Is water the best for hydration?

Who hasn’t heard the recommendation that we all should drink 8 glasses of water a day?  Yes, drinking water is good for our health.  Water is actually a nutrient we need every day.  How much water?  The Institute of Medicine recommends women consume about 91 ounces of water a day (about 11.3 cups) from food and beverages and men consume 125 ounces a day (about 15.6 cups) from food and beverages.  Thus, not just water counts but all liquids like coffee, milk, tea, juice and the many foods that contribute water.   Many people don’t think of foods as hydrating, but foods like watermelon are up to 90% water so do contribute water to our daily needs.  In fact, the Institute of Medicine notes, “About 80 percent of people’s total water comes from drinking water and beverages – including caffeinated beverages- and the other 20 percent is derived from food.”  Thus, the Institute doesn’t recommend hydration in terms of the number of glasses of water per day as we can meet our body’s water needs from many different beverages – think milk, juice, coffee, tea as well as many of the foods we eat.  

But for hydration, is water really the best choice?  Well, researchers in Britain have studied the best ways to hydrate.  They came up with a hydration index and found that some fluids stay in your body longer than other fluids.  Thus, would be more hydrating.  They had 72 males drink a liter each of 13 different fluids and measured how much stayed in their bodies after 2 hours.  Water was given a score of 1.0.  What beverages had a higher hydration score than water?  Four beverages:  Pedialyte, fat-free (skim) milk, whole milk, and even orange juice. 

Beverage	Oral rehydration score
Water	1.0
Pedialyte	1.5
Fat-Free (skim) Milk	1.5
Whole Milk	1.5
Orange Juice	1.1

Surprising to some, drinking milk is a good way to hydrate.  Milk contains protein and some carbs.  Whole milk has fat and milk provides minerals like some sodium and also potassium.  The nutrients slow down absorption and helps the body take up more water and retain more water.  Thus, milk and orange juice are more hydrating than plain water.  I am not surprised.  Often after a walk on a hot summer day, I like to have a glass of orange juice on ice.  It always seemed more refreshing than a glass of ice water and now research shows this may be true.  

Milk: a good way to hydrate

Time magazine had a recent article on, Why Drinking Water All Day Long Is Not the Best Way to Stay Hydrated.  Drinking some water before meals or during a meal is a recommended way to hydrate.  Why?  Because the nutrients in food, the fat, protein, vitamins and minerals all work together to help the body retain water.  This is why milk or fruit juice do well in hydration studies.  The article also noted that eating a banana post-exercise instead of a sports drink may actually be a better way to recover after exercise.  So post-exercise a good way to hydrate is eating a piece of fruit + water.  The fruit will help the body take up and retain the water.  Researchers also found that sipping some water throughout the day was better than guzzling down many ounces at one time.  

Juice is also a good way to hydrate

The take home message isn’t to stop drinking water.  But to also remember to drink some water before meals or drink water with a piece of fruit.  And that other beverages including milk and fruit juices can be more hydrating than plain water.  And think about sipping small amounts of water throughout the day.  I usually carry some water with me throughout the day or have a glass of water on my desk or nearby.  

Drinking water with a fruit is a good way to recover post-exercise

Sources:  Institute of Medicine, notes, researchers, hydration index,  Image Sources:  milk, Orange juice, Bananas