One of the most critical medical interventions of the 20th century is a saline solution. Chances are if the hospital takes you in and gives you an infusion that delivers saline directly into your veins. Saline is one of the earliest products to be shipped to disaster sites and is at times so in demand that the drug companies that make saline are suffering from shortages
We need salt and water
Saline is just a fancy name for salt water, and the saline you get at the hospital is 0.9% sodium chloride. Several years ago, the American Society of Health System Pharmacists (ASHP) recommended using oral hydration whenever possible due to the lack of saline solution. Oral hydration is a quirky term for drinking.
Most of us naturally get the right amount of water and salt by drinking and eating water. We need both water and salt to maintain adequate blood sodium levels of 140 millimoles of sodium per liter of plasma.2 This number is finely tuned; Falling below 135 mEq / L can lead to a variety of problems, including:
The medical term for this is hyponatremia. 3
Several things cause hyponatremia, including persistent vomiting and diarrhea. It can also occur in endurance athletes who drink too much. When an athlete uses more water than they excrete through sweat and urine, the total body water content increases compared to the total exchangeable sodium
How much is enough
This leads to an interesting question: how do you know if you are drinking too much water? And how much water should you drink?
Maybe not eight glasses a day, suggests Eduardo Dolhun, a doctor with a special interest in dehydration. (He also founded Drip Drop, an electrolyte powder5 that contains an accurate proportion of electrolytes specifically designed for oral rehydration therapy, so there may be financial bias.) "Do you see the Maasai walking with bottles of water?" He asks in James Hamblin's book, "If our bodies could talk." 6th
He has an argument. I looked for pictures of Kenyans exercising and couldn't find a single picture of someone with a water bottle. The Kenyans are among the fastest people in the world. Although their climate is relatively temperate (they exercise in the mornings and late afternoons when it's often in their low 50s and 60s) it is also high altitude and they don't move slowly.
Fascinated, I conducted a PubMed search7 to find out more about the drinking habits of Kenyans. It turns out that researchers have found that Kenyans are hydrated with ad libitum fluid intake on a daily basis. Ad libitum fluid intake means that you can drink, whenever you want, how much you want. They also eat little processed foods, including lots of vegetables and the occasional glass of whole milk. Hence, their eating habits may meet their daily needs without too much additional tinkering
It's worth noting that urinating and thirst are the ways we regulate our fluid status. We also have the built-in ability to know what type of drink we intuitively need– The taste buds in the mouth send messages to the brain about how much salt to consume and how much water is needed. These messages cause a cascade of predictive reflexes that send information about when to start and stop drinking. This happens before the water gets into the bloodstream. These signals come from both the gut and the brain. 9
Drinking in modern culture is not necessarily based on thirst. It is based on:
- Pleasure (alcohol, hot chocolate, or lemonade on a summer day)
- To cheer us up (caffeine)
- To calm us down (chamomile tea)
We can either prevent thirst signals (drink because we feel like we should) or ignore thirst signals, just as we learn to ignore other interoceptive signals such as pain, tenderness, or hunger.
Listen to our bodies
Interoceptive signals are your internal cues about how you are feeling. Much like information from the external environment, such as what you see, hear and smell, affect your sense of security and play a large role in your movements and behavior, so does your conscious and unconscious interpretation of your interoceptive cues.
Perhaps part of what takes us out of our physiological point of equilibrium is a departure from listening. When we reconnect with the ability to pay attention to what our body demands, the solution often shows up immediatelywhether it is drinking water, a specific food or a specific exercise.
Listening is easyand simplicity is often confused with a lack of depth, as if the simple solution cannot be the real solution because it is too simple. Instead, we look for complexity, and within that complexity we may lose touch with what we need.
When was the last time you sat on the floor and allowed yourself to move to see what came up? And maybe you allowed yourself to move around in a way that felt good and nutritious instead of fighting your initial instincts because you weren't sure they were right?
- Food can show up as strengthening or stretching.
- A nourishing movement can also show up as a gentle movement that doesn't fit exactly in a box, but still feels kind of supportive.
You can try this now. I'll take a break from writing and do it with you. I usually do this for the length of a song, but if music isn't your thing, set a timer for four minutes and see what happens. And if you've never made an improvisational move and don't know where to start, pick a body part and start moving it. Watch the movement unfold, spend time with what feels interesting, and see where it takes you.
How was it? How are you feeling now compared to four minutes ago?
I feel so much better and I didn't even know I wasn't feeling right before. The first song was too short (two minutes) so I played two songs, or about six minutes.
I started doing stretching and rolling movements for my legs, which were sore from my workout two days ago and turned into a fascinating upper extremity load, the exploration of leg mobility. My legs feel less sore, I feel more energetic, and I feel more connected throughout my system.
When things are so out of whack, you can't remember how to listen to your internal cues, and you can't tell when you are thirsty or when to use broccoli. Take a moment to pause and listen. Honor what you hear and see what happens.
Fred Rogers once said, "I feel so strong that deep and simple is much more important than flat and complex."
Perhaps learning to apply this rationale to ourselves is the ultimate biohacking technique. Or maybe that's too easy.
1.U.S. Food & Drug Administration. FDA Commissioner Scott Gottlieb, M.D., "Announces Some Persistent Bottlenecks Associated with IV Fluids," Press Release, 2018, Jan. 16.
2. Parsons P. E., & Wiener-Kronish J. P., 2013. Chapter 45: Hyponatremia and Hypernatremia. In B.W. Metzger and K.D. Liu (Ed.), "Critical Care: Fifth Edition", pp. 322-328. Elsevier. Google books.
3. James L. Lewis III, MD. Hyponatremia. On Merck Manual Professional Version. 2020.
4. Hew-Butler, Tamara et al. "Exercise-Associated Hyponatremia: Update 2017," Frontiers in Medicine, Volume 4: March 21, 3, 2017.
5. DripDrop, ORS, "Oral Rehydration Solutions (ORS) are a breakthrough science that treats and prevents dehydration for millions of people worldwide." Accessed August 30, 2020.
6. James Hamblin. "If Our Bodies Could Talk: A Guide to Using and Maintaining a Human Body." Double day. 2016.
7. Fudge B.W., Easton C., Kingsmore D., Kiplamai F.K., Onywera V.O., Westerterp K.R., Kayser B., Noakes T.D., & Pitsiladis Y.P., (2008). "Elite Kenyan endurance athletes are hydrated with ad libitum fluid intake daily." Medicine and Science in Sports and Exercise. 2008 Jun; 40 (6), 1171-1179.
8. Christensen, Dirk L. "Diet intake and endurance performance in Kenyan runners." Equine and comparative movement physiology 1, No. 4 (2004): 249–53.
9. Popkin B.M., D'Anci, K.E. & Rosenberg, I.H., "Water, Hydration and Health". Nutrition Review, Volume 68 (8): 439-458. 2011.