Thursday, April 3, 2008

Water Myths

Many of you are going to love this. A nephrologist at University of Pennsylvania, that some of you many know, Dan Negoianu, published a piece in the Journal of the American Society of Nephrology on the Myths of Water Intake. I'm sure many of you have been told to drink "8 glasses of water a day."

Dan debunks four common myths:
1. "Water improves clearance of toxins and improves organ function"- a few studies to examine this effect (or a surrogate of toxin clearance) have not demonstrated this to be the case.

2. "Water makes you feel full and decreases caloric intake"- the few studies examining this have not found this benefit.

3. "Water intake decreases headache"- the one study performed found a slight decrease in the number of hours of headache in the group that drank more water, but it did not reach statistical significance

4. "Water drinking improves skin tone"- no evidence

The authors' closing statement:

Although we wish we could demolish all of the urban myths found on the Internet regarding the benefits of supplemental water ingestion, we concede there is also no clear evidence of lack of benefit. In fact, there is simply a lack of evidence in general. Given the central role of water not only in our bodies but also in our profession, it seems a deficit worthy of repletion.

The news from this article is all of the news wires and networks:

Before all of you stop drinking any water now, remember, everything in moderation. As Dr. Goldfarb points out, "A little mild dehydration for the most part is OK, and a little mild water excess for the most part is OK. It's the extremes that one needs to avoid."

And, people with a history of kidney stones certainly need to drink lots of water to prevent recurrent stone formation. If your thirsty, you need water. And remember that caffeine is a weak diuretic, thus caffeinated drinks can actually make you thirstier. Finally, we all need to drink fluids with meals. If are trying to watch your calorie intake, soft drinks contain loads of empty calories, so water is a great way to avoid unnecessary calorie intake.


Will said...

The greatest benefit of promoting 8 glasses of water/day is something that might be hard to study but probably has enough face validity to not need studying:
it decreases the drive to drink other stuff that's unequivocally worse than water (which is just about everything).

julie said...

But obviously, we need to drink *some* water ... or is it just that we need to drink some of *any* fluid? And if we need to drink some amount of water, what is the critical mass that that we need?