Drinking up to eight glasses of water a day might not be that beneficial for our health as previously believed, researchers say.

Dr. Stanley Goldfarb and Dr. Dan Negoianu of the University of Pennsylvania in Philadelphia reviewed all the studies dealing with the healthy benefits of drinking lots of water.

Their review, published in the Journal of the American Society of Nephrology, concluded that people in hot, dry climates, athletes or people with certain diseases might do better with increased fluid intake, but for average healthy people, more water did not seem to mean better health.

“There is no clear evidence of benefit from drinking increased amounts of water,” Dr. Goldfarb wrote, but he also added, “There is also no clear evidence of lack of benefit.” There’s a general lack of evidence either way.

Goldfarb and Negoianu analyzed what Goldfarb called “four major myths” regarding the benefits of extra water drinking: that it leads to more toxin excretion, improves skin tone, makes one less hungry, and reduces headache frequency.

"Our bottom line was that there was no real good science -- or much science at all -- behind these claims, that they represent probably folklore," Goldfarb said.

Referring to the first myth, Golfarb said it was no scientific study supporting the idea that more water intake leads to more toxin excretion. “The kidneys clear toxins. This is what the kidneys do. They do it very effectively. And they do it independently of how much water you take in. when you take in a lot of water, all you do is put out more urine but not more toxins in the urine.”

Also, there was no scientific evidence that water had any benefits for the other three myths. That’s why Goldfarb concluded that while it may not help a person to drink lots of water, it may not harm them much either. “If someone enjoys it, I say that’s wonderful, keep doing it. They’re not doing anything that’s going to hurt them. 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,” Goldfarb said.

On the average, the body uses between 1 and 1.5 liters of water daily and more in high temperatures or when exercising. Much of this water is replaced through drinks but a large amount is also contained in food, so it is not necessary to drink an equivalent amount to replace water levels.

On the other hand, too much water can affect the balance in the body causing “water intoxication,” which can be fatal.

No matter the results of this research, the Food Standards Agency (in the UK) is sticking to its recommendation to drink six to eight glasses of fluid a day.