Ages ago I delved into the recommendation that to stay hydrated we had to drink eight glasses of water a day . I found no robust data to support this advice.
Furthermore, I disagree with purists who say only water will truly hydrate you. That’s nonsense.
The body interprets all the liquids you drink, or eat in foods, as rehydrating.
So when I heard about the beverage hydration index, I wanted to know if other drinks could hydrate you as efficiently as I believe.
A British study has tracked how long 13 common drinks stay in the body after being drunk, which equates to better hydration.
“In the last 25 years, we’ve done many studies on rehydration after exercise,” said Ronald J Maughan, a hydration expert from Loughborough University, and lead author of the study.
“We thought it was time to look at hydration in typical consumers who aren’t exercising.”
The new hydration index shows that some fluids last longer in your body than others.
Do the maths. If you drink a cup of water and then immediately pee half of it you haven’t added eight ounces to your body water, only four.
Thirteen common beverages were tested in 72 men, who drank a litre of water as the standard beverage.
The amount of water still remaining in subjects’ bodies two hours later – that is, not voided in urine – was assigned a score of 1.0.
All other beverages were evaluated the same way and then scored in comparison to water.
A score higher than 1.0 indicates the beverage hydrates better than water while a score lower than 1.0 indicates that it hydrates worse.
Four beverages have a significantly higher hydration index than water: oral rehydration solution, fat-free milk , whole milk and orange juice. The first three scored around 1.5, with orange juice at 1.1.
“It’s a very clever, even brilliant study,” said Lawrence Armstrong, a hydration expert at the University of Connecticut, US.
“It assumes that water is the optimal rehydration fluid, which is biologically correct, and then compares others to it.”
Why is milk so efficient at rehydration?
“Normally when you drink, it signals the kidneys to get rid of the extra water by producing more urine,” Dr Maughan said.
“However, when beverages contain nutrients and electrolytes like sodium and potassium, as milk does, the stomach empties more slowly with a less dramatic effect on the kidneys.”
So fluid is retained and you continue to remain hydrated.
Drinks containing caffeine, alcohol and sugar have hydration indices no different from water. And regular fizzy drinks can hydrate you just as well as water, but watch out for the sugar content.
Source: Mirror
Link: http://www.mirror.co.uk/incoming/you-think-water-best-way-9017638