Blog post by Bernadette Keefe MD
In U.S. collegiate sports “The Elite Eight“, are the final eight teams in the national tournament; two from each region. The outcome of those four games becomes, “The Final Four”. In this summer time edition of The Elite Eight, we’re talking about the revered “eight glasses of plain water per day” health dictum.
While optimal hydration is essential for health, and water is considered the “gold standard” of hydration, we do not need 64 ounces of plain water a day. We do, however, need 64 ounces or 1.9 liters of total fluid obtained via drinks and food for optimal functioning and health, especially during the warm weather and exercise.
Furthermore, what makes the eight glasses of water per day advice “elite”/special is that consuming a zero calorie beverage might just be the antidote to the current epidemic of obesity and Type 2 diabetes. Americans typically satisfy their thirst with sugary beverages. Shockingly, these drinks contribute the majority of our daily ingestion of sugar!
Also, for many, thirst and hunger signals can be easily confused, that is, we feel the need to eat when we are just thirsty. Given this confusion, when we feel hunger pangs, it’s best to remember “the elite eight” and drink water first!
In this piece, I wish to cover the basics of dehydration and hydration, the body’s fluid regulation including the thirst mechanism, the high-risk populations for dehydration, the drinks – obesity connection, and the most effective, healthy and fun ways of staying hydrated. Ultimately, we need our “elite eight” through food and drinks, but we can and must make the hydration healthy. Furthermore, to insure our success and foster enjoyment, we can craft ways to be creative about it!
The Nutritional Role of Water
The human body is 70-75 % water. Sixty percent of that water is located within our cells. The remaining 40% of body water is outside of the cells, within fluids such as blood and in the digestive and urinary tracts.
Water participates in a number of essential bodily functions:
- As a primary building block of cells
- As an insulator, regulating internal body temperature.
- In the digestion of proteins and carbohydrates used as food
- For lubrication of joints, and keeping body surfaces such as the eye moist.
- For insulation and as a shock absorber around organs and the fetus.
- Used to flush waste and toxins from the body and urine.
The Regulation of Water Output – ADH
Water output is regulated by a hormone called vasopressin or ADH (anti-diuretic hormone). This hormone is released when the percentage of water in the blood declines. The resulting effect is that less water is removed from circulating blood by the kidneys, we urinate less and retain more water. This process is described in the slide below:
The Regulation of Water Input – The “Thirst Center”
The body’s thirst center, located in the hypothalamus, is activated when we have lost about 2-3% of our body’s water. Thirst is also stimulated by a decrease blood pressure, or increased ingestion of salt.
Sometimes, we can mistake the sense of thirst as a need to eat. This causes us to needlessly take in more calories while trying to quench our thirst with food! Only after eating, and still feeling the sensation, do we realize that we must be thirsty and drink!
Dehydration – Risk Factors and Warning Signs
There are known risk factors for, and populations at risk of, dehydration. In these situations it is prudent to be particularly proactive/attentive about hydration.
The Risk Factors – “The 4 A s”
- Acute disease – such as fever/infection, gastrointestinal upset cause fluid loss.
- Alcohol –Alcohol-containing beverages can adversely impact fluid balance by blocking the release of ADH, and thus increasing fluid loss through urination.
- Aging – The older person may have a diminished thirst sensation causing decrease desire to drink and decrease overall intake of fluids.
- Also: In Exercise & Hot weather – Increased evaporation from skin and perspiration, resulting in overall water depletion.
The Warning Signs of Dehydration
Most of us are familiar with the symptoms of mild dehydration. The info-graphic below provides a reminder of the degrees of dehydration and accompanying symptoms. Given upcoming long hours spent outside during warm summer weather for many school age children, the possibility of inadequate/absent air conditioning for cooling with summer storms, and the enlarging aging population, this information is worth knowing!
How to Hydrate Healthfully
A ) Drinks- Water, & Water Infusions
Instead of water, which has zero calories, most of us choose beverages which are heavily sugared and highly caloric, such as: juices, sodas, smoothies and sweetened coffees. Plain water simply doesn’t have the same appeal!
The infographic below shows how easily we can consume 50-75% of the recommended calorie intake in drinks alone. Notably most of these drinks provide minimal nutritional content.
There is, however, a refreshing, low calorie and appealing alternative to those sugary drinks: water infusions. Water infusions are cold drinks made with chilled water, ice and cut up juicy fruits or vegetables. In the winter, hot teas provide another type of healthy infused water! Replacement of high calorie drinks with water infusions would greatly decrease our total daily caloric and sugar intake.
B.) Foods – Juicy fruits and vegetables
Happily, we are not confined to drinks when trying to maintain normal hydration. A wide variety of foods, especially the succulent fruits and vegetables of summer, contain abundant water and can provide much of our hydration needs.
Below is an info-graphic of the most hydrating, juicy fruits and vegetables.
In summary, the health maxim “eight glasses or 64 ounces of water per day” is not “The Elite Eight”. The special/ “elite” eight is the 64 ounces of fluid we want to ingest daily by eating healthy, juicy fruits and vegetables and drinking refreshing, low calorie water infusions. Small amounts of coffee, abundant hot and cold tea infusions, and, of course, added plain water are all great!
Additionally, since we are already 2-3% dehydrated when the thirst mechanism kicks in, and we may confuse thirst with hunger, a smart course of action is to be proactive in our hydration habits and think, “The Elite Eight First”. This is especially important in the summer, during outdoor sports and routine exercise, and in the aging population who have diminished thirst sensation.
So let’s have a renewed interest in the “The Elite Eight” and craft healthier ways to keep up with our fluids!
The Elite Eight” Recipe:
- Start with simple water
- Add ice and juicy fruits to make a drink infusion
- For eating: enjoy fresh, juicy, fruits and vegetables in abundance!
Meanwhile, avoid the other drink choices as much as possible!
Join the #hcldr community on Tuesday June 21st at 8:30pm ET (for your local time click here) when we will discuss the following topics:
- T1 How are you with hydration status; always behind or successfully keeping up?
- T2 When you are really thirsty, what do you reach for?
- T3 Have you or a loved one ever experienced moderate-severe dehydration? Your symptoms and treatment?
- T4 What are some of your favorite, healthy, and creative hydration tips?
No, You Do Not Have to Drink 8 Glasses of Water a Day http://www.nytimes.com/2015/08/25/upshot/no-you-do-not-have-to-drink-8-glasses-of-water-a-day.html?_r=0
Do we really need eight glasses of water a day? http://www.chatelaine.com/health/do-we-really-need-eight-glasses-of-water-a-day/
Water: How much should you drink every day? http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256?pg=2
Daily Water Intake Among U.S. Men and Women, 2009–2012 http://www.cdc.gov/nchs/products/databriefs/db242.htm
Physiology of Hydration
Water balance, fluids and the importance of good hydration http://www.eufic.org/article/en/artid/water-balance-fluids-hydration/
How Much of Your Body Is Water? http://chemistry.about.com/od/waterchemistry/f/How-Much-Of-Your-Body-Is-Water.htm
12 Unexpected Reasons to Drink More Water http://greatist.com/health/reasons-to-drink-water
The Regulation of Fluid Balance in the Body
Water Balance: ADH, Angiotensin, Aldosterone http://schoolworkhelper.net/water-balance-adh-angiotensin-aldosterone/
Recognising and preventing dehydration among patients http://www.nursingtimes.net/clinical-archive/nutrition/recognising-and-preventing-dehydration-among-patients/5076560.fullarticle
5 Ways To Enhance Your Exercise Recovery
The Thirst Mechanism – Thirst/Hunger Connection
The Neural Regulation of Thirst http://www.brainfacts.org/brain-basics/neural-network-function/articles/2008/the-neural-regulation-of-thirst/
From: Central Nervous System Dr. Anderson GCIT. Animal Body Plans. http://slideplayer.com/slide/7711748/
Are you hungry or thirsty? It’s hard to tell http://www.strauss-water.com/are-you-hungry-or-thirsty-its-hard-tell
Healthy Hydration Through the Diet
8 Amazing Infused Water Recipes To Drink Instead of Soda http://www.healthyfoodhouse.com/8-amazing-infused-water-recipes-to-drink-instead-of-soda/
Water vs. Soda http://ifitandhealthy.com/water-vs-soda/
IWK Health Centre stops selling pop and juice http://www.cbc.ca/beta/news/canada/nova-scotia/iwk-no-longer-selling-pop-or-juice-1.3620622
Fresh Ideas For Making Infused Water http://dish.allrecipes.com/fresh-ideas-for-making-infused-water/
Water, glasses – Pixabay.com