, so once you get out of near IR, at about 1,400 or 1,500 nanometers, the water is absorbing nearly all the wavelengths and virtually none of infrared is entering your body. Once you get out to mid-IR, and certainly when you get to far-IR wavelengths, they’re 100 percent absorbed by water. This means that far-IR saunas are essentially surface-heating you, and heating you in a conductive fashion. With near-IR wavelengths, you get radiant, penetrating heat. This is a much more efficient way to heat biological tissues.
You can observe a similar effect when you are outside on a sunny summer day and feel the heat of the sun on your skin. When a cloud passes over, the warmth instantly disappears. Did you ever wonder why? It’s because clouds are loaded with water and they absorb the far-infrared; it never reaches your skin, so you don’t heat up.
Most people who have done some level of studying natural health understand how important regular sunlight exposure is to our health. And nearly everyone understands that exposure to sunlight creates vitamin D in your skin (far better than swallowing vitamin D capsules). It is exposure to ultraviolet B (UVB) wavelengths that causes your body to make vitamin D.
Traditionally, the benefit of sun exposure is thought to be almost universally due to UVB radiation. You might be surprised to learn that UVB in sunlight is less than one-half of 1 percent of the sunlight spectrum, while 40 percent of sunlight—yes, 40 percent, or nearly 100 times more than UVB—is in the near-IR spectrum. This strongly supports the idea that near IR is an important frequency to be exposed to.
Photobiomodulation (PBM) is the term used to describe light’s beneficial effects in your body. Interestingly, near IR has a number of wavelengths that can activate proteins called cytochromes in your mitochondria’s electron transport chain. This activation helps your mitochondria become more efficient in producing energy.
Far-IR frequencies do not appear to have any PBM impacts on your mitochondria. In addition to activating your mitochondria, near IR and red light that is also present in heat lamp bulbs helps to structure the water in your body and provide it with energy that can be used in a variety of different ways.
So now you understand that sunlight exposure is doing more than heating your body or promoting vitamin D production. It actually activates an entirely different healing system. Since you have mitochondria in every cell of your body, with the exception of red blood cells, it’s a core restorative healing system.
There’s a great deal of confusion on this issue, and many sauna makers take advantage of that confusion. Makers of far-IR saunas often promote their products as doing exactly what near-IR saunas do. But remember, far-IR saunas are NOT providing radiant heat; they heat your body by conduction, which is why you have to heat them up to a relatively high temperature before you go in or you simply won’t sweat.
Two other common problems with far-IR saunas are that a) they claim to be “full-spectrum,” when in fact they emit virtually no near IR; and b) they emit high levels of electromagnetic fields (EMFs), even while claiming to be low- or no-EMF-emitting.
I’ve measured many of these low-EMF far-IR saunas, and while there were many with very low magnetic fields (the “M” in EMF), they virtually all emitted high amounts of electric fields (the “E” in EMF) and many had extraordinarily high and dangerous electric fields.
There are many so-called full-spectrum far-IR saunas available now that have far-IR emitters for heat, but they’ve added in near-IR emitters in one of two ways. One way is to use LEDs. You can make digital LEDs now that emit only a few monochromatic near-IR wavelengths and not the full range of more than 700 frequencies in the near-IR spectrum. But it still doesn’t have the same natural spectral power curve shape as an incandescent bulb, or as the sunlight.
There are also some saunas that use low-energy near-IR emitters that are basically heating elements that are hotter than the far IRs. They do emit a small amount of near IR, but it’s at a very low power level, what is termed irradiance in light therapy, which has very little biological impact.
The incandescent light bulb is the most efficient way to heat tissue because it is almost exclusively full-spectrum near IR. While incandescent light bulbs use far more energy than LED bulbs, the heating they provide has profound therapeutic benefits. Farmers have long used incandescent light bulbs to incubate animal life and keep livestock warm, for example. Incandescent light bulbs can also be used for incandescent sauna therapy.
Sadly, the U.S. and most of Europe have shifted to LEDs and fluorescents to reduce energy consumption. Doing so has removed many of the healing wavelengths of light for the sake of energy efficiency, but with very detrimental consequences to your health. It’s not just about detox. It’s the vasodilation, the blood circulation, and the structuring of water. There are so many aspects that are beneficial to us.
While it can be quite difficult to find incandescent light bulbs these days, and they cost more than LEDs, you can still find the 250-watt incandescent heat lamps for sauna therapy. You just need to make sure they have no Teflon coating, as the Teflon will vaporize fluoride into your sauna, which is not a great health strategy.
Even with light therapy, you don’t want excessive exposure. Just like you can’t be in the sun for an unlimited amount of time, you don’t want to be in the sauna for eight hours. With the sauna, you’re going to heat-shock your body—raising cell temperature a few degrees to get detox responses. This works out to a 20- to 30-minute near-IR sauna session delivering the appropriate amount of energy (around 36 to 54 joules at 1½ to 2 feet from the bulbs).
Essentially, what you’re doing with near-IR sauna therapy is stimulating your mitochondria to release nitric oxide (NO) and boosting ATP production. Together, your mitochondria, NO, and ATP work in concert to promote healing effects, such as DNA repair and cellular regeneration.
There are a number of companies that produce heat lamp near-IR saunas. SaunaSpace is one of the best, as it has a no-EMF version that not only has no electric and magnetic fields, but also shields against radiofrequency waves from cell phones and Wi-Fi and creates an ideal parasympathetic detox environment. However, they are expensive.
The least-expensive approach would be to build your own near-IR sauna with Teflon-free heat lamps. Instructions can be found in Dr. Lawrence Wilson’s book Sauna Therapy for Detoxification and Healing, available on Amazon. This type of sauna was used in Dr. John Harvey Kellogg’s sanitariums and spas in the early 1900s.
The core of the sauna is made up of four 250-watt Philips incandescent bulbs, which can be purchased for less than $40. You just want to make sure the bulbs you buy do not have a Teflon coating (which some bulbs do, to prevent breakage). When heated, the Teflon emits harmful chemicals. Avoid Teflon to ensure you’re not vaporizing fluoride and breathing it in.
Although far less expensive, this approach does present some challenges. First are the materials, as they need to be toxin free and hypoallergenic, which means they can be harder to find and tend to cost more than their more readily available counterparts. Natural materials are best and off-gassing plastics should be avoided.
Second, the bulbs get very hot. You don’t want to touch the surface of an incandescent bulb, which can burn. To protect yourself, you need something professionally designed. A hardware cloth or some flexible wire is typically not sufficient.
The third alternative and midtier cost would be a hybrid approach. You can purchase the fixtures and bulb protectors from companies that sell near-IR saunas and use your own enclosure. The fixtures are typically diamond-shaped with one bulb on the top and bottom and two bulbs in the middle.
The heating you want occurs as a result of the light shining onto your body, so you don’t really need a sauna tent. But you do need the air around you to be above body temperature, preferably above 100 degrees Fahrenheit, which happens very quickly once you turn the bulbs on. You can hang the heat-lamp-bulb fixture in your shower or even a dedicated closet or small room. Just be careful when using a small room; if surrounding materials like paint or finished wood or carpet have petrochemicals in them, undesirable toxic off-gassing can occur. Also, since the heating is directional, remember to rotate your body so that different parts are exposed.
If you already have a far-IR wood sauna, you could use the near-IR bulb fixture in there—not by turning the sauna on, but by using its four walls, ceiling, and floor as your enclosure.
Moderate use of a sauna is safe for most people. However, if you have a heart condition, it is wise to consult with your physician first. Further precautions include:
If you are purchasing a sauna, make sure the manufacturer supplies you with third-party analysis that shows its levels of near infrared (in the 800 to 850 nanometer range) are just as high as the far infrared. Most saunas have far-infrared levels that are 20 times higher than near infrared. It’s important to do your homework before making such an important health investment.
Always listen to your body when deciding how much heat stress you can tolerate. If you’ve never used a sauna, you may need to start with just four minutes the first time, adding 30 seconds to each subsequent sauna until you reach 15 to 30 minutes. In some cases, the detoxification process may be severe. This schedule helps your body to slowly acclimate to sweating and eliminating toxins.
Avoid the sauna if you’ve had too much to drink in the past 24 hours as well. While you may have heard sauna use will shorten a hangover, it actually increases your risk of dehydration at a time when you are already dehydrated from the alcohol.