You may have noticed that the recent news to capture major headlines with an article that stated that drinking 8 glasses of water a day was a myth. Of course any headline that can create the reader to sit up and pay attention is a good one for the media. As a friend of mine used to always say, “Dog bites man, that’s not news – Man bites dog, that’s news.”
Unfortunately, for those of us who are passionate about the facts, the whole truth, and the impact these things can have on our client’s performance, eye-popping headlines aren’t so entertaining. Even worse, this type of “sound bite” reporting can cause confusion and makes people suspicious as to what is the truth anymore.
Recently, Dr. Margaret McCartney wrote a commentary in the British Medical Journal regarding hydration, which made many of the news headlines. In the summary, Dr. McCartney reported that there was no reason for keeping yourself hydrated above your thirst indicator and declared that there was no clear evidence of any benefit to higher levels of hydration. The problem is that this study only looked at hydration in terms of urine output and concentration and this only tells part of the story.
If you look at the whole picture of hydration, and the function of water in the body, you have to look at it from several angles. First, given that the brain is composed of 80% water and the body is close to 60% water, water balance in the body impacts every physiological function in the body. Second, we store water in three compartments in the body: our cells (where the majority of metabolic activity happens), between our cells (interstitial fluids) and lastly, and systemically in our cardiovascular and lymphatic system. Interestingly, 93% of the water in our body is located in our cells and between our cells. Third, optimal hydration is critical for the proper functioning of our kidneys, digestive tract, brain, cardiac system, and joints to ensure adequate nutrient availability for all cells in the body.
In Dr. McCartney’s conclusions, she does not differentiate or clarify whether all three compartments are optimally hydrated based on thirst. Similarly, since only urine tests were used as the key hydration indicator, it is unlikely to measure adequate hydration in all three of these areas.
If we look at the cellular studies, and the body’s need for water, we know that water functions as a catalyst for enzymatic reactions in the body, including digestion, detoxification, transport, and the production of energy. When cells are not adequately hydrated, these functions become impaired and compromised. Unfortunately, currently no good practical test exists (and researchers are diligently looking to find one) to assess whether inside the cells and/or between the cells are fully hydrated. We do know that physiologically we are hard-wired to always divert water levels to support the systemic (cardiovascular) system, at all cost. In fact, the body will shift water from inside the cells, and between the cells, to support the systemic system. This means that by the time the body registers the cardiovascular system is at risk for dehydration, and the thirst mechanism is initiated, the water balance within the cells and between the cells has been disrupted. Interestingly, if the urine test is the only hydration indicator used, it would register adequate because the systemic system had been preserved.
At Tignum we are always looking at the latest research to help us fine tune our strategies. We are also constantly listening to the experiential feedback our clients have from “doing” our strategies while they perform in their highly demanding lives. Based upon these criteria, after increasing their daily hydration levels, they report less brain fog, improved focus, greater concentration, less afternoon fatigue, and less joint pain. Additionally, while traveling they report less jet lag symptoms, less food cravings, and a stronger immune system (get sick less).
Reframing my frustration, I must admit, there is one positive aspect to this type of nutrition “sound bite” reporting. Without a doubt it can challenge us to experiment with our nutritional habits and see what we feel, and how we perform. It may even motivate us to dig deeper, beyond the headlines, and verify for ourselves what enhances our sustainable high performance.
I would love to know what you think and what you have experienced as you’ve experimented with your own hydration levels.
Partner // Director of Nutrition