So how much plain water should we be
drinking, if any?
After writing the article about what had happened with my mom, I started digging more. Comments from certain individuals, got me looking further into this topic of hydration. And what I found was rather intriguing. We have sent people to the moon. We, as a race, luckily have amongst us some individuals that simply can’t be stopped once they put their mind to something. So very likely, we’ll be on Mars within the next decade. We have AI that can crack sophisticated encryption algorithms. We have dancing robots and of course, the same person who will beat the governments of the world to Mars, Elon Musk, who decided enough was enough. And restarted the EV revolution. We can even apparently create a vaccine for all of humanity in record time.
But after a few millennia of recorded civilization, there is no consensus
on how much plain water a human should drink.
Interesting.
I ended the first revision of my original article about
how my sister saved my mom from dying of dehydration, by citing this piece of literature,
from the National Academy of Sciences,
Engineering and Medicine. But I erred in my original blog. My eyes went
straight to the numbers - 2.7L of water for women and 3.7L of water for men. And
that is what I initially posted. That everyone should be drinking 2.7L to 3.7L
of water a day. Plain drinking water or plain water intake (PWI). What the
article actually said, was that one should consume 2.7L to 3.7L of Total
Water Intake (TWI). Which includes beverages (such as plain water) and
food.
I posted this information to a number of places on the Internet. Including Dr. Peter Attia's website. After becoming a member in December of 2020, I asked Dr. Attia, a question of whether hydration was being taken seriously during Covid. That we should be drinking more water. Citing the pub med article by Stookey et al. I figured that if I was a member, he might actually engage me in discussion. He did not reply to me directly, but instead in January of 2021, he came out with an article called "Do I really need 8 glasses of water a day?"
As of today, September 17, 2023, that article is not accessible anymore. At least not on Dr. Attia's website. But it is available on the Way Back Machine.
While reference to it exists on Dr. Attia's website if you search under hydration, clicking on the link brings you to his membership page.
In his article, Dr. Attia cites the work of Heinz Valtin, who attempted to debunk the "apparent myth" of drinking 8 glasses of water a day.
What about the science for the recommendation of drinking 8 glasses of water 8 times a day?
As it turns out, there have been multiple studies done, trying to nail down where the recommendation for drinking 8 glasses or roughly 2L of water a day comes from. One individual, Heinz Valtin, set out to debunk the myth of 8 glasses of water 8 times a day. In his paper entitled
"Drink at least 8 glasses of water a Day" Really? Is there scientific evidence for "8 x 8"?
Mr. Valtin goes about attempting to find some scientific evidence for 8 glasses 8 times a day (or roughly 2L of water), and comes up empty handed. He does give some credence to higher intake of water for those that might have some medical conditions of the urinary system, but he doesn't go so far as to universally condone the extra application of water. He does however, dwell on water intoxication and hyponatremia as being another reason why one might not want to drink a lot of water.
Understood.
Water intoxication (high volume hyponatremia or hypervolemia) can happen when you drink more water in a set period of time, than your kidneys can safely excrete. Anyone into gaming and the console world remember when a young lady in 2007 oblivious to this limitation of the human body (and incidentally, not informed by the people who were running the contest of the dangers), drank over 7 liters of water in a very short period of time, trying to win a Nintendo Wii, and perished as a result.
According to Noakes et al, the maximum "pee" rate for humans is around 900ml/hr.
I don't know about you, but I did not know this rate was so low. Another eye opener.
What this basically means, if that you're going to plow back more than 1 liter of anything in an hour, you face the possibility of inducing water intoxication. With the potential outcome of death.
What happens inside your body when water intoxication (high volume hyponatremia) starts to happen?
Wikipedia does a great job explaining. Basically, when your body's cells are faced with water outside them that has less solutes (things that are dissolved in water) than what is inside the cell, the cell tries to balance that difference, by introducing some of that excess water into the cell to dilute the cell's solute concentration. Problem is, the cell starts to swell with this excess water. Not as big of a problem, if the cell in question can take a little bit of stretching, like perhaps a skin cell. But the water is presented to all your body's cells. Including the ones in the brain. When brain cells start to swell, the person could have a seizure, brain damage, coma or death.
Woah.
Note, this can also happen when you replace the water that you've lost due to extreme exercise (think running a marathon or triathlon or playing a soccer match under a scorching sun) with plain drinking water alone. Without the proper electrolyte replacements to go with that water. Enter low volume hyponatremia or hypovolemia. If you do extreme sports, or heck, even have a bad bout of vomiting or diarrhea, you might be losing a significant amount of electrolytes along with that water as well. Replacing your body fluids with Plain Drinking Water, can setup the same problem as water intoxication.
This time due to sweating (or vomiting or diarrhea), you've not only lost water, but some sodium and potassium. If you drink pure water here is what happens. Water is introduced to your body's cells. The cells see that there are less solutes (electrolytes like sodium and potassium) outside their own cell walls, and do the same thing as with high volume hypernatremia and bring in more water into the cells to dilute the concentration within. The cells swell, due to the excess amount of water inside them. High endurance athletes that forego the electrolyte replenishments have noted bloated ankles while running after hydrating with plain drinking water during a long marathon. Same problems though. Unless they get the proper balance of electrolytes into their bodies pronto, they could suffer the same ultimate fate. A premature seizure, coma or even death.
So Valtin has a point.
If you're going to try to drink more than 1L of water an hour consistently, you may die. If you're a water junkie, make sure that you drink less than 800ml of water an hour and you should be fine.
If you sweat a lot (like endurance athletes), and you replace all that sweat with plain drinking water only, you may die. Make sure you take electrolytes in at the same time.
Two statistically small groups of people with very extreme outcomes. What about the rest of us?
Interestingly enough, in November of 2021, a mere 10 months after posting his "Do I really need 8 glasses of water a day" article, Dr. Peter Attia gave blood. Typical donation amounts = 500 ml. He does not mention whether he hydrated an equivalent amount of water that day, but what he did post to his followers and membership, was that when he got up the next day he passed out, due to low blood pressure and the volume depletion. Very likely linked to the blood donation the previous day. What he did afterwards, was humbly post this article regarding hydration. And admit that he hadn't taken hydration / dehydration as seriously as he should have.
Valtin wrote his paper in 2002. A lot of papers hadn't been made available to online searches as of that time. It would interesting to know if he had known of the following paper, by Edward Adolph in 1921 (Mr. Valtin has sadly passed away since then).
"The Regulation of the Water Content of the Human Organism."
In this paper, Mr. Adolph goes about getting his test subjects drinking different amounts of water and depriving subjects of water entirely, to test diuresis rates (how much they would pee per hour). He would also measure the amount of weight (water) loss due to rest, exercise, diuresis due to salt, sweating, metabolism and bathing in warm water. The results were rather interesting. If his numbers were anywhere near what a typical and relatively sedentary individual, living in a temperate climate might be expected to lose, then the numbers tell all. At 100g of water lost per hour (due to excretion of urine, sweat and metabolism) for a sedentary individual, doing nothing but resting, one would lose around 2400g a day, just sitting or lying around (24 x 100g). Add in exercise and those number would go up. Remember, that 1g = 1 cubic ml of water, so that 2400g = 2400ml or 2.4L of water.
So could those initial numbers in the 1945 publication have come from Mr. Adolph's findings?
So of course, I couldn't stand the suspense. So I tested Mr. Adolph's findings. For a sedentary individual. His findings were for a 72kg male. I am an 80kg male. I would measure my weight at bedtime after emptying my bladder, and then consuming a 250ml of water before retiring. I would then weigh myself immediately after waking in the morning, empty my bladder and then weigh myself again. Here is what I found over 7 days.
But I’ll bite. Let’s take the argument that a typical, semi-sedentary, North American individual is already getting enough water everyday. Let’s examine a typical North American days worth of food consumed and see what we get out of it.
From the government of Manitoba’s agriculture website, the province from where yours truly hails from. The following table, which I’ve resorted by percentage of water:
For Breakfast:
Two pieces of toast
Three pieces of bacon
Two eggs
One cup of coffee (black)
1st coffee break:
One cup of coffee
For lunch we’ll have North America's finest:
McDonald’s Big Mac w two all beef patties, special sauce, lettuce, cheese, pickles, onions on a sesame seed bun
Large fries
Large Coke
Afternoon break:
We’re feeling the effects of that rather large lunch. So we’ll have a
One granola bar
One cup of coffee
For dinner:
One chicken Breast
Some assorted cooked veggies
Some pasta
A salad (spinach, carrot, cucumber, tomato, onion)
9 ounces of red wine
For a late night snack:
A small bag of regular potato chips
One cup of water
Let’s add up the water content. According to water content table mentioned previously, here are the numbers.
The total water from liquid sources was 2131ml or 2.131Litres. Biggest supplier of water was the Large Coke that the test subject had for lunch, followed by the 3 cups of coffee.
Now the fun part.
Both
caffeine and alcohol are classified as diuretics. What the heck is that? This
from Wikipedia:
“A diuretic is any substance that promotes diuresis, the increased production of urine. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.”
Caffeine causes you to urinate. At least if you’re not used to it. Or if you overdo it. You need the water it provides as it usually makes it into your body not by its lonesome, but in some other form - a cup of coffee or a caffeinated beverage. But unfortunately, due to the diuretic properties of caffeine, you wind up peeing out 1.17 ml of water, for every 1 MG of caffeine that consume. Again, if you’re not used to its effects. If you are a seasoned and hard core caffeine consumer, you aren’t hit by its diuretic effects. The scientific paper titled “Caffeine ingestion and fluid balance”, in the Journal of Dietetics, by Maughn and Griffin (2003), came back with the conclusion that “Individuals who habitually consume caffeine-containing drinks can be reassured that intakes of less than 300 mg/day caffeine will not compromise hydration status.” A typical cup of coffee has about 95mg of caffeine in it. So, if you drink less than 3 cups of coffee, you get to keep all of the water you drank from that cup of coffee.
However, we know how most people are with following guidelines. Especially ones they know nothing about. People tend to do things in excess. Not everyone. But according to this paper, by Neuhauser-Berthold et al, 10% of the German population drinks more than 5 cups of coffee a day. That’s when coffee’s diuretic qualities come to the forefront. Americans? 20-30% drink more than 5 cups of coffee a day, with 10% drinking way more than that. And that's not even mentioning, the caffeinated beverage world, which is massive.
Caffeine’s classification as a type of diuretic is in the Xanthines column. Most
classifications of diuretics have an effect on your electrolytes in some way –
they either promote sodium excretion, sodium absorption, potassium excretion,
etc. In addition to urine production. Xanthines inhibit reabsorption of NA+
(sodium ion), and an increase in the estimated Glomerular Filtration Rate (how
quickly your kidneys filter stuff out of your blood – most kidney diseases are
associated with a drop in eGMR so an increase might appear at first glance to be
a good thing).
So, for this fictitious individual, who had around 366mg of caffeine this fine
day, if they were new to coffee, they likely would have lost about 366 x 1.7 = 429ml to diuresis from caffeine alone. If they were a seasoned veteran of coffee, they would have only lost about 66 x 1.7 = 112ml of water.
But it was alcohol’s classification in the diuretic column that caught my eye.
It is by itself with water at the top of the diuretics table in Wikipedia.
Further research has alcohol classified as an aquaretic. What is confusing, is
that normal water is also classified as an aquaretic – meaning that it produces
the excretion of free water and doesn’t affect sodium or potassium levels in
the body. What is interesting about alcohol is that it turns off the vasopressin,
which controls urine production in your kidney. No vasopressin? The kidneys
start creating urine immediately, once the receptors in your mouth sense a
liquid is being ingested.
But alcohol goes one step further. For every 1mg of alcohol that you
ingest, you will excrete out an additional 10ml of water. In addition to the
original amount that came with the alcohol.
Example: You consume a 300ml bottle of 5% (alcohol) beer. You will then excrete out
the ENTIRE 300ml as urine. You do not get to keep a drop of that beer and
say you just hydrated yourself using beer. Doesn’t work that way. PLUS you
will pee out an additional (5% x 300 = 15ml alcohol x 10ml = 150ml of water
from your body. The science was based on this scientific paper by Eggleton (1941).
No wonder people who drink a lot of alchohol are massively dehydrated the morning after. Take your typical beer, Canadian beer. A bottle will hold 341ml at 5% alcohol. That’s 17ml of alcohol. Drink a single one, you pee out the entire 341ml and then an additional 170ml of water. That’s defined as a negative water balance. Drink a six pack? You’re down 1.02L of water. You have to drink an entire litre of water just to get you back to the same hydration levels you were at BEFORE you started drinking the 6 pack of beer.
Here's a bit of a surprise. Only because I've never thought about it. What is more diuretic? A 355ml can of Corona, a 9 ounce (261ml) glass of Pizzela Malbec or 1 ounce shot (29ml) of Crown Royal?
The glass of wine wins hands down. In fact you'd have to drink 2 beers or have 3 shots of Crown Royal to "catch up" to the dehydrative effects of a single glass of good Malbec.
So a typical north American diet might get a typical male close to 3.0L of water. But after we take into account the wonders of diuretics, that someone would be down to only 2 litres of water. At best. If they drink more than 3 glasses of coffee and 1 glass of wine or 2 beers a day? And they’re not hydrating optimally? They are likely dehydrated. At least by the Academy of Medicine, Science and Engineering standards.
By how much?
In our hypothetical male's example, by about 1.7 Litres of water or about 7 glasses of water, if you are to take the National Academy of Science as your source of information.
Sure, you say. The guy made the numbers up to equal 8 glasses of water. Actually, I mimicked what my own meals have been over the many years of dieting, not dieting, fad dieting, and plain just experimenting. And eating a lot of fast food.
Now my daily meals are more like this:
Breakfast
4 cups of smoothie featuring a blend of about a dozen of the following fresh fruits, veggies, spices and seeds with 1 cup of plain drinking water.
Celery, frozen bananas, blueberries, raspberries, orange, pear or apple, slice of fresh ginger, slice of fresh tumeric, chia seeds, romaine lettuce or swiss chard (red or green), cucumbers, spinach, frozen peaches or mangos, coconut, pineapple, flax seeds.
Break
Glass plain drinking water
Handful (35g) of assorted nuts (Macadamia, Pecans, Walnuts, Almonds, Peanuts, Pumpkin Seeds, Sunflower Seeds, Cashews, Pistachio)
Lunch
Glass plain drinking water
Quinoa salad (1 cup)
Break
Glass plain drinking water
Two handfuls (70g) of assorted nuts
Supper (varies, combos of the following)
Glass of plain drinking water
Two cups cooked vegetables (Assorted, peas, celery, mushroom, chopped tomatos, chickpeas, various spices)
Two cups salad (assorted - spinach, kale, arugula, cucumbers, tomatoes, onions, mushrooms, etc)
One cup whole grain brown rice, quinoa, lentils, sorghum, whole grain pasta
Jojo's guilt free chocolate or similar high fiber to carb ratio snack (highlight of the day:)
Late Snack
One piece of Fruit (Orange or an apple)
One cup herbal tea
Before Bed
Glass of plain drinking water
If I run that day, I add 500ml of plain drinking water prior to the run and 500ml of plain drinking water post run with LMNT for electrolytes.
This menu typically gets me about 3.0L of water a day. 50% from food and 50% from liquids (including the smoothie). If you eat more of a fresh plant based diet, you will need less plain drinking water. Less veggies and less fruit in your diet? You're not going to get that water from your steak. And if you're not drinking a lot of plain drinking water, you're very likely dehydrated. Drinking plain water gives the typical North American, a chance to dilute the concentrated and dehydrated food they eat every day.
And the numbers that I posed are for someone in a temperate climate, basically
doing very little in the way of exercise or physical exertion. Do you
actually sweat when you’re at work? Then you need WAY more water. That much was
written about back in 1912 by Hunt in his paper entitled “The Regulation of Body Temperature in
Extremes of Dry Heat”. In it he talks about how workers in India were
regularly consuming 13L of water a day to offset their body’s need to replenish
their body’s need for water for cooling, metabolism and perspiration. Not to
even mention the electrolytes that you are losing through sweat. Not all at once. Remember the problems with drinking more than 1L of water an hour - hyponatremia. But at 1L an hour, you could theoretically drink up to 16L of water during your waking hours. If you didn't sweat as much as Hunt's test subjects, you'd simply be running to the toilet a lot.
Can we trust our sensation of thirst to save the day? For people who drink a lot of coffee, and ingest a lot of caffeine through the course of a normal day, the authors of the previously cited paper on Coffee consumption do not think so. Neuhauser-Berthold et al. write,
“Losses of body water of more than 0.5% of BW (Body Weight) or a decline in
TBW (Total Body Water) of more than 1-2% usually trigger a sensation of thirst.
Although in our study group losses of BW and TBW both exceeded these limits,
only 2 subjects experienced thirst. Therefore, in view of the widespread
habitual heavy coffee consumption throughout the world, it might be of interest
to devote future studies to establishing the level at which TBW losses provoked
by coffee consumption is compensated and by which mechanisms compensation
occurs.”
In other words, their subjects were not sensing thirst. Yet their Total Body Water was suboptimal. The authors are suggesting further study as to how these people will regain their proper body water. Meaning that they couldn’t believe that they would stay in a dehydrated state.
Or would they?
How prevalent is dehydration?
In 2010,
Popkin et al. did a study called “Water, Hydration and Health.” In it they speak
about a long-standing problem with governments and health agencies around the
world, not having sent a plain, concise and relevant message to the people of
the world as to how much water should everyone be drinking. From their article:
“The US Dietary
Recommendations for water are based on median water intakes with no use of
measurements of dehydration status of the population to assist. One-time
collection of blood samples for the analysis of serum osmolality has been used
by NHANES. At the population level we have no accepted method of assessing
hydration status and one measure some scholars use, hypertonicity, is not
even linked with hydration in the same direction for all age groups.6 Urine indices are used often but
reflect recent volume of fluid consumed rather than a state of hydration.7 Many scholars use urine osmolality
to measure recent hydration status.8–12 Deuterium dilution techniques
(isotopic dilution with D2O or deuterium oxide) allows measurement of total
body water but not water balance status.13 Currently we feel there are no
adequate biomarkers to measure hydration status at the population level.”
Lots of different ways of telling whether one is dehydrated or possibly hydrated properly. But NO DEFINITIVE way of telling whether you have enough water in you. No easy way. And easy is what the general public needs. Rather than tell people that they shouldn’t be drinking 8 ounces of water 8 times a day, the message should be you need to drink X amount of water, based on these criteria.
The public need a simple message, and that message can’t be
“trust your thirst sensors”, because as the coffee study showed above, people
who drink a lot of caffeinated beverages, can’t really tell when they are
thirsty. Furthermore, people who drink alcohol on a regular basis, would
have to cover their alcohol intake first and then compensate for the water loss
just to get to their level of hydration PRIOR to consuming alcohol. And
finally, older people’s ability to use thirst as a mechanism for hydration, just doesn’t work that well.
Not to mention ultra processed foods, which can be unhealthy and consequently, dehydrating.
Not to mention stress, which can be dehydrating.
Not to mention illness, which can be dehydrating.
Not to mention drugs, which can be dehydrating.
In 2006, the following guidance was issued from the International Life Sciences Institute North America Conference on Hydration and Health Promotion (November 29–30, 2006,Washington, DC):
“Most healthy people adequately meet their daily water needs when they let
thirst be their guide. However, this is not true for athletes, military in
hot environments, people who are ill, the elderly or infants. The sense of
thirst (or the ability to communicate it) of these populations is not an
adequate reflection of their water needs.”
In light of the fact that the people that we are trying to protect from
Covid-19 are the elderly and that they fall into this category is central to
this discussion. The elderly are the ones that have been left to their own
devices during this pandemic. Both they and the ones that look after them need to be told the truth about
hydration.
Unless you are getting enough water from your diet, you have to consciously drink more water, than thirst alone might dictate. How much, is still left to debate, but as evidence shows, most of us are not getting enough.
Postscript:
I wrote this article about hydration back in March of 2021. Today is September 17, 2023. Just prior to that date in December of 2020, I was looking for places on the Internet, where I might find a medical mentor, someone who had a following, where the issue of hydration might be taken seriously and conveyed to a wide readership. I came across Dr. Peter Attia's site, after listening to him on Tim Ferris's blog. I became a subscriber.
One of the bonuses of being a member of Dr. Attia's website, is that you could ask Peter anything. I asked Peter Attia in early January 2021 whether society and governments were taking hydration seriously enough during Covid. Or something to that effect, as I used his website to enter the question, and the original wording is lost to me now. Peter is an avid self-proclaimed longevity expert, and he and his team had dove headlong into numerous different aspects of longevity, so it seemed a simple enough question with potentially far-reaching consequences to someone who should know a thing or two about hydration.
So, it was with slight disappointment to say the least, when he and his team replied with an article in late January about the myth of "Do I really need 8 glasses of water a day?" I subsequently cancelled my membership as my replies to his post of were censored and removed. As it appeared that Peter was not truly open minded, and diligent in his research. Otherwise, he would not have written that article so quickly and with very little research to back his claim that hydration was not a concern.
So, it was with a bit of jubilant restraint that I read his post in November of 2021 that he had been dehydrated when he awoke one morning, got up too quickly and passed out, getting smacked by a table on his way to the floor. He had passed out due to low blood pressure, depletion of blood volume and ultimately, dehydration. The day after giving blood and not sensing thirst to replenish his water stores.
Hydration and the lack of associated thirst, our main mechanism to thwart dehydration, was a concern after all.
Most good science comes only after a massive
amount of failure.” – David M. Sabatini
Luckily for Peter, and the rest of us in turn, the blow to the head was a glancing one, as he posted pictures of his face on Instagram afterwards.
He followed up that post of his personal experience with dehydration with a great article regarding hydration in March of 2022. Showing me a side of him, that I had not expected. One of being open-minded, admitting to making a mistake. A sign of true integrity. Something that does not come easy for web bloggers.
Peter and his team also wrote an article recently citing that which Stookey et. al and a number of hydration epidemiologists have been saying all along during Covid. That seniors are most at risk for dehydration.
Peter, please give thanks to your night table from the rest of us. Your articles on hydration/dehydration since your close inspection of the woodwork near your bed, have been the tonic that we have been seeking. Much thanks.
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