Myth risks

"Roll up! Come and buy the most efficaciousAnother word for effective. remedy known to mankind!"  A crowd of curious townspeople and cowboys gathered round the smartly dressed salesman. "My snake-oil linimentA medical liquid that is rubbed on the skin. It is not to be confused with lineament, which means a distinctive shape or feature. will cure any pain," he went on. "Headache, toothache, lumbago - whatever ails you. Buy a bottle now before it all goes!"

Clark Stanley was one of many fraudsters who travelled around 19^th-Century America selling medicine which was actually useless. Stanley's "snake-oil" was in fact a mixture of mineral oil, red pepper and turpentineA fluid made from liquid taken from pine trees.. And he made a fortune from it.

People throughout history have been all too gullible Easily fooled. when it comes to health. Some myths have survived for centuries. These are just seven, old and new.

1. Fever glitch "Starve a fever, feed a cold" is one of the best-known sayings about health. In fact, you should keep eating as well as you can if you are feverish. You may not feel like eating, but your body needs more calories when you are ill in order to heal itself.

2. Wet-hair scare Many people believe that going out in chilly weather with wet hair leads to a cold. The truth is that a cold is a virus caught from another person. However, it is a good idea to wear a hat if your hair is wet, as medical expert Chad Masters explains: "Water carries heat away from the body much faster than air does, so you lose heat more quickly when you or the clothing you're wearing is wet." That makes you more vulnerable to hypothermiaA dangerous drop in body temperature caused by exposure to cold..

3. Spot rot To test the belief that chocolate gives you acne, researchers studied 65 teenagers for a month. Some of them were given bars containing 10 times the normal amount of cocoa The most important ingredient in chocolate., and others bars with no cocoa at all. At the end of the experiment, there was no noticeable increase in acne in either group.

4. Bathroom doom Toilet seats are often seen as a source of disease. In fact, they are normally quite clean: you are more likely to pick up germs from the door handle - so make sure you wash your hands after touching it.

5. H2O no-no Huge amounts of bottled water are bought by people who think it is healthier. This may be true in certain countries, but in many nations tap water is usually fine. It contains useful minerals - magnesium and calcium - and is much better for the planet, since it does not lead to plastic waste.  

6. Joint point Cracking your knuckles can be very annoying to others, but does not lead to arthritis, as some people believe. According to nutrition expert Kristine Scheney: "The 'crack' is simply the popping of bubbles in the fluid that lubricates the hands, known as synovial fluid. While this practice does not cause arthritis, it does have some negative consequences... it can lead to reduced grip strength and swelling in the hands."

7. Cracking snack Egg yolks are sometimes said to be bad for you because they contain cholesterol which causes heart disease. But there are different types of cholesterol, some bad and some good. The cholesterol in egg yolks, HDLShort for high-density lipoprotein., is a good type and can actually protect you from bad cholesterol.

Is health just a matter of science?

Yes: Medicine has made enormous strides in the past century, and continues to do so. We can rely on doctors to cure most diseases, or at least dramatically reduce the suffering they cause.   

No: Health is largely a matter of common sense: we can avoid many problems simply through rational behaviour. But health is also about how you feel, and sometimes following old advice can be a source of comfort.

Or... Science is a relative term. Doctors in past centuries believed that they were treating diseases in a highly scientific manner, but we now know that many of their methods were completely wrong.