How to Optimize Your Water Quality & Intake for Health

**Andrew D. Huberman** (0:00)
Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we're discussing water. Now, to some of you, water might seem like a boring topic, but I assure you that water is anything but a boring topic. In fact, water as a substance is incredibly interesting for a variety of reasons that I'll explain today. In fact, we are going to discuss the physics and chemistry of water. And I promise to make it accessible to anyone and everyone, regardless of whether or not you have a physics or chemistry background. And I will discuss how your body needs and utilizes water, depending on what type of water you drink, the temperature of that water, when you drink the water, and indeed how you drink that water. Now, water is actually a pretty controversial topic. In fact, in preparing for this episode, which took me several months, in fact, I ran into highly contradictory information and had to go on some real deep dives in order to ferret out the best and most accurate knowledge for you. I also found that there are generally two camps of people out there in terms of how they think about water and the consumption of water. One camp, generally speaking, is of the mind that tap water is completely safe. Perhaps it needs a little bit of filtering, but that in most areas of the world, if it runs out of the tap, and unless there's a warning sign directly above the faucet, that you can drink the tap water. The other camp seems to be the camp that does not trust anything that comes out of the tap and is excited by, and in fact relies on things like reverse osmosis, deuterium depleted, hydrogen rich, or other forms of water that sometimes can be very expensive or at least involve some substantial steps in order to clean, filter, alter the chemistry of, or in some other way adjust before they are willing to consume it. So today, what we're going to try and do is to address all the stances around water. For instance, we will discuss whether or not tap water is indeed safe and I will give you some tools that will allow you to address whether or not the water coming out of your tap is safe, as well as some tools that will allow you to address how to clean that water if indeed it does need filtering and cleaning in particular for things like fluorides and endocrine disruptors, which it turns out are quite prominent in a lot, not all, but a lot of tap water sources. I will also talk about the more, quote unquote, esoteric forms of water that I mentioned a few minutes ago. So I will go systematically through the list of distilled, reverse osmosis, spring water, deuterium depleted water, high pH water. And for those of you that are already screaming out as you hear this, oh no, he's going to tell us that pH water can alter the pH of our body in helpful ways. I'm not going to tell you that, but I will tell you that the alkalinity or acidity of the water, that is the pH of the water that you drink, has a profound impact on your ability to absorb and utilize that water and the impact that those water molecules have on specific biological systems. So it turns out pH is very important, but not for the reasons that you've probably heard about previously. I will talk about how the temperature of water that you drink does indeed turn out to be important for the rate of absorption of that water and its impact on the cells, tissues, and organs of your body and thereby your health. And I will talk about various zero cost and low cost tools that you can use in order to get the most out of the water that you drink. And finally, I will talk about when and how to hydrate your body best. Before we dive into today's topic, I want to share with you some very interesting results that were just published on the use of deliberate cold exposure to benefit fat loss. Now, deliberate cold exposure is a topic I've covered before in this podcast. We have an entire episode about that, that I've linked in the show note captions. Deliberate cold exposure can be done by way of cold showers or immersion in cold or ice water up to the neck. That's typically the ways that it's done. It has been shown to reduce inflammation, to increase metabolism. And I think some of the most exciting results that have been published are the results, certainly in humans, showing that deliberate cold exposure can increase the release of so-called catecholamines, which are dopamine, norepinephrine and epinephrine. And those increases in those three molecules are quite long lasting and lead to substantial increases in mood and focus throughout the day. Now, many people out there hear about deliberate cold exposure and cringe. Other people hear about it and cringe because they've heard that deliberate cold exposure, especially by way of immersion in water, can block the adaptation to strength or hypertrophy training. What I mean by that is yes, indeed, there are data showing that if one gets into very cold water, up to the neck, in the six hours, anytime that is, in the six hours after strength or hypertrophy training, that some of the strength and hypertrophy increases that one would observe are blocked by that deliberate cold exposure. However, after six hours does not seem to be a problem. So it can be done on other days besides the strength and hypertrophy training. It can be done before strength and hypertrophy training. It can be done after endurance work. And I should mention that it does not appear that cold showers disrupt the adaptations to strength and hypertrophy training, even if they are done immediately after strength or hypertrophy training. Okay, with that said, many people do enjoy the effects of deliberate cold exposure, in particular, for those increases in mood and alertness that are the consequence of those increases in the catecholamines, dopamine, norepinephrine, and epinephrine. And again, those increases are very long lasting. So it's not just during the exposure to cold. It is for several hours, up to four, maybe even five or six hours, depending on how cold and how long the deliberate cold exposure happens to be. Again, there's a lot to say and explore about deliberate cold exposure. So again, I'll just refer you to the episode on deliberate cold exposure. If you want to explore the mechanisms and the positive health outcomes, some of the controversies within the data, et cetera, within that episode. Meanwhile, I definitely want to share with you the results of this recent study that just came out. The title of this study is, Impact of Cold Exposure on Life Satisfaction and Physical Composition of Soldiers. The reason this study is very interesting is that it's one of the few studies that used, I should say, explored both, Deliberate Cold Exposure by Immersion in Cold Water, as well as Deliberate Cold Exposure by Way of Cold Showers as it relates to weight loss. Now, there's already data out there on the effects of Deliberate Cold Exposure and Metabolism. And here I'm mainly referring to the beautiful work of Dr. Susanna Soberg and colleagues in Scandinavia that showed that people that do 11 minutes total of Deliberate Cold Exposure by Immersion in Cold Water up to the neck per week. So 11 minutes per week total spread out across some different sessions by way of getting into water that's uncomfortably cold up to the neck and then getting out and then doing that several times per week to hit that 11 minutes or more threshold. And this is very important. We'll come up in a moment in the context of this new study and warming up not by getting into a warm shower, which is frankly what I do after my cold showers or getting into the ice bath or cold water immersion, but rather forcing their body to warm up naturally by using its own metabolic abilities. In those studies, they observed substantial increases in brown fat stores, which are fat stores that you really want around the heart and clavicles, increases in metabolism that were quite dramatic, in my opinion, and that could be very beneficial for allowing people to feel more comfortable at cold temperatures when they're not in cold water and on and on. So lots of benefits shown in that study. In this study, what I thought was particularly interesting is, again, they explored both immersion in cold water and cold showers, and the duration of cold exposure that they found led to substantial fat loss, especially around the abdomen, was very brief, deliberate cold exposure. Let me give you a few details about this study. The study involved 49 subjects that include both males and females. This is also really important. The beautiful work of Susanna Soberg and colleagues, as far as I know, only looked at males. This study looked at males and females. They were 19 to 30 years old, and there basically were two groups. People are either were assigned to get deliberate cold exposure, or they were not assigned to deliberate cold exposure. The form of deliberate cold exposure involved one session per week of cold immersion in cold water up to the neck. And to just give you a sense of how cold it was, it was three degrees Celsius, which translates to about 37.5 degrees Fahrenheit. That's pretty darn cold, but it was only for two minutes. Okay, so one session at three degrees Celsius, otherwise known as 37.4 degrees Fahrenheit, for two minutes every week, once a week. In addition, the same subjects did five cold showers per week or a minimum of five cold showers per week. And those cold showers were slightly warmer than the immersion in cold water condition. So they were 10 degrees Celsius approximately or 50 degrees Fahrenheit, still pretty cold. And the duration of that cold water exposure in the shower was just for 30 seconds. Okay, so this is interesting to me because many people don't have access to cold water immersion. They might not have an ice bath or any place they can do that, but most people do have access to a cold shower of some sort. Plus I think most people could do probably one ice bath per week or find a place where they could get into cold water safely. Now I should point out that some people will not do well going into 37.5 degree Fahrenheit, AKA three degrees Celsius water, having never done anything like this before. So if you're going to try and employ these sorts of protocols that were used in the study, I do recommend that you ease into it over the course of a week or so and become somewhat adapted to the shock of cold water exposure. So maybe start at 50 degrees Fahrenheit, kind of ease your way back in terms of the cold water immersion especially. Now, another critical feature of this study is as with the beautiful work by Susanna Soberg, the subjects were told to warm up naturally after the deliberate cold exposure. So they basically hung out outside of the cold water immersion or outside of the cold shower for 10 minutes after they were exposed to the cold in their bathing suit or I'm assuming they were wearing something.