99 Body Myths That Have Survived Too Long

We grow up hearing myths about our bodies, change our habits accordingly, and before long, we’re swearing by fiction instead of the facts. Today we separate the truth from the myths.

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The Diet Myths You Have to Stop Believing (3:32)

1. Certain foods can trigger increased sexual desire.

Food does not induce a physical reaction that leaves you hungry for sex. But it can be psychologically suggestive.

2. Shaving makes your hair grow back thicker and darker.

When you shave, you cut your hair at an angle. It looks thicker as a result, even though it isn't. It isn't darker either.

More: Shave, Wax or Laser?

3. Late night eating guarantees weight gain.

If you consume a meal before bed with more or less the same amount of calories as other meals you typically have during the day, then you’re not likely to gain weight. Late night binge eating, however, will get you in trouble.

Watch: How to Stop the Cycle of Binge Eating

4. Alcohol kills your brain cells.

Alcohol does not kill brain cells; irresponsible consumption can cause enough damage in other ways.

Watch: Smoking Alcohol

5. You're able to sweat out toxins.

Sweat is mostly water, sodium, chloride, and small amounts of potassium. There are only trace amounts of toxins that exit the body through sweat.

Watch: The Science of Sweat and Stink

6. We have only five senses.

We've got many senses beyond sight, hearing, taste, smell, touch. Here's one: equilibrioception, or our sense of balance.

7. If you go outside with wet hair in the winter, you'll catch a cold.

Wet hair isn't to blame for your winter cold—if you catch a cold, you've caught a virus.

8. To stop a nosebleed, you should tilt your head back.

Rather, you should tilt your head forward while pinching just below the bridge of your nose to prevent the blood from rushing out (make sure you breathe through your mouth).

Watch: Bleeding: Life Saving Do's and Don'ts 

9. The perfect hair product can mend your split ends.

No shampoo or conditioner, however fancy, can mend a split end.

10. It's best to leave a wound uncovered at night.

Leaving your wound uncovered at night exposes it to a dry environment, and that can cause cells to die. You want to the opposite effect. Thus, you should keep your wound covered.

11. A longer workout is always a better workout.

In fact, you build momentum over the course of a lengthy workout, so that by the end, your muscles aren't being tested as much as you'd like them to be. Of course, this depends on your particular workout routine on a given day. One way to ensure that you get the most out of your trip to the gym is to do sets of slow, drawn-out exercises. Adam Zickerman, founder of InForm Fitness, and author of Power of 10: The Once A Week Fitness Revolution 57, is a strong proponent of quality over quantity when it comes to working out.

12. When you sneeze, your heart skips a beat.

This one isn't necessarily a myth. It's just unremarkable. Your heart rate can slow or skip a beat while you're gagging, coughing, or any other bodily process that affects what doctors call the vagus nerve.

13. If you don't have a fever, then you're not contagious.

A fever is a pretty reliable indicator that you're sick and potentially contagious. But there are many ways to be sick and contagious without a fever.

Watch: All About Immunity Boosters

14. Sleeping in a closed room with a fan is fatal.

Plain and simple, this is not true.

Watch: Quiz: What Is Your Chronotype?

15. Popcorn, nuts, and seeds stick to the lining of your stomach.

These don't linger in your stomach any longer than gum does—all exit the same way.

16. If your mucus is green, then you've got a sinus infection.

This is an unreliable way to distinguish between a viral and bacterial sinus infection.

17. To sober up, you ought to take a cold shower.

A shower might provide a burst of energy, but it will do nothing to lower your blood alcohol content (BAC).

18. Swallowed gum gets stuck in your stomach.

It doesn’t. Gum doesn’t even stay in your gut any longer than food or beverages do. Yes, your body can’t digest it—just as it can’t digest the outer shell of corn, for example—but gum will exit your body in a day or two the same way everything else does.

19. Men cannot get sex off their minds.

We've all heard that men think about sex every seven seconds. There's no research to support this, although there is research that suggests men think about sex more than women do.

20. We use only 10 percent of our brain power.

In one capacity or another, we use almost all of our brain power.

21. If you crack your knuckles too often, you'll develop arthritis.

It's not exactly clear, somewhat surprisingly, why joints crack. One explanation: when you crack your knuckles, you exert a negative pressure on the joint, which fills with gas.

22. Writing or reading in low light can damage your eyesight.

Working in low light can cause eye strain, but not eye damage. Because muscles within the eye work harder to allow more light to enter the eye in low light, these muscles can become strained and cause a headache.

23. A slow metabolism is the reason for weight gain.

There's not a perfect correlation between metabolism and weight. In fact, very thin people often have a slow metabolism, because they have smaller muscle mass with which to burn calories.

24. There's no wrong way to breathe.

There is. Many of us breathe from our chest. The proper way to breathe is from the stomach.

Watch: How to Practice 10-Minute Step Breathing 

25. Yellow teeth are a sign of poor dental hygiene.

Teeth can certainly turn yellow without proper maintenance. But discoloration can occur even with ideal maintenance—from having a high fever as an infant, excessive exposure to fluoride, or by using the antibiotic tetracycline before age 8, to name a few. All things being equal, their color is largely determined by your genes.

26. Certain foods can trigger increased sexual desire.

Food does not induce a physical reaction that leaves you hungry for sex. But it can be psychologically suggestive.

27. Deprived of oxygen, your blood turns blue.

Human blood, no matter if it's inside or outside of our veins, is red.

28. You're either left-brained or right-brained.

It's true that certain interests and activities stimulate specific areas of the brain. It's not true that such brain activity occurs independent of other areas of the brain—on either side.

29. After "breaking the seal," you'll have to urinate more frequently.

You will urinate more frequently once you decide to "break the seal," but that's only because you've decided to succumb to the urge—the only thing that changes, in other words, is your willingness to go to the bathroom.

30. Beer before liquor makes you sicker.

There's no evidence that a particular regimen of alcohol consumption is better than another.

31. You should starve a fever.

You might make it more difficult for your body to fight a fever without sufficient energy (which comes from calories).

Watch: The 5 Best Cures From Around the World 

32. Stress is a primary cause of high blood pressure.

Stress typically causes temporary spikes in blood pressure. Chronic high blood pressure, though, has more to do with diet, exercise, and other habits, such as smoking. Still, while stress is not a cause of high blood pressure, the temporary spikes in blood pressure that stress causes can worsen heart health in someone who already has high blood pressure.

33. Tongue-rolling is a matter of genetics.

They've studied this. People can learn to roll their tongues.

34. Carrots improve your eyesight.

Vitamin A is important for strong eyesight, and carrots are a good source of vitamin A—but so are sweet potatoes, kale, and many other foods. Beef liver is a great source of vitamin A.

35. Certain foods—such as chocolate—can cause acne.

Acne is correlated with hormonal fluctuations, and diet can cause hormonal levels to fluctuate. But this is only an indirect relationship; breakouts can surface on people with the healthiest of diets.

36. The appendix is useless.

Your appendix is not useless. It works hand in hand with your immune system.

37. For the growing adolescent and young adult, too much coffee can stunt growth.

This might’ve come from our parents’ well-intentioned efforts to keep us away from the highs and lows of daily caffeine. But there’s no evidence to suggest that those who get started on coffee earlier and in excess will be shorter than they’d be if they were to avoid caffeine.

38. People with flat feet are more likely to get injured.

Research suggests that flat feet might not be disadvantageous to athletes after all. What is clear is that flat feet are completely functional.

39. The skin prunes after a long shower because it's absorbing water.

Your skin prunes when blood vessels constrict beneath your skin. Your skin is not working to absorb water. One theory is that these grooves allow for better grip under water, which is why only our palms and soles prune.

Watch: Dry Skin Myths 

40. By the age of 2, we develop all of our brain cells.

In fact, you can generate new brain cells as an adult. This process is called neurogenesis.

41. Hair and fingernails continue to grow even after a person has died.

Death is not instantaneous for all parts of the body. Hair and fingernails cease to grow in more or less the same amount of time as everything else. Dehydration of the skin surrounding hair and fingernails after death gives the false appearance of hair and nails having grown due to retraction of the skin.

42. Poison ivy is contagious.

Poison ivy is itchy and irritating, but it's not contagious.

43. It's best to stretch before you exercise.

Muscles might actually tense up if you stretch before exercise.

Watch: Stretches to Relieve Neck, Wrist and Arm Pain

44. You must stay awake after you've suffered a concussion.

Researchers no longer believe this is necessary. In any case, it's certainly best to follow doctor’s orders.

45. On average, each of us swallows eight spiders per year.

How this myth took root is unclear, but it is not grounded in reality. Evidence confirms what you'd expect, even if you'd prefer to forget—that, in a place where spiders have gathered, they occasionally bite their human roommates at night.

46. Warm milk will help you fall asleep faster.

Milk contains tryptophan, an amino acid that produces serotonin—in theory, that process should lead to a better sleep. The evidence, however, is lacking. (Tryptophan from food might not be enough to do the trick.)

47. Hydrogen peroxide cleans a wound.

In fact, hydrogen peroxide can make a wound worse by killing both bacterial cells and healthy cells alike. You’re better off rinsing the wound with water and soap.

48. With proper hygiene, you'll never develop bad body odor.

Body odor can be caused by hormonal fluctuations, regardless of flawless personal hygiene.

More: Natural Cures for Your Most Embarrassing Problems 

49. Muscle turns to fat if you abandon your exercise routine.

When you abandon your exercise routine, your muscle cells shrink. They don’t turn into fat cells. 

50. If a pregnant mother carries high, she’ll give birth to a boy; if she carries low, she’ll give birth to a girl.

You cannot predict the gender of a baby by looking at the way the mother carries during pregnancy.

51. A human's mouth is dirtier than a dog's.

A dog’s mouth has its own array of bacteria—it’s just that the bacteria (and therefore, illnesses) that live in dogs are much different than the bacteria found in humans.

52. Turkey makes you tired.

Turkey doesn’t make you tired for the same reason milk doesn’t make you tired. Tryptophan isn’t enough to make you sleepy.

53. We get drunk faster at high altitudes.

The theory is that due to lower oxygen levels, you feel drunker. In reality, you’re experiencing the lightheadedness and euphoria from lower oxygen levels in the brain.

54. Ice cream can trigger brain freeze.

You certainly feel as though your head has gone frozen, but the discomfort comes from the nerves on the roof of your mouth.

55. Color-blind people see the world in black and white.

There are various degrees of colorblindness. Very few people see only black and white—which is called rod monochromacy.

56. With antibiotics, your body is equipped to fight the common cold.

The common cold is a virus. Antibiotics fight bacteria.

57. Heart attacks hurt. 

A heart attack does not always hurt, especially for diabetics and women. It can feel like heartburn, tooth pain, or just a funny feeling.

Watch: Dr. Oz Explains a Silent Heart Attack

58. Big hips make for easy childbirth.

It’s the size of the bones of the pelvis that matters, and not the muscle and fat of the hips.

59. A temperature higher than 98.6°F is a fever.

Your body temperature fluctuates over the course of the day, and can differ in different parts of the body. A fever above 100.4°F is cause for concern.

60. Junk food provides emotional comfort.

Fatty, sugary and salty food certainly light up the brain’s reward response, and complex carbs increase mood boosting chemicals, but there is no evidence this translates to a lasting boost in mood.

61. Touch a frog, and you'll get a wart.

Frogs have bumpy skin but they do not have warts.

62. Different parts of the tongue are for different tastes—sweet, sour, bitter, etc.

The tongue map is such a neat idea that it’s hard to accept this idea as false. But it is false—receptors for different tastes are spread all across our tongues.

63. Lying in bed is just as restorative as sleeping.

This belief provides a lot of comfort in the middle of a restless night, but research is clear that there’s really no substitute for sleep.

64. With age, our bodies require fewer hours of sleep.

As we get older, we find it harder to fall asleep (and stay asleep). The problem is, our body still needs those hours.

More: The Sleep Doctor's Sleep Slim Smoothie 

65. Counting sheep will help you get to sleep faster.

Forget this as soon as possible. Counting sheep is more likely to keep your mind in processing mode, and thereby, keep you awake.

66. You can "catch up" on sleep.

Your weekend snooze fest cannot counteract a week’s worth of deprivation. You need one to two hours tacked on per night to make it up.

67. We must be in REM sleep to dream.

In REM sleep, we’re more likely to really drop into our dreams and experience them as such. But we dream during non-REM sleep as well.

68. When we yawn, we must be tired.

For the most part, yawning remains a mystery. We do know, however, that it’s contagious.

69. Antibiotics cancel out birth control.

Only one antibiotic, rifampin, has been shown to counteract birth control. Most antibiotics do not interfere with oral contraceptives.

70. Menopause necessarily reduces a woman's sex drive.

Menopause does not inevitably lead to reduced libido. Diet and exercise matter, and of course, the preservation of an intimate physical relationship plays a role.

Watch: Sex, Menopause and More Gas

71. It's impossible for a woman to get pregnant during her period.

You might be unlikely to get pregnant during your period, but it’s not unheard of. Sperm can live inside of you for up to five days waiting for ovulation, and sex towards the end of your cycle plus five days can put you in the window of ovulation, leading to pregnancy.

72. All sweat smells bad.

Most sweat is odorless. It’s when bacteria on the skin enter the equation that you start to smell not so rosy.

73. Body odor is a purely physical phenomenon.

It's not—stress and anxiety can affect body odor.

74. It's best to shower daily.

There are many benefits to skipping a shower from time to time. Specifically, your hair will use the oil to protect itself and the top layer of your skin will maintain its moisture.

Watch: What Happens When You Skip Shampoo for a Week?

75. Oral health is simply that—oral health.

In fact, poor oral hygiene can put you at risk for various health conditions, including respiratory infections and even heart disease.

76. Serotonin is found mostly in the brain.

While serotonin is most active in the brain, 90 percent of serotonin is actually made in the gut.

77. All beans make you gassy.

Yes, beans are difficult to digest, but certain beans might be easier to digest than others. Black eyed peas are among the easiest to digest; navy beans are among the hardest.

78. Earwax is all bad.

Excessive earwax, of course, is unhealthy. But a healthy amount of earwax protects your ears from bacteria.

79. Cross your eyes too often, and they'll stay crossed.

You’ll strain the muscles in your eyes, but your eyes will not stay crossed.

80. Milk, yogurt, and other dairy products will make you congested.

Certain dairy products might thicken the mucus already in your throat. Your body won’t produce more mucus, though.

Watch: Which Greek Yogurt Brand Should You Buy? 

81. You can never be too hydrated.

In fact, it’s possible to drink too much water. And you do not need eight glasses of water a day.

82. If you’re sleepwalking, and are awoken from a midnight stroll, you’ll die.

You won’t die from a heart attack, as the myth goes. If you’re awoken abruptly, though, you might descend into sleep inertia, which will leave you groggy and insufficiently alert.

Watch: What Your Sleep Score Means

83. Your body temperature rises with a drink of alcohol.

You’ll feel warmer, but that’s only because alcohol causes your blood vessels to dilate. The blood is closer to the skin’s surface as a result.

84. You can never have enough vitamin C.

You can. And the rest exits through your urine.

85. If you sneeze with your eyes open, your eyes will pop out.

A sneeze stimulates the cranial nerves between the nose and eyes. That’s why you have a reflex to blink when you sneeze. But even if you could sneeze with your eyes open (and some people can) there’s no risk of your eyes popping out. The logic here, that a build-up of pressure would cause the eyes to pop, is false: while cranial nerves run between the eyes and nose, the nose is not actually connected to the eye socket—so the pressure cannot be transferred from one to the other.

86. There’s no harm in licking a cut.

Actually, you’re increasing your chances of getting an infection when you lick a cut. What you’re doing is exposing the wound to more bacteria from your mouth.

87. As you get older, your metabolism is to blame for your body’s changes.

The reason your body looks less toned as you get older is because your body struggles to build and maintain muscle mass.

Watch: Mega Metabolism Boosters

88. Shampoo causes you to shed hair.

It’s easy to understand how this myth got started. Water washes away hair that has fallen out, and you’re most likely to see that hair in the shower. But fear not—shampoo is safe. (Over-washing with harsh chemicals, however, can cause dryness of the scalp, and in turn, lead to hair loss.)

89. Your body burns more fat running than it does lifting weights.

Both help you get rid of fat. But you’ll burn more calories the next day if you lift weights and run, instead of only running.

90. You lose the most heat through your head.

Heat escapes from your head to the same degree it escapes from any other part of your body.

91. Identical twins have identical fingerprints.

No two fingerprints are the same, even in the case of identical twins.

92. Your shoes are to blame for your bunions.

Oddly enough, bunions are largely inherited.

93. If you can move your arm, or walk on your feet, you haven’t broken a bone.

The pain has more to do with the degree of the break. In a complicated fracture, where there is severe swelling into a joint, the bone may be immovable. If there is trauma to the muscle, the bone may be immovable.

94. If you wake up in the middle of the night, you’ll struggle to get through the day.

Some research suggests that the benefits of sleeping straight through the night might be overstated. Two, four-hour periods of sleep, with a brief period of wakefulness in between, might be equally restorative.

95. Regularity means once a day.

Studies show that healthy people do not uniformly have bowel movements once a day. Frequency of bowel movements varies. Medically speaking, ‘normal frequency’ is anything from one time in three days to three times in one day.

96. Hiccups are only caused by eating too fast.

Actually, stress and excitement, among other things, can cause hiccups.

97. If you swim within an hour after eating, you’ll suffer fatal cramps.

It’s probably best to give yourself time to digest after a meal, but you’re not going to die if you jump in the water.

98. A little tan is harmless, and even healthy.

Consider any tan to be a sign of skin damage from the sun. No tanning is safe.

99. It’s best to eat many small meals as opposed to three full ones.

Unless you’re diabetic, there is no reason to have constant meals through the day. Three moderate sized meals, interspersed with small healthy snacks to keep cravings at bay are sufficient.

Watch: Health Myths You Believe: Exposed!