5 Medical myths you can stop believing now

There are many widely-believed myths about our bodies, from how many spiders we eat a year, to what type of food helps heal wounds. But where do these myths come from?

Thankfully, those who really know what's up are here to lend a helping hand. Dr Pemberton debunks some famous medical myths.

Real flu—as opposed to a bad cold that the more dramatic of us describe as flu—is a very unpleasant infection caused by the influenza virus. The good news is that the influenza vaccine offers protection against this. The vaccine is dead, so there’s absolutely no way it can cause influenza—that’s a complete lie. There’s a nasal spray that uses a live virus, but it’s been designed to not cause infection. It can never “revert” to the infectious type.

A very small number of people experience side effects from the vaccine—joint aches or a low-grade fever for a day or so. This isn’t flu, but it might have helped the myth along. It’s rare to have these side effects, but they soon pass. It’s also possible to have caught flu just before or just after getting the vaccine, and before it’s been able to protect you—so it can appear that the jab has caused it, when in fact it’s bad timing.

About 4,000 people a year in the UK die from flu, and the NHS currently recommends the flu vaccine every year for those over 65, health workers or those with chronic illnesses. Some people shouldn’t get the jabs: if you’re allergic to egg, or you already have a fever or moderate-to-severe infection. For everyone else, though, the flu jab provides great protection against this horrible infection and saves lives in doing so.

Not only does butter not provide any relief from a burn and does nothing to help it heal, but it can actually cause harm. When you burn yourself, the flesh absorbs some of the heat, so that the skin continues to burn even after the heat source has been removed. Butter actually retains heat, so by putting it on the skin you can make the burn worse.

Also, a bad burn will mean that the skin has been damaged and it no longer offers protection from infections. Butter is full of bacteria, so by placing it on burned skin you risk introducing infection.

It’s likely that this is partly down to butter being cold, and so people assume it’s a good way of cooling the skin, not realising that in fact the burn heats up the butter. Butter is also good at removing tar from burns when the tar has stuck to the skin. Years ago, this was one way that workmen would get burning tar off their skin, and it’s likely it was therefore assumed butter is useful in all burns. Now, specially designed creams are used for removing burning tar.

Leave the butter in the fridge. The right way to deal with a burn depends on how severe it is. For a mild burn, run it under cool water. Don’t apply ice, as this can also damage the delicate skin tissue. For a large burn, seek medical advice immediately.

Studies have shown that bacteria can contaminate food more or less instantaneously when it’s dropped. There was no difference in rates of contamination between food left for one or six seconds.

However, after one minute, contamination rates are about ten times higher. Most bacteria cause no harm, but bugs that cause food poisoning, such as E coli, can live for over a month on the floor. If the food lands by a colony of E coli, it will be instantly contaminated.

You often hear people shout, “Five-second rule!” as they scoop some food off the floor they’ve just dropped, before popping it in their mouths. It’s not entirely clear where the “rule” comes from, but it’s firmly entrenched in folklore to the extent that many believe it’s a fact. 

The moisture levels and surface shape of the food have been found to affect how much bacteria attaches to it, as well as where it’s dropped—areas of high traffic have more bacteria than others. In general though, it’s a judgment call whether you want to eat something after it’s been on the floor. Just don’t assume that if you rush to pick it up in under five seconds, it’ll be safe.

Logical reasoning helps with this one. Most people move while they’re asleep and that would scare spiders. Most people don’t sleep with their mouth open—and even those who do, tend not to swallow if something enters it. You can test this by putting your finger in someone’s mouth as they sleep. They’re far more likely to wake up and ask what on earth you’re doing than try to swallow it.

Also, spiders tend to avoid open mouths—if they didn’t, evolution would have made sure they became extinct, instead of one of the most successful groups of animals on the planet.

It’s thought that it was first mentioned in a book on insect and spider folklore in 1954. Then in 1993, a journalist called Lisa Holst wrote an article about the urban myths circulating in the early days of email and quoted this entirely false statistic as an example of how gullible people were. The result was that people began quoting her article as the source of the “fact”, despite Holst so clearly saying that it was untrue.

Theoretically, a spider could drop into your mouth if it was hanging from the ceiling. But the chances that this would happen just as you opened your mouth and were about to swallow is so infinitesimally small as to not be worth worrying about.

The concern that vaccines might in some way be linked to autism was first suggested in 1998 by a paper published in The Lancet, a well respected medical journal. It looked at 12 children with developmental problems, some of whom had autism and who had been vaccinated with the measles, mumps and rubella (MMR) vaccine. It wasn’t a proper clinical study, merely a report of the cases. However, this was picked up by the media and the subsequent furore caused many parents to assume there was a link.

Since the paper was published, extensive further research has been done and absolutely no link has been found. Studies involving hundreds of thousands of children have now been conducted—and have discredited the link. Most of the doctors involved in the original Lancet publication have retracted it. The lead author has been discredited and struck off the medical register.

The risks of complications from childhood infections are very real and should be of far more concern to a parent than the entirely false association between vaccines and autism. The simple truth of the matter is that vaccines save lives, while fear of vaccines results in children developing crippling or even fatal conditions.

Max is a hospital doctor and author. He’s also the resident doctor on ITV’s This Morning

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