True or False?

October 8, 2008

I’m talking here about medical myths and old wives tales, beliefs that for one reason or another have been trusted for years.  Some are actually based on fact but most are simply misunderstood concepts about health and the body. It’s amazing how we automatically accept the veracity of these sayings purely on the basis of hearing them repeated again and again. Below are some of the more popular myths, and the truth behind them.

Myth: Taking vitamin C will help you avoid getting a cold.

Reality: Vitamin C, also known as ascorbic acid, is good for preventing scurvy, which British sailors discovered in the mid-1700s. Many people are convinced that taking large quantities of vitamin C will keep them from getting sick. To test this theory, several large-scale, controlled studies involving children and adults have been conducted. To date, no conclusive data has shown that large doses of vitamin C prevent colds. The vitamin may reduce the severity or duration of symptoms, but there is no clear evidence. Taking vitamin C over long periods of time in large amounts may actually be harmful. Too much vitamin C can cause severe diarrhoea, a particular danger for elderly people and small children.

And, despite what thousands of mothers have told their offspring through the ages, you cannot develop the common cold by going out while your hair is wet!

Myth: Putting butter on a burn will ease the pain.

Reality: Immediately after receiving a burn, it is important to cool the skin in order to stop the burning process. Putting butter or other greasy ointments on a burn may actually make things worse, since the grease will slow the release of heat from the skin, allowing damage to the skin from the burn to continue. The best way to cool the skin after a burn is with cool water, not ice or ice water. An antibiotic ointment and a bandage will aid the healing process. 

Save the butter for your toast!

Myth: Standing up straight for a long period can cause fainting.

Reality: People faint for a variety of reasons. Standing, particularly when associated with heat or emotional stress, can cause blood to pool in the lower extremities. If dehydration is present the situation is worsened. The low rate of blood return to the heart in these situations results in hypo-perfusion of the brain and at times the fainting spell. Standing at attention, or with one’s knees locked, may amplify the process.  One of the methods of counteracting the blood-pooling problem is to contract the leg muscles or move about, thus stimulating the blood return to the heart and improving circulation to the brain. You may recall that the first aid treatment for fainting is to lay the person on his back and elevate the legs. This increases blood flow to the head and upper body and is often all that is necessary to achieve recovery.

Myth: Feed a cold and starve a fever.

Reality: Not only is it a bad idea to starve a fever, it will hinder your ability to recover from the cold. Drinking plenty of fluids is important since fever promotes fluid loss from the body and dehydration can result. Another popular belief, that chicken soup is good for a cold, is actually true to a certain extent, as drinking warm liquids such as soup helps open up the nasal passages. This allows patients to breathe easier and get the rest needed to fully recuperate.

Myth: Drinking eight glasses of water a day is good for your overall health and will prevent kidney stones.

Reality: Everyone has heard that we should drink eight glasses of water a day but there’s no way to determine where this belief originated nor has there ever been a scientific study to support it. People are advised to simply let their thirst guide their fluid intake unless there is a specific medical reason to do differently.  Fluid intake is, however, a key to reducing kidney stone formation.  Stones generally form when you are relatively dehydrated and your urine becomes concentrated.  So, how much water should you drink to reduce kidney stones?  It depends on your environment and activity. A simple rule is drink enough to keep your urine looking like water. Avoid letting your urine turn dark yellow or golden brown, that means it’s too concentrated.

Myth: Reading in dim light ruins your eyesight.

Closeup of person wearing glasses.

Reality: As a rule, you cannot damage your eyes by using them. There are a few specific exceptions, like looking directly into sunlight and laser light, but other than this, reading in dim or bright light will not change the health or function of your eyes. It may feel more difficult to focus if the lighting is suboptimal, but this has no permanent effect on the structure of your eyes. In addition, any challenging visual activity will generally decrease a person’s blink rate and lead to discomfort from drying. This is obviously temporary and easily treated with lubricating eye drops. Likewise, sitting too close or too far from the TV will also have no permanent effect on your vision.

Myth: You can get the flu by getting a flu shot.

Reality: The best way to avoid getting the flu is to get the influenza vaccine, available by injection, each autumn before the flu season starts. The vaccines work by exposing your immune system to the flu virus. Your body will build up antibodies to the virus to protect you from getting the flu. Some people who get the vaccine will still get the flu, but they will usually get a milder case than people who aren’t vaccinated. The vaccine is especially recommended for people who are more likely to get really sick from flu-related complications.

Myth: Eating chocolate causes acne.

Reality: Although ‘acne diets’ prohibiting chocolate and other goodies were popular years ago, the good news for acne patients is that dermatologists these days no longer recommend acne diets. Currently, there is no good evidence to link chocolate or other specific foods to acne. Acne treatments today focus on keeping the pores open and controlling oil production and bacteria in the skin.

Myth: Cracking your knuckles causes arthritis.

Reality: There’s no evidence that knuckle cracking causes arthritis but it may cause temporary soreness of the joint. These Joints are surrounded by synovial fluid, a thick, clear liquid.  When you crack your knuckles, you’re causing the bones of the joint to pull apart.  This causes a gas bubble to form in the joint.  The cracking or popping sound you hear is the breaking of the adhesive seal in the joint.  It may take a while for the joint to reseal before you can crack your knuckles again.  The repetitive motion of cracking wears down the joints and their protective cushioning, so the habit could worsen osteoarthritis, but plays no role in rheumatoid arthritis, which is caused when a person’s own immune system attacks the joints.

Myth:  You can catch a venereal disease by using a public toilet.

Reality: Venereal diseases, or more recently called sexually transmitted diseases, are transmitted by direct contact with the bacteria or virus that is the specific cause of specific diseases.  In order to catch VD from a toilet seat, you would have to have direct contact at the site on the skin with the microbial pathogen. This would very rarely, if ever, occur but you should never say never!

So, there you go! I hope this post will help to clarify some of the beliefs out there.

This information is adapted from: Find the Truth Behind Medical Myths, UAMS (University of Arkansas for Medical Sciences).