Sauna -- Not Just For Slackers

Sauna might look like naked people sitting and sweating. It is that, but much more.

I discovered sauna while studying one of my interests -- longevity. David Sinclair is a leading researcher in aging and long life, and his excellent book “Lifespan" provides a thorough introduction to the biology of aging, and things we do that degrade or improve it. How quickly we age is partly in our genes. Humans live longer than mice, and whales live longer than humans. And some humans live longer and healthier than others. But genes are predispositions, not destiny. Researchers have significantly extended lifespans of organisms in labs, and are learning to apply those results to humans.

One of the mechanisms that controls aging is called telomeres. Telomeres wrap the ends of our DNA, like the plastic end of a shoelace, preventing unraveling and malfunction. When cells age, they replicate. This keeps fresh cells available, but each replication shortens the telomeres. Eventually this leads to fraying of the DNA, and results in system failures or aberrations like cancer -- and aging.

DNA is a string of genes, which are sequences of four specific molecules that provide instructions to build proteins as needed to support the chemical processes that keep us alive. These genes can be silenced or activated as needed, a process called gene expression.

Our cells have a switch that puts them in a mode of using its energy for growth and reproduction when resources are plentiful, or an energy saving mode for hard times to allow survival until resources are again available. This is controlled by gene expression, so determining which genes activate those aging controls is a focus of aging research.

One set of genes called DAF-16 includes one called FOXO3 which has been associated with longer life in many organisms. FOXO3 is also believed to support telomeres.

If you have had your genes decoded, the gene location rs2764264 is an indicator of FOXO3 activity, with C associated with longer life expectancy, and T associated with less. There are two genes at each location, called alleles, one inherited from our father, one from mom. The best outlook is inheriting a C from both parents. That’s how natural selection works.

One popular theory is a process called hormesis drives our cells to switch to longevity mode when confronted with stressors like hunger, injury, cold, and heat. Saunas seem to provide a useful stress that puts our body into endurance mode. The biology and the benefits still aren’t precisely understood, but longstanding traditions in many cultures make it seem worth considering.

Saunas have been used for millenia in many societies -- Greece, Rome, and Turkey bath houses, native American sweat lodges, and Scandinavian countries, especially Finland and Sweden, used saunas that have become the model for popular saunas used today. They typically are wooden rooms heated to 150 to 200 degrees with a traditional wood fire, or more modern gas or electric. The wood construction prevents skin burns. Some hope that high tech solutions like far-infrared heating can produce the same benefits with lower temperatures, but deeper penetration of the heat into the skin. Some people find it difficult to breathe in the dry, hot sauna, and prefer steam rooms with higher humidity and lower temperatures necessary to prevent scalding. All seem to produce some hormesis benefits, but not enough study has been done of these options to confirm an optimum approach.

My choice was made easier because my local gym has one sauna with a gas stove that maintains 180 degrees near the ceiling, and an adjacent steam room. When I first considered this activity, my gym was closed by government covid orders. The gym was allowed to re-open in March, but sauna was forbidden for unstated reasons until May. I’m guessing viruses wouldn’t last long there, and I haven’t heard of anyone getting sick. I’ve become a regular user, and have had no ill effects from the hormetic stress or the virus. The benefits are harder to measure.

I was saddened to find that my co-ed sauna protocol is not naked. Maybe I’ll look for a sauna where the participants are less inhibited, and more enthusiastic about taking full advantage of all that heat stress. But this one is satisfactory for now.

So, what benefits are suggested by sauna use, aside from the theoretical lifespan extension? I’ll report on lifespan in about 50 years, perhaps. An interesting paper by Dr Michael Ruscio at https://drruscio.com/sauna-therapy/ has a good discussion of saunas and cites 32 research papers that you might find interesting. This report discusses possible improvements in:

• Cardiovascular health problems

• Autoimmune, chronic pain, and fatigue conditions

• Mental health

• Exercise performance and metabolism

• Detoxification

He suggests 15-20 minute sessions, 1-3 days per week. I tend to add a cushion to my plans, just to be sure, and I usually go for 25 minutes, followed by a cold shower. Dr Sinclair, who I mentioned earlier, recommends an ice bath, Scandinavian style, but my gym doesn’t have that. The cold shower is certainly invigorating. Maybe it helps.

Remember that comfort doesn’t induce hormesis, which seems to be the beneficial effect.

Other benefits are suggested by other authors, such as cancer. Research shows body temperatures 104-111 degrees are toxic to cancer cells, called hyperthermia in medical practice. Sauna does raise body temperature, but not that high, so maybe it depends on how close the cancer is to the skin.

I checked my oral temperature today. Measured 96.4 before, 99.6 after. My mouth was closed during the sauna -- nobody wanted to chat today. I don’t know what that means for my core temperature. I don’t have any melanomas, but they might be in the danger zone. And breathing 180 degree air probably warms the lungs.

Some say sauna promotes weight loss. My thought is we lose a lot of water weight, but that is quickly restored by normal hydration, which is always important for good health but especially when we sweat a lot. But studies show that the process of sweating produces physiological changes such as increased human growth hormone production and increased blood sugar levels that increase fat metabolism.

Infrared sauna also increases collagen and elastin in the skin, reducing wrinkles and improving texture. Regular sauna moisturizes the skin, and reduces acne. These benefits are cited in an article, Get Your Sweat on: 11 Sauna Benefits You Need To Know at https://foodrevolution.org/blog/sauna-benefits/

As a (almost former) cardiac patient with Alzheimer’s genes, I can say my doctors are happy with my tolerance of this activity. My observations are that my health remains good, but I can’t determine how much of that success is due to my sauna practice. My only measurements so far have been pulse on my watch, and before and after blood pressure checks a few times. The pulse was most interesting. When I first started, I would observe pulse was about normal when I entered, but it steadily increased to low 130s after 25 minutes. That’s like a pretty good workout, while sitting and chatting with the ladies. That reaction has gradually declined to the teens, today it peaked at 118, so I appear to be adapting. My blood pressure drops around 20 points with each session, temporarily, then normalizes. Today was 138 after a workout, before the sauna, and 118 after. I’ve never felt dizziness or light headed from the reduction in pressure. Alcohol increases this effect, and can also cause heart arrhythmia, and should be avoided. And, of course, drink plenty of water.

I plan to continue this experiment. It’s a pleasant activity and might provide important health benefits. I hope you’ll consider it, too, unless you want to use my gym -- it’s a little bit crowded sometimes.

If you have experience with this kind of activity, I hope you’ll share in the comments.