Gem of the Week: Forget 8 Glasses of Water a Day

AlexBClark/<a href="http://www.flickr.com/photos/37072792@N06/4292188381/sizes/z/in/photostream/">Flickr</a>

Get your news from a source that’s not owned and controlled by oligarchs. Sign up for the free Mother Jones Daily.


For many years, people have been told they should drink eight eight-ounce glasses of water a day. That’s 64 ounces, or nearly 2 liters. This week,  Scottish practitioner Margaret McCartney is calling it “thoroughly debunked nonsense” in the current issue of the British Medical Journal.

McCartney took on medical claims disseminated by Hydration for Health, a water-pushing health organization created by the company that owns Volvic and Evian. McCartney wrote that she did not see any high-quality scientific literature provided by Hydration for Health proving drinking so much water was essential. In fact, she found evidence that mental performance suffers when people drink more water than they’re thirsty for. “In other words, there is still no evidence that we need to drink more than we naturally want, and there may be unintended harms from an enforcement to drink more water,” McCartney wrote.

While McCartney didn’t see evidence backing up the 2-liter-a-day rule, she did see bottled water companies pushing the “water=health” idea to sell more of their products. As McCartney wrote on her blog: “The bottled water industry is pushing the idea that we should drink more than we normally would with the promise of health benefits, and I don’t think there are any. That’s all. And I would recommend tap rather than bottled water: cheaper, and far better for environment.” The bottled water companies were not happy with McCartney’s attitude. In response, the European Federation of Bottled Waters wrote a letter to BMJ about McCartney’s article and cited a recommendation that “at least two liters of water should be consumed per day.”

The British National Health Service still recommends that everyone drink “six to eight glasses” a day, but in the US, the Mayo Clinic’s site says that the eight eight-ounce glasses of water a day “isn’t really supported by scientific evidence” and that “if you drink enough fluid so that you rarely feel thirsty” and produce enough clear or light yellow urine a day, you should be fine.

BEFORE YOU CLICK AWAY!

“Lying.” “Disgusting.” “Scum.” “Slime.” “Corrupt.” “Enemy of the people.” Donald Trump has always made clear what he thinks of journalists. And it’s plain now that his administration intends to do everything it can to stop journalists from reporting things they don’t like—which is most things that are true.

No one gets to tell Mother Jones what to publish or not publish, because no one owns our fiercely independent newsroom. But that also means we need to directly raise the resources it takes to keep our journalism alive. There’s only one way for that to happen, and it’s readers like you stepping up. Please help with a donation today if you can—even a few bucks will make a real difference. A monthly gift would be incredible.

payment methods

BEFORE YOU CLICK AWAY!

“Lying.” “Disgusting.” “Scum.” “Slime.” “Corrupt.” “Enemy of the people.” Donald Trump has always made clear what he thinks of journalists. And it’s plain now that his administration intends to do everything it can to stop journalists from reporting things they don’t like—which is most things that are true.

No one gets to tell Mother Jones what to publish or not publish, because no one owns our fiercely independent newsroom. But that also means we need to directly raise the resources it takes to keep our journalism alive. There’s only one way for that to happen, and it’s readers like you stepping up. Please help with a donation today if you can—even a few bucks will make a real difference. A monthly gift would be incredible.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate