I’ve read a lot of testimonies about the miraculous healing properties of cold showers.
- “They’ll increase your testosterone”
- “They’ll kick start your metabolism by burning tons of calories to stay warm”
- “You’ll feel amazing after”
- Or the classic with this line of thinking “People didn’t shower in hot water as cavemen” Or heavily chlorinated water.
But is it something besides the cold water that truly makes cold showers healthier? I think it’s possible. I’ve had a shower filter since I first got into weird health stuff in 2006. I never really questioned whether or not it was useful – just was a no brainer to use something that might help that’s so cheap. So I bought one, and have used it wherever I’ve lived even though I probably didn’t come close to replacing the filter as often as needed.
Chlorine. Sounds relatively harmless -right? We use it on our clothes for whitening. It’s used in the water supply. It’s used as a mixture with water for an everyday household cleaner. People use it to bleach their hair.
I once cleaned my non-ventilated bathroom with chlorine bleach + water dilution. I felt like ass for the three following days. This stuff gets in your lungs.
Why’s it bad? Well, it’s toxic. But, from a Ray Peat / metabolism perspective, chlorine displaces iodine and bromine from molecules. Potassium iodide becomes potassium chloride + iodine. Four Iodine atoms form thyroxine (T4) with tyrosine. Deiodinase is a liver enzyme that cleaves off one iodine atom leaving Triiodothyronine (T3). Needless to say, iodine has an important role in the formation of thyroid hormones. One that will be analyzed further in another article.
Turns out massive amounts of chlorine gas break out from hot water while showering. You inhale lots of it. Whether the chlorine messes with your iodine levels or your thyroid hormone is something I don’t know, but imagine it’s possible. Water also has lots of flouride which can displace iodide, bromide and chloride. I’m not sure if fluoride is worse in shower or drinking water, but I’m sure someone has an article on it.
“Humans can detect low levels of chlorine gas. In humans, the threshold concentration for detection of the odor of chlorine gas ranges from 0.1–0.3 ppm. At 1–3 ppm, there is mild mucus membrane irritation that can usually be tolerated for about an hour. At 5–15 ppm, there is moderate mucus membrane irritation. At 30 ppm and beyond, there is immediate substernal chest pain, shortness of breath, and cough. At approximately 40–60 ppm, a toxic pneumonitis and/or acute pulmonary edema can develop.”
So cold showers = lots less vapor-phase chlorine. Could it be that simple? It probably doesn’t hurt. Cold water stimulates your metabolism BUT with inadequate fuel your body will require catecholamines and glucorticoids (stress hormones) to mobilize fat and muscle to generate glucose. Not all that good for you in the long run.
Water treatment plants are now treating water with chloramines that may be just as bad as chlorine – so that’s something else to consider as you do research. Unfortunately carbon filters (like the Sprite filter below) alone don’t do much for cleaning water at high temperatures – I don’t know why, but I’ve read it in multiple places.
So, I suggest the following options –
1) Whole house water filter – Not reverse osmosis as this strips too many required minerals from the water. A good whole house filter installed in front of a water heater will adequately remove chlorine at normal temperatures from your water before it ever gets to become gas in the shower.
2) Aquasana shower filter – copper-zinc media in combination with charcoal. According to Aquasana, it removes both chlorine and chloramine. The downside of this filter is you cannot install a huge shower head as it will hit the filter casing when attempting to install
3) Sprite Carbon Filter – Used in line with the following filter should work well to remove toxins and chlorine
3) Vita Fresh vitamin C shower filter – ascorbic acid block neutralizes chlorine and chloramines at high temperatures; can be used in line with an Aquasana to ensure adequate removal
Here are some nice shower head options to maintain pressure – Oxygenics Skincare Showerhead, ZenFresh Filtration Showerhead I don’t actually believe that the stones filter the water for the latter option, but the agitation may increase the Co2 or mineral content of the water.