1. Drink eight glasses of water each day
The authors found references as early as 1945 suggesting that healthy people should stay hydrated by drinking eight glasses of water each day. But they say there’s a complete lack of evidence supporting that recommendation. Studies also show that most people get enough fluids through daily consumption of juice, milk and even caffeinated drinks.
2. People only use 10 percent of their brains
This myth has been around for more than a century. Some believe it came from Albert Einstein, although the authors found no evidence of that. What they did find were studies that show people use much more than 10 percent of their brains. For example, when almost any area of the brain is damaged, it has “specific and lasting effects on mental, vegetative and behavioral capabilities.” Also, imaging studies have found no area of the brain is completely inactive.
3. Hair and fingernails keep growing after death
While it’s impossible for the body to continue the complex hormone regulation needed to cause hair and nails to grow after death, this myth does have a basis in a biological phenomenon that sometimes occurs after death.
When someone dies, dehydration of the body can cause the skin around the hair or nails to retract, creating the appearance of increased length. But the authors say this is an optical illusion.
4. Reading in dim light ruins your eyesight
While reading in dim light can cause eye strain, and the uncomfortable effects that go along with it such as dryness and difficulty focusing, it does not cause permanent damage, the authors say.
5. Eating turkey makes you especially tired
The authors say turkey doesn’t contain “an exceptional amount of tryptophan.” In fact, turkey, chicken and minced beef contain nearly the same amounts of the amino acid.
Perhaps the reason turkey has long been accused of making people extra sleepy is because of all the overeating we do on Thanksgiving. Studies show that eating any large, solid meal can make you tired because blood flow and oxygenation to the brain decreases. Plus, meals that are high in protein or carbohydrates can cause sleepiness. So can wine.
6. Cell phones cause significant electromagnetic interference in hospitals
Hospitals widely banned cell phone use after a front page Wall Street Journal story cited an article detailing more than 100 reports of suspected electromagnetic interference with medical devices before 1993. But an internet search by the study’s authors could not find any cases of death caused by use of a mobile phone in a hospital. They did find reports of less serious events, such as false alarms or incorrect medical readings.
Meanwhile, subsequent studies show little or no interference. For example, a 2007 study examining mobile phones “used in a normal way” found no interference in 300 tests in 75 treatment rooms.
VOCABULARY
Medical Myths - commonly-held beliefs, rarely based in fact, that people have grown up with
Other Medical myths
Which ones do you believe in? Why / why not?
1. Too many carrots will turn skin orange
2. Eating sugar causes diabetes
3. Cold, wet weather causes colds and flu
4. Don’t cross your eyes they might stick
5. Chocolate causes acne
6. Worry and stress can turn your hair gray
7. Shaving hair causes it to grow back faster, darker, or coarser
Focus on talking
• Do you know any other medical myths? What are they?
• How do medical myths originate?
• Do you believe that medical myths are harmless?