I graduated from medical school in 1968 with the advice to my patients to drink 8 glasses of water a day. If there is one health myth that will not die, it is this: You should drink eight glasses of water a day. It’s just not true. There is no science behind it. Yet the number of people who carry around expensive bottled water seems to be growing each day. A recent White House policy declared that 40 percent of Americans drink less than half of the recommended amount of water daily
There has been a fear that otherwise healthy adults and children are walking around dehydrated, even that dehydration has reached epidemic proportions.
Let’s put these claims under scrutiny.
There was a myth that people should drink at least eight 8-ounce glasses of water a day. The source of this myth was a 1945 Food and Nutrition Board recommendation that said people need about 2.5 liters or about two quarts of water a day. This report also pointed out that most of this quantity is contained in prepared foods. Water is present in fruits and vegetables. It’s in juice, it’s in beer, it’s even in tea and coffee. Before anyone writes me to tell me that coffee is going to dehydrate you, research shows that’s not true either.
Although I recommended water as the best beverage to consume, it’s certainly not your only source of hydration. You don’t have to consume all the water you need through drinks. You also don’t need to worry so much about never feeling thirsty. The human body is finely tuned to signal you to drink long before you are actually dehydrated.
Contrary to many stories you may hear, there’s no real scientific proof that, for otherwise healthy people, drinking extra water has any health benefits. For instance, reviews have failed to find that there’s any evidence that drinking more water keeps skin hydrated and makes it look healthier or wrinkle free.
Other studies fail to find benefits in kidney function or all-cause mortality when healthy people increase their fluid intake.
One possible exception is that drinking water may lead to the prevention of the recurrence of some kinds of kidney stones.
Bottom Line: There is no formal recommendation for a daily amount of water people need. That amount obviously differs by what people eat, where they live, how big they are and what they are doing. In New Orleans with high temperatures and high humidity, consuming more water especially when working or playing outside in the summer is probably a good idea.