Story at a glance
- Milk scored better than water on a test of how long various fluids stayed in the body before exiting as urine.
- The researchers reason that the longer liquid stays in the body the better it hydrates you.
- Milk scored its unexpected hydration win because of its mix of electrolytes, sugars, proteins and fats. The electrolytes are essential for good hydration and the other nutrients cause the stomach to empty more slowly, delaying the liquid’s exit from the body.
- Milk scored its unexpected hydration win because of its mix of electrolytes, sugars, proteins and fats. The electrolytes are essential for good hydration and the other nutrients cause the stomach to empty more slowly, delaying the liquid’s exit from the body.
- This doesn’t mean you should start chugging milk, unless you’re really thirsty and could use the extra calories. But it can help you stay hydrated longer.
“It’s so hot, milk was a bad choice!” bemoans a scraggly Will Ferrell in the 2004 comedy “Anchorman.” But maybe it wasn’t such a bad choice after all. It’s not likely to appear on most people’s top 10 thirst quenching beverages, but two studies found milk outperformed water (despite it’s unfortunate, growing association with white supremacists), The New York Times reports.
It’s still common to hear that we should all be drinking eight glasses of water every day, or, if you’re Tom Brady, guzzling an ounce of water for every half pound of bodyweight (for the football star that means 112 ounces a day, minimum). But the scientific evidence supporting these claims and those of sports drink manufacturers like Gatorade is surprisingly slim.
This doesn’t mean hydration isn’t important, but the best guideline may also be the simplest: Drink when you’re thirsty.
The study that flagged milk as a top hydration performer tracked how long 13 beverages stayed in the body after a person drank them. The idea was to use this measure of how long fluids lasted before being peed out to develop a hydration index similar to the glycemic index, which measures how quickly different foods cause one’s blood sugar to spike. The basic principle is that the longer a liquid stays in the body the more effectively it hydrates you.
The study measured how much liquid remained in 72 men two hours after drinking a liter of a beverage. Researchers used water as a baseline, assigning it a score of one. Anything that hung around longer would score above one and anything that left the body faster than water would score less than one. Oral rehydration solution (think Pedialyte), skim milk and whole milk all scored 1.5, and orange juice scored 1.1.
But why?
“Normally when you drink, it signals the kidneys to get rid of the extra water by producing more urine,” lead study author Ronald Maughan, of Loughborough University, tells The New York Times. “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.”
This isn’t exactly new information: “This study tells us much of what we already knew: Electrolytes – like sodium and potassium – contribute to better hydration, while calories in beverages result in slower gastric emptying and therefore slower release of urination,” Melissa Majumdar, a registered dietician, personal trainer and spokeswoman for the Academy of Nutrition and Dietetics, said in an interview with CNN.
This doesn’t necessarily mean you should start chugging milk, unless you’re really thirsty and could use the extra calories. But if you want to stay hydrated longer, with fewer trips to the bathroom, milk is a good choice.
changing america copyright.
