Drink eight glasses of water a day
In 1945, the U.S. Food and Nutrition Board told people to consume eight glasses of fluid daily. Before long, most of us believed we needed eight glasses of water, in addition to what we eat and drink, every day.
The Truth: Water’s great, but you also whet your whistle with juice, tea, milk, fruits, and vegetables—quite enough to keep you hydrated. Even coffee quenches thirst, despite its reputation as a diuretic; the caffeine makes you lose some liquid, but you’re still getting plenty.
Contrary to common belief, urine color is not a great sign of dehydration, says Rachel Vreeman, MD, a fellow in Children’s Health Services Research at the Indiana University School of Medicine in Indianapolis: “If you’re thirsty, you should drink.” But don’t overdo it. Drinking too much can lead to hyponatremia, in which sodium levels fall, causing an electrolyte imbalance that can make you very sick.
Stress will turn your hair gray
The carpool, the spilled milk, the deadlines. Who doesn’t believe that hair products make covering them a cinch.
Reading in poor light ruins your eyes
It’s the common-sense refrain of mothers everywhere—reading under the covers or by moonlight will ruin your eyesight.
The Truth: “Reading in dim light can strain your eyes,” Snyderman explains. “You tend to squint, and that can give you a headache. But you won’t do any permanent damage, except maybe cause crow’s-feet.”
Your overtired eyes can get dry and achy, and may even make your vision seem less clear, but a good night’s rest will help your peepers recover just fine. (Read about vision-friendly foods here.)
