Don't tell it to the hulk lugging a gallon jug of water around the gym, but the notion that you should drink eight glasses of water a day is probably bogus.
New research puts another nail in the coffin of the health myth that won't die and helps explain the mechanism by which the body regulates water intake. The study also comes with a warning label: Don't forget that if you drink too much water, you could drop dead.
A new study from an Australian research team found that there's no minimum water intake necessary to stay healthy. Thanks to your finely tuned bod, simply follow your desire to drink liquid and you should be just fine.
"If we just do what our body demands us to we'll probably get it right—just drink according to thirst rather than an elaborate schedule," Michael Farrell, an associate professor at Monash University who oversaw the study, said in a press release.
In the study, which will be published in the Proceedings of the Natural Academy of Sciences, researchers used MRI scans to study areas of the brain in subjects when they were thirsty following exercise and later after they had drunk to satiety. Subjects were then asked to rate how much more difficult they found it to drink when they were full.
The subjects reported that it was three times harder to drink when they weren't thirsty. Moreover, MRI scans revealed there was heightened activity in the right prefrontal cortex when subjects drank beyond satiety, suggesting that the brain kicks in to stop people from swallowing when the body doesn't need water.
That's your brain protecting you. If you drink too much water, you can die from hyponatremia, a condition also known as water intoxication in which the level of sodium in your blood falls to such low levels that it ultimately causes brain swelling. It's rare, but it has happened to athletes who drank enormous amounts of water before events in hopes of staying hydrated. In 2007, one woman died from it while participating in a water-drinking contest held by a local radio station.
So don't sweat it if you aren't chugging eight glasses a day. You're probably not going to die. Unless, say, you're that vegan model who omitted water from his diet entirely—and even he seems to be doing just fine.