"Hydration" foolishness

I’ve always believed that this obsession with “hydration” was silly—everyone running around with bottles of water. There is absolutely no scientific evidence that drinking eight glasses of water a day has any health benefits. But it seems to be a persistent myth. In the words of Dr. Margaret McCartney in the British Medical Journal, it’s “thoroughly debunked nonsense.” My feelings exactly.

Basically, your body well tell you when you need to drink. And the drink needn’t be water. It can be anything, including beer and coffee. (The idea that coffee is a diuretic is also a myth.)  Fruits and vegetables also contain a lot of water.

If I sweat a lot, I drink a lot. If not, I don’t. As Dr. Aaron E. Carroll, professor of pediatrics at Indiana University School of Medicine says, “the human body is finely tuned to signal you to drink long before you are actually dehydrated.” Dr. Heinz Valtin, from Dartmouth University tells us that a large body of published experiments “attest to the precision and effectiveness of the osmoregulatory system for maintaining water balance” (i.e., if we need water, we get thirsty; if we have excess water, we get rid of it.)

You can actually die of excess water (a condition called hyponatremia). Since 2008 several high school football players are known to have died from drinking too much fluid during and after a practice. In cases like these, the body can’t rid itself of the surplus fast enough through sweating or urination. In trying to equalize sodium levels by drawing water from the blood and into the surrounding cells, the cells begin to swell. If this process occurs in the brain, it can be lethal.

The benefits of drinking extra water accrue mostly to the purveyors of bottled water, an industry worth more than $15 billion annually. They help keep the myth alive by sponsoring “public service” messages and programs to promote more water drinking. For example, an initiative called Hydration for Health, is sponsored by the manufacturers of Evian. Nestle sponsored a study that concluded that almost two-thirds of children in New York and Los Angeles weren't getting enough water. Give me a break. 

But here are some things you should know about these water bottlers:

• Half the leading bottled water brands get their water from drought-stricken California (my state).
• Twenty-five percent of the water sold in the US comes from a municipal source.
• Fans of bottled water pay more than a 4,000 percent markup to buy a product that’s virtually free.
• Manufacturers use 17 million barrels of crude oil in their bottle production.
• Americans buy 29 billion water bottles a year—an environmental problem.

So just say no. If you’re thirsty, get a drink from your tap.

Next week: "Sell by" dates: ignore them

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