(RealSimple.com) -- You've Always Heard That...

You Shouldn't Cut Off the Bread's Crust. It's Full of Vitamins.

The truth is: In a 2002 German study, researchers found that the baking process produces a novel type of cancer-fighting antioxidant in bread that is eight times more abundant in the crust than in the crumb. That said, it's more important to serve whole-wheat bread, with or without the crust, because it's all around higher in nutrients, such as fiber, says New York City nutritionist Keri Glassman, author of The O2 Diet ($25, amazon.com). Make sure the ingredients list "100% whole-wheat flour." Breads simply labeled "wheat" are usually made with a mixture of enriched white flour and whole-wheat flour and have less fiber.

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If You Go Out With Wet Hair, You'll Catch a Cold.

The truth is: You will feel cold but will be just fine healthwise, says Jim Sears, a board-certified pediatrician in San Clemente, California, and a cohost of the daytime-TV show The Doctors. He cites a study done at the Common Cold Research Unit, in Salisbury, England, in which a group of volunteers was inoculated with a cold virus up their noses. Half the group stayed in a warm room while the rest took a bath and stood dripping wet in a hallway for half an hour, then got dressed but wore wet socks for a few more hours. The wet group didn't catch any more colds than the dry. Sears's conclusion: "Feeling cold doesn't affect your immune system."

If You Cross Your Eyes, They'll Stay That Way.

The truth is: "There's no harm in voluntary eye crossing," says W. Walker Motley, an assistant professor of ophthalmology at the University of Cincinnati College of Medicine. But if you notice your child doing this a lot (when he's not mimicking a cartoon character), he might have other vision problems.

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You Should Feed a Cold and Starve a Fever.

The truth is: In both cases, eat and drink, then drink some more. "Staying hydrated is the most important thing to do, because you lose a lot of fluids when you're ill," says Sears, who adds that there's no need for special beverages containing electrolytes (like Gatorade) unless you're severely dehydrated from vomiting or diarrhea.

Gum Stays in Your Stomach for Seven Years.

The truth is: Your Little Leaguer's wad of Big League Chew won't (literally) stick around until high school graduation. "As with most nonfood objects that kids swallow, fluids carry gum through the intestinal tract, and within days it passes," says David Pollack, a senior physician in the Children's Hospital of Philadelphia Care Network. And even though gum isn't easily broken down in the digestive system, it probably won't cause a stomachache, either.

An Apple a Day Keeps the Doctor Away.

The truth is: A handful of blueberries a day will keep the doctor away more effectively. Blueberries are a nutritional jackpot, rich in antioxidants and fiber, and they're also easy to toss into cereal and yogurt. That said, eating a variety of fruits and vegetables is important to prevent many chronic illnesses, such as heart disease, high blood pressure, and diabetes, down the road. (To find out how much earth-grown goodness your child should be getting, enter his or her age, sex, and level of physical activity at fruitsandveggiesmatter.gov.)

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You Lose 75 Percent of Your Body Heat Through Your Head.

The truth is: "This adage was probably based on an infant's head size, which is a much greater percentage of the total body than an adult head," says Pollack. That's why it's important to make sure an infant's head remains covered in cold weather. (This also explains those ubiquitous newborn caps at the hospital.) But for an adult, the figure is more like 10 percent. And keep in mind that heat escapes from any exposed area (feet, arms, hands), so putting on a hat is no more important than slipping on gloves.

To Get Rid of Hiccups, Have Someone Startle You.

The truth is: Most home remedies, like holding your breath or drinking from a glass of water backward, haven't been medically proven to be effective, says Pollack. However, you can try this trick dating back to 1971, when it was published in The New England Journal of Medicine: Swallow one teaspoon of white granulated sugar. According to the study, this tactic resulted in the cessation of hiccups in 19 out of 20 afflicted patients. Sweet.

Eating Fish Makes You Smart.

The truth is: For kids up to age three or four, this is indeed the case. Fish, especially oily ones, such as salmon, are packed with omega-3 fatty acids, including DHA (docosahexaenoic acid). "DHA is particularly beneficial in the first two years of life for brain development, cognition, and visual acuity," says Beverly Hills pediatrician Scott W. Cohen, the author of Eat, Sleep, Poop: A Common Sense Guide to Your Baby's First Year ($16, amazon.com). And a 2008 study in Clinical Pediatrics showed an increase in vocabulary and comprehension for four-year-olds who were given daily DHA supplements. Omega-3 options for the fish-phobic? Try avocados, walnuts, and canola oil.

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You Shouldn't Swim for an Hour After Eating.

The truth is: Splash away. "After you eat, more blood flows to the digestive system and away from the muscles," says Cohen. "The thinking was that if you exercised strenuously right after eating, that lack of blood would cause you to cramp up and drown." But that won't happen. Sears concurs: "You might have less energy to swim vigorously, but it shouldn't inhibit your ability to tread water or play."

Every Child Needs a Daily Multivitamin.

The truth is: Children who are solely breast-fed during their first year should be given a vitamin D supplement. After that, a multivitamin won't hurt anyone, but many experts say that even if your child is in a picky phase, there's no need to sneak Fred, Wilma, and company into his applesauce. "Even extremely fussy eaters grow normally," Cohen says. "Your kids will eventually get what they need, even if it seems as if they're subsisting on air and sunlight."

Warm Milk Will Help You Fall Asleep.

The truth is: Milk contains small amounts of tryptophan (the same amino acid in turkey), "but you would have to drink gallons to get any soporific effect," says Michael Breus, a clinical psychologist in Scottsdale, Arizona, who specializes in sleep disorders. "What is effective is a routine to help kids wind down," he says. And if a glass of warm milk is part of the process, it can have a placebo effect, regardless of science.

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