We’ve all heard the message. Drink 8- 8oz glasses of water each day. I don’t think it would be a stretch to say that this piece of advice is the most commonly repeated advice anywhere. You’ll find it mentioned in practically every news segment or article on health or weight loss, by grandmothers across the country, and on blogs all over the internet. Question is; what if that information is wrong, or at the very least misunderstood?
“There’s nothing so absurd that if you repeat it often enough, people will believe it.” –William James (1842-1910), the father of modern psychology
It turns out that the 8 x 8 (8 glasses, of 8 oz each) guideline may be based on a misunderstanding. In 1945 the Food and Nutrition Board, now part of the National Academy of Science’s Institute of Medicine made a recommendation for daily water consumption. They suggested a fifth of a teaspoon per calorie of food consumed. This works out to be about 64 to 80 ounces. The last sentence stated that “most of this water is contained in prepared food”. Somehow, this part of the report has been lost in the communication of the guidelines. Dependant on your diet, the amount of water necessary to supplement your food varies. Most people need 3-4 cups a day, although during strenous exercise, pregnancy or in hot weather that amount goes up. In 2004 the board reviewed their earlier guidelines. The conclusion of their study was that “the vast majority of healthy people adequately meet their daily hydration needs by letting thirst be their guide.”
Dr. Valtin, a kidney specialist, is the author of two textbooks on the kidneys and water balance. He is a professor at Dartmouth Medical School. He spent nearly a year searching for evidence that supported the 8 x 8 guidelines. He couldn’t find a single scientific report supporting the recommendations. Surveys of fluid intake on both men and women were published as peer-reviewed documents. These strongly suggest that such large amounts of additional fluids are not needed. Since then, other studies have come along supporting his conclusions. It is now being recognized that other fluids, such as coffee, tea, and even alcohol in moderate amounts, can count towards our necessary hydration requirements. Dr. Valtin’s final recommendation was to let your thirst be your guide, rather than force yourself to drink a specific amount of water.
As I was doing research on hydration I found a fascinating correlation between weight and hydration levels. Water in the body is measured in two ways; dehydration is measured by the amount (or lack of) of water circulating along with the blood, while hydration is the amount of water being held in bodily tissue. Dehydration occurs when the concentration of blood has risen by 5 percent. Body water percentages are helpful for understanding hydration. It would be easy to think that if you want to hydrate, then you just drink more fluids. It’s not quite that simple. The body is a finely tuned balancing machine. Drinking excess water doesn’t actually increase hydration, it only decreases the blood concentration (by increasing the blood volume), and throws the electrolytes out of balance. Hydration is the body holding onto the fluid, storing it in the tissues. The bodily tissues that retain water, and are used for measuring our hydration levels, are muscle, and fat. So based on the amount of muscle and fat your body contains, you have a limit on your potential hydration levels. Turns out muscles hold more water in their fibers than fats do. A fat cell can only hold 15%- 25% water, whereas a healthy muscle cell can hold up to 72%. In light of this information, I started tracking my own body hydration percentages, and found this to be true. Over the last 2 months, as my body fat percentage has gone down, my body hydration percentages have gone up. It is difficult to be properly hydrated if you are overweight. To increase hydration you need to increase your muscle mass and decrease excess fat. Without having proper “storage tanks” guzzling water will only make you have to go to the bathroom more, and deplete your nutritional stores.
What could be the harm in drinking too much??
We often like to think of water as being the perfect “healthy” drink at best, and at worst, totally harmless. Dr Valtin, said “The fact is, there is potentially harm, even in water”. Too much water can cause water intoxication. The symptoms of water intoxication include mental confusion, seizures, and even death. Unfortunately deaths from water intoxications do occur. In 2007 a young mother lost her life due to water intoxication. She was participating in a radio station contest “hold your wee for a wii” and drank too much water. A recent study in the British Journal of Sports Medicine highlighted the case of a runner in the London marathon who collapsed and died, after crossing the finish line, due to exercise-associated water intoxication. Most cases involving death, are the results of a prank/contest, ecstasy use (causes the sensation of extreme thirsty), or uneducated athletes consuming excess amounts of water in an attempt to avoid dehydration. What most people don’t realize is that harm can and is done to the body long before the intoxication reaches fatal levels.
There is a popular theory going around that drinking more water is necessary to properly detox the toxins in our body. This might be true if the kidneys worked like a carbon filter, forcing water to trickle through at a slow and steady pace. There is no filter controlling the flow of water. The more you drink (esp. at one time) the faster the water flows into your kidneys. Your kidney filters, in part, using a series of capillary beds called glomeruli. The glomeruli do get damaged by wear and tear. Drowning your kidneys with large amounts of water is one of the suspected causes of this wear and tear. As far as removing toxins, one study found that at best, drinking water resulted in little to no increase in the ability to remove toxins, and at worse, the body was actually LESS able to remove toxins (as is the case with the glomeruli in the kidneys). So it’s hard on your kidneys to drink excessive amounts of water, and has little benefit, if any at all.
When your body processes water, it not only removes toxins- but also uses and loses minerals. When we drink too much water, a mineral imbalance occurs. Thanks to commercials for Gatorade, most people have an idea of what electrolytes are. Although I would not recommend Gatorade as a healthy drink, they at least understand that water alone does not create the proper balance needed. The electrolytes necessary for the body are: sodium, potassium, chloride, calcium, magnesium, bicarbonate, phosphate, and sulfate. Despite the bad rap that sodium (salt) gets in the media, it’s a vital nutrient. Hyponatraemia develops when you don’t have the proper salt to water ratio. Acute hyponatraemia can result in a coma, brain herniation, and death. Potassium is another one of the minerals that is lost with excess water. This can lead to constipation. It’s actually not the water that keeps our stools soft, it is potassium. Potassium helps the body reabsorb water, and a deficit results in hard stools. Calcium is another important mineral lost through excess water. Lose too much calcium and you may end up paying the price with kidney stones. Other conditions potentially created by mineral loss are: heart disease, heart attack, angina, arrhythmia, unstable blood pressure, degenerative bone diseases, muscular disorders, fibromyalgia and fatigue.
One more downside to guzzling unnecessary amounts of water is unnecessary trips to the bathroom! True, it’s a silly complaint- but if we don’t need all that water, why waste time with all those bathroom trips? I don’t know about you, but as a mom- time is at a premium. Plus- I don’t want leave a 20 month old alone for too long- man-o-man can they think up a lot of “no no’s” to do in a short amount of time!
What about when you’re sick????
In 2004 a study was done to see whether increasing fluids (ie, past the point of thirst) when sick was beneficial, benign, or harmful. This study published in the British Medical Journal. I was very surprised to see the results of their findings. Apparently when sick, the body releases an anti-diuretic hormone. The release of this hormone is most common in lower respiratory infections (chesty colds). The body is trying to conserve all its energy and nutrients for healing. It seems like it would make sense to drink extra water, especially with mucus as a symptom. Instead, giving extra fluids while sick might lead to hyponatraemia and fluid overload. In the data they cited, there were several deaths in children caused by this. The conclusions reached by the research team are:
“We found data to suggest that giving increased fluids to patients with respiratory infections may cause harm. To date there are no randomized controlled trials to provide definitive evidence, and these need to be done. Until we have this evidence, we should be cautious about universally recommending increased fluids to patients, especially those with infections of the lower respiratory tract”
I would like to point out that this data is for “increased fluids”. I don’t think we need to limit fluids while sick, just reassess the common practice of “pushing fluids” Certain illnesses will require more water. For example, having a fever increases the need for hydration by about 1 cup per day. Trusting your thirst mechanism should supply your body with the fluids you need.
Common water myths:
- Thirst = Dehydration
- It’s on blogs, in articles, and now even in those “forward to your friends if you care” chain emails. It reads something like this “If you are thirsty than it’s too late: you are already dehydrated!” While that might be a nice scare tactic to sell more bottles of water, it’s total malarkey. Your thirst mechanism is triggered by a 2% rise in blood concentration. Dehydration does not occur until a 5% rise in blood concentration. So just being thirsty, does not mean you are dehydrated. Studies done by Barbara Rolls, a professor of nutrition sciences at Pennsylvania State University, found no evidence that people are chronically dehydrated. Apart from some drugs that cause problems with thirst regulation, she feels that most people are adequately hydrated.
- Urine should be clear
- No. Although urine should not be dark brown, it shouldn’t be clear either. Urine color is affected by concentration levels, vitamins, minerals, medications, and the foods we eat. A lemony yellow is perfectly acceptable for urine color. Every person is different, and the color and output amount is going to vary from person to person. If you have to wake up in the middle of the night, or go more than 5 times per day- (and aren’t pregnant!) then you are drinking too much.
- Weight loss is improved
- The theory goes: drink more water, feel more full, lose more weight. There are a couple of issues with this thinking.
- Having the goal of a “full stomach” results in a stretched out stomach. Eating to satiety (using fat) is a much more effective way to lose and then maintain weight.
- Although you might feel full at the table: that “feeling” goes away rather quickly once you get up
- Drinking water with your meal dilutes your digestive enzymes. Besides making your body less effective at digestion, this can also lead to heart burn, acid reflux, and other digestive issues
- Let’s get real here: We as a society are drinking more water than ever! Take a look around you next time you’re out somewhere and see how many people are walking around with water bottles. Are we seeing a decline in obesity levels? No, they are still increasing. So while this myth might seem like the magic weight loss pill, it’s obviously not having a positive effect on our waistlines!
Ok- so bottom line? I have come to the conclusion we need to let our healthy thirst signals be our guide. Unfortunately – our thirst mechanism isn’t always health. It’s out of whack from guzzling water so much, that our body is in “flush” mode. This is because the body senses the huge amount of liquid you’re suddenly downing and releases a diuretic hormone in an attempt to bring your fluid levels back to normal. In the short-term, this reactive offloading (your half hourly flights to the bathroom) can be over-compensatory, leaving you dehydrated.
Here’s my suggestions. Note- these suggestions are not necessarily for someone on the Standard American Diet. The SAD has too much grains and fiber in it. Excess fiber basically “spoils” in your intestines, and requires more water to work its way through your system. Ever eat a couple of crackers without any water? Even if you are eating the SAD – rethink how much water you are drinking. Don’t feel guilty if it’s not the 8×8. After all- as we established above- there is no scientific evidence backing it up, and even some studies suggesting it’s too much. For my readers who are eating a traditional food diet, a low carb- high fat diet, or the liberation diet, let’s retrain our bodies to have accurate thirst indicators on them. My thirst indicator was out of whack, and with Kevin’s (author of the liberation diet) encouragement and guidance, this is what I did.
- Stop drinking water……..take a deep breath. I said water, not liquids. Water depletes our system, while not really adding anything of value back in. Although I still drink an occasional glass of water, especially if I’m out, it’s not the first thing I grab anymore. Kefir, water kefir, moderate amounts of raw milk, herbal tea, small amounts of coffee (esp. with raw cream), kombucha, and even a good bone broth are all great ways to hydrate your body. Although they still require nutrients to process (like water), they are adding something back to your body at the same time.
- Ditch the “Texas sized” glasses. Confession time- I grew up loving big glasses. In fact, once I moved out on my own, I would steal one or two of my favorites (from my mom), to keep at my house (Sorry mom!). Right now my cabinet is full of 24 oz glasses. In the past I would fill them to the brim, and then stand at the sink and chug, chug, chug away. Now that I’ve found my natural balance, I still use them, but I only fill them about 1/3 of the way full (including ice) – and sip over time.
- Give it a week or two. Honestly, I was so used to over hydrating, that I trained my body to be prepared for that. Kevin encouraged me to drink just a small amount a day (read: normal) for a week, and not to drink 3 hours before bed. At first I found that really difficult. I had become accustomed to taking that 24 oz glass to bed and drinking it all before I went to sleep. It was mostly mental, but my mouth felt dry at night. I found sucking on an ice-cube for a min or two really helped at those times. For me, it was less than 1 week until I had “reset” my thirst mechanism. I don’t walk around feeling thirsty. My urine is a nice lemon yellow, my skin looks hydrated, and I have energy.
- Get a tea-cup. Now I know you think I’ve lost my mind, but this really helps. Until your body is balanced, and not in flush mode- when you are thirsty, drink you choice of beverage (not water) from a tea-cup (not a coffee cup). Now I don’t mean stand there and fill it up over and over! Fill it up once, drink (not guzzle), and then walk away. Most the time you will find that your thirst is quite quenched. If not, then go back and get some more 😀
Want to read more? Here are some of the articles and resources about water I used.
http://espace.library.uq.edu.au/eserv/UQ:74274/UQ_PV_74274.pdf (this one is the study on drinking extra fluid while sick)
This post is part of Fight back fridays- at food renegade